R. Scott Mitchell

All Publications

• Symptomatic Myocardial Bridging in D-Transposition of the Great Arteries Post-Arterial Switch JACC: Case Reports, Vol 8, Iss , Pp 101730- (2023) Vaikunth, S. S., Murphy, D. J., Tremmel, J. A., Schnittger, I., Mitchell, R. S., Maeda, K., Rogers, I. S. 2023

  View details for DOI 10.1016/j.jaccas.2022.101730

• Commentary: Reoperative surgery on the aortic arch is not for the inexperienced. Seminars in thoracic and cardiovascular surgery Mitchell, R. S. 2021

  View details for DOI 10.1053/j.semtcvs.2021.04.017

  View details for PubMedID 34004287

• Type A Aortic Dissection-Experience Over 5 Decades: JACC Historical Breakthroughs in Perspective. Journal of the American College of Cardiology Zhu, Y. n., Lingala, B. n., Baiocchi, M. n., Tao, J. J., Toro Arana, V. n., Khoo, J. W., Williams, K. M., Traboulsi, A. A., Hammond, H. C., Lee, A. M., Hiesinger, W. n., Boyd, J. n., Oyer, P. E., Stinson, E. B., Reitz, B. A., Mitchell, R. S., Miller, D. C., Fischbein, M. P., Woo, Y. J. 2020; 76 (14): 1703–13

  Abstract

  The Stanford classification of aortic dissection was described in 1970. The classification proposed that type A aortic dissection should be surgically repaired immediately, whereas type B aortic dissection can be treated medically. Since then, diagnostic tools and management of acute type A aortic dissection (ATAAD) have undergone substantial evolution. This paper evaluated historical changes of ATAAD repair at Stanford University since the establishment of the aortic dissection classification 50 years ago. The surgical approaches to the proximal and distal extent of the aorta, cerebral perfusion methods, and cannulation strategies were reviewed. Additional analyses using patients who underwent ATAAD repair at Stanford University from 1967 through December 2019 were performed to further illustrate the Stanford experience in the management of ATAAD. While technical complexity increased over time, post-operative survival continued to improve. Further investigation is warranted to delineate factors associated with the improved outcomes observed in this study.

  View details for DOI 10.1016/j.jacc.2020.07.061

  View details for PubMedID 33004136

• Off-Pump Mini Thoracotomy Versus Sternotomy for Left Anterior Descending Myocardial Bridge Unroofing. The Annals of thoracic surgery Wang, H. n., Pargaonkar, V. S., Hironaka, C. E., Bajaj, S. S., Abbot, C. J., O'Donnell, C. T., Miller, S. L., Honda, Y. n., Rogers, I. S., Tremmel, J. A., Fischbein, M. P., Mitchell, R. S., Schnittger, I. n., Boyd, J. H. 2020

  Abstract

  Myocardial bridge (MB) of the left anterior descending (LAD) coronary artery occurs in approximately 25% of the population. For patients with a symptomatic, hemodynamically significant MB who fail medical therapy, MB unroofing represents the optimal surgical management. Here, we evaluated minimally invasive MB unroofing in selected patients compared with sternotomy.MB unroofing was performed in 141 adult patients via sternotomy on-pump (ST-on, n=40), sternotomy off-pump (ST-off, n=62), or mini thoracotomy off-pump (MT, n=39). Angina symptoms were assessed preoperatively and 6-months postoperatively using the Seattle Angina Questionnaire. Matching included all MT patients and 31 ST-off patients with similar MB characteristics, no previous cardiac surgery or coronary interventions, and no concomitant procedures.MT patients tended to have a shorter MB length than ST-on and ST-off patients (2.57 vs 2.93 vs 3.09 cm, p=0.166). ST-on patients had a longer hospital stay than ST-off and MT patients (5.0 vs 4.0 vs 3.0 days, p<0.001), and more blood transfusions (15.2% vs 0.0% vs 2.6%, p=0.002). After matching, MT patients had a shorter hospital stay than ST-off patients (3.0 vs 4.0 days, p=0.005). No deaths or major complications occurred in any group. In all groups, MB unroofing yielded significant symptomatic improvement regarding physical limitation, angina stability, angina frequency, treatment satisfaction, and quality of life.We report the largest experience of off-pump minimally invasive MB unroofing, which may be safely performed in carefully selected patients, yielding dramatic improvements in angina symptomatology at 6 months after surgery.

  View details for DOI 10.1016/j.athoracsur.2020.11.023

  View details for PubMedID 33333083

• Commentary: Endograft repair of complicted aortic dissection in Marfan patients JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Mitchell, R. 2019; 157 (6): E303

  View details for DOI 10.1016/j.jtcvs.2018.08.023

  View details for Web of Science ID 000468116200001

• Commentary: Is surgical field insufflation with carbon dioxide an antidote for airhead(s)? The Journal of thoracic and cardiovascular surgery Mitchell, R. S. 2019

  View details for DOI 10.1016/j.jtcvs.2019.04.099

  View details for PubMedID 31230810

• Endovascular Versus Open Repair of Intact Descending Thoracic Aortic Aneurysms JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Chiu, P., Goldstone, A. B., Schaffer, J. M., Lingala, B., Miller, D., Mitchell, R., Woo, Y., Fischbein, M. P., Dake, M. D. 2019; 73 (6): 643–51

  Abstract

  For the management of descending thoracic aortic aneurysms, recent evidence has suggested that outcomes of open surgical repair may surpass thoracic endovascular aortic repair (TEVAR) in as early as 2 years.The purpose of this study was to evaluate the comparative effectiveness of TEVAR and open surgical repair in the treatment of intact descending thoracic aortic aneurysms.Using the Medicare database, a retrospective study using regression discontinuity design and propensity score matching was performed on patients with intact descending thoracic aortic aneurysms who underwent TEVAR or open surgical repair between 1999 and 2010 with follow-up through 2014. Survival was assessed with restricted mean survival time. Perioperative mortality was assessed with logistic regression. Reintervention was evaluated as a secondary outcome.Matching created comparable groups with 1,235 open surgical repair patients matched to 2,470 TEVAR patients. The odds of perioperative mortality were greater for open surgical repair: high-volume center, odds ratio (OR): 1.97 (95% confidence interval [CI]: 1.53 to 2.61); low-volume center, OR: 3.62 (95% CI: 2.88 to 4.51). The restricted mean survival time difference favored TEVAR at 9 years, -209.2 days (95% CI: -298.7 to -119.7 days; p < 0.001) for open surgical repair. Risk of reintervention was lower for open surgical repair, hazard ratio: 0.40 (95% CI: 0.34 to 0.60; p < 0.001).Open surgical repair was associated with increased odds of early postoperative mortality but reduced late hazard of death. Despite the late advantage of open repair, mean survival was superior for TEVAR. TEVAR should be considered the first line for repair of intact descending thoracic aortic aneurysms in Medicare beneficiaries.

  View details for PubMedID 30765029

• A real-world experience: Really? JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Mitchell, R. 2018; 156 (6): 2074–75

  View details for DOI 10.1016/j.jtcvs.2018.05.082

  View details for Web of Science ID 000450355500016

• Acute aortic dissections with entry tear in the aortic arch: International Registry of Acute Aortic Dissection to the rescue JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Mitchell, R. 2018; 156 (5): 1794

  View details for DOI 10.1016/j.jtcvs.2018.08.008

  View details for Web of Science ID 000447417800013

• Surgical unroofing of hemodynamically significant myocardial bridges in a pediatric population Maeda, K., Schnittger, I., Murphy, D. J., Tremmel, J. A., Boyd, J. H., Peng, L., Okada, K., Pargaonkar, V. S., Hanley, F. L., Mitchell, R., Rogers, I. S. MOSBY-ELSEVIER. 2018: 1618–26

  View details for DOI 10.1016/j.jtcvs.2018.01.081

  View details for Web of Science ID 000445221200079

• Acute aortic dissections with entry tear in the aortic arch: International Registry of Acute Aortic Dissection to the rescue. The Journal of thoracic and cardiovascular surgery Mitchell, R. S. 2018

  View details for PubMedID 30217634

• Surgical unroofing of hemodynamically significant myocardial bridges in a pediatric population. The Journal of thoracic and cardiovascular surgery Maeda, K., Schnittger, I., Murphy, D. J., Tremmel, J. A., Boyd, J. H., Peng, L., Okada, K., Pargaonkar, V. S., Hanley, F. L., Mitchell, R. S., Rogers, I. S. 2018

  Abstract

  BACKGROUND: Although myocardial bridges (MBs) are traditionally regarded as incidental findings, it has been reported that adult patients with symptomatic MBs refractory to medical therapy benefit from unroofing. However, there is limited literature in the pediatric population. The aim of our study was to evaluate the indications and outcomes for unroofing in pediatric patients.METHODS: We retrospectively reviewed all pediatric patients with MB in our institution who underwent surgical relief. Clinical characteristics, relevant diagnostic data, intraoperative findings, and postoperative outcomes were evaluated.RESULTS: Between 2012 and 2016, 14 pediatric patients underwent surgical unroofing of left anterior descending artery MBs. Thirteen patients had anginal symptoms refractory to medical therapy, and 1 patient was asymptomatic until experiencing aborted sudden cardiac arrest during exercise. Thirteen patients underwent exercise stress echocardiography, all of which showed mid-septal dys-synergy. Coronary computed tomography imaging confirmed the presence of MBs in all patients. Intravascular ultrasound imaging confirmed the length of MBs: 28.2±16.3mm, halo thickness: 0.59±0.24mm, and compression of left anterior descending artery at resting heart rate: 33.0±11.6%. Invasive hemodynamic assessment with dobutamine confirmed the physiologic significance of the MBs with diastolic fractional flow reserve: 0.59±0.13. Unroofing was performed with the patient under cardiopulmonary bypass (CPB) in the initial 9 cases and without CPB in the subsequent 5 cases. All patients were discharged without complications. The 13 symptomatic patients reported resolution of symptoms on follow-up, and improvement in symptoms and quality of life was documented using the Seattle Angina Questionnaire version 7.CONCLUSIONS: Unroofing of MBs can be safely performed in pediatric patients, with or without use of CPB. In symptomatic patients, unroofing can provide relief of symptoms refractory to medical therapy.

  View details for PubMedID 30005887

• A real-world experience: Really? The Journal of thoracic and cardiovascular surgery Mitchell, R. S. 2018

  View details for PubMedID 29980300

• Outcomes of hybrid procedure for type B aortic dissection with an aberrant right subclavian artery COMMENTARY JOURNAL OF VASCULAR SURGERY Mitchell, R. 2018; 67 (3): 711–12

  View details for Web of Science ID 000425912200008

  View details for PubMedID 29477198

• Acute Limited Intimal Tears of the Thoracic Aorta. Journal of the American College of Cardiology Chin, A. S., Willemink, M. J., Kino, A. n., Hinostroza, V. n., Sailer, A. M., Fischbein, M. P., Mitchell, R. S., Berry, G. J., Miller, D. C., Fleischmann, D. n. 2018; 71 (24): 2773–85

  Abstract

  Limited intimal tears (LITs) of the aorta (Class 3 dissection variant) are the least common form of aortic pathology in patients presenting with acute aortic syndrome (AAS). LITs are difficult to detect on imaging and may be underappreciated.This study sought to describe the frequency, pathology, treatment, and outcome of LITs compared with other AAS, and to demonstrate that LITs can be detected pre-operatively by contemporary imaging.The authors retrospectively reviewed 497 patients admitted for 513 AAS events at a single academic aortic center between 2003 and 2012. AAS were classified into classic dissection (AD), intramural hematoma, LIT, penetrating atherosclerotic ulcer, and rupturing thoracic aortic aneurysm. The prevalence, pertinent risk factors, and detailed imaging findings with surgical and pathological correlation of LITs are described. Management, early outcomes, and late mortality are reported.Among 497 patients with AAS, the authors identified 24 LITs (4.8% of AAS) in 16 men and 8 women (17 type A, 7 type B). Patients with LITs were older than those with AD, and type A LITs had similarly dilated ascending aortas as type A AD. Three patients presented with rupture. Eleven patients underwent urgent surgical aortic replacement, and 2 patients underwent endovascular repair. Medial degeneration was present in all surgical specimens. In-hospital mortality was 4% (1 of 24), and in total, 5 patients with LIT died subsequently at 1.5 years (interquartile range [IQR]: 0.3 to 2.5 years). Computed tomography imaging detected all but 1 LIT, best visualized on volume-rendered images.LITs are rare acute aortic lesions within the dissection spectrum, with similar presentation, complications, and outcomes compared with AD and intramural hematoma. Awareness of this lesion allows pre-operative diagnosis using high-quality computed tomography angiography.

  View details for PubMedID 29903350

• Impact of Discordant Views in the Management of Descending Thoracic Aortic Aneurysm SEMINARS IN THORACIC AND CARDIOVASCULAR SURGERY Chiu, P., Sailer, A., Baiocchi, M., Goldstone, A. B., Schaffer, J. M., Trojan, J., Fleischmann, D., Mitchell, R., Miller, D., Dake, M. D., Woo, Y., Lee, J. T., Fischbein, M. P. 2017; 29 (3): 283–91

  Abstract

  Thoracic endovascular aortic repair has a lower perceived risk than open surgical repair and has become an increasingly popular alternative. Whether general consensus exists regarding candidacy for either operation among open and endovascular specialists is unknown. A retrospective review of isolated descending thoracic aortic aneurysm at our institution between January 2005 and October 2015 was performed, excluding trauma and dissection. Two cardiac surgeons, 2 cardiovascular surgeons, 1 vascular surgeon, and 1 interventional radiologist gave their preference for open vs endovascular repair. Interobserver agreement was assessed with the kappa coefficient. k-means clustering agnostically grouped various patterns of agreement. The mean rating was predicted using least absolute shrinkage and selection operator regression. Negative binomial regression predicted the discrepancy between our panel of raters and the historical operation. Generalized estimating equation modeling was then used to evaluate the association between the extent of discrepancy and the adverse perioperative outcome. There were 77 patients with preoperative imaging studies. Pairwise interobserver agreement was only fair (median weighted kappa 0.270 [interquartile range 0.211-0.404]). Increasing age and proximal neck length predicted an increasing preference for thoracic endovascular aortic repair in our panel; larger proximal neck diameter predicted a general preference for open surgical repair. Increasing proximal neck diameter predicted a larger discrepancy between our panel and the historical operation. Greater discrepancy was associated with adverse outcome. Substantial disagreement existed among our panel, and an exploratory analysis of the effect of increasing discrepancy demonstrated an association with adverse perioperative outcome. An investigation of the effect of a thoracic aortic team with open and endovascular specialists is warranted.

  View details for PubMedID 29195571

• Surgical Unroofing of Hemodynamically Significant Left Anterior Descending Myocardial Bridges. Annals of thoracic surgery Boyd, J. H., Pargaonkar, V. S., Scoville, D. H., Rogers, I. S., Kimura, T., Tanaka, S., Yamada, R., Fischbein, M. P., Tremmel, J. A., Mitchell, R. S., Schnittger, I. 2016

  Abstract

  Left anterior descending artery myocardial bridges (MBs) range from clinically insignificant incidental angiographic findings to a potential cause of sudden cardiac death. Within this spectrum, a group of patients with isolated, symptomatic, and hemodynamically significant MBs despite maximally tolerated medical therapy exist for whom the optimal treatment is controversial. We evaluated supraarterial myotomy, or surgical unroofing, of the left anterior descending MBs as an isolated procedure in these patients.In 50 adult patients, we prospectively evaluated baseline clinical characteristics, risk factors, and medications for coronary artery disease, relevant diagnostic data (stress echocardiography, computed tomography angiography, stress coronary angiogram with dobutamine challenge for measurement of diastolic fractional flow reserve, and intravascular ultrasonography), and anginal symptoms using the Seattle Angina Questionnaire. These patients then underwent surgical unroofing of their left anterior descending artery MBs followed by readministration of the Seattle Angina Questionnaire at 6.6-month (range, 2 to 13) follow-up after surgery.Dramatic improvements were noted in physical limitation due to angina (52.0 versus 87.1, p < 0.001), anginal stability (29.6 versus 66.4, p < 0.001), anginal frequency (52.1 versus 84.7, p < 0.001), treatment satisfaction (76.1 versus 93.9, p < 0.001), and quality of life (25.0 versus 78.9, p < 0.001), all five dimensions of the Seattle Angina Questionnaire. There were no major complications or deaths.Surgical unroofing of carefully selected patients with MBs can be performed safely as an independent procedure with significant improvement in symptoms postoperatively. It is the optimal treatment for isolated, symptomatic, and hemodynamically significant MBs resistant to maximally tolerated medical therapy.

  View details for DOI 10.1016/j.athoracsur.2016.08.035

  View details for PubMedID 27745841

• Pre- and Postoperative Imaging of the Aortic Root. Radiographics Hanneman, K., Chan, F. P., Mitchell, R. S., Miller, D. C., Fleischmann, D. 2016; 36 (1): 19-37

  Abstract

  Three-dimensional datasets acquired using computed tomography and magnetic resonance imaging are ideally suited for characterization of the aortic root. These modalities offer different advantages and limitations, which must be weighed according to the clinical context. This article provides an overview of current aortic root imaging, highlighting normal anatomy, pathologic conditions, imaging techniques, measurement thresholds, relevant surgical procedures, postoperative complications and potential imaging pitfalls. Patients with a range of clinical conditions are predisposed to aortic root disease, including Marfan syndrome, bicuspid aortic valve, vascular Ehlers-Danlos syndrome, and Loeys-Dietz syndrome. Various surgical techniques may be used to repair the aortic root, including placement of a composite valve graft, such as the Bentall and Cabrol procedures; placement of an aortic root graft with preservation of the native valve, such as the Yacoub and David techniques; and implantation of a biologic graft, such as a homograft, autograft, or xenograft. Potential imaging pitfalls in the postoperative period include mimickers of pathologic processes such as felt pledgets, graft folds, and nonabsorbable hemostatic agents. Postoperative complications that may be encountered include pseudoaneurysms, infection, and dehiscence. Radiologists should be familiar with normal aortic root anatomy, surgical procedures, and postoperative complications, to accurately interpret pre- and postoperative imaging performed for evaluation of the aortic root. Online supplemental material is available for this article. (©)RSNA, 2015.

  View details for DOI 10.1148/rg.2016150053

  View details for PubMedID 26761529

• This side up-Handle with care JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Fann, J. I., Mitchell, R. 2015; 150 (6): 1639–40

  View details for PubMedID 26573358

• Midterm Outcomes of Open Descending Thoracic Aortic Repair in More Than 5,000 Medicare Patients ANNALS OF THORACIC SURGERY Schaffer, J. M., Lingala, B., Fischbein, M. P., Dake, M. D., Woo, Y. J., Mitchell, R. S., Miller, D. C. 2015; 100 (6): 2087-2094

  Abstract

  Diseases involving the descending thoracic aorta (DTA) represent a heterogeneous substrate with a variety of therapeutic options. Although thoracic endovascular aortic repair has been increasingly applied to DTA disease, open surgical repair is ostensibly more durable.A total of 5,578 patients who underwent open DTA repair (Current Procedural Terminology code 33875) from 1999 to 2010 were identified from the Medicare database; 5,489 patients had complete data. Survival was assessed with Kaplan-Meier analysis. Cox regression determined predictors of death. Hospital and surgeon volume and variability were modeled, and their association with survival assessed.Median survival after open DTA repair was only 4.3 years (95% confidence interval: 4.0 to 4.6). The likelihood of death varied significantly by certain aortic diseases: aortic rupture and acute aortic dissection patients had the highest early mortality. Survival beyond 180 days was best for patients with acute aortic dissection and isolated thoracic aortic aneurysm, and lowest for patients with thoracoabdominal aneurysm and aortic rupture. Hospital and surgeon volume, as well as interhospital and intersurgeon variability, had associations with overall survival.Open DTA repair has treated a spectrum of aortic diseases in Medicare beneficiaries. Overall mortality was high, predominately confined to the initial postoperative hazard phase. Independent hospital and surgeon effects, hospital and surgeon volume, and a more recent date of surgery correlated with improved survival, while increased operative urgency and complexity correlated with worse outcomes. These observations argue for regionalization of DTA treatment for Medicare patients in specialized centers to concentrate expertise, which should translate into better outcomes.

  View details for DOI 10.1016/j.athoracsur.2015.06.068

  View details for PubMedID 26431919

• Consensus statement on surgical pathology of the aorta from the Society for Cardiovascular Pathology and the Association for European Cardiovascular Pathology: I. Inflammatory diseases CARDIOVASCULAR PATHOLOGY Stone, J. R., Bruneval, P., Angelini, A., Bartoloni, G., Basso, C., Batoroeva, L., Buja, L. M., Butany, J., D'Amati, G., Fallon, J. T., Gittenberger-de Groot, A. C., Gouveia, R. H., Halushka, M. K., Kelly, K. L., Kholova, I., Leone, O., Litovsky, S. H., Maleszewski, J. J., Miller, D. V., Mitchell, R. N., Preston, S. D., Pucci, A., Radio, S. J., Rodriguez, E. R., Sheppard, M. N., Suvarna, S. K., Tan, C. D., Thiene, G., van der Wal, A. C., Veinot, J. P. 2015; 24 (5): 267-278

  View details for DOI 10.1016/j.carpath.2015.05.001

  View details for PubMedID 26051917

• Midterm survival after thoracic endovascular aortic repair in more than 10,000 Medicare patients JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Schaffer, J. M., Lingala, B., Miller, C., Woo, J., Mitchell, R. S., Dake, M. D. 2015; 149 (3): 808-820

  Abstract

  Aneurysms and dissections of the descending thoracic aorta represent a complex substrate with a variety of therapeutic options. The introduction of thoracic endovascular aortic repair (TEVAR) has revolutionized the treatment of thoracic aortic disease. However, longitudinal analyses of post-TEVAR outcomes appropriately stratified by aortic disease remain limited.A total of 11,996 patients undergoing TEVAR from 2005-2010 were identified from the Medicare/Centers for Medicare and Medicaid Services database. Patients were stratified by underlying aortic disease and the presence of Current Procedural Terminology (CPT) codes. Survival was assessed using Kaplan-Meier analysis. Cox proportional hazards analysis determined predictors of survival from TEVAR.After TEVAR, patients had a median survival of 57.6 months (95% confidence interval, 54.9-61.3 months). Although patients without CPT codes had significantly fewer recorded comorbidities, TEVAR survival was comparable between patients with and without CPT codes (56.3 vs 59.5 months, P = .54). The early and late incidence of death varied significantly by aortic disease. Patients with aortic rupture, acute aortic dissection, and aortic trauma had the highest early incidence of death, whereas late survival was highest in patients with acute aortic dissection, aortic trauma, and isolated thoracic aortic aneurysm. Although hospital TEVAR volume was not associated with survival, an independent hospital effect (determined by using a mixed-effect Cox model) associated certain hospitals with a hazard for death 50% of what it was at other hospitals.TEVAR has been applied to a multitude of aortic diseases in the Medicare population; early and late post-TEVAR survival varies by aortic disease. The late incidence of death remains high in TEVAR recipients, although certain aortic diagnoses such as acute aortic dissection, aortic trauma, and isolated thoracic aortic aneurysm were associated with improved late survival. An independent hospital effect, but not hospital volume, is correlated with post-TEVAR survival. Future analyses of TEVAR outcomes using the Medicare database should adjust for underlying aortic diagnoses and the presence of CPT codes.

  View details for DOI 10.1016/j.jtcvs.2014.10.036

  View details for Web of Science ID 000351930600052

  View details for PubMedID 25541408

• Tirone David procedure for bicuspid aortic valve disease: impact of root geometry and valve type on mid-term outcomes†. Interactive cardiovascular and thoracic surgery Kari, F. A., Kvitting, J. E., Stephens, E. H., Liang, D. H., Merk, D. R., Fischbein, M. P., Mitchell, R. S., Miller, D. C. 2014; 19 (3): 375-381

  Abstract

  A 180/180° configuration has been reported to increase repair durability after valve-sparing aortic root replacement (V-SARR) for bicuspid aortic valve (BAV) disease. We studied the impact of commissural angular configuration (CAC) and of BAV type on valve performance after V-SARR.A total of 85 BAV patients (68 males, age 44 ± 11 years) underwent Tirone David-V V-SARR between 1997 and 2013. BAV type was documented intraoperatively, and CAC determined from pre- and postoperative computed tomography scans as the angle subtended by the non-fused cusp. Transthoracic echocardiogram was performed at 6 ± 3 days and at 2.9 ± 2.1 years. Functional end-points included freedom from aortic regurgitation (AR) 1+, AR 2+ and freedom from AR progression (0 to 1+, or 1+ to 2+). Tested variables included preoperative CAC (>160 vs <160°) and changes in CAC after V-SARR (Δ > 30° vs Δ < 30°) and Sievers' BAV type (SØ or S1).CAC in SØ-BAV (n = 26) changed minimally from 164 ± 12 to 171 ± 11° (mean Δ = 7.2 ± 16°, P = 0.044), whereas in S1-BAV (n = 59) CAC changed substantially from 132 ± 19 to 156 ± 18° (mean Δ = 27 ± 21°, P < 0.001). Larger postoperative CAC angles were not linked to better mid-term valve performance, but Sievers' BAV type had a major effect on valve performance: mild AR in S1/i BAV progressed more often (76 vs 32% at 4 years, P = 0.017) and 1+ AR was more frequent (70 vs 36% at 4 years, P = 0.008) compared with SØ-BAV.BAV type, including number of raphes, sinuses and commissures (SØ superior to S1) but not commissure geometry within the neoroot alone, appears to be linked to functional outcomes after V-SARR for BAV.

  View details for DOI 10.1093/icvts/ivu123

  View details for PubMedID 24903440

• Incidence and progression of mild aortic regurgitation after Tirone David reimplantation valve-sparing aortic root replacement JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Stephens, E. H., Liang, D. H., Kvitting, J. E., Kari, F. A., Fischbein, M. P., Mitchell, R. S., Miller, D. C. 2014; 147 (1): 169-?

  Abstract

  The study objective was to determine whether recurrent or residual mild aortic regurgitation, which occurs after valve-sparing aortic root replacement, progresses over time.Between 2003 and 2008, 154 patients underwent Tirone David-V valve-sparing aortic root replacement; 96 patients (62%) had both 1-year (median, 12 ± 4 months) and mid-term (62 ± 22 months) transthoracic echocardiograms available for analysis. Age of patients averaged 38 ± 13 years, 71% were male, 31% had a bicuspid aortic valve, 41% had Marfan syndrome, and 51% underwent aortic valve repair, predominantly cusp free margin shortening.Forty-one patients (43%) had mild aortic regurgitation on 1-year echocardiogram. In 85% of patients (n = 35), mild aortic regurgitation remained stable on the most recent echocardiogram (median, 57 ± 20 months); progression to moderate aortic regurgitation occurred in 5 patients (12%) at a median of 28 ± 18 months and remained stable thereafter; severe aortic regurgitation developed in 1 patient, eventually requiring reoperation. Five patients (5%) had moderate aortic regurgitation at 1 year, which did not progress subsequently. Two patients (2%) had more than moderate aortic regurgitation at 1 year, and both ultimately required reoperation.Although mild aortic regurgitation occurs frequently after valve-sparing aortic root replacement, it is unlikely to progress over the next 5 years and should not be interpreted as failure of the valve-preservation concept. Further, we suggest that mild aortic regurgitation should not be considered nonstructural valve dysfunction, as the 2008 valve reporting guidelines would indicate. We need 10- to 15-year follow-up to learn the long-term clinical consequences of mild aortic regurgitation early after valve-sparing aortic root replacement.

  View details for DOI 10.1016/j.jtcvs.2013.09.009

  View details for PubMedID 24176278

• Chest Pain, Dyspnea On Exertion, And Severe Exercise Intolerance: Evaluation And Diagnosis In An Adolescent With Multiple Medical Comorbidities Tracy, M. C., Rogers, I. S., Maeda, K., Mitchell, R., Tremmel, J., Schnittger, I., Robinson, T. E. AMER THORACIC SOC. 2014

  View details for Web of Science ID 000209838206541

• Tirone David valve-sparing aortic root replacement and cusp repair for bicuspid aortic valve disease JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Kari, F. A., Liang, D. H., Kvitting, J. E., Stephens, E. H., Mitchell, R. S., Fischbein, M. P., Miller, D. C. 2013; 145 (3): S35-?

  Abstract

  The durability of valve-sparing aortic root replacement with or without cusp repair in patients with bicuspid aortic valve (BAV) disease is questioned. We analyzed the results of 75 patients with a BAV undergoing Tirone David reimplantation valve-sparing aortic root replacement.Average age was 45 ± 10 years; 80% were male; 31% had 2+ or greater aortic regurgitation (AR); annular diameter averaged 28 ± 3 mm; 32% had a Sievers' type 0 BAV, and 66% underwent concomitant cusp repair (usually cusp free margin shortening) to correct prolapse. Early (6 ± 3 days) and late (2.9 ± 1.7, 1-10 years) postoperative echocardiographic results were compared (cumulative echocardiographic follow-up, 190 patient-years; median late interval, 2 years [interquartile range, 0.68, 4.2]). Seven patients remained at risk beyond 6 years. Clinical outcome and valve function were analyzed using log-rank calculations.Actuarial survival was 99% ± 2%; freedom from reoperation was 90% ± 5%, infection 98% ± 2%, and stroke 100% at 6 years. After initial improvement in degree of AR (P < .001), minor subclinical progression of AR was observed (P > .5); however, freedom from AR of more than 2+ was 100%. Cusp free margin shortening was not associated with valve deterioration, but commissural suspensory polytetrafluoroethylene neochord creation (n = 4) portended a higher probability of recurrent AR (P = .025).After David procedure and cusp repair in patients with a BAV, midterm clinical and valve function outcomes were favorable out to 6 years. More follow-up is required to determine long-term valve durability and the hazard of other clinically important late adverse events, including eventual reoperation, to beyond 10 years.

  View details for DOI 10.1016/j.jtcvs.2012.11.043

  View details for PubMedID 23260433

• David valve-sparing aortic root replacement: Equivalent mid-term outcome for different valve types with or without connective tissue disorder JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Kvitting, J. E., Kari, F. A., Fischbein, M. P., Liang, D. H., Beraud, A., Stephens, E. H., Mitchell, R. S., Miller, D. C. 2013; 145 (1): 117-?

  Abstract

  Although implicitly accepted by many that the durability of valve-sparing aortic root replacement in patients with bicuspid aortic valve disease and connective tissue disorders will be inferior, this hypothesis has not been rigorously investigated.From 1993 to 2009, 233 patients (27% bicuspid aortic valve, 40% Marfan syndrome) underwent Tirone David valve-sparing aortic root replacement. Follow-up averaged 4.7 ± 3.3 years (1102 patient-years). Freedom from adverse outcomes was determined using log-rank calculations.Survival at 5 and 10 years was 98.7% ± 0.7% and 93.5% ± 5.1%, respectively. Freedom from reoperation (all causes) on the aortic root was 92.2% ± 3.6% at 10 years; 3 reoperations were aortic valve replacement owing to structural valve deterioration. Freedom from structural valve deterioration at 10 years was 96.1% ± 2.1%. No significant differences were found in survival (P = .805, P = .793, respectively), reoperation (P = .179, P = .973, respectively), structural valve deterioration (P = .639, P = .982, respectively), or any other functional or clinical endpoints when patients were stratified by valve type (tricuspid aortic valve vs bicuspid aortic valve) or associated connective tissue disorder. At the latest echocardiographic follow-up (95% complete), 202 patients (94.8%) had none or trace aortic regurgitation, 10 (4.7%) mild, 0 had moderate to severe, and 1 (0.5%) had severe aortic regurgitation. Freedom from greater than 2+ aortic regurgitation at 10 years was 95.3% ± 2.5%. Six patients sustained acute type B aortic dissection (freedom at 10 years, 90.4% ± 5.0%).Tirone David reimplantation valve-sparing aortic root replacement in carefully selected young patients was associated with excellent clinical and echocardiographic outcome in patients with either a tricuspid aortic valve or bicuspid aortic valve. No demonstrable adverse influence was found for Marfan syndrome or connective tissue disorder on durability, clinical outcome, or echocardiographic results.

  View details for DOI 10.1016/j.jtcvs.2012.09.013

  View details for PubMedID 23083792

• Bicuspid aortic valve configuration and aortopathy pattern might represent different pathophysiologic substrates JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Kari, F. A., Fazel, S. S., Mitchell, R. S., Fischbein, M. P., Miller, D. C. 2012; 144 (2): 516-517

  View details for DOI 10.1016/j.jtcvs.2012.05.035

  View details for PubMedID 22698560

• Invited commentary. Annals of thoracic surgery Mitchell, R. S. 2012; 93 (5): 1501-?

  View details for DOI 10.1016/j.athoracsur.2012.02.043

  View details for PubMedID 22541182

• Endovascular repair of traumatic thoracic aortic injury: Clinical practice guidelines of the Society for Vascular Surgery JOURNAL OF VASCULAR SURGERY Lee, W. A., Matsumura, J. S., Mitchell, R. S., Farber, M. A., Greenberg, R. K., Azizzadeh, A., Murad, M. H., Fairman, R. M. 2011; 53 (1): 187-192

  Abstract

  The Society for Vascular Surgery® pursued development of clinical practice guidelines for the management of traumatic thoracic aortic injuries with thoracic endovascular aortic repair. In formulating clinical practice guidelines, the Society selected a panel of experts and conducted a systematic review and meta-analysis of the literature. They used the Grading of Recommendations Assessment, Development and Evaluation methods (GRADE) to develop and present their recommendations. The systematic review included 7768 patients from 139 studies. The mortality rate was significantly lower in patients who underwent endovascular repair, followed by open repair, and nonoperative management (9%, 19%, and 46%, respectively, P < .01). Based on the overall very low quality of evidence, the committee suggests that endovascular repair of thoracic aortic transection is associated with better survival and decreased risk of spinal cord ischemia, renal injury, graft, and systemic infections compared with open repair or nonoperative management (Grade 2, Level C). The committee was also surveyed on a variety of issues that were not specifically addressed by the meta-analysis. On these select matters, the majority opinions of the committee suggest urgent repair following stabilization of other injuries, observation of minimal aortic defects, selective (vs routine) revascularization in cases of left subclavian artery coverage, and that spinal drainage is not routinely required in these cases.

  View details for DOI 10.1016/j.jvs.2010.08.027

  View details for Web of Science ID 000286085200026

  View details for PubMedID 20974523

• Early outcomes of deliberate nonoperative management for blunt thoracic aortic injury in trauma JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Caffarelli, A. D., Mallidi, H. R., Maggio, P. M., Spain, D. A., Miller, D. C., Mitchell, R. S. 2010; 140 (3): 598-605

  Abstract

  Traumatic blunt aortic injury has traditionally been viewed as a surgical emergency, whereas nonoperative therapy has been reserved for nonsurgical candidates. This study reviews our experience with deliberate, nonoperative management for blunt thoracic aortic injury.A retrospective chart review with selective longitudinal follow-up was conducted for patients with blunt aortic injury. Surveillance imaging with computed tomography angiography was performed. Nonoperative patients were then reviewed and analyzed for survival, evolution of aortic injury, and treatment failures.During the study period, 53 patients with an average age of 45 years (range, 18-80 years) were identified, with 28% presenting to the Stanford University School of Medicine emergency department and 72% transferred from outside hospitals. Of the 53 patients, 29 underwent planned, nonoperative management. Of the 29 nonoperative patients, in-hospital survival was 93% with no aortic deaths in the remaining patients. Survival was 97% at a median of 1.8 years (range, 0.9-7.2 years). One patient failed nonoperative management and underwent open repair. Serial imaging was performed in all patients (average = 107 days; median, 31 days), with 21 patients having stable aortic injuries without progression and 5 patients having resolved aortic injuries.This experience suggests that deliberate, nonoperative management of carefully selected patients with traumatic blunt aortic injury may be a reasonable alternative in the polytrauma patient; however, serial imaging and long-term follow-up are necessary.

  View details for DOI 10.1016/j.jtcvs.2010.02.056

  View details for PubMedID 20579668

• Invited commentary. Annals of thoracic surgery Mitchell, R. S. 2010; 90 (1): 100-?

  View details for DOI 10.1016/j.athoracsur.2010.03.089

  View details for PubMedID 20609756

• Invited commentary. Annals of thoracic surgery Mitchell, R. S. 2010; 89 (6): 1864-1865

  View details for DOI 10.1016/j.athoracsur.2010.02.063

  View details for PubMedID 20494040

• The Society for Vascular Surgery Practice Guidelines: Management of the left subclavian artery with thoracic endovascular aortic repair JOURNAL OF VASCULAR SURGERY Matsumura, J. S., Lee, W. A., Mitchell, R. S., Farber, M. A., Murad, M. H., Lumsden, A. B., Greenberg, R. K., Safi, H. J., Fairman, R. M. 2009; 50 (5): 1155-1158

  Abstract

  The Society for Vascular Surgery pursued development of clinical practice guidelines for the management of the left subclavian artery with thoracic endovascular aortic repair (TEVAR). In formulating clinical practice guidelines, the society selected a panel of experts and conducted a systematic review and meta-analysis of the literature. They used the grading of recommendations assessment, development, and evaluation (GRADE) method to develop and present their recommendations. The overall quality of evidence was very low. The committee issued three recommendations. Recommendation 1: In patients who need elective TEVAR where achievement of a proximal seal necessitates coverage of the left subclavian artery, we suggest routine preoperative revascularization, despite the very low-quality evidence (GRADE 2, level C). Recommendation 2: In selected patients who have an anatomy that compromises perfusion to critical organs, routine preoperative LSA revascularization is strongly recommended, despite the very low-quality evidence (GRADE 1, level C). Recommendation 3: In patients who need urgent TEVAR for life-threatening acute aortic syndromes where achievement of a proximal seal necessitates coverage of the left subclavian artery, we suggest that revascularization should be individualized and addressed expectantly on the basis of anatomy, urgency, and availability of surgical expertise (GRADE 2, level C).

  View details for DOI 10.1016/j.jvs.2009.08.090

  View details for Web of Science ID 000271390300029

  View details for PubMedID 19878791

• Infolding and collapse of thoracic endoprostheses: Manifestations and treatment options JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Sze, D. Y., Mitchell, R. S., Miller, D. C., Fleischmann, D., Frisoli, J. K., Kee, S. T., Verma, A., Sheehan, M. P., Dake, M. D. 2009; 138 (2): 324-333

  Abstract

  We sought to review the clinical sequelae and imaging manifestations of thoracic aortic endograft collapses and infoldings and to evaluate minimally invasive methods of repairing such collapses.Two hundred twenty-one Gore endografts (Excluder, TAG; W. L. Gore & Associates, Inc, Flagstaff, Ariz) were deployed in 145 patients for treatment of pathologies including aneurysms and pseudoaneurysms, dissections, penetrating ulcers, transections, fistulae, mycotic aneurysms, and neoplastic invasions in 6 different prospective trials at a single institution from 1997 to 2007. Device collapses and infoldings were analyzed retrospectively, including review of anatomic parameters, pathologies treated, device sizing and selection, clinical sequelae, methods of repair, and outcome.Six device collapses and infoldings were identified. Oversized devices placed into small-diameter aortas and imperfect proximal apposition to the lesser curvature were seen in all proximal collapses, affecting patients with transections and pseudoaneurysms. Infoldings in patients undergoing dissection represented incomplete initial expansion rather than delayed collapse. Delayed collapse occurred as many as 6 years after initial successful deployment, apparently as a result of changes in the aortic configuration from aneurysmal shrinkage. Clinical manifestations ranged from life-threatening ischemia to complete lack of symptoms. Collapses requiring therapy were remedied percutaneously by bare stenting or in one case by branch vessel embolization.Use of oversized devices in small aortas carries a risk of device failure by collapse, which can occur immediately or after years of delay. When clinically indicated, percutaneous repair can be effectively performed.

  View details for DOI 10.1016/j.jtcvs.2008.12.007

  View details for PubMedID 19619775

• Factors Portending Endoleak Formation After Thoracic Aortic Stent-Graft Repair of Complicated Aortic Dissection CIRCULATION-CARDIOVASCULAR INTERVENTIONS Sze, D. Y., Van den Bosch, M. A., Dake, M. D., Miller, D. C., Hofmann, L. V., Varghese, R., Malaisrie, S. C., van der Starre, P. J., Rosenberg, J., Mitchell, R. S. 2009; 2 (2): 105-112

  Abstract

  Endoleaks after stent-graft repair of aortic dissections are poorly understood but seem substantially different from those seen after aneurysm repair. We studied anatomic and clinical factors associated with endoleaks in patients who underwent stent-graft repair of complicated type B aortic dissections.From 2000 to 2007, 37 patients underwent stent-graft repair of acute (< or =14 days; n=23), subacute (15 to 90 days; n=10) or chronic (>90 days; n=4) complicated type B aortic dissections using the Gore Thoracic Excluder (n=17) or TAG stent-grafts (n=20) under an investigator-sponsored protocol. Endoleaks were classified as imperfect proximal seal, flow through fenestrations or branches, or complex (both). Variables studied included coverage of the left subclavian artery, aortic curvature, completeness of proximal apposition, dissection chronicity, and device used. Endoleaks were found during follow-up (mean, 22 months) in 59% of patients, and they were associated with coverage of the left subclavian artery (complex, P<0.001), small radius of curvature (type 1 and complex, P=0.05), and greatest length of unapposed proximal stent graft (complex, P<0.0001). During follow-up, 10 endoleaks resolved spontaneously, 6 required reintervention for false lumen dilatation, and 2 were stable without clinical consequences.Endoleaks are common after stent-graft repair of aortic dissection and may lead to false lumen enlargement necessitating reintervention. Anatomic complexities such as acute aortic curvature and covered side branches were associated with endoleaks, illustrating the need for dissection-specific device development.

  View details for DOI 10.1161/CIRCINTERVENTIONS.108.819722

  View details for PubMedID 20031703

• Improvement in coronary anastomosis with cardiac surgery simulation JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Fann, J. I., Caffarelli, A. D., Georgette, G., Howard, S. K., Gaba, D. M., Youngblood, P., Mitchell, S., Burdon, T. A. 2008; 136 (6): 1486-1491

  Abstract

  Cardiac surgery trainees might benefit from simulation training in coronary anastomosis and more advanced procedures. We evaluated distributed practice using a portable task station and experience on a beating-heart model in training coronary anastomosis.Eight cardiothoracic surgery residents performed 2 end-to-side anastomoses with the task station, followed by 2 end-to-side anastomoses to the left anterior descending artery by using the beating-heart model at 70 beats/min. Residents took home the task station, recording practice times. At 1 week, residents performed 2 anastomoses on the task station and 2 anastomoses on the beating-heart model. Performances of the anastomosis were timed and reviewed.Times to completion for anastomosis on the task station decreased 20% after 1 week of practice (351 +/- 111 to 281 +/- 53 seconds, P = .07), with 2 residents showing no improvement. Times to completion for beating-heart anastomosis decreased 15% at 1 week (426 +/- 115 to 362 +/- 94 seconds, P = .03), with 2 residents demonstrating no improvement. Home practice time (90-540 minutes) did not correlate with the degree of improvement. Performance rating scores showed an improvement in all components. Eighty-eight percent of residents agreed that the task station is a good method of training, and 100% agreed that the beating-heart model is a good method of training.In general, distributed practice with the task station resulted in improvement in the ability to perform an anastomosis, as assessed by times to completion and performance ratings, not only with the task station but also with the beating-heart model. Not all residents improved, which is consistent with a "ceiling effect" with the simulator and a "plateau effect" with the trainee. Simulation can be useful in preparing residents for coronary anastomosis and can provide an opportunity to identify the need and methods for remediation.

  View details for DOI 10.1016/j.jtcvs.2008.08.016

  View details for PubMedID 19114195

• Pre- and Postoperative Imaging of the Aortic Root for Valve-Sparing Aortic Root Repair (V-SARR) SEMINARS IN THORACIC AND CARDIOVASCULAR SURGERY Fleischmann, D., Liang, D. H., Mitchell, R., Miller, D. 2008; 20 (4): 365–73

  View details for DOI 10.1053/j.semtcvs.2008.11.009

  View details for Web of Science ID 000416343300016

• Acute Aortic Syndromes: New Insights from Electrocardiographically Gated Computed Tomography SEMINARS IN THORACIC AND CARDIOVASCULAR SURGERY Fleischmann, D., Mitchell, R., Miller, D. 2008; 20 (4): 340–47

  View details for DOI 10.1053/j.semtcvs.2008.11.011

  View details for Web of Science ID 000416343300013

• Complicated acute type B aortic dissection: Midterm results of emergency endovascular stent-grafting 31st Annual Meeting of the Western-Thoracic-Surgical-Association Verhoye, J. P., Miller, D. C., Sze, D., Dake, M. D., Mitchell, R. S. MOSBY-ELSEVIER. 2008: 424–30

  Abstract

  This study assessed midterm results of emergency endovascular stent-grafting for patients with life-threatening complications of acute type B aortic dissection.Between November 1996 and June 2004, 16 patients with complicated acute type B aortic dissections (mean age 57 years, range 16-88 years) underwent endovascular stent-grafting within 48 hours of presentation. Complications included contained rupture, hemothorax, refractory chest pain, and severe visceral or lower limb ischemia. Stent-graft types included custom-made first-generation endografts and second-generation commercial stent-grafts (Gore Excluder or TAG; W. L. Gore & Associates, Inc, Flagstaff, Ariz.). Follow-up was 100% complete, averaged 36 +/- 36 months, and included postprocedural surveillance computed tomographic scans.Early mortality was 25% +/- 11% (70% confidence limit), with no late deaths. No new neurologic complications occurred. According to the latest scan, 4 patients (25%) had complete thrombosis of the false lumen; the lumen was partially thrombosed in 6 patients (38%). Distal aortic diameter was increased in only 1 patient. Actuarial survival at 1 and 5 years was 73% +/- 11%; freedom from treatment failure (including aortic rupture, device fault, reintervention, aortic death, or sudden, unexplained late death) was 67% +/- 14% at 5 years.With follow-up to 9 years, endovascular stent-grafting for patients with complicated acute type B aortic dissection conferred benefit. Consideration of emergency stent-grafting may improve the dismal outlook for these patients; future refinements in stent-graft design and technology and earlier diagnosis and intervention should be associated with improved results.

  View details for DOI 10.1016/j.jtcvs.2008.01.046

  View details for PubMedID 18692652

• Treatment of acute type b aortic dissection: New and improved? JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Mitchell, R. S. 2008; 135 (6): 1201-1201

  View details for DOI 10.1016/j.jtcvs.2007.07.072

  View details for Web of Science ID 000256494200003

  View details for PubMedID 18544353

• The aortopathy of bicuspid aortic valve disease has distinctive patterns and usually involves the transverse aortic arch 33rd Annual Meeting of the Western-Thoracic-Surgical-Association Fazel, S. S., Mallidi, H. R., Lee, R. S., Sheehan, M. P., Liang, D., Fleischman, D., Herfkens, R., Mitchell, S., Miller, D. C. MOSBY-ELSEVIER. 2008: 901–U54

  Abstract

  Bicuspid aortic valves are associated with a poorly characterized connective tissue disorder that predisposes to aortic catastrophes. Because no criterion exists dictating the appropriate extent of aortic resection in aneurysmal disease of the bicuspid aortic valve, we studied the patterns of aortic dilation in this population.Sixty-four patients with bicuspid aortic valves who underwent computed tomographic or magnetic resonance angiography and echocardiography were retrospectively identified between January 2002 and March 2006. Orthonormal 2-dimensional or 3-dimensional aortic diameters were measured at 10 levels. Agglomerative hierarchic clustering with centered correlation distance measurements and complete linkage analysis was used to detect distinct patterns of aortic dilatation.Mean aortic diameter was 28.1 +/- 0.7 mm at the annulus and 21.7 +/- 0.4 mm at the diaphragmatic hiatus. The aorta was largest in the tubular ascending aorta (45.9 +/- 1.0 mm). Compared with the descending aorta, the transverse aortic arch was also dilated (P < .01). Cluster analysis showed 4 patterns of aortic dilatation: cluster I, aortic root alone (n = 8, 13%); cluster II, tubular ascending aorta alone (n = 9, 14%); cluster III, tubular portion and transverse arch (n = 18, 28%); and, cluster IV, aortic root and tubular portion with tapering across the transverse arch (n = 29, 45%).Distinct patterns of aortic dilatation in patients with bicuspid aortic valves call for an individualized degree of aortic replacement to minimize late aortic complications and reoperation. Patients in clusters III and IV should have transverse arch replacement (plus concomitant root replacement in cluster IV). Patients in cluster I should undergo complete aortic root replacement, whereas in patients in cluster II supracommissural ascending aortic grafting is adequate.

  View details for DOI 10.1016/j.jtcvs.2008.01.022

  View details for PubMedID 18374778

• Invited commentary. Annals of thoracic surgery Mitchell, R. S. 2008; 85 (2): 464-?

  View details for DOI 10.1016/j.athoracsur.2007.11.034

  View details for PubMedID 18222244

• Acute aortic syndromes: new insights from electrocardiographically gated computed tomography. Seminars in thoracic and cardiovascular surgery Fleischmann, D., Mitchell, R. S., Miller, D. C. 2008; 20 (4): 340-347

  Abstract

  The development of retrospective electrocardiographic (ECG)-gating has proved to be a diagnostic and therapeutic boon for computed tomography (CT) imaging of patients with acute thoracic aortic diseases, such as aortic dissection/intramural hematoma (AD/IMH), penetrating atherosclerotic ulcer (APU), and ruptured/leaking aneurysm. The notorious pulsation motion artifacts in the ascending aorta confounding regular CT scanning can be eliminated, and involvement of the sinuses of Valsalva, the valve cusps, the aortic annulus, and the coronary arteries in aortic dissection can be clearly depicted or excluded. Motion-free images also allow reliable identification of the site of the primary intimal tear, the location, and extent of the intimomedial flap, and branch artery involvement. ECG-gated CTA also allows the detection of more subtle lesions and variants of aortic dissection, which may ultimately expand our understanding of these complex, life-threatening disorders.

  View details for DOI 10.1053/j.semtcvs.2008.11.011

  View details for PubMedID 19251175

• Pre- and postoperative imaging of the aortic root for valve-sparing aortic root repair (V-SARR). Seminars in thoracic and cardiovascular surgery Fleischmann, D., Liang, D. H., Mitchell, R. S., Miller, D. C. 2008; 20 (4): 365-373

  Abstract

  Valve-sparing aortic root repair (V-SARR) using the David reimplantation method is an increasingly popular alternative to composite valve graft aortic root replacement in patients with aortic root aneurysms or dissections who wish to avoid anticoagulation. Computed tomography (CT) with retrospective electrocardiograph (ECG)-gating has become routine before and following V-SARR at Stanford. CT allows accurate measurement of aortic dimensions and provides unprecedented three-dimensional (3D) images of the sinuses, the aortic valve cusps, and coronary arteries in patients with the Marfan syndrome (MFS), with a bicuspid aortic valve (BAV), or other aortic diseases. This helps the surgeon to conceptualize the size of the aortic grafts required and how much reduction is necessary proximally (aortic annulus) and distally. These maneuvers are used to reduce the aortic annular diameter (when necessary) and replace the sinuses and ascending aorta (T. David-V, Stanford modification V-SARR). Postoperative ECG-gated CT confirms the reconstructed geometry and reliably detects coronary or other anastomotic problems.

  View details for DOI 10.1053/j.semtcvs.2008.11.009

  View details for PubMedID 19251178

• Advances in aortic surgery Mitchell, R. S. ELSEVIER IRELAND LTD. 2007: 1–2

  View details for Web of Science ID 000252310200006

• Intraoperative monitoring of elephant trunk kinking with transesophageal echocardiography JOURNAL OF CARDIOTHORACIC AND VASCULAR ANESTHESIA Oakes, D. A., Sze, D. Y., Frisoli, J. K., Mitchell, R. S., Harris, E. J., Thu, C., van der Starre, P. J. 2007; 21 (4): 584-586

  View details for DOI 10.1053/j.jvca.2006.11.002

  View details for Web of Science ID 000248766100023

  View details for PubMedID 17678793

• Rapid aneurysmal degeneration of a Stanford type B aortic dissection in a patient with Loeys-Dietz syndrome JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Lee, R. S., Fazel, S., Schwarze, U., Fleischmann, D., Berry, G. J., Liang, D., Miller, D. C., Mitchell, R. S. 2007; 134 (1): 242-U32

  View details for DOI 10.1016/j.jtcvs.2007.03.004

  View details for PubMedID 17599521

• Invited commentary. Annals of thoracic surgery Mitchell, R. S. 2007; 83 (5): 1640-?

  View details for PubMedID 17462372

• Endovascular stent grafting versus open surgical repair of descending thoracic aortic aneurysms in low-risk patients: A multicenter comparative trial 85th Annual Meeting of the American-Association-for-Thoracic-Surgery Bavaria, J. E., Appoo, J. J., Makaroun, M. S., Verter, J., Yu, Z., Mitchell, R. S. MOSBY-ELSEVIER. 2007: 369–U17

  Abstract

  Results are presented from the first completed multicenter trial directed at gaining approval from the US Food and Drug Administration of endovascular versus open surgical repair of descending thoracic aortic aneurysms.Between September 1999 and May 2001, 140 patients with descending thoracic aneurysms were enrolled at 17 sites and evaluated for a Gore TAG Thoracic Endograft. An open surgical control cohort of 94 patients was identified by enrolling historical and concurrent subjects. Patients were assessed before treatment, at treatment, and at hospital discharge and returned for follow-up visits at 1 month, 6 months, and annually thereafter.One hundred thirty-seven of 140 patients had successful implantation of the endograft. Perioperative mortality in the endograft versus open surgical control cohort was 2.1% (n = 3) versus 11.7% (n = 11, P < .001). Thirty-day analysis revealed a statistically significant lower incidence of the following complications in the endovascular cohort versus the surgical cohort: spinal cord ischemia (3% vs 14%), respiratory failure (4% vs 20%), and renal insufficiency (1% vs 13%). The endovascular group had a higher incidence of peripheral vascular complications (14% vs 4%). The mean lengths of intensive care unit stay (2.6 +/- 14.6 vs 5.2 +/- 7.2 days) and hospital stay (7.4 +/- 17.7 vs 14.4 +/- 12.8 days) were significantly shorter in the endovascular cohort. At 1 and 2 years' follow-up, the incidence of endoleaks was 6% and 9%, respectively. Through 2 years of follow-up, there were 3 reinterventions in the endograft cohort and none in the open surgical control cohort. Kaplan-Meier analysis revealed no difference in overall mortality at 2 years.In this multicenter study early outcomes with descending aortic endovascular stent grafting were very encouraging when compared with those of a well-matched surgical cohort. However, at 2 years' follow-up, there is an incidence of endoleaks and reinterventions associated with endovascular versus open surgical repair. Continued vigilant surveillance of patients treated with an endograft is important.

  View details for DOI 10.1016/j.jtcvs.2006.07.040

  View details for Web of Science ID 000243783900016

  View details for PubMedID 17258566

• Early computed tomographic control JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Mitchell, R. S. 2006; 132 (6): 1257-1257

  View details for DOI 10.1016/j.jtcvs.2006.08.039

  View details for Web of Science ID 000242626200004

  View details for PubMedID 17140936

• Stent-graft repair of an aortic rupture caused by invasive hemangiopericytoma ANNALS OF THORACIC SURGERY van der Starre, P. J., Sze, D. Y., Guta, C., Mitchell, R. S., Dake, M. D. 2006; 81 (6): 2300-2302

  Abstract

  We describe a patient with a history of hemangiopericytoma, who had hemoptysis develop due to a pseudoaneurysm of the thoracic aorta from an intrathoracic metastasis. Stent-graft repair successfully excluded the aneurysm from the aorta. Transesophageal echocardiography showed to be an important guide for correct placement of the device.

  View details for DOI 10.1016/j.athoracsur.2005.07.016

  View details for Web of Science ID 000238027600059

  View details for PubMedID 16731179

• Unusual case of late thoracic stent graft failure after cardioversion ANNALS OF THORACIC SURGERY Caffarelli, A. D., BANOVAC, F., Cheung, S. C., Fleischmann, D., Mitchell, R. S. 2006; 81 (5): 1875-1877

  Abstract

  We report the unusual case of successful endovascular exclusion of a thoracic aortic aneurysm with subsequent thoracic aortic aneurysm reduction, and development of an interval, acute type III endoleak after cardioversion 5 years after stent graft deployment.

  View details for DOI 10.1016/j.athoracsur.2005.04.087

  View details for Web of Science ID 000237001700052

  View details for PubMedID 16631691

• Aortic neck morphology after endovascular repair of descending thoracic aortic aneurysms 59th Annual Meeting of the Society-for-Vascular-Surgery Hassoun, H. T., Mitchell, R. S., Makaroun, M. S., Whiting, A. J., Cardeira, K. R., Matsumura, J. S. MOSBY-ELSEVIER. 2006: 26–31

  Abstract

  Endovascular repair has emerged as a less-invasive treatment for descending thoracic aortic (DTA) aneurysms. However, the durability of this procedure relies on the stability of proximal and distal fixation sites. This study analyzes 3 years of computed tomography (CT) data on aortic neck morphology after endovascular DTA aneurysm repair.Between 1999 and 2001, 139 patients underwent successful endovascular DTA repair as part of a prospective, multicenter clinical trial investigating the Gore TAG thoracic endoprosthesis. Contrast-enhanced, high-resolution CT scans were obtained at 1 (baseline), 12, 24, and 36 months and submitted to an independent core laboratory for image analysis. The aorta was carefully measured by using computerized planimetry and a standardized protocol. Neck diameter was measured at 10-mm intervals for 2 cm above and below the aneurysm and correlated with graft migration and endoleak.The mean proximal neck diameter increased from a baseline of 30.2 +/- 4.6 mm to 32.0 +/- 4.3 mm at 36 months (P <.05), and the annual diameter increase was 0.8, 0.4, and 0.6 mm at 12, 24, and 36 months. The mean distal neck diameter increased from 29.4 +/- 3.8 mm to 32.1 +/- 5.0 mm at 36 months (P <.05), and the annual diameter increase was 1.1, 0.4, and 1.2 mm at 12, 24, and 36 months. At 36 months, freedom from neck dilation of > or =5 mm was 87%, and freedom from migration of > or =10 mm was 83%. An endoleak was present in 11 (9%) of 122 patients at baseline, 7 (7%) of 96 at 12 months, 6 (9%) of 68 at 24 months, and 1 (3%) of 33 at 36 months. Neck dilation was not associated with graft migration or endoleak.Three years after endovascular repair of DTA aneurysms, there is progressive enlargement of the proximal and distal aortic necks. Although uncommon for patients to develop significant neck dilation, when it does occur, it is not associated with graft migration or endoleak. Continued surveillance of aortic neck morphology after descending thoracic aneurysm endografting is recommended.

  View details for DOI 10.1016/j.jvs.2005.09.041

  View details for Web of Science ID 000234659600008

  View details for PubMedID 16414383

• Third International Summit on thoracic aortic endografting: Lessons from long-term results of thoracic stent-graft repairs JOURNAL OF ENDOVASCULAR THERAPY Mitchell, R. S., Ishimaru, S., Criado, F. J., Ehrlich, M. P., Ivancev, K., Lachat, M., Malina, M., May, J., Orend, K. H., Rousseau, H., Williams, D. M. 2005; 12 (1): 89-97

  View details for PubMedID 15683277

• Midterm results of endovascular repair of descending thoracic aortic aneurysms with first-generation stent grafts 29th Annual Meeting of the Western-Thoracic-Surgical-Association Demers, P., Miller, D. C., Mitchell, R. S., Kee, S. T., Sze, D., Razavi, M. K., Dake, M. D. MOSBY-ELSEVIER. 2004: 664–73

  Abstract

  Five years after reporting our initial stent-graft repair of descending thoracic aortic aneurysms experience, we determined the 5- to 10-year results of stent-graft treatment and identified risk factors for adverse late outcomes.Between 1992 and 1997, 103 patients (mean age 69 +/- 12 years) underwent repair using first-generation (custom-fabricated) stent grafts. Sixty-two patients (60%) were unsuitable candidates for conventional open surgical repair ("inoperable"). Follow-up was 100% complete (mean 4.5 +/- 2.5 years; maximum 10 years). Outcome variables included death and treatment failure (endoleak, aortic rupture, reintervention, and/or aortic-related or sudden death).Overall actuarial survival was 82% +/- 4%, 49% +/- 5%, and 27% +/- 6% at 1, 5, and 8 years. Survival in open surgical candidates was 93% +/- 4% and 78% +/- 6% and at 1 and 5 years compared with 74% +/- 6% and 31% +/- 6% in those deemed inoperable (P <.001). Independent risk factors for death were older age (hazard ratio = 1.1; P =.008), previous stroke (hazard ratio = 2.8; P =.003), and being designated an inoperable candidate (hazard ratio = 1.9; P =.04). Actuarial freedom from aortic reintervention and treatment failure at 8 years was 70% +/- 6% and 39% +/- 8%, respectively. Earlier operative year (hazard ratio = 1.2; P =.07), larger distal landing zone diameter (hazard ratio = 1.1; P =.001), and transposition of the left subclavian artery (hazard ratio = 3.3; P =.008) were determinants of treatment failure.Survival after aneurysm repair using crude, first-generation stent grafts was satisfactory in good operative candidates but bleak in the inoperable cohort, raising the question of whether asymptomatic patients should have even been treated. Late aortic complications were detected in many patients, reemphasizing the importance of serial imaging surveillance.

  View details for DOI 10.1016/j.jtcvs.2003.10.047

  View details for PubMedID 15001894

• Chronic traumatic aneurysms of the descending thoracic aorta: mid-term results of endovascular repair using first and second-generation stent-grafts EUROPEAN JOURNAL OF CARDIO-THORACIC SURGERY Demers, P., Miller, C., Mitchell, R. S., Kee, S. T., Chagonjian, R. N., Dake, M. D. 2004; 25 (3): 394-400

  Abstract

  Endovascular stent-graft repair holds promise for treating traumatic injuries of the descending thoracic aorta. The durability of this approach, however, remains unknown. The objective is to evaluate the mid-term results of stent-graft repair of chronic traumatic aneurysms of the descending thoracic aorta.Between 1993 and 2000, endovascular repair of the descending thoracic aorta with first (custom-fabricated) and second-generation (commercial) stent-grafts was performed in 15 patients (mean age 54+/-13 years) at an average of 18+/-14 years after the injury. Because of comorbidities, 4 patients (27%) were judged not to be reasonable surgical candidates for conventional open surgical approach. Follow-up was 100% complete and averaged 55+/-29 months.Stent-graft deployment was successful in all without need for surgical conversion. One patient died early postoperatively. No neurologic complications occurred. Two patients had a primary endoleak, one of them was successfully treated before discharge. Actuarial survival estimates at 1 and 6 years were 93+/-6% and 85+/-10%. Actuarial freedom from reintervention on the descending thoracic aorta was 93+/-6% and 70+/-15% at 1 and 6 years, respectively. Actuarial freedom from treatment failure (a conservative, all-encompassing performance indicator including endoleak, device mechanical fault, reintervention, late aortic-related death, or sudden, unexplained late death) at 1 and 6 years was 87+/-8% and 51+/-15%.Stent-grafting is safe in selected patients with chronic traumatic aneurysms and associated with satisfactory-but not optimal-mid-term durability. Serial follow-up surveillance imaging is mandatory to detect late stent-graft complications. Younger, good risk patients should be offered conventional open operation, reserving stent-grafting for those who are at prohibitive operative risk or who have limited life expectancy.

  View details for DOI 10.1016/j.ejcts.2003.11.035

  View details for Web of Science ID 000220286800015

  View details for PubMedID 15019666

• Stent-graft repair of penetrating atherosclerotic ulcers in the descending thoracic aorta: Mid-term results ANNALS OF THORACIC SURGERY Demers, P., Miller, D. C., Mitchell, R. S., Kee, S. T., Chagonjian, L., Dake, M. D. 2004; 77 (1): 81-86

  Abstract

  Localized aortic pathoanatomic abnormalities are good targets for endovascular stent-grafting but only short-term results have been reported. Our objective was to determine the effectiveness of endovascular stent-graft treatment of patients with descending thoracic atherosclerotic penetrating atherosclerotic ulcers (PAU) and to identify risk factors for treatment failure.Between 1993 and 2000 endovascular repair of PAU with first-generation (custom-fabricated) and second-generation (commercial) stent-grafts was performed in 26 patients (mean age, 70 years), 6 (23%) of whom had rupture. Fourteen patients (54%) were not candidates for open surgical repair. Follow-up was 100% complete (average, 51 months; maximum, 114 months). Outcome variables considered in the multivariable analysis included death and treatment failure (composite end-point comprising early death, endoleak, stent-graft mechanical fault, late aortic event, reintervention, and aortic-related or sudden death).Three patients (12% +/- 7% [+/-70% confidence limits]) died within 30 days and 2 had an early type I endoleak. Primary success rate was 92%. Actuarial survival estimates at 1, 3, and 5 years were 85% +/- 8%, 76% +/- 8% and 70% +/- 10% respectively and actuarial freedom from treatment failure was 81% +/- 8%, 71% +/- 9% and 65% +/- 10%. Multivariable analyses identified previous cerebrovascular accident (hazard ratio [HR] 17.1, p = 0.02) and female sex (HR 7.4, p = 0.08) as independent risk factors for death. For treatment failure the predictors were increasing aortic diameter (HR 1.1 [per mm above the mean value], p = 0.01) and female sex (HR 5.5, p = 0.09).Endovascular stent-graft repair is effective but not curative treatment for selected, high surgical risk, elderly patients with a descending aortic PAU over the medium term. Assiduous serial follow-up imaging after stent-grafting is mandatory to detect late complications especially in those with a large aorta.

  View details for DOI 10.1016/S0003-4975(03)00816-6

  View details for PubMedID 14726040

• Acute type A aortic dissection complicated by aortic regurgitation: Composite valve graft versus separate valve graft versus conservative valve repair 28th Annual Meeting of the Western-Thoracic-Surgical-Association Lai, D. T., Miller, D. C., Mitchell, R. S., Oyer, P. E., Moore, K. A., Robbins, R. C., Shumway, N. E., Reitz, B. A. MOSBY-ELSEVIER. 2003: 1978–86

  Abstract

  To clarify the merits of various surgical approaches, we studied the outcome after composite valve graft versus separate valve and graft replacement versus conservative valve treatment with replacement of the ascending aorta in patients with acute type A aortic dissection complicated by aortic regurgitation.Between 1967 and 1999, 123 patients (mean age 56 +/- 15 years) underwent composite valve graft replacement (n = 21), separate valve and graft replacement (n = 20), or conservative valve treatment (n = 82 [commissural resuspension in 46]); follow-up averaged 6.5 years (95% complete).The 30-day, 1-year, and 6-year survival estimates of 85% +/- 4%, 79% +/- 5%, and 69% +/- 5% (+/-1 standard error of mean), respectively, after conservative valve treatment were similar to 86% +/- 8%, 81% +/- 9%, and 65% +/- 16%, respectively, with composite valve graft replacement and better (but insignificantly so) than 70% +/- 10%, 70% +/- 10%, and 45% +/- 11%, respectively, with separate valve and graft replacement. The 6-year freedom from proximal reoperation was 95% +/- 3%, 89% +/- 10%, and 100% in conservative valve graft, separate valve and graft, and composite valve graft subgroups, respectively (P = not significant). Cox regression multivariable analysis identified that previous sternotomy (hazard ratio [or e(beta)] 95% confidence interval 1.4-10.9, P =.006), hypertension (0.99-2.9, P =.05), cardiac tamponade (1.1-4.0, P =.03), and stroke (1.7-7.0, P =.001) increased the hazard of death. No factors predicting a higher likelihood of late proximal reoperation were identified.In patients with acute type A aortic dissection and aortic regurgitation, there was no significant difference in overall survival or reoperation rates among these surgical approaches. We try to save the valve whenever possible unless the aortic root is pathologically dilated (eg, Marfan syndrome or annuloaortic ectasia) or destroyed by the dissection process, when composite valve graft or valve-sparing aortic root replacement is indicated.

  View details for DOI 10.1016/S0022-5223(03)01279-0

  View details for PubMedID 14688716

• Femoro-femoral partial bypass in the treatment of thoracoabdominal aneurysms. Seminars in thoracic and cardiovascular surgery Coady, M. A., Mitchell, R. S. 2003; 15 (4): 340-344

  Abstract

  This article describes our rationale for the use of femoro-femoral bypass as a primary modality for perfusion in the repair of thoracoabdominal aortic aneurysms at Stanford University School of Medicine. Benefits and limitations of this method are discussed and compared with other described techniques.

  View details for PubMedID 14710375

• Cavoatrial tumor thrombus excision without circulatory arrest UROLOGY Shinghal, R., Vricella, L. A., Mitchell, R. S., Presti, J. 2003; 62 (1): 138-140

  Abstract

  Traditional methods of cavoatrial thrombus excision use deep hypothermic circulatory arrest with significant associated morbidity and mortality. We describe a novel technique that avoids circulatory arrest, yet provides a bloodless field for tumor excision.A 59-year-old woman presented with a left renal mass and tumor thrombus with extension into the right atrium. After left radical nephrectomy, an aortic occlusion balloon was placed in the abdominal aorta at the level of the diaphragm, limiting flow in the inferior vena cava for tumor excision and maintaining both cerebral and spinal cord perfusion during cardiopulmonary bypass. Tumor excision was successfully performed using this technique with minimal postoperative morbidity in the patient described. She remained free of recurrence at 9 months of follow-up.Cavoatrial tumor thrombus excision can be successfully performed without deep hypothermic circulatory arrest.

  View details for DOI 10.1016/S0090-4295(03)00258-9

  View details for Web of Science ID 000183892600036

  View details for PubMedID 12837443

• Endovascular stent-graft repair of descending thoracic aortic penetrating atherosclerotic ulcers: Mid-term results 52nd Annual Scientific Session of the American-College-of-Cardiology Demers, P., Miller, D. C., Mitchell, R. S., Kee, S. T., Chagonjian, L., Dake, M. D. ELSEVIER SCIENCE INC. 2003: 236A–236A

  View details for Web of Science ID 000181669501020

• Is medical therapy still the optimal treatment strategy for patients with acute type B aortic dissections? 27th Annual Meeting of the Western-Thoracic-Surgical-Association Umana, J. P., Lai, D. T., Mitchell, R. S., Moore, K. A., Rodriguez, F., Robbins, R. C., Oyer, P. E., Dake, M. D., Shumway, N. E., Reitz, B. A., Miller, D. C. MOSBY-ELSEVIER. 2002: 896–910

  Abstract

  The optimal treatment of patients with acute type B dissections continues to be debated.A 36-year clinical experience of medical and surgical treatments in 189 patients was retrospectively analyzed (multivariable Cox proportional hazards model) with respect to three outcome end points: all deaths, freedom from reoperation, and freedom from late aortic complications or death. Propensity score analysis identified 2 quintiles (quintiles I and II, consisting of 142 comparable patients) for further comparison of the effects of surgical versus medical treatment.Shock (hazard ratio 14.5, 95% confidence interval 4.7-44.5, P <.001) and visceral ischemia (hazard ratio 10.9, 95% confidence interval 3.9-30.3, P <.001) largely predominated as determinants of death, along with 6 other risk factors (arch involvement, rupture, stroke, previous sternotomy, and coronary or lung disease), which roughly doubled the hazard of death. Female sex was a significant but weaker predictor of death. Renal dysfunction, year of presentation, age, and mode of therapy (medical vs surgical) had no important bearing on overall survival. The actuarial survival estimates for all patients were 71%, 60%, 35%, and 17% at 1, 5, 10, and 15 years, respectively, and were similar for the medical and surgical patients. Reoperation and late aortic complications were predicted by the presence of Marfan syndrome. For the propensity-matched patients in quintiles I and II, survival, freedom from reoperation, and freedom from aortic complications were almost identical in the medically treated and surgical subsets.The prognosis for patients with acute type B aortic dissection is bleak and determined primarily by dissection-related and patient-specific risk factors, which do not appear to be readily modifiable.

  View details for DOI 10.1067/mtc.2002.123131

  View details for PubMedID 12407372

• What is the best treatment for patients with acute type B aortic dissections - Medical, surgical, or endovascular stent-grafting? Aortic Surgery Symposium VIII Umana, J. P., Miller, D. C., Mitchell, R. S. ELSEVIER SCIENCE INC. 2002: S1840–S1843

  Abstract

  Controversy continues regarding treatment for patients with acute type B aortic dissection.One hundred eighty-nine patients with acute type B aortic dissection managed over a 36-year period were analyzed retrospectively for three outcome endpoints: survival; freedom from reoperation, and freedom from late aortic-related complications or late death. Risk factors for death were identified using a multivariable Cox proportional hazards model. Then to account for patient selection bias, heterogeneity of the population, and continuous evolution in techniques, propensity score analysis was used to identify risk-matched cohorts (quintiles I and II) in which the results of medical (n = 111) or surgical (n = 31) therapy were compared more comprehensively.The two main determinants of death were shock (hazard ratio [HR] = 14.5, 95% confidence level [CL] 4.7, 44.5; p < 0.001) and visceral ischemia (HR = 10.9, 95% CL 3.9, 30.3; p < 0.001). Arch involvement, rupture, stroke, previous sternotomy, and coronary or lung disease roughly doubled the hazard. Female sex was also a significant but weaker independent predictor of death. Actuarial survival estimates for all patients were 71%, 60%, 35%, and 17% at 1, 5, 10, and 15 years, respectively, and were similar for the medical and surgical patients. The Marfan syndrome predicted reoperation and late aortic complications or late death. In a separate analysis of the 142 patients in quintiles I and II, survival, freedom from reoperation, as well as freedom from late aortic complications or death were almost identical in the medical and surgical subsets.The poor long-term prognosis of patients with acute type B aortic dissection is determined primarily by dissection-related and patient-specific risk factors, which are not readily modifiable. Whether the outlook in the future will be improved using stent-grafts remains to be determined.

  View details for PubMedID 12440677

• Stent grafts for the thoracic aorta: A new paradigm? Aortic Surgery Symposium VIII Mitchell, R. S. ELSEVIER SCIENCE INC. 2002: S1818–S1820

  Abstract

  The treatment of thoracic aortic pathology is complicated by the morbidity of the surgical procedure, and the comorbidities encountered in an elderly population. Stent grafts have now been used for approximately 10 years for the treatment of thoracic aneurysmal disease, management of aortic dissections, intramural hematoma, and giant penetrating ulcers, and for traumatic aortic tears, with impressive early results. However, these efforts have been significantly limited by the lack of a commercially available stent graft specifically designed for the thoracic aorta, the lack of real long-term follow-up, and the failure of experience in the abdominal aorta to translate to the thoracic aorta. Nevertheless, significant and even unique therapies have been enabled by stent graft technology for the treatment of the above-mentioned diseases. It is likely that, with more sophisticated technology and improved understanding of thoracic aortic pathology, stent graft use will expand, and its utility will be further clarified.

  View details for Web of Science ID 000179262300102

  View details for PubMedID 12440673

• Does profound hypothermic circulatory arrest improve survival in patients with acute type a aortic dissection? Circulation Lai, D. T., Robbins, R. C., Mitchell, R. S., Moore, K. A., Oyer, P. E., Shumway, N. E., Reitz, B. A., Miller, D. C. 2002; 106 (12): I218-28

  Abstract

  No evidence exists that profound hypothermic circulatory arrest (PHCA) improves survival or reduces the likelihood of distal aortic reoperation in patients with acute type A aortic dissection.Records of 307 patients with acute type A aortic dissection from 1967 to 1999 were retrospectively reviewed. The influence of repair using PHCA (n=121) versus without PHCA (n=186) on death and freedom from distal aortic reoperation was analyzed using multivariable Cox regression models. Propensity score analysis identified a subset of 152 comparable patients in 3 quintiles (QIII-V) in which the effects of PHCA (n=113) versus no PHCA (n=39) were further compared.For all patients, 30-day, 1-year, and 5-year survival estimates were 81+/-2%, 74+/-3%, and 63+/-3% (+/-1 SE). Survival rates and actual freedom from distal aortic reoperation was not significantly different between treatment methods in the entire patient cohort nor in the matched patients in quintiles III-V. Treatment method was not associated with differences in early major complications, late survival, or distal aortic reoperation rates in the entire patient sample or in quintiles III-V.Aortic repair with or without circulatory arrest was associated with comparable early complications, survival, and distal aortic reoperation rates in patients with acute type A aortic dissection. Despite the lack of concrete evidence favoring the use of PHCA, it does no harm, and most of our group uses PHCA regularly because of its practical technical advantages and theoretical potential merit.

  View details for PubMedID 12354737

• Does profound hypothermic circulatory arrest improve survival in patients with acute type a aortic dissection? CIRCULATION Lai, D. T., Robbins, R. C., Mitchell, R. S., Moore, K. A., Oyer, P. E., Shumway, N. E., Reitz, B. A., Miller, D. C. 2002; 106 (13): I218-I228

  Abstract

  No evidence exists that profound hypothermic circulatory arrest (PHCA) improves survival or reduces the likelihood of distal aortic reoperation in patients with acute type A aortic dissection.Records of 307 patients with acute type A aortic dissection from 1967 to 1999 were retrospectively reviewed. The influence of repair using PHCA (n=121) versus without PHCA (n=186) on death and freedom from distal aortic reoperation was analyzed using multivariable Cox regression models. Propensity score analysis identified a subset of 152 comparable patients in 3 quintiles (QIII-V) in which the effects of PHCA (n=113) versus no PHCA (n=39) were further compared.For all patients, 30-day, 1-year, and 5-year survival estimates were 81+/-2%, 74+/-3%, and 63+/-3% (+/-1 SE). Survival rates and actual freedom from distal aortic reoperation was not significantly different between treatment methods in the entire patient cohort nor in the matched patients in quintiles III-V. Treatment method was not associated with differences in early major complications, late survival, or distal aortic reoperation rates in the entire patient sample or in quintiles III-V.Aortic repair with or without circulatory arrest was associated with comparable early complications, survival, and distal aortic reoperation rates in patients with acute type A aortic dissection. Despite the lack of concrete evidence favoring the use of PHCA, it does no harm, and most of our group uses PHCA regularly because of its practical technical advantages and theoretical potential merit.

  View details for DOI 10.1161/01.cir.000032890.55215.27

  View details for Web of Science ID 000178318900039

• Prognosis of aortic intramural hematoma with and without penetrating atherosclerotic ulcer - A clinical and radiological analysis CIRCULATION Ganaha, F., Miller, C., Sugimoto, K., Do, Y. S., Minamiguchi, H., Saito, H., Mitchell, R. S., Dake, M. D. 2002; 106 (3): 342-348

  Abstract

  Advances in imaging techniques have increased the recognition of aortic intramural hematomas (IMHs) and penetrating atherosclerotic ulcers (PAUs); however, distinction between IMH and PAU remains unclear. We intended to clarify differences between IMH coexisting with PAU and IMH not associated with PAU by comparisons of clinical features, imaging findings, and patient outcome to derive the optimal therapeutic approach.We performed a retrospective analysis of 65 symptomatic patients with aortic IMH. There were 34 patients with IMH associated with PAU (group 1) and 31 patients with IMH unaccompanied by PAU (group 2). Involvement of the ascending aorta (type A) was more frequent in group 2 (8 of 31, 26%), whereas most of the patients in group 1 had exclusive involvement of the descending aorta (type B) (31of 34, 91%). Patients were subdivided into 2 categories, those with clinical progression and those with stable disease. Forty-eight percent of patients in group 1 and 8% in group 2 were in the progressive category (P=0.002). Clinical and radiological findings were compared between those group 1 patients who had a progressive disease course (n=12) and those who were stable (n=13). Sustained or recurrent pain (P<0.0001), increasing pleural effusion (P=0.0003), and both the maximum diameter (P=0.004) and maximum depth (P=0.003) of the PAU were reliable predictors of disease progression.This study suggests a difference in disease behavior that argues for the prognostic importance of making a clear distinction between IMH caused by PAU and IMH not associated with PAU. IMH with PAU was significantly associated with a progressive disease course, whereas IMH without PAU typically had a stable course, especially when limited to the descending thoracic aorta.

  View details for DOI 10.1161/01.CIR.0000022164.26075.5A

  View details for PubMedID 12119251

• First International Summit on Thoracic Aortic Endografting: roundtable on thoracic aortic dissection as an indication for endografting. Journal of endovascular therapy Mitchell, R. S., Ishimaru, S., Ehrlich, M. P., Iwase, T., Lauterjung, L., Shimono, T., Fattori, R., Yutani, C. 2002; 9: II98-105

  View details for PubMedID 12166849

• Ruptured abdominal aortic aneurysm after endovascular repair JOURNAL OF VASCULAR SURGERY Bernhard, V. M., Mitchell, R. S., Matsumura, J. S., Brewster, D. C., Decker, M., Lamparello, P., Raithel, D., Collin, J. 2002; 35 (6): 1155-1162

  Abstract

  The purpose of this study was to present the experience with aneurysm rupture after deployment of Guidant/EVT (Guidant) endografts and review previously reported cases with other devices.Records from Guidant/EVT clinical trials and postmarket approval databases from February 1993 to August 2000 were analyzed to identify patients with rupture and to extract pertinent data. Previously reported cases were obtained with a Medline search.Seven ruptures were found with Guidant/EVT devices. Five of these occurred among the 686 patients in US Food and Drug Administration protocols (group I) who were followed for a mean of 41.8 +/- 21.9 months and limited to the subgroup of 93 first generation tube endografts. Two ruptures occurred in group II (3260 patients after market approval with limited follow-up), specifically in the subgroup of 166 patients who underwent treatment with second generation tube grafts. No ruptures were found in patients with bifurcation or unilateral iliac implants followed for a mean of 37.5 months. All ruptures were caused by distal aortic type I endoleaks on the basis of attachment system fractures (first generation devices only), aortic neck dilatations, persistent primary endoleaks, migration, overlooked imaging abnormalities, refused reintervention, and poor patient selection. The mortality rate was 57% (4/7) overall and was 50% for surgical repair (3/6). A literature search identified 40 additional ruptures related to other devices, for a total of 47. All 44 that were documented with adequate data were caused by endoleaks (26 type I, 2 type II, 11 type III, and 5 source not reported). Other contributing factors were graft module separation and graft wall deterioration. The overall mortality rate for the combined series was 50%, with an operative mortality rate of 41%.Postendograft AAA rupture is infrequent, although the true incidence rate is unclear because of inadequate follow-up of individual device designs. Tube endografts should be limited to the rare patient with ideal anatomy, no other alternatives, and at high risk for standard open repair. Prevention of aneurysm rupture requires long-term surveillance with attention to subtle imaging abnormalities and the establishment of reliable follow-up protocols for specific devices. The outcome of postendograft aneurysm rupture is similar to that of rupture without prior endograft therapy.

  View details for DOI 10.1067/mva.2002.123758

  View details for Web of Science ID 000176178500021

  View details for PubMedID 12042725

• First international summit on thoracic aortic endografting: Roundtable on thoracic aortic dissection as an indication for endografting JOURNAL OF ENDOVASCULAR THERAPY Mitchell, R. S., Ishimaru, S., Ehrlich, M. P., Iwase, T., Lauterjung, L., Shimono, T., Fattori, R., Yutani, C. 2002; 9: 98-105

  View details for Web of Science ID 000177054300016

• Thoracic aortic stent-grafts CORONARY ARTERY DISEASE Umana, J. P., Mitchell, R. S. 2002; 13 (2): 103-111

  View details for Web of Science ID 000175470200005

  View details for PubMedID 12004262

• Does hypothermic circulatory arrest (PHCA) improve survival in patients with acute type A aortic dissection? Lai, D. T., Robbins, R. C., Mitchell, R. S., Moore, K. A., Oyer, P. E., Shumway, N. E., Reitz, B. A., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 2001: 524–24

  View details for Web of Science ID 000171895002459

• Treatment of endocarditis with valve replacement: The question of tissue versus mechanical prosthesis ANNALS OF THORACIC SURGERY Moon, M. R., Miller, D. C., Moore, K. A., Oyer, P. E., Mitchell, R. S., Robbins, R. C., Stinson, E. B., Shumway, N. E., Reitz, B. A. 2001; 71 (4): 1164-1171

  Abstract

  It remains unknown whether there is any important clinical advantage to the use of either a bioprosthetic or mechanical valve for patients with native or prosthetic valve endocarditis.Between 1964 and 1995, 306 patients underwent valve replacement for left-sided native (209 patients) or prosthetic (97 patients) valve endocarditis. Mechanical valves were implanted in 65 patients, bioprostheses in 221 patients, and homografts in 20 patients.Operative mortality was 18+/-2% and was independent of replacement valve type (p > 0.74). Long-term survival was superior for patients with native valve endocarditis (44+/-5% at 20 years) compared with those with prosthetic valve endocarditis (16+/-7% at 20 years) (p < 0.003). Survival was independent of valve type (p > 0.27). The long-term freedom from reoperation for patients who received a biologic valve who were younger than 60 years of age was low (51+/-5% at 10 years, 19+/-6% at 15 years). For patients older than 60 years, however, freedom from reoperation with a biological valve (84+/-7% at 15 years) was similar to that for all patients with mechanical valves (74+/-9% at 15 years) (p > 0.64).Mechanical valves are most suitable for younger patients with native valve endocarditis; however, tissue valves are acceptable for patients greater than 60 years of age with native or prosthetic valve infections and for selected younger patients with prosthetic valve infections because of their limited life expectancy.

  View details for PubMedID 11308154

• Endovascular treatment of aortic dissections and thoracic aortic aneurysms. Seminars in vascular surgery Umana, J. P., Mitchell, R. S. 2000; 13 (4): 290-298

  Abstract

  Diseases of the thoracic aorta pose a significant challenge to the surgeon because of the complexity of the disease and the characteristics of the patient population. Frequent comorbidities and increasing age account for mortality rates between 5% and 20% for surgical repair of descending thoracic aortic aneurysms and in excess of 50% for Stanford type B aortic dissections, when complicated by preoperative end-organ ischemia. Endovascular techniques of fenestration, stenting, and stent-grafting have emerged as viable alternatives to conventional surgery in these patients. The authors review their experience using endovascular stent-grafts in the treatment of 103 patients with descending thoracic aortic aneurysms and 19 patients with acute aortic dissections. Fenestration and stenting are also addressed as adjuvant therapies in the treatment of complicated aortic dissections. Actuarial survival for aneurysms was 81% +/- 5% at 1 year and 73% +/- 5% at 2 years. Stent-grafting for acute aortic dissections achieved instant relief of symptoms in 71% of cases with an early procedural mortality of 16%, and endovascular revascularization of ischemic beds was achieved in 93% +/- 4% of cases of peripheral or visceral ischemia. The authors' experience supports the use of endovascular techniques in the treatment of thoracic aortic pathologic conditions. Longer follow-up and results of ongoing trials that use newer devices will help define the indications for their future use.

  View details for PubMedID 11156057

• Endovascular repair of abdominal aortic aneurysms: Eligibility rate and impact on the rate of open repair JOURNAL OF VASCULAR SURGERY Wolf, Y. G., Fogarty, T. J., Olcott, C., Hill, B. B., Harris, E. J., Mitchell, R. S., Miller, D. C., Dalman, R. L., Zarins, C. K. 2000; 32 (3): 519-523

  Abstract

  The purpose of this study was to determine the rate of eligibility among patients with abdominal aortic aneurysms (AAAs) considered for endovascular repair and to examine the effect of an endovascular program on the institutional pattern of AAA repair.All patients evaluated for endovascular AAA repair since the inception of an endovascular program were reviewed for determination of eligibility rates and eventual treatment. Open AAA repairs were categorized as simple (uncomplicated infrarenal), complex (juxtarenal, suprarenal, thoracoabdominal, infected), or ruptured, and their rates before and after initiation of an endovascular program were compared.Over 3 years, 324 patients were considered for endovascular AAA repair; 176 (54%) were candidates, 138 (43%) were not candidates, and 10 (3%) did not complete the evaluation. The rate of eligibility increased significantly from 45% (66/148 patients) during the first half of this period to 63% (110/176 patients) during the second half (P <. 001). Candidates were significantly younger (74.4 +/- 7.6 years) than noncandidates (78.3 +/- 6.7 years) (P <.01), and their aneurysm diameter tended to be smaller (57.6 +/- 9.2 mm compared with 60.8 +/- 12.3 mm; P =.06). The most common reason for ineligibility was an inadequate proximal aortic neck. Of 176 candidates, 78% underwent endovascular repair, and 6% underwent open repair. Of 138 noncandidates, 56% underwent surgical repair. Over a period of 6 years, 542 patients with AAAs (429 simple, 86 complex, 27 ruptured) underwent open repair. The total number and ratio of simple to complex open repairs for nonruptured aneurysms during the 3 years before the initiation of the endovascular program (213 simple, 44 complex) were not significantly different from the repairs over the subsequent 3-year period (216 simple, 42 complex). Similarly, no difference in the total number and the ratio of simple to complex open repairs was found between the first and the second 18-month periods since the initiation of the endovascular program.The rate of eligibility of patients with AAA for endovascular repair appears to be higher than previously reported. The presence of an active endovascular program has not decreased the number or shifted the distribution of open AAA repair.

  View details for PubMedID 10957658

• Endovascular solutions for diseases of the thoracic aorta. Cardiology clinics Mitchell, R. S. 1999; 17 (4): 815-?

  Abstract

  Technology is proceeding at a very brisk pace. Harnessing that technology for clinical use is both a challenge and an opportunity. This combination of surgical and interventional methods has allowed for improved clinical outcomes in certain complex aortic problems. This article explores and discusses new techniques used in detection and treatment of diseases of the thoracic aorta.

  View details for PubMedID 10589348

• Percutaneous balloon fenestration and stenting for life-threatening ischemic complications in patients with acute aortic dissection 24th Annual Meeting of the Western-Thoracic-Surgical-Association Slonim, S. M., Miller, D. C., Mitchell, R. S., Semba, C. P., Razavi, M. K., Dake, M. D. MOSBY-ELSEVIER. 1999: 1118–26

  Abstract

  Acute aortic dissection frequently causes life-threatening ischemia of end-organs, historically associated with mortality exceeding 60%. Reperfusion with the use of interventional radiologic methods has evolved as a promising treatment. We report results of our initial 6 years of experience with percutaneous balloon fenestration of the intimal flap and endovascular stenting.Forty patients (32 male and 8 female) with a median age of 53 years (range 16-86 years) underwent percutaneous treatment for peripheral ischemic complications of 10 type A and 30 type B acute aortic dissections since 1991. Twenty patients had ischemia of multiple organ systems. Thirty patients had renal, 22 had leg, 18 had mesenteric, and 1 had arm ischemia.Fourteen patients were treated with stenting of either the true or false lumen combined with balloon fenestration of the intimal flap, 24 with stenting alone, and 2 with fenestration alone. Successful revascularization was achieved in 93% +/- 4% (+/-70% confidence levels) of patients (37/40). Nine patients had procedure-related complications. The 30-day mortality rate was 25% +/- 7% (10/40), often related to irreversible ischemia of intra-abdominal organs that was present before the procedure. Of the remaining 30 patients, 5 have died and the remaining 25 continue to have relief of ischemic symptoms at a mean follow-up of 29 months.Percutaneous balloon fenestration of the intimal flap and endovascular stenting is an effective treatment for life-threatening ischemic complications of acute aortic dissection.

  View details for PubMedID 10343260

• Thoracic aortic aneurysm repair with an endovascular stent graft: The "first generation" Aortic Surgery Symposium VI Mitchell, R. S., Miller, D. C., Dake, M. D., Semba, C. P., Moore, K. A., Sakai, T. ELSEVIER SCIENCE INC. 1999: 1971–74

  Abstract

  The feasibility and efficacy trial of an endovascular stent-grafting system for the treatment of aneurysms of the descending thoracic aorta was investigated.After Institutional Review Board approval, 103 patients (mean age 69 years) underwent stent graft repair of a descending thoracic aortic aneurysm between July 1992 and November 1997. The stent graft was fabricated using self-expanding "Z" stents covered by a woven Dacron tube graft. Follow-up, which averaged 22 months, was 100% complete. Simultaneous open abdominal aortic aneurysm repair was performed in 19 patients.Complete aneurysm thrombosis was achieved in 86 patients (83%). Early mortality, defined as a death during the same hospitalization or in less than 30 days, was 9 +/- 3%, and was significantly associated with preoperative cerebrovascular accident (CVA) or myocardial infarction. Major perioperative morbidity occurred in 31 patients, and included paraplegia in 3, CVA in 7, and respiratory insufficiency in 12 patients each. Actuarial survival was 81 +/- 4% at 1 year, and 73 +/- 5% at 2 years. Treatment failure (including all late, sudden, unexplained deaths) occurred in 38 patients, and only 53 +/- 10% of patients were free of treatment failure at 3.7 years. Five patients required late operative therapy for endoleaks associated with aneurysm enlargement.Satisfactory results were achieved using this "first-generation" homemade stent graft device. Mortality and morbidity occurred frequently, but may have been associated with the high-risk character of this patient population. Medium-term results were acceptable, but continued aortic enlargement, with the late development of endoleaks, is a significant concern. Second-generation devices with commercial development, coupled with this initial experience, should allow improved clinical results in the future. Longer term follow-up is still necessary to fully define the efficacy of this endovascular approach.

  View details for PubMedID 10391350

• Endovascular stent-graft placement for the treatment of acute aortic dissection NEW ENGLAND JOURNAL OF MEDICINE Dake, M. D., Kato, N., Mitchell, R. S., Semba, C. P., Razavi, M. K., Shimono, T., Hirano, T., Takeda, K., Yada, I., Miller, D. C. 1999; 340 (20): 1546-1552

  Abstract

  The standard treatment for acute aortic dissection is either surgical or medical therapy, depending on the morphologic features of the lesion and any associated complications. Irrespective of the form of treatment, the associated mortality and morbidity are considerable.We studied the placement of endovascular stent-grafts across the primary entry tear for the management of acute aortic dissection originating in the descending thoracic aorta. We evaluated the feasibility, safety, and effectiveness of transluminal stent-graft placement over the entry tear in 4 patients with acute type A aortic dissections (which involve the ascending aorta) and 15 patients with acute type B aortic dissections (which are confined to the descending aorta). Dissections involved aortic branches in 14 of the 19 patients (74 percent), and symptomatic compromise of multiple branch vessels was observed in 7 patients (37 percent). The stent-grafts were made of self-expanding stainless-steel covered with woven polyester or polytetrafluoroethylene material.Placement of endovascular stent-grafts across the primary entry tears was technically successful in all 19 patients. Complete thrombosis of the thoracic aortic false lumen was achieved in 15 patients (79 percent), and partial thrombosis was achieved in 4 (21 percent). Revascularization of ischemic branch vessels, with subsequent relief of corresponding symptoms, occurred in 76 percent of the obstructed branches. Three of the 19 patients died within 30 days, for an early mortality rate of 16 percent (95 percent confidence interval, 0 to 32 percent). There were no deaths and no instances of aneurysm or aortic rupture during the subsequent average follow-up period of 13 months.These initial results suggest that stent-graft coverage of the primary entry tear may be a promising new treatment for selected patients with acute aortic dissection. This technique requires further evaluation, however, to assess its therapeutic potential fully.

  View details for PubMedID 10332016

• Endografts for the treatment of descending thoracic aortic aneurysm: Results of the first 150 procedures Dake, M., Semba, C., Kee, S., Razavi, M., Slonim, S., Samuels, S., Sze, D., Mitchell, R., Miller, D. INT SOC ENDOVASCULAR SPECIALIST. 1999: 189–89

  View details for Web of Science ID 000083522600024

• The "first generation" of endovascular stent-grafts for patients with aneurysms of the descending thoracic aorta 78th Annual Meeting of the American-Association-for-Thoracic-Surgery Dake, M. D., Miller, D. C., Mitchell, R. S., Semba, C. P., Moore, K. A., Sakai, T. MOSBY-ELSEVIER. 1998: 689–703

  Abstract

  Our goal was to determine whether endovascular stent-grafting is feasible and effective for patients with aneurysms of the descending thoracic aorta.Starting in July 1992, we conducted a prospective, uncontrolled clinical trial in 103 patients (mean age 69 years [range 34-89 years]) who underwent endovascular treatment of aneurysms of the descending thoracic aorta using a custom-fabricated, self-expanding stent-graft device. Follow-up was 100% complete and averaged 22 months. Sixty-two patients (60%) were judged not to be reasonable candidates for a conventional "open" surgical procedure.Complete thrombosis of the aneurysm was ultimately achieved in 86 (83%) patients. The early mortality rate was 9% +/- 3% (+/- 70% CL). Multivariable analysis revealed that myocardial infarction or stroke was linked with a higher likelihood of early death (P = .001). Early serious complications included paraplegia in 3% +/- 2% and stroke in 7% +/- 3%. Actuarial survival estimates at 1 year and 2 years were 81% +/- 4% and 73% +/- 5% (+/- 1 SE), respectively; being judged not to be a surgical candidate portended a higher probability of death (P = .003). According to the intent-to-treat principle, "treatment failure" (including all late sudden unexplained deaths) occurred in 38 patients; 53% +/- 10% of patients were free from treatment failure at 3.7 years. Stent-graft related complications occurred commonly and were linked with several anatomic, technical, and patient-related risk factors.This 5-year clinical trial involving use of a "first generation" device indicates that endovascular stent-grafting of descending thoracic aortic aneurysms is feasible with acceptable medium-term results. More refined, commercially developed devices available today offer less traumatic and more precise stent-graft deployment; these major technical advantages, coupled with important lessons we have learned over time and better patient selection, should be associated with more salutary clinical results in the future.

  View details for PubMedID 9806376

• Endovascular stent-graft placement to obliterate the entry tear: A new treatment for acute aortic dissection Dake, M. D., Kato, N., Slonim, S. M., Razavi, M. K., Semba, C. P., Kee, S. T., Sze, D. Y., Samuels, S. L., Mitchell, R. S., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1998: 67–67

  View details for Web of Science ID 000076594400382

• Aneurysm of an aberrant right subclavian artery: Treatment with PTFE covered stentgraft JOURNAL OF VASCULAR SURGERY Davidian, M., Kee, S. T., Kato, N., Semba, C. P., Razavi, M. K., Mitchell, R. S., Dake, M. D. 1998; 28 (2): 335-339

  View details for Web of Science ID 000075344600021

  View details for PubMedID 9719329

• Treatment of aortoiliac aneurysms with use of single-piece tapered stent-grafts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Kato, N., Dake, M. D., Semba, C. P., Razavi, M. K., Kee, S. T., Slonim, S. M., Samuels, S. L., Terasaki, K. K., Zarins, C. K., Mitchell, R. S., Miller, D. C. 1998; 9 (1): 41-49

  Abstract

  The authors describe their experience with the use of single-piece, tapered stent-grafts for the treatment of abdominal aortic or aortoiliac aneurysms.Single-piece, tapered stent-grafts were placed in 15 patients for the treatment of abdominal aortic aneurysms with small distal necks (n = 13), and aortoiliac aneurysms (n = 2). There were 13 men and two women who ranged in age from 59 to 83 years (mean, 71 years). Usual open surgery was considered high risk in all patients because of comorbid medical conditions. The stent-grafts were made of Z stents covered with polytetrafluoroethylene (PTFE). Additional stent-grafts needed to treat perigraft leaks were made of Z stents covered with woven polyester (n = 5), Wallstents covered with PTFE (n = 2), Z stents covered with PTFE (n = 1), and a PTFE-covered Palmaz stent (n = 1). After stent-graft placement, the contralateral iliac artery was occluded by a blocking device composed of either a PTFE-covered Palmaz (n = 1) or Z stent (n = 13), and a femoral-femoral bypass was created.After placement of the stent-grafts, immediate perigraft leaks were observed in eight patients (53%). These were at the proximal (n = 5) or the distal end (n = 3). All, except one, were treated successfully with additional stent-grafts. The one failure was in a patient who developed aortic rupture after balloon dilation, requiring open surgical repair. Second procedures were required in four patients (27%), including three leaks treated successfully with coil embolization and/or a back-up stent-graft, and one stent-graft migration and thrombosis treated by thrombolysis and placement of an additional stent-graft. One patient died of respiratory failure 23 days after placement of the stent-graft. The mean follow-up was 12 months (range, 4-26 months). On the last follow-up, the aneurysms in the 13 living patients remained thrombosed.Treatment of aortoiliac aneurysms with use of single-piece, tapered stent-grafts is feasible in selected patients. The morbidity and mortality rates compare favorably with those of the open surgical procedures in a high-risk population. Further improvements in the technique and longer follow-up data are needed before this procedure can be recommended for the treatment of all aortoiliac aneurysms.

  View details for PubMedID 9468394

• Mycotic aneurysms of the thoracic aorta: Repair with use of endovascular stent-grafts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Semba, C. P., Sakai, T., Slonim, S. M., Razavi, M. K., Kee, S. T., Jorgensen, M. J., Hagberg, R. C., Lee, G. K., Mitchell, R. S., Miller, D. C., Dake, M. D. 1998; 9 (1): 33-40

  Abstract

  Standard therapy of mycotic aneurysms in the descending aorta consists of thoracotomy and in situ graft placement or extraanatomic bypass. The alternative use of endovascular stent-grafts was evaluated for management of infected aneurysms of the thoracic aorta.In a retrospective analysis during a 5-year period, 112 patients underwent stent-graft placement for thoracic aortic aneurysms. Three patients (mean age, 68.6; range, 64-70 years) had mycotic thoracic aneurysms. Stent-grafts were constructed from Z stents covered with polyester fabric and were delivered remotely through a catheter under fluoroscopic guidance.Complete thrombosis of the mycotic aneurysms was achieved in all patients. One patient required a second separate stent-graft placement procedure because of migration of the initial device; the second patient underwent surgical repair of a ruptured mycotic abdominal aortic aneurysm followed immediately by stent-graft placement for a chronic mycotic thoracic aneurysm; a third patient underwent repair of two infected false aneurysms secondary to complete rupture of a surgical interposition graft. There were no complications of persistent bacteremia despite placement of the stent-graft device at the site of primary infection, reinfection, delayed rupture, paraplegia, distal emboli, or surgical conversion. One patient died of cardiac arrest at 25 months; there were no perioperative deaths (< or = 30 days). The remaining two patients were alive and well at median follow-up of 24 months (range, 4-25 months).Endovascular stent-grafts combined with antibiotic therapy may be an alternative to conventional thoracotomy in managing mycotic aneurysms of the descending thoracic aorta.

  View details for PubMedID 9468393

• Traumatic thoracic aortic aneurysm: Treatment with endovascular stent-grafts RADIOLOGY Kato, N., Dake, M. D., Miller, D. C., Semba, C. P., Mitchell, R. S., Razavi, M. K., Kee, S. T. 1997; 205 (3): 657-662

  Abstract

  To demonstrate the feasibility and safety of endovascular stent-graft placement for treatment of traumatic aortic aneurysm.Ten patients with traumatic aortic aneurysm were treated with endovascular stent-grafts. Three patients had an acute traumatic aneurysm; seven had a chronic aneurysm. Stent-grafts were constructed from modified Z-stents covered with woven polyester or expanded polytetrafluoroethylene graft material and were deployed through a 20-24-F delivery sheath in an exposed artery located remotely from the lesion.Stent-graft placement and thrombosis of the aneurysmal sac were successful in all patients. Major complications were encountered in three patients after endovascular treatment. One patient had a peri-graft leak; complete thrombosis of the aneurysmal sac was achieved after coil embolization of the leak. Transposition of the left subclavian artery was necessary to relieve left arm ischemia in another patient. In the third patient, stent placement in the left main stem bronchus was needed to relieve left lung atelectasis. All patients were alive and without complications during the follow-up period (mean, 15 months).Transluminal placement of endovascular stent-grafts is a technically feasible method for treatment of traumatic thoracic aortic aneurysm and may be an effective alternative to open-chest surgery.

  View details for PubMedID 9393517

• Stent-graft repair of thoracic aortic aneurysms. Seminars in vascular surgery Mitchell, R. S., Miller, D. C., Dake, M. D. 1997; 10 (4): 257-271

  Abstract

  Aneurysmal disease of the thoracic aorta continues to be a very challenging management problem for physicians because of the many comorbidities harbored by these patients, as well as the morbidity of the conventional open repair via left thoracotomy. In a combined effort between interventional radiology and cardiovascular surgery, an endovascular stent graft repair has been devised for these patients in an effort to reduce morbidity. This report documents the results in the first 108 patients so treated. The graft itself, custom-made for each individual, is composed of interlocked, self-expanding "Z" stents covered with a woven Dacron graft. Compressed in a loading capsule, the graft can then be advanced through a 27-French (outside diameter; OD) sheath, which is positioned within the aneurysm under fluoroscopic guidance. Relatively normal 2- to 3-cm segments of proximal and distal aorta allow an adequate friction seal to prevent stent graft dislodgement and also provide a hemostatic seal to obliterate aneurysm filling. Complete aneurysm thrombosis was achieved primarily in 103 patients. There were 10 deaths (9.25%) within the first 30 days, four of which were directly attributable to the stent graft procedure. Perioperative strokes occurred in four patients, and there were four instances of paraplegia. There have been two documented stent graft failures in a mean follow-up of 21.8 months (range, 1 to 57 months). Although the long-term durability of this procedure remains unknown, we believe this less invasive endovascular approach will prove to be an effective and less morbid treatment for aneurysmal disease of the descending thoracic aorta.

  View details for PubMedID 9431597

• Composite valve graft versus separate aortic valve and ascending aortic replacement: is there still a role for the separate procedure? Circulation Yun, K. L., Miller, D. C., Fann, J. I., Mitchell, R. S., Robbins, R. C., Moore, K. A., Oyer, P. E., Stinson, E. B., Shumway, N. E., Reitz, B. A. 1997; 96 (9): II-368 75

  Abstract

  To ascertain if operative technique has any bearing on outcome, the surgical results after aortic root replacement using either a composite valve graft (CVG) or a separate graft and valve (GV) were analyzed.Three hundred and ninety consecutive, nonrandomized patients treated for aortic valve disease and ascending aortic aneurysm (n=278) or type A dissection (n=112 [45 acute]) between 1965 and 1995 were analyzed retrospectively. One hundred and thirty-five patients received a CVG, and 255 had separate GV replacement. Mean age was 52+/-16 years (+/-1 SD). Eighty-two patients (44% of the CVG group) had the Marfan syndrome (MFS). Follow-up (96% complete) totaled 2247 patient-years and extended to 27 years. The operative mortality rate was 10+/-3% (+/-70% confidence limits) for patients receiving a CVG and 15+/-2% for GV replacement (P=NS). The 15-year actuarial survival estimate was higher for the CVG group (53+/-14% [+/-SEM] versus 36+/-4%, P=.037). Seven patients in the CVG group required reoperation on the aortic valve or ascending aorta, as did 49 in the GV group. The probabilities of freedom from reoperation on the aortic rootwere 82+/-9% and 75+/-4% at 10 years for the CVG and GV group (P=NS). Thirty variables were analyzed in a multivariate model: pulmonary disease, higher New York Heart Association functional class, and longer cardiopulmonary bypass time were linked with higher operative mortality risk; older age, emergency operation, coronary artery disease, and liver dysfunction were independent determinants of late death. Younger age and use of a bioprosthesis were predictors of late reoperation. Type of procedure (GV versus CVG) was not a significant predictor of any outcome variable.The long-term results after CVG or GV were similar, which reflects proper patient selection. Use of a composite valve graft theoretically confers more protection against recurrent aortic root aneurysm, and, unless one opts for a valve-sparing aortic root replacement procedure, is most appropriate for younger patients, those with the MFS (including acute dissections), and others with marked pathological involvement of the sinuses. On the other hand, use of a separate GV should not be abandoned; in carefully selected patients (and if properly performed, eg, excision of the sinuses), GV also provides satisfactory results.

  View details for PubMedID 9386126

• Surgical treatment of endocarditis: Is there a role for mechanical prostheses? Moon, M. R., Miller, D. C., Stinson, E. B., Mitchell, R. S., Oyer, P. E., Robbins, R. C., Shumway, N. E., Reitz, B. A. LIPPINCOTT WILLIAMS & WILKINS. 1997: 2409–

  View details for Web of Science ID A1997YC88002397

• Endovascular stent graft repair of thoracic aortic aneurysms. Seminars in thoracic and cardiovascular surgery Mitchell, R. S. 1997; 9 (3): 257-268

  Abstract

  Aneurysmal disease of the thoracic aorta continues to present vexing challenges to the aortic surgeon. Not only does the incidence of the disease seem to be increasing, but the older population also harbors more comorbidities. In an effort to reduce the perioperative mortality and morbidity, surgeons and interventional radiologists at Stanford University Medical Center devised a less invasive, endovascular stent-graft repair. This report details the results of the first 81 patients, and reviews some other pertinent developments. The stent-graft is composed of interlocked, self-expanding "Z" stents covered with a woven Dacron graft, which can then be introduced through a hollow 27F Teflon sheath under fluoroscopic guidance and deployed across the aneurysm. Aneurysms of the descending thoracic aorta are most easily treated, but distal arch pathology can occasionally be accommodated. A friction seal prevents movement of the stent, and complete exclusion of the aneurysm sac from the circulation is usually possible. Degenerative aneurysms accounted for the majority of the diseased aortas. Results: There were 7 (9% +/- 3%) deaths, 3 directly attributable to the stent-graft procedure, including two strokes presumably from atheroemboli from the aortic arch. Paraplegia occurred in three patients, but in only one with an uncomplicated stent-graft placement without protracted hypotension. Two nonfatal strokes also occurred. There has been only a single instance of documented late graft failure, which resulted in a fatal hemorrhage. Although the long-term durability of the stent-grafts in unknown at this early stage, we believe this technology to be a significantly less morbid treatment for aneurysmal disease of the descending thoracic aorta. Only long-term follow-up will further define its utility.

  View details for PubMedID 9263344

• Acute rupture of the descending thoracic aorta: Repair with use of endovascular stent-grafts JOURNAL OF VASCULAR AND INTERVENTIONAL RADIOLOGY Semba, C. P., Kato, N., Kee, S. T., Lee, G. K., Mitchell, R. S., Miller, D. C., Dake, M. D. 1997; 8 (3): 337-342

  Abstract

  To describe the use of endovascular stent-grafts to treat acute ruptures of the descending thoracic aorta as an alternative to surgery in high-risk patients.From July 1992 to August 1996, 95 patients underwent stent-grafting of the descending thoracic aorta for a variety of lesions. Of these, 11 patients with acute (< or = 7 days) rupture from aneurysms (n = 8) or trauma (n = 3) underwent repair with use of endovascular stent-grafts. Rupture was confirmed with preoperative imaging studies and occurred in the mediastinum (n = 9), the pleural space (n = 1), or the lung (n = 1). All patients were considered high surgical risk due to generalized cardiopulmonary disease and/or previous thoracotomies. Stent-grafts were constructed from Z stents covered with polyester fabric and delivered through a catheter under fluoroscopic control from a remote access site.Stent-graft deployment was successful in all patients. There were no complications of perigraft leak, stent migration, paraplegia, or intraoperative death. Two patients died in the follow-up period: one of ventricular perforation during unrelated thoracic surgery for tumor resection (day 1) and one of cardiac arrest (day 28). All others are alive (mean follow-up, 15.1 months).For acute rupture of the thoracic aorta, endovascular stent-graft repair is technically feasible and may be a therapeutic alternative to a surgical interposition graft in patients considered high risk for conventional thoracotomy. Long-term studies are necessary to determine the role of stent-grafts in preventing future aortic rupture.

  View details for PubMedID 9152904

• Simultaneous abdominal aortic replacement and thoracic stent-graft placement for multilevel aortic disease Joint Annual Meeting of the Society-for-Vascular-Surgery and the North-American-Chapter of the International-Society-for-Cardiovascular-Surgery Moon, M. R., Mitchell, R. S., Dake, M. D., Zarins, C. K., Fann, J. I., Miller, D. C. MOSBY-YEAR BOOK INC. 1997: 332–40

  Abstract

  Patients with aneurysmal disease involving both the descending thoracic and abdominal aorta have historically required simultaneous or sequential conventional operations, but the morbidity rate is high with either approach in these patients, who often exhibit coexisting cardiopulmonary disease. Transluminally placed endovascular grafts have recently been developed for repair of aortic aneurysms, and we have implemented these techniques to eliminate the need for a thoracotomy in patients with multilevel aortic disease.Since January 1994, 18 patients have undergone conventional abdominal aortic replacement with endovascular stent-graft placement into the descending thoracic aorta under fluoroscopic guidance through a 10 mm Dacron side limb off the abdominal graft. Abdominal aortic replacement required a tube graft in eight patients and bifurcated grafts in 10 patients. Thoracic stent-grafts (custom fabricated, woven Dacron covered, self-expandable stents) averaged 12.2 +/- 4.2 cm (mean +/- SD) in length.One patient died, resulting in a hospital mortality rate of 6%. No patients required further surgical intervention to treat their aortic disease. Seventeen patients (94%) are currently well 14 +/- 8 months after surgery (range, 3 to 29 months) with completely excluded thoracic aortic disease, no stent migration, and no change in stent configuration documented by serial radiologic examinations.Simultaneous abdominal aortic replacement and deployment of a thoracic stent-graft can safely exclude multilevel aortic aneurysmal disease and may be a valuable treatment option for these otherwise high-risk patients.

  View details for PubMedID 9052568

• Thoracic aortic aneurysm repair with endovascular stent-grafts. Vascular medicine Semba, C. P., Mitchell, R. S., Miller, D. C., Kato, N., Kee, S. T., Chen, J. T., Dake, M. D. 1997; 2 (2): 98-103

  Abstract

  The purpose of the study was to describe the clinical experience is using endoluminal stent-grafts for the treatment of thoracic aortic aneurysms in high-risk patients. Patients with aneurysms of the descending thoracic aorta who were considered high surgical risks underwent evaluation for endoluminal repair. The prosthesis was constructed from Z stents covered with polyester fabric using dimensions based upon preprocedural computed tomography scans and angiography. Through a femoral arteriotomy or left retroperitoneal flank incision, a 22-24 Fr delivery catheter was inserted and advanced through the aorta to the target site under fluoroscopic guidance in the operating suite. The stent-graft prosthesis was deployed at the site of the aneurysm. 44 patients (36 male, 8 female; mean age 36 years) underwent stent-graft repair for thoracic aneurysms (mean diameter 6.3 cm). The deployment was technically successful in all cases, with complete aneurysm thrombosis in 88%. The 30-day perioperative mortality rate was 6.8% and 35-month actuarial survival was 82%. There were no cases of stent migration, surgical conversion or intraprocedural death. Paraplegia occurred in two patients who underwent simultaneous surgical infrarenal aortic aneurysm repair immediately followed by stent-graft placement for a coexisting thoracic aneurysm. The conclusion was that placement of endoluminal stent-grafts for repair of thoracic aortic aneurysms is technically feasible in high-risk patients in whom conventional surgery is contraindicated. Long-term studies are needed to determine protection against aneurysm rupture and patient survival.

  View details for PubMedID 9546963

• Twenty-year clinical experience with porcine bioprostheses 32nd Annual Meeting of the Society-of-Thoracic-Surgeons Fann, J. I., Miller, D. C., Moore, K. A., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Robbins, R. C., Reitz, B. A., Shumway, N. E. ELSEVIER SCIENCE INC. 1996: 1301–11

  Abstract

  For the past 25 years, porcine valves have been the most widely implanted bioprosthesis, thereby becoming the standard for comparison with newer bioprosthetic valves.We retrospectively analyzed 2,879 patients who underwent aortic (AVR; n = 1,594) or mitral (MVR; n = 1,285) valve replacement between 1971 and 1990. Follow-up was 97% complete and extended to 20 years (total, 17,976 patient-years). Patient age ranged from 16 to 94 years; mean age in patients who underwent AVR was 60 +/- 15 (+/- standard deviation) years; that for patients who underwent MVR was 58 +/- 13 years.The operative mortality rates were 7% +/- 1% (70% confidence limits) for AVR and 10% +/- 1% for MVR. Actuarial estimates of freedom from structural valve deterioration at 10 and 15 years were 78% +/- 2% (SE) and 49% +/- 4%, respectively, for the AVR subgroup; and 69% +/- 2% and 32% +/- 4%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from reoperation at 10 and 15 years were 76% +/- 2% and 53% +/- 4%, respectively, for the AVR subgroup and 70% +/- 2% and 33% +/- 4%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from thromboembolism at 10 and 15 years were 92% +/- 1% and 87% +/- 2%, respectively, for the AVR subgroup and 86% +/- 1% and 77% +/- 3%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from anticoagulant-related hemorrhage at 10 and 15 years were both 96% +/- 1% for the AVR subgroup and 93% +/- 1% and 90% +/- 2%, respectively, for the MVR subgroup (AVR > MVR; p < 0.05). Estimates of freedom from valve-related mortality at 10 and 15 years were 86% +/- 1% and 78% +/- 3%, respectively, for the AVR subgroup and 84% +/- 2% and 70% +/- 4%, respectively, for the MVR subgroup (p = not significant). Multivariate analysis (Cox model) showed younger age, later year of operation, and valve site (MVR > AVR) to be significant risk factors for structural valve deterioration. Younger age, later year of operation, valve site (MVR > AVR), and renal insufficiency were the significant, independent risk factors for reoperation. Multivariate analysis revealed that higher New York Heart Association functional class, longer cardiopulmonary bypass time, congestive heart failure, renal insufficiency, and longer cross-clamp time were significant risk factors for valve-related mortality. Valve manufacturer did not emerge as a factor in any analysis.These long-term results with porcine bioprostheses were satisfactory, particularly in older patients and those undergoing AVR. As expected, younger age was a significant risk factor for structural valve deterioration and reoperation in both groups. Surprisingly, the durability of porcine bioprosthetic valves has not improved over time, which possibly can be attributed to more enhanced postoperative surveillance and earlier reintervention. These first-generation Hancock and Carpentier-Edwards porcine bioprostheses achieved similar long-term performance.

  View details for PubMedID 8893561

• Composite versus separate aortic valve and ascending aortic replacement - 30 year experience Yun, K. L., Fann, J. I., Miller, D. C., Mitchell, R. S., Robbins, R. C., Oyer, P. E., Stinson, E. B., Reitz, B. A., Shumway, N. E. LIPPINCOTT WILLIAMS & WILKINS. 1996: 1017–17

  View details for Web of Science ID A1996VN11901015

• True lumen obliteration in complicated aortic dissection: Endovascular treatment 1995 Annual Meeting of the Radiological-Society-of-North-America Slonim, S. M., NYMAN, U. R., Semba, C. P., Miller, D. C., Mitchell, R. S., Dake, M. D. RADIOLOGICAL SOC NORTH AMER. 1996: 161–66

  Abstract

  To evaluate endovascular treatment of ischemic complications caused by true lumen obliteration in aortic dissection.Endovascular techniques were used to treat true lumen obliteration in 11 patients with complicated aortic dissection. In all cases, the true lumen was compressed to a paper-thin sliver by the expanded false lumen. Two patients had Stanford type A (chronic) and nine had type B (six acute, three chronic) dissections. Obliteration of the true lumen was associated with branch vessel ischemia that included renal (n = 7), mesenteric (n = 6), and lower-extremity (n = 6) arterial compromise. Two patients were treated with aortic stents, four with balloon fenestration of the intimal flap, and three with both stent placement and fenestration. In two patients, ischemic complications caused by true lumen obliteration could not be treated with endovascular techniques.Revascularization was technically successful with relief of clinical symptoms in nine patients. Revascularization was unsuccessful in one patient in whom surgical revascularization of the superior mesenteric artery was necessary and in one in whom hypertension was managed medically. One patient developed thrombosis of a renal artery in which a stent had been placed. The 30-day mortality rate was 9%, and the mean follow-up was 10.1 months (range, 2 weeks to 39 months).True lumen obliteration can be safely and effectively treated with endovascular stent placement and balloon fenestration.

  View details for PubMedID 8816538

• Accuracy of biplane and multiplane transesophageal echocardiography in diagnosis of typical acute aortic dissection and intramural hematoma JOURNAL OF THE AMERICAN COLLEGE OF CARDIOLOGY Keren, A., Kim, C. B., Hu, B. S., Eyngorina, I., Billingham, M. E., Mitchell, R. S., Miller, D. C., Popp, R. L., Schnittger, I. 1996; 28 (3): 627-636

  Abstract

  The purpose of this study was to evaluate the diagnostic accuracy of biplane and multiplane transesophageal echocardiography in patients with suspected aortic dissection, including intramural hematoma.Transesophageal echocardiography is a useful technique for rapid bedside evaluation of patients with suspected acute aortic dissection. The sensitivity of transesophageal echocardiography is high, but the diagnostic accuracy of biplane and multiplane transesophageal echocardiography for dissection and intramural hematoma is less well defined.We studied 112 consecutive patients at a major referral center who had undergone biplane or multiplane transesophageal echocardiography to identify aortic dissection. The presence, absence and type of aortic dissection (type A or B, typical dissection or intramural hematoma) were confirmed by operation or autopsy in 60 patients and by other imaging techniques in all. The accuracy of transesophageal echocardiography for ancillary findings of aortic dissection (intimal flap, fenestration and thrombosis) was assessed in the 60 patients with available surgical data.Of the 112 patients, aortic dissection was present in 49 (44%); 10 of these had intramural hematoma (5 with and 5 without involvement of the ascending aorta). Of the remaining 63 patients without dissection, 33 (29%) had aortic aneurysm and 30 (27%) had neither dissection nor aneurysm. The overall sensitivity and specificity of transesophageal echocardiography for the presence of dissection were 98% and 95%, respectively. The specificity for type A and type B dissection was 97% and 99%, respectively. The sensitivity and specificity for intramural hematoma was 90% and 99%, respectively. The accuracy of transesophageal echocardiography for diagnosis of acute significant aortic regurgitation and pericardial tamponade was 100%.Biplane and multiplane transesophageal echocardiography are highly accurate for prospective identification of the presence and site of aortic dissection, its ancillary findings and major complications in a large series of patients with varied aortic pathology. Intramural hematoma carries a high complication rate and should be treated identically with aortic dissection.

  View details for PubMedID 8772749

• Port-access coronary artery bypass with cardioplegic arrest: Acute and chronic canine studies 32nd Annual Meeting of the Society-of-Thoracic-Surgeons Stevens, J. H., Burdon, T. A., Siegel, L. C., Peters, W. S., Pompili, M. F., STGOAR, F. G., Berry, G. J., Ribakove, G. H., Vierra, M. A., Mitchell, R. S., Toomasian, J. M., Reitz, B. A. ELSEVIER SCIENCE INC. 1996: 435–40

  Abstract

  Our goal is to perform minimally invasive coronary artery bypass grafting without sacrificing the benefits of myocardial protection with cardioplegia.Twenty-three dogs underwent acute studies and 4 dogs underwent survival studies. The left internal mammary artery was taken down using a thoracoscope. Cardiopulmonary bypass was conducted via femoral cannulas and using an endovascular balloon catheter for ascending aortic occlusion, root venting, and delivery of antegrade blood cardioplegia. Pulmonary artery venting was achieved with a jugular vein catheter. An internal mammary artery-to-coronary artery anastomosis was performed using a microscope through a 10 mm port.All animals were weaned from cardiopulmonary bypass in sinus rhythm without inotropes. Cardiopulmonary bypass duration was 104 +/- 28 minutes and aortic clamp duration was 61 +/- 22 minutes. Cardiac output and pulmonary artery occlusion pressure were unchanged. The internal mammary artery was anastomosed to the left anterior descending artery (25) or the first diagonal (2) with patency shown in 25 of 27. One dog in the survival study had a very short internal mammary artery pedicle under tension and was euthanized for excessive postoperative hemorrhage. Three weeks postoperatively the remaining dogs had angiographically patent anastomoses, normal transthoracic echocardiograms, and histologically normal healing and patent grafts.Endovascular cardiopulmonary bypass using a balloon catheter is effective in arresting and protecting the heart to allow thoracoscopic internal mammary artery-to-coronary artery anastomosis.

  View details for PubMedID 8694602

• Endovascular stent-graft repair of thoracic aortic aneurysms 21st Annual Meeting of the Western-Thoracic-Surgical-Association Mitchell, R. S., Dake, M. D., Semba, C. P., Fogarty, T. J., Zarins, C. K., Liddell, R. P., Miller, D. C. MOSBY-YEAR BOOK INC. 1996: 1054–60

  Abstract

  Conventional repair of aneurysms of the descending thoracic aorta entails thoracotomy and graft interposition. For elderly patients and those with previous operations, obesity, respiratory insufficiency, or other comorbidities, such a procedure entails significant mortality and morbidity. Transluminal stent-graft placement offers an alternative approach with potentially less morbidity and quicker recovery; however, the effectiveness and durability of stent-grafts remain uncertain.Since July 1992, thoracic aortic stent-grafts have been placed in 44 patients with a variety of pathologic conditions. Each graft was individually constructed from self- expanding, stainless-steel Z stents covered with a woven Dacron polyester fabric graft. Craft dimensions were determined from spiral computed tomographic scans. All implants were performed in the operating theater under fluoroscopic and transesophageal echocardiographic guidance. Follow-up was by computed tomography and contrast angiography in all cases. PATIENT DATA: There were 36 men and 8 women. Mean age was 66 years (range 35 to 88 years). Mean aneurysmal diameter was 6.3 cm (range 4.0 to 9.4 cm). Etiologies included 23 degenerative aneurysms, four posttraumatic aneurysms, four pseudoaneurysms, and one chronic aortic dissection.There were three early deaths (<30 days) and two late deaths. One early death resulted from graft failure. There were two instances of paraparesis or paraplegia, with one associated early death. A single stent was deployed in 27 patients, two stents were required in 14 patients, and three stents were required in three patients. In 23 patients, vascular access was attained through the femoral artery; abdominal aortic access, either native or graft, was necessary in the remaining 21 patients. Twelve grafts were placed in conjunction with open abdominal aortic surgical procedures. Mean follow-up (98% complete) was 12.6 months (range 1 to 34 months). One late death occurred from aneurysmal expansion and rupture in a patient with a persistent midgraft leak. The second late death may have resulted from aneurysmal rupture. Immediate thrombosis was achieved in 36 patients, and late thrombosis was achieved in three others. Failure to achieve complete aneurysmal thrombosis occurred in five patients, however, and one individual (previously noted) died of aneurysmal expansion and rupture; the remaining four are being carefully monitored. Only one patient has required conversion of the stent to an open procedure; a contained rupture of the false lumen of a chronic dissection eventually necessitated total descending thoracic aortic exclusion.These early results support the hypothesis that endovascular stent-graft placement may be a safe and durable treatment for selected patients with aneurysmal disease of the descending thoracic aorta. Large introducer size (26F outer diameter) and relatively limited angulation capability, as well as imprecise deployment techniques, currently limit its applicability. Distal embolization and stent migration have not been observed. Failure to achieve complete aneurysmal thrombosis may allow continued aneurysmal expansion and rupture. Further follow-up is clearly necessary to evaluate the true long-term effectiveness of this procedure.

  View details for PubMedID 8622303

• Anesthetic considerations for port-access cardiac surgery Siegel, L. C., Peters, W. S., STGOAR, F. G., Stevens, J. H., Pompili, M. F., Howard, S. K., Burdon, T. A., Ribakove, G. H., Mitchell, R. S. LIPPINCOTT WILLIAMS & WILKINS. 1996: SCA79–SCA79

  View details for Web of Science ID A1996UD16400079

• Endoluminal aortic grafting: A preliminary animal study of graft healing JOURNAL OF SURGICAL RESEARCH Harris, E. J., Harris, E. J., Berry, G. J., Mitchell, R. S. 1996; 61 (2): 404-412

  Abstract

  Our purpose was to evaluate the placement, long term performance, and healing of a transluminally delivered endoluminal graft and attachment system, in an animal model using large adult sheep. Nineteen sheep in the weight range of 105-125 kg were entered into this study. Under fluoroscopic guidance in anesthetized animals, an endoluminal delivery system was inserted through a common femoral arteriotomy into the infrarenal aorta, and the graft and attachment system were deployed. Fixation of the proximal and distal ends of the graft to the aortic wall was achieved by hooks on the self expanding attachment system, and seated by balloon expansion. Explantation of the prosthesis was performed prior to euthanasia at 1-, 3-, and 6-month intervals. Aortograms were obtained before and after implantation and before explantation for evaluation of placement, patency, anastomotic seal, migration, and graft infolding. In situ gross examination of the prosthesis under anesthesia prior to sacrifice was performed in all animals. Histologic sections were obtained from both attachment sites ("anastomoses"), from the midgraft and hook insertion sites, and from normal aorta inferior and superior to the endoluminal prosthesis. Scanning electron microscopy was performed randomly on specimens derived from the superior and inferior anastomotic sites at each time point. Selected intervals of healing were 1 month (N=5), 3 months (N=5), and 6 months (N=8). One sheep was euthanized at 1 week due to paraplegia. At all intervals, all prostheses were patent, were well incorporated at the aortic wall-anastomotic sites, and were without mural thrombus. The attachment hooks penetrated the aortic adventitia in all animals. There was no graft migration. At one month, initial pannus formation covered the anastomoses and the entire luminal graft, yet the endothelial-like surface coverage was incomplete. At 3 months and at 6 months, the anastomoses and luminal surfaces displayed more uniform pannus and endothelial-like surface coverage. We conclude that this endoluminal delivery system, passed through a femoral arteriotomy, can effectively deploy an endoluminal graft with self expanding attachment system having consistent patency, secure fixation, and incorporation of the anastomoses with the aortic wall in this animal model.

  View details for Web of Science ID A1996TZ90100018

  View details for PubMedID 8656616

• Port-access coronary artery bypass grafting: A proposed surgical method JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Stevens, J. H., Burdon, T. A., Peters, W. S., Siegel, L. C., Pompili, M. F., Vierra, M. A., STGOAR, F. G., Ribakove, G. H., Mitchell, R. S., Reitz, B. A. 1996; 111 (3): 567-573

  Abstract

  Minimally invasive surgical methods have been developed to provide patients the benefits of open operations with decreased pain and suffering. We have developed a system that allows the performance of cardiopulmonary bypass and myocardial protection with cardioplegic arrest without sternotomy or thoracotomy. In a canine model, we successfully used this system to anastomose the internal thoracic artery to the left anterior descending coronary artery in nine of 10 animals. The left internal thoracic artery was dissected from the chest wall, and the pericardium was opened with the use of thoracoscopic techniques and single lung ventilation. The heart was arrested with a cold blood cardioplegic solution delivered through the central lumen of a balloon occlusion catheter (Endoaortic Clamp; Heartport, Inc., Redwood City, Calif.) in the ascending aorta, and cardiopulmonary bypass was maintained with femorofemoral bypass. An operating microscope modified to allow introduction of the 3.5x magnification objective into the chest was positioned through a 10 mm port over the site of the anastomosis. The anastomosis was performed with modified surgical instruments introduced through additional 5 mm ports. In the cadaver model (n = 7) the internal thoracic artery was harvested and the pericardium opened by means of similar techniques. A precise arteriotomy was made with microvascular thoracoscopic instruments under the modified microscope on four cadavers. In three other cadavers we assessed the exposure provided by a small anterior incision (4 to 6 cm) over the fourth intercostal space. This anterior port can assist in dissection of the distal internal thoracic artery and provides direct access to the left anterior descending, circumflex, and posterior descending arteries. We have demonstrated the potential feasibility of grafting the internal thoracic artery to coronary arteries with the heart arrested and protected, without a major thoracotomy or sternotomy.

  View details for PubMedID 8601971

• Aortic dissection: Percutaneous management of ischemic complications with endovascular stents and balloon fenestration 49th Annual Meeting of the Society-for-Vascular-Surgery Slonim, S. M., Nyman, U., Semba, C. P., Miller, D. C., Mitchell, R. S., Dake, M. D. MOSBY-ELSEVIER. 1996: 241–51

  Abstract

  The purpose of this study was to evaluate endovascular stenting (EVS) and balloon fenestration (BF) of intimal flaps for the management of lower extremity, renal, and visceral ischemia in acute or chronic aortic dissection.Twenty-two patients (16 male, 6 female) with a median age of 53 years (range 35 to 77 years) underwent percutaneous treatment for peripheral ischemic complications of 12 type A (five acute, seven chronic) and 10 type B (nine acute, one chronic) aortic dissections.Ten patients had leg ischemia, 13 had renal ischemia, and 6 had visceral ischemia. Sixteen patients were treated with EVS including 11 with renal, 6 with lower extremity, 2 with superior mesenteric artery, and 2 with aortic stents. Three patients had BF of the intimal flap, and three had BF in combination with EVS. Revascularization with clinical success was achieved in all 22 patients. Two patients died 3 days and 13.4 months after the procedure was performed, respectively. Of the remaining 20 patients, 1 is lost to follow-up, and 19 have persistent relief of clinical symptoms. Mean follow-up time is 13.7 months (range 1.1 to 46.5 months). One case was complicated by guidewire-induced perinephric hematoma.EVS and BF provide a safe and effective percutaneous method for managing peripheral ischemic complications of aortic dissection.

  View details for PubMedID 8637101

• MR and cerebrospinal fluid enzymes as sensitive indicators of subclinical cerebral injury after open-heart valve replacement surgery AMERICAN JOURNAL OF NEURORADIOLOGY Steinberg, G. K., Delapaz, R., Mitchell, R. S., Bell, T. E., Albers, G. W. 1996; 17 (2): 205-212

  Abstract

  To evaluate MR imaging and lumbar cerebrospinal fluid enzymes as potential sensitive indicators of cerebral injury after open-heart valve replacement surgery.Thirty-four patients with cardiac valvular disease were prospectively entered into this study and then underwent valve replacement or repair under cardiopulmonary bypass using a membrane oxygenator. In 26 patients, MR head images were obtained 12 to 24 hours before surgery; repeat MR images were obtained between 1 and 2 weeks after surgery. In 18 patients, lumbar puncture cerebrospinal fluid was analyzed 24 to 48 hours after surgery; the analyses included measurement of lactic dehydrogenase, creatine phosphokinase, adenylate kinase, and neuron-specific enolase.After surgery, MR imaging showed new ischemic lesions in 15 (58%) of 26 patients: 7 with deep white matter hyperintense lesions; 5 with brain stem, caudate, cerebellar, or thalamic/basal ganglia infarcts; 1 with intraparenchymal hemorrhage; 1 with a subdural hematoma and cortical infarct; and 1 with a corpus callosum lesion consistent with calcium or air. These new ischemic lesions seen on MR images were associated with a focal neurologic deficit in only 4 (27%) of the 15 patients. Neuron-specific enolase and lactic dehydrogenase were abnormally elevated after surgery in 5 (28%) of 18 patients. Adenylate kinase and creatine phosphokinase (brain isozymes) were elevated in one (67%) of the patients. Two (40%) of the five patients with abnormally high neuron-specific enolase or lactic dehydrogenase after surgery also showed a new focal neurologic deficit.MR imaging is a sensitive measure of subclinical cerebral ischemia after cardiac valve replacement under cardiopulmonary bypass. Cerebrospinal fluid neuron-specific enolase and lactic dehydrogenase are less sensitive than MR imaging for detecting subclinical cerebral ischemia, but these values were elevated after surgery more frequently than was adenylate kinase in our patients.

  View details for Web of Science ID A1996TW23400001

  View details for PubMedID 8938287

• SURGICAL-MANAGEMENT OF AORTIC DISSECTION DURING A 30-YEAR PERIOD CIRCULATION Fann, J. I., Smith, J. A., Miller, D. C., Mitchell, R. S., Moore, K. A., Grunkemeier, G., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. 1995; 92 (9): 113-121

  View details for Web of Science ID A1995TE55900020

• Surgical management of aortic dissection during a 30-year period. Circulation Fann, J. I., Smith, J. A., Miller, D. C., Mitchell, R. S., Moore, K. A., Grunkemeier, G., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. 1995; 92 (9): II113-21

  Abstract

  Certain recent studies have demonstrated improved surgical outcome in patients with aortic dissection. We analyzed the surgical survival rates of patients with acute aortic dissections and the late prognosis of those with aortic dissection during a 30-year period.Between 1963 and 1992, 360 patients (256 men and 104 women; mean +/- 1 SD age, 57 +/- 14 years) underwent surgery for aortic dissection: 174 patients had an acute type A (AcA), 46 an acute type B (AcB), 106 a chronic type A (ChA), and 34 a chronic type B (ChB) aortic dissection. The overall operative mortality rate was 24 +/- 8% (26 +/- 3% for AcA, 39 +/- 8% for AcB, 17 +/- 4% for ChA, and 15 +/- 6% for ChB, [+/- 70% confidence limit]). The operative mortality rates for patients with acute aortic dissection (AcA or AcB) were assessed for five time "windows": 1963 to 1972 (42 +/- 8%), 1973 to 1977 (37 +/- 8%), 1978 to 1982 (15 +/- 6%), 1983 to 1987 (27 +/- 6%), and 1988 to 1992 (26 +/- 6%). Logistic regression analysis suggested that the low operative mortality rate during the 1978-to-1982 interval occurred by chance. Multivariate analysis showed earlier operative year, hypertension, cardiac tamponade, renal dysfunction, and older age were independent determinants of operative death. Actuarial survival rates (including early deaths) after 5, 10, and 15 years for AcA patients were 55%, 37%, and 24%; for AcB, 48%, 29%, and 11%; for ChA, 65%, 45%, and 27%; and for ChB, 59%, 45%, and 27%. Multivariate analysis revealed that older age and previous operation were significant predictors for late death. Freedom from reoperation for all patients was 84%, 67%, and 57% at 5, 10, and 15 years, respectively.Although the operative mortality rate decreased over time for patients with aortic dissection, the risk for those with acute aortic dissection during the last 10 years (1983 to 1992) is probably more realistic than that observed in the preceding 5-year interval (1978 to 1982). The operative mortality rates for patients with chronic aortic dissection have remained relatively static. Earlier diagnosis of acute aortic dissection before development of cardiac tamponade and renal impairment is critical to improve the operative salvage rate. Long-term outcome still is not optimal, which emphasizes the need for better serial postoperative aortic imaging surveillance and medical follow-up and blood pressure control.

  View details for PubMedID 7586393

• TRUE LUMEN OBLITERATION IN COMPLICATED AORTIC DISSECTION - ENDOVASCULAR MANAGEMENT Slonim, S. M., Dake, M. D., Semba, C. P., Razavi, M. K., NYMAN, U. R., Miller, D. C., Mitchell, R. S. LIPPINCOTT WILLIAMS & WILKINS. 1995: 602–

  View details for Web of Science ID A1995TB48000597

• DURABILITY OF THE HANCOCK-MO BIOPROSTHESIS COMPARED WITH STANDARD AORTIC-VALVE BIOPROSTHESES VI International Symposium for Cardiac Bioprostheses Yun, K. L., Miller, D. C., Moore, K. A., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Robbins, R. C., Reitz, B. A., Shumway, N. E. ELSEVIER SCIENCE INC. 1995: S221–S228

  Abstract

  To compare the durability of the Hancock modified orifice (Hancock MO, model 250 [H-MO]) valve with two other commonly used standard aortic valve bioprostheses, a cohort of 1,602 patients undergoing aortic valve replacement using porcine valves between 1971 and 1990 (excluding simultaneous mitral valve replacement) was analyzed retrospectively using Cox model multivariate techniques. Five hundred sixty-one patients received a composite H-MO valve, 652 received a standard Hancock model 242 (H) valve, and 389 received a Carpentier-Edwards model 2625 (C-E) valve. Mean age was 60 +/- 15 years (+/- 1 standard deviation) (71% male). Follow-up (10,247 patient-years) extended to 15 years and was 97% complete. The main focus of this study was bioprosthetic durability, using The American Association for Thoracic Surgery/The Society of Thoracic Surgeons guidelines to define structural valve deterioration (SVD). Multivariate analysis revealed that (younger) age (p < 10(-5), liver disease (p = 0.02), and 1981 to 1985 operative period (p = 0.012) were the only significant, independent predictors of SVD. In concordance with previous reports, the SVD freedom estimate was greater than 90% at 15 years for patients older than 70 years of age. Hepatic dysfunction had an adverse effect on SVD (estimated freedom from event at 10 years was 34 +/- 17% [standard error of mean] versus 78 +/- 2% for those without liver disease), but this affected only 3% of patients. Interestingly, one operative period (1981 to 1985) was associated with a slightly higher risk of SVD compared to the three other 5-year time windows. Valve type did not emerge as a significant risk factor for SVD.(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 7646163

• TRANSLUMINAL PLACEMENT OF ENDOVASCULAR STENT-GRAFTS FOR THE TREATMENT OF DESCENDING THORACIC AORTIC-ANEURYSMS NEW ENGLAND JOURNAL OF MEDICINE Dake, M. D., Miller, D. C., Semba, C. P., Mitchell, R. S., Walker, P. J., Liddell, R. P. 1994; 331 (26): 1729-1734

  Abstract

  The usual treatment for thoracic aortic aneurysms is surgical replacement with a prosthetic graft, but the associated morbidity and mortality are considerable. We studied the use of transluminally placed endovascular stent-graft devices as an alternative to surgical repair.We evaluated the feasibility, safety, and effectiveness of transluminally placed stent-graft to treat descending thoracic aortic aneurysms in 13 patients over a 24-month period. Atherosclerotic, anastomotic, and post-traumatic true or false aneurysms and aortic dissections were treated. The mean diameter of the aneurysms was 6.1 cm (range, 5 to 8). The endovascular stent-grafts were custom-designed for each patient and were constructed of self-expanding stainless-steel stents covered with woven Dacron grafts.Endovascular placement of the stent-graft prosthesis was successful in all patients. There was complete thrombosis of the thoracic aortic aneurysm surrounding the stent-graft in 12 patients, and partial thrombosis in 1. Two patients initially had small, residual patent proximal tracts into the aneurysm sac, but both tracts thrombosed within two months after the procedure. In four patients, two prostheses were required to bridge the aneurysm adequately. There have been no deaths or instances of paraplegia, stroke, distal embolization, or infection during an average follow-up of 11.6 months. One patient with an extensive chronic aortic dissection required open surgical graft replacement four months later because of progressive dilatation of the arch.These preliminary results demonstrate that endovascular stent-graft repair is safe in highly selected patients with descending thoracic aortic aneurysms. This new method of treatment will, however, require careful long-term evaluation.

  View details for PubMedID 7984192

• Surgical management of aortic dissection in patients with the Marfan syndrome. Circulation Smith, J. A., Fann, J. I., Miller, D. C., Moore, K. A., DeAnda, A., Mitchell, R. S., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. 1994; 90 (5): II235-42

  Abstract

  Aortic dissection is one of the most lethal potential complications in patients with the Marfan syndrome.Among 360 patients undergoing operative treatment of aortic dissection between 1963 and 1992, 40 had the Marfan syndrome. There were 24 men and 16 women with a mean age of 35 +/- 9 years (+/- 1 SD; range, 15 to 54 years). These patients included 16 with acute type A, 2 with acute type B, 18 with chronic type A, and 4 with chronic type B aortic dissections. The aortic arch was involved in 29 cases. Preoperative complications included acute aortic valvular insufficiency in 13 patients, rupture into the pericardial space in 3, and loss of peripheral pulses in 9. The site of primary intimal tear was the ascending aorta in 25 patients, the aortic arch in 2, the descending aorta in 7, and not identified in 6. Operations included ascending aortic and aortic valvular replacement (with or without coronary artery reimplantation) in 22 patients, ascending aortic replacement alone in 5, and descending thoracic aortic replacement in 9. Four operative deaths (10 +/- 5% [+/- 70% confidence limits]) occurred in 3 acute patient-years and 1 chronic type A patient-years. Long-term follow-up (216 patient-years; range, 1 month to 22 years; mean, 5.4 years) revealed 15 late deaths, 7 from late aortic sequelae. The overall actuarial survival estimates were 71 +/- 8%, 54 +/- 10%, and 22 +/- 11% at 5, 10, and 15 years, respectively. Twenty late aortic operations were required in 14 patients.Despite satisfactory early results, the long-term survival of patients with the Marfan syndrome was suboptimal (albeit similar to those without the Marfan syndrome). Future progress will pivot on reducing the incidence of aortic dissection in these patients with medical therapy and/or earlier surgical intervention and enhanced postoperative serial imaging surveillance of the entire aorta.

  View details for PubMedID 7955259

• SURGICAL-MANAGEMENT OF AORTIC DISSECTION IN PATIENTS WITH THE MARFAN-SYNDROME 66th Scientific Sessions of the American-Heart-Association:Cardiovascular Surgery 1993 Smith, J. A., Fann, J. I., Miller, D. C., Moore, K. A., DeAnda, A., Mitchell, R. S., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. AMER HEART ASSOC. 1994: 235–42

  View details for Web of Science ID A1994PR28700043

• TRANSLUMINALLY PLACED ENDOVASCULAR STENT GRAFTS FOR THE TREATMENT OF ABDOMINAL AORTIC AND NON-AORTIC ANEURYSMS Dake, M. D., Semba, C. P., Mitchell, R. S., Zarins, C. K., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1994: 206–

  View details for Web of Science ID A1994PN41701137

• SURGICAL-MANAGEMENT OF AORTIC DISSECTION OVER 30 YEARS Fann, J. I., Smith, J. A., Miller, D. C., Mitchell, R. S., Moore, K., Oyer, P. E., STINSOUN, E. B., Reitz, B. A., Shumway, N. E. LIPPINCOTT WILLIAMS & WILKINS. 1994: 96–96

  View details for Web of Science ID A1994PN41700549

• CLOSED-CHEST CORONARY-ARTERY BYPASS WITH CARDIOPLEGIC ARREST IN THE DOG Stevens, J. H., Siegel, L. C., Mitchell, R. S., Burdon, T. A., Ribakove, G. H., Smith, J. A., STGOAR, F. G., Peters, W. S., Vierra, M. A., Pompili, M. F., Reitz, B. A. LIPPINCOTT WILLIAMS & WILKINS. 1994: 251–51

  View details for Web of Science ID A1994PN41701385

• AS ORIGINALLY PUBLISHED IN 1986 - PHARMACOLOGICAL, HEMATOLOGICAL, AND PHYSIOLOGICAL-EFFECTS OF A NEW THROMBOXANE SYNTHETASE INHIBITOR (CGS-13080) DURING CARDIOPULMONARY BYPASS IN DOGS (REPRINTED FROM ANN-THORAC-SURG, VOL 42, PG 690-6, 1986) ANNALS OF THORACIC SURGERY DECAMPLI, W. M., GOODWIN, D., KOSEK, J. C., HANDEN, C. E., MITCHELL, R. S., DEANDA, A., MILLER, D. C. 1994; 57 (3): 778–80

  View details for DOI 10.1016/0003-4975(94)90597-5

  View details for Web of Science ID A1994NE91500061

• THE USE OF ENDOVASCULAR TECHNIQUES FOR THE TREATMENT OF COMPLICATIONS OF AORTIC DISSECTION JOURNAL OF VASCULAR SURGERY Walker, P. J., Dake, M. D., Mitchell, R. S., Miller, D. C. 1993; 18 (6): 1042-1051

  Abstract

  Intravascular ultrasonography, balloon angioplasty, stent placement, and endovascular septal fenestration have been used in the evaluation and treatment of vascular complications of acute and chronic aortic dissection in five patients. There were three men and two women with an average age of 52 years (range 39 to 64 years). There were three chronic type A dissections, one acute type B, and one subacute type B dissection. Intravascular ultrasonography was used in all five cases. The three patients with chronic type A dissections underwent unilateral renal artery angioplasty (RA PTA) and stent placement; one patient with an acute type B dissection and associated fibromuscular dysplasia underwent bilateral RA PTA without stent placement. These procedures were performed to ameliorate severe hypertension. The final patient, with a subacute type B dissection, underwent iliac artery stenting to correct severe lower extremity ischemia. During a second intervention, this patient, who also had bowel ischemia and nonresolving acute renal failure, underwent balloon dilatation of a preexisting septal fenestration to augment visceral blood supply and bilateral RA PTA and stent placement in an effort to improve renal function. This patient eventually died of gut ischemia. After RA PTA and stent placement, one patient had a major intrarenal hemorrhage that required coil embolization and transfusion. In the four survivors, RA PTA and stent placement resulted in immediate improvement in blood pressure control. This response has been sustained during follow-up intervals ranging from 8 to 18 months (average 10 months). Intravascular ultrasonography can clearly demonstrate the pathologic anatomy associated with aortic dissection (even when angiography is ambiguous) and is essential for guiding therapeutic endovascular interventions. Further exploration of the efficacy of these endovascular techniques is warranted in this high-risk group of patients with aortic dissection who have appropriate clinical indications.

  View details for PubMedID 8264033

• Randomized, prospective assessment of bioprosthetic valve durability. Hancock versus Carpentier-Edwards valves. Circulation Sarris, G. E., Robbins, R. C., Miller, D. C., Mitchell, R. S., Moore, K. A., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. 1993; 88 (5): II55-64

  Abstract

  Although the major limitation of porcine valves is their finite durability, no controlled clinical data exist regarding the relative durability of the two porcine bioprostheses implanted most commonly today, the Carpentier-Edwards (C-E) and Medtronic Hancock I (H) valves.To assess this question, 174 patients undergoing aortic (AVR) or mitral (MVR) valve replacement with a bioprosthesis between March 1980 and March 1982 were randomized to receive either a C-E or a H valve. There were 102 AVRs (54 C-E and 48 H) and 74 MVRs (39 C-E and 35 H). For both the AVR and MVR cohorts, the average patient age was 58 +/- 14 years (+/- SD). The male/female ratio was 2.2:1 for AVR and 0.57:1 for MVR. Clinical follow-up was undertaken periodically; the most recent follow-up closing interval was July through October 1992, and current follow-up was 96% complete. Cumulative follow-up totaled 1369 patient-years (mean, 7.7 +/- 3.6 years; median, 9.1 years; maximum, 12.0 years). The main focus of this analysis was bioprosthetic durability, using the AATS/STS guidelines defining "Structural Valve Deterioration" (SVD). Multivariate analysis revealed that (younger) age was the only significant (P = .024) independent predictor of SVD. Valve manufacturer (C-E versus H) and valve site (aortic versus mitral) did not emerge as significant independent risk factors for SVD. Actuarial rates (Cutler-Ederer) expressed as percent free of SVD (+/- SEM) at 10 years (n = number of patients remaining at risk) were 71 +/- 7% and 59 +/- 9% for the C-E (n = 26) and H (n = 17) groups, respectively, for the AVR cohort; for the MVR cohort, these estimates were 60 +/- 10% (n = 12) and 72 +/- 10% (n = 11), respectively, but these differences were not statistically significant (P = NS, Lee-Desu).After 10 years, there was no statistically significant difference in durability or other valve-related complications between the H and C-E aortic or mitral valves. Based on current information, the choice of a porcine bioprosthesis should be based on factors other than durability, including ease of implantation, hemodynamic performance, and cost.

  View details for PubMedID 8222197

• Management of patients with intramural hematoma of the thoracic aorta. Circulation Robbins, R. C., McManus, R. P., Mitchell, R. S., LATTER, D. R., Moon, M. R., Olinger, G. N., Miller, D. C. 1993; 88 (5): II1-10

  Abstract

  Intramural hematoma of the thoracic aorta (IMH) is a diagnosis of exclusion and represents spontaneous, localized hemorrhage into the wall of the thoracic aorta in the absence of bona fide aortic dissection, intimal tear, or penetrating atherosclerotic ulcer. This process may arise from primary vasa vasorum hemorrhage within the aortic media or rupture of an atherosclerotic plaque. The clinical presentation of patients with IMH mimics that of acute aortic dissection; moreover, considerable diagnostic confusion exists despite the use of many different imaging modalities. The optimal mode of management of patients with IMH (medical versus medical plus surgical) remains problematic because of the paucity of information available.Thirteen patients with IMH were managed at two medical centers between 1983 and 1992. Patients with IMH caused by giant penetrating atherosclerotic ulcers were specifically excluded. There were 8 women and 5 men (mean age, 70 years [range, 54 to 82 years]). The admitting clinical diagnosis was acute aortic dissection, and all patients had a history of hypertension. There was no evidence of aortic dissection or intimal disruption as assessed by computed tomographic (CT) scan (n = 11), aortography (n = 10), magnetic resonance imaging (MRI) scan (n = 9), transesophageal echocardiography (TEE) (n = 6), or intravascular ultrasound (n = 1). The diagnosis of IMH was established by exclusion. The descending thoracic aorta was involved in 10 cases and the ascending/arch in 3. Conservative medical management was attempted initially. All 3 patients with IMH involving the ascending aorta ultimately required operative intervention, and 2 individuals died; 2 of 10 patients with descending aortic involvement eventually underwent surgery. Average hospital stay was 11 days; the mean follow-up interval for discharged patients was 29 months.IMH is a distinct pathological entity, should not be confused with aortic dissection, and probably will be identified more frequently in the future. All patients with IMH should be monitored carefully and treated with aggressive antihypertensive therapy. Frequent serial assessment is necessary using TEE or MRI/CT scans. Based on this small experience, patients with ascending/arch IMH, ongoing pain, or IMH expansion should probably undergo early graft replacement. Patients with IMH involving the descending thoracic aorta who have no evidence of progression and become pain free can probably be treated conservatively but require antihypertensive therapy and serial aortic imaging surveillance indefinitely.

  View details for PubMedID 8222144

• MANAGEMENT OF PATIENTS WITH INTRAMURAL HEMATOMA OF THE THORACIC AORTA 65TH Scientific Sessions of the American-Heart-Association Robbins, R. C., McManus, R. P., Mitchell, R. S., LATTER, D. R., Moon, M. R., Olinger, G. N., Miller, D. C. AMER HEART ASSOC. 1993: 1–10

  View details for Web of Science ID A1993ME83400001

• RANDOMIZED, PROSPECTIVE ASSESSMENT OF BIOPROSTHETIC VALVE DURABILITY - HANCOCK VERSUS CARPENTIER-EDWARDS VALVES CIRCULATION Sarris, G. E., Robbins, R. C., Miller, D. C., Mitchell, R. S., Moore, K. A., Stinson, E. B., Oyer, P. E., Reitz, B. A., Shumway, N. E. 1993; 88 (5): 55-64

  View details for Web of Science ID A1993ME83400009

• EARLY EXPERIENCE WITH CRYOPRESERVED SAPHENOUS-VEIN ALLOGRAFTS AS A CONDUIT FOR COMPLEX LIMB-SALVAGE PROCEDURES 8TH ANNUAL MEETING OF THE WESTERN-VASCULAR-SOC Walker, P. J., Mitchell, R. S., McFadden, P. M., James, D. R., MEHIGAN, J. T. MOSBY-ELSEVIER. 1993: 561–69

  Abstract

  The lack of a suitable alternative to autogenous vein is often the limiting factor for complex lower extremity vascular reconstruction, especially when previously placed grafts have failed. Cryopreserved saphenous vein allografts have been used as an alternative conduit. This report reviews our early experience with this conduit in a series of complex redo revascularization procedures for limb salvage when no suitable autogenous vein was available.Thirty-five patients underwent 39 lower extremity bypass grafts on 36 limbs. These patients had undergone a combined total of 72 prior revascularization procedures on the symptomatic limb, an average of two procedures per patient. Only five bypasses were performed as a primary procedure. There were 18 men and 17 women with a mean age of 71 years. Sixteen of the patients had diabetes. Thirty-four bypasses were performed for rest pain or ulceration, four for disabling claudication, and one for replacement of an aneurysmal vein graft. There were 35 femorotibial, three below-knee femoropopliteal, and one femoropedal reconstruction. Twenty-five grafts were constructed with cryopreserved vein only, whereas 14 were composite grafts; 10 were constructed with polytetrafluoroethylene, one with Dacron, and three with spliced native saphenous vein. The mean follow-up was 9 months (range 1 to 25 months).There was one early death (< 30 days) and two late deaths. Two patients died with a patent graft. There have been 12 early graft closures and an additional 17 late failures, resulting in primary cumulative graft patency rates of 67%, 56%, 43%, 28%, and 14% at 1, 3, 6, 12, and 18 months, respectively. Surgically correctable causes, including technical error and anastomotic stenosis, could be identified in 13 of the 29 graft failures. Salvage of failed grafts resulted in secondary cumulative graft patency rates of 87%, 77%, 61%, 46%, and 37% at these same intervals. There was no significant difference in primary or secondary graft patency rates related to diabetes, ABO graft compatibility, graft composition or orientation, indication for surgery, state of the outflow tract, or site of distal anastomosis. Limb salvage was attained in 24 (67%) of the 36 limbs. Two amputations were necessary despite patent grafts.Because of the poor overall graft patency rates, cryopreserved saphenous vein allografts should be used only as a last resort when no alternative autogenous conduit is available. Unless patency rates superior to those achievable with currently available prosthetic or biologic conduits can be attained by adjunctive measures such as routine anticoagulation or immunosuppressive therapy, the use of cryopreserved saphenous vein allografts for lower extremity revascularization should be deferred until improved preparation techniques provide a more durable conduit.

  View details for Web of Science ID A1993MB16500002

  View details for PubMedID 8411463

• 3-DIMENSIONAL SPIRAL COMPUTED TOMOGRAPHIC ANGIOGRAPHY - AN ALTERNATIVE IMAGING MODALITY FOR THE ABDOMINAL-AORTA AND ITS BRANCHES 8TH ANNUAL MEETING OF THE WESTERN-VASCULAR-SOC Rubin, G. D., Walker, P. J., Dake, M. D., Napel, S., Jeffrey, R. B., McDonnell, C. H., Mitchell, R. S., Miller, D. C. MOSBY-ELSEVIER. 1993: 656–65

  Abstract

  We sought to apply a new technique of computed tomographic angiography (CTA) to the preoperative and postoperative assessment of the abdominal aorta and its branches.After a peripheral intravenous contrast injection, the patient is continuously advanced through a spiral CT scanner, while maintaining a 30-second breath-hold. Thirty-five patients with abdominal aortic, renal, and visceral arterial disease have undergone CTA.Diagnostic three-dimensional images were obtained in patients with aortic aneurysms (n = 9), aortic dissections (n = 4), and mesenteric artery stenoses (n = 4). The technique has also been used to assess vessels after operative reconstruction or endovascular intervention in 18 patients. These preliminary studies have correlated well with conventional arteriographic findings. In aneurysmal disease both the lumen and mural thrombus and associated renal artery stenoses are visualized. The true and false channels of aortic dissections and the perfusion source of the visceral vessels are clearly shown; patency of visceral and renal reconstruction or stent placement are confirmed. CTA is relatively noninvasive and can be completed in less time than conventional angiography with less radiation exposure.This initial experience suggests that CTA may be a valuable alternative to conventional arteriography in the evaluation of the aorta and its branches.

  View details for PubMedID 8411473

• INTRAVASCULAR STENTING OF ACUTE EXPERIMENTAL TYPE-B DISSECTIONS 1992 Annual Meeting of the Association-for-Academic-Surgery Moon, M. R., Dake, M. D., Pelc, L. R., Liddell, R., Castro, L. J., Mitchell, R. S., Miller, D. C. ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS. 1993: 381–88

  Abstract

  To evaluate the efficacy of intravascular stenting for acute aortic dissection, 12 dogs underwent surgical creation of an acute type B dissection. Intravascular ultrasound evaluated luminal diameter, distal propagation, and branch involvement. Three animals underwent no further treatment (control). In 9 dogs, balloon-expandable intravascular stents (15-20 mm) were placed proximally to compress the intimal flap. One dog with a small dissection had complete obliteration of the false lumen after initial stent placement. Six dogs with extension below the diaphragm were initially stented proximally to restore flow; 3 were left with a residual distal false lumen, while 3 had additional stents placed to obliterate their entire false lumen. In the final 2 dogs, proximal stenting resulted only in partial compression of the false lumen. Two animals died within 24 hr due to prolonged hemodynamic instability and aortic rupture at the intimal flap, respectively. Six weeks later, radiologic and histologic evaluation was performed on the 10 surviving animals. All stented true lumens were patent without thrombus formation, and stents were covered by neointima. In dogs with stenting of the entire dissection, the aortic wall had healed and no false lumen was present. However, in all dogs with only proximal obliteration, 1/2 with partial compression, and 2/3 controls, a patent false channel was present indicative of a chronic dissection. Thus, we found that intravascular stents can restore true lumen flow and obliterate the false lumen in experimental dissections; however, stenting limited to the proximal dissection does not prevent formation of a chronic residual patent false lumen.

  View details for PubMedID 8331933

• Composite aortic valve replacement and graft replacement of the ascending aorta plus coronary ostial reimplantation: how I do it. Seminars in thoracic and cardiovascular surgery Miller, D. C., Mitchell, R. S. 1993; 5 (1): 74-83

  View details for PubMedID 8425007

• Successful percutaneous balloon catheter treatment of renal artery occlusion and anuria. Annals of vascular surgery Schneider, J. R., Wright, A., Mitchell, R. S. 1992; 6 (6): 533-536

  Abstract

  Progressive renal failure may be due to renal artery stenosis and occlusion. Gradual occlusion of the renal arteries may allow the development of collateral arterial supply sufficient to avoid dialysis. Even when dialysis is required, significant viable renal parenchyma may still be present to allow escape from dialysis following revascularization of one or both kidneys. The chance of success in such cases is thought to be better if the patient still produces a significant amount of urine. We report here a patient who was completely anuric for five days and in whom excellent renal function returned after balloon angioplasty of one of two occluded renal arteries.

  View details for PubMedID 1463668

• CLINICAL USE OF INTRAVASCULAR ULTRASOUND IN STENTING ISCHEMIC COMPLICATIONS OF AORTIC DISSECTION Dake, M. D., Wexler, L., Walker, P. J., Mitchell, R. S., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1992: 364–64

  View details for Web of Science ID A1992JT66001471

• RANDOMIZED, PROSPECTIVE ASSESSMENT OF BIOPROSTHESIS DURABILITY - HANCOCK VS CARPENTIER-EDWARDS VALVES Sarris, G. E., Robbins, R. C., Miller, D. C., Mitchell, R. S., Moore, K. A., Stinson, E. B., Oyer, P. E., Starnes, V. A., Shumway, N. E. LIPPINCOTT WILLIAMS & WILKINS. 1992: 496–96

  View details for Web of Science ID A1992JT66001991

• MANAGEMENT OF INTRAMURAL HEMATOMA OF THE THORACIC AORTA Robbins, R. C., MACMANUS, R. P., Mitchell, R. S., LATTER, D. R., Olinger, G. N., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1992: 12–12

  View details for Web of Science ID A1992JT66000078

• DURABILITY OF PORCINE VALVES AT 15 YEARS IN A REPRESENTATIVE NORTH-AMERICAN PATIENT POPULATION JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Burdon, T. A., Miller, D. C., Oyer, P. E., Mitchell, R. S., Stinson, E. B., Starnes, V. A., Shumway, N. E. 1992; 103 (2): 238-252

  Abstract

  Isolated aortic (n = 857) or mitral (n = 793) valve replacement with a porcine bioprosthesis was performed in 1650 patients between 1971 and 1980. Follow-up (total = 12,012 patient-years) extended to more than 15 years and was 96% complete. Patient age ranged from 16 to 87 years; mean age was 59 +/- 11 years (+/- 1 standard deviation) for the aortic valve replacement cohort and 56 +/- 12 years for the mitral valve replacement cohort. The operative mortality rates were 5% +/- 1% (+/- 70% confidence limits) and 8% +/- 1%, respectively, for the aortic and mitral subgroups. Estimated freedom from structural valve deterioration (+/- 1 standard error of the mean) after 10 and 15 years was significantly higher for the aortic than for the mitral valve replacement subgroup (85% +/- 0.4% and 63% +/- 3% versus 78% +/- 2% and 45% +/- 3%, respectively, p = 0.001). Reoperation-free actuarial estimates were also significantly greater for the aortic valve replacement cohort: 83% +/- 2% and 57% +/- 3% versus 78% +/- 2% and 43% +/- 3% for mitral valve replacement at 10 and 15 years, respectively. The mortality rate for reoperative aortic valve replacement was 11% +/- 1%; it was 8% +/- 1% for reoperative mitral valve replacement. Importantly, the estimates of freedom from valve-related death (including sudden, unexplained deaths) were relatively high at 10 and 15 years: 78% +/- 2% and 69% +/- 3% in the aortic cohort and 74% +/- 2% and 63% +/- 3% in the mitral cohort (p = not significant). Excluding sudden, unexplained deaths, these estimates were 81% +/- 3% (aortic) and 73% +/- 4% (mitral) at 15 years. Thromboembolism-free rates were 84% +/- 3% (aortic) and 78% +/- 6% (mitral) at 15 years, and freedom from anticoagulant-related hemorrhage was 96% +/- 1% and 89% +/- 2%, respectively. At the time of current follow-up, 13% of patients having aortic valve replacement and 50% of patients having mitral valve replacement were receiving warfarin sodium. The hazard functions for thromboembolism and prosthetic valve endocarditis were constant and remained less than 1%/pt-yr over the entire follow-up period.(ABSTRACT TRUNCATED AT 400 WORDS)

  View details for PubMedID 1735989

• AORTIC DISSECTION RESULTING FROM TEAR OF TRANSVERSE ARCH - IS CONCOMITANT ARCH REPAIR WARRANTED 16TH ANNUAL MEETING OF THE WESTERN THORACIC SURGICAL ASSOC Yun, K. L., Glower, D. D., Miller, D. C., Fann, J. I., Mitchell, R. S., White, W. D., Rankin, J. S., Wolfe, W. G., Shumway, N. E. MOSBY-ELSEVIER. 1991: 355–70

  Abstract

  Forty-seven patients with aortic dissection resulting from a primary tear located in the transverse aortic arch underwent surgical treatment. Twenty-six patients had acute type A, 7 had acute type B, 7 had chronic type A, and 7 had chronic type B aortic dissections. Of the 33 patients with acute dissections, 11 (7 acute type A and 4 acute type B) underwent concomitant arch repair with an operative (less than or equal to 30 days) mortality rate of 55% (35% to 73%, +/- 1 asymmetric 70% confidence limit) (2 of 7 acute type A and 4 of 4 acute type B). Concomitant arch repair was omitted in 22 patients with acute dissections (19 acute type A and 3 acute type B); the operative mortality rate was 41% (29% to 54%) (7 of 19 acute type A and 2 of 3 acute type B) (p = not significant versus arch repair). The overall survival rate for those with arch repair was 45% +/- 15% (+/- 1 standard error of the estimate) at 4 years, compared with 43% +/- 11% for patients without arch repair (p = not significant). Considering the type of dissection, the 4-year survival estimate for patients with acute type A dissections who underwent arch repair (5 hemiarch and 2 total arch) was 71% +/- 17% (versus 44% +/- 12% for acute type A patients without arch repair). There were no survivors among the 4 patients with acute type B dissections who had an arch repair (1 hemiarch and 3 total arch), whereas patients with acute type B dissections who did not undergo concomitant arch repair had a 4-year survival estimate of 33% +/- 27% (p = not significant versus arch repair). Four other patients with acute type B dissections resulting from an arch tear were managed medically and tended to have a slightly better prognosis (2-year survival estimate of 75% +/- 22% versus 14% +/- 13% for all surgically treated acute type B patients), but again this difference was not statistically significant. Multivariate analysis of the 47 surgical patients revealed that advanced age (p = 0.0008), preoperative dissection complications (p = 0.02), and other coexistent medical problems (p = 0.03) were the only significant, independent determinants of overall mortality. Initial arch repair was not a significant predictor. Nine percent (2/22) of patients with acute type A dissections who initially underwent isolated ascending aortic replacement required subsequent arch replacement; 1 died after reoperation.(ABSTRACT TRUNCATED AT 400 WORDS)

  View details for PubMedID 1881176

• TREATMENT OF PATIENTS WITH AORTIC DISSECTION PRESENTING WITH PERIPHERAL VASCULAR COMPLICATIONS ANNALS OF SURGERY Fann, J. I., Sarris, G. E., Mitchell, R. S., Shumway, N. E., Stinson, E. B., Oyer, P. E., Miller, D. C. 1990; 212 (6): 705-713

  Abstract

  The incidence of peripheral vascular complications in 272 patients with aortic dissection during a 25-year span was determined, as was outcome after a uniform, aggressive surgical approach directed at repair of the thoracic aorta. One hundred twenty-eight patients (47%) presented with acute type A dissection, 70 (26%) with chronic type A, 40 (15%) with acute type B, and 34 (12%) with chronic type B dissections. Eighty-five patients (31%) sustained one or more peripheral vascular complications: Seven (3%) had a stroke, nine (3%) had paraplegia, 66 (24%) sustained loss of a peripheral pulse, 22 (8%) had impaired renal perfusion, and 14 patients (5%) had compromised visceral perfusion. Following repair of the thoracic aorta, local peripheral vascular procedures were unnecessary in 92% of patients who presented with absence of a peripheral pulse. The operative mortality rate for all patients was 25% +/- 3% (68 of 272 patients). For the subsets of individuals with paraplegia, loss of renal perfusion, and compromised visceral perfusion, the operative mortality rates (+/- 70% confidence limits) were high: 44% +/- 17% (4 of 9 patients), 50% +/- 11% (11 of 22 patients), and 43% +/- 14% (6 of 14 patients), respectively. The mortality rates were lower for patients presenting with stroke (14% +/- 14% [1 of 7 patients]) or loss of peripheral pulse (27% +/- 6% [18 of 66 patients]). Multivariate analysis revealed that impaired renal perfusion was the only peripheral vascular complication that was a significant independent predictor of increased operative mortality risk (p = 0.024); earlier surgical referral (replacement of the appropriate section of the thoracic aorta) or more expeditious diagnosis followed by surgical renal artery revascularization after a thoracic procedure may represent the only way to improve outcome in this high-risk patient subset. Early, aggressive thoracic aortic repair (followed by aortic fenestration and/or abdominal exploration with or without direct visceral or renal vascular reconstruction when necessary) can save some patients with compromised visceral perfusion; however, once visceral infarction develops the prognosis is also poor. Increased awareness of these devastating complications of aortic dissection and the availability of better diagnostic tools today may improve the survival rate for these patients in the future. The initial surgical procedure should include repair of the thoracic aorta in most patients.

  View details for PubMedID 2256762

• DIFFERENCES IN HANCOCK AND CARPENTIER-EDWARDS PORCINE XENOGRAFT AORTIC-VALVE HEMODYNAMICS - EFFECT OF VALVE SIZE CIRCULATION Khan, S. S., Mitchell, R. S., Derby, G. C., Oyer, P. E., Miller, D. C. 1990; 82 (5): 117-124

  View details for Web of Science ID A1990EJ51000016

• Differences in Hancock and Carpentier-Edwards porcine xenograft aortic valve hemodynamics. Effect of valve size. Circulation Khan, S. S., Mitchell, R. S., Derby, G. C., Oyer, P. E., Miller, D. C. 1990; 82 (5): IV117-24

  Abstract

  We prospectively compared the hemodynamic performance of Hancock and Carpentier-Edwards bioprosthetic aortic valves in a randomized study of 100 patients. A total of 47 patients received the Hancock valve, and 53 received the Carpentier-Edwards valve. Mean pressure gradients were measured using micromanometer catheters and cardiac outputs by thermodilution. Multiple measurements were made in each patient with atrial pacing, volume infusion, and inotropic drugs for a total of 319 observations. The pressure gradients and Gorlin valve areas showed significant scatter caused by both flow-dependent and patient-dependent variability. Mean transvalvular pressure gradients were therefore compared after adjustment for flow rate and for random interpatient differences using analysis of variance and covariance. Pressure gradients were lower and Gorlin valve areas larger for the Hancock valve than for the Carpentier-Edwards valve, but the differences were significant only for the smaller valve sizes. Compared with the Carpentier-Edwards valve, the mean pressure gradients were significantly lower for the Hancock 19-mm modified orifice (MO) valves (16.9 versus 31.7 mm Hg, p = 0.04), for the 21-mm valves (15.2 versus 22.4 mm Hg, p = 0.003), and for the 23-mm MO valve (9.2 versus 13.8 mm Hg, p = 0.04). The Gorlin areas were also significantly larger for the Hancock 19-mm MO valve (0.85 versus 0.77 cm2, p = 0.004) and the 21-mm MO valve (1.11 versus 0.89 cm2, p = 0.0009) but not for the 23-mm MO valve (1.59 versus 1.14, p = 0.08). Mean gradients and valve areas were not different for any of the larger valve sizes.(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 2225396

• Hemodynamic comparison of Hancock and Carpentier-Edwards mitral bioprosthetic valves. Circulation Khan, S., Mitchell, R. S., Derby, G. C., Oyer, P. E., Miller, D. C. 1990; 82 (5): IV75-81

  Abstract

  Although it is known that pressure gradients and calculated valve areas in bioprosthetic valves are highly flow dependent, no studies have compared bioprosthetic valve performances while adjusting for differences in flow rate. We therefore studied 75 patients undergoing mitral valve replacement who were randomized to receive either Hancock (n = 35) or Carpentier-Edwards (n = 40) bioprosthetic valves. Pressure gradients were measured using transducer-tipped catheters to record left ventricular and left atrial pressures and cardiac outputs by thermodilution. Repeated measurements were made in each patient after either pacing, fluid infusion, or pharmacological intervention to vary flow rates for a total of 239 measurements (mean, 3.2 measurements per patient). Using analyses of variance and covariance, mean valve gradients and the calculated Gorlin area were adjusted for flow rate, valve size, valve type, and interpatient differences to compare hemodynamics. Without flow and interpatient adjustment, the univariate analysis suggested higher mean gradients in the Carpentier-Edwards 29-mm valves (p = 0.038), with a trend toward higher gradients and smaller areas in the Hancock 33-mm valves (p = 0.057 and 0.059, respectively). After adjustment for flow rate and interpatient differences, however, there was no difference at any valve size in the mean pressure gradients (p = 0.13-0.89) or Gorlin valve areas (p = 0.34-0.96). Although measurements within a given patient were consistent, marked interpatient variabilities in gradients and areas were observed for identical valve types and sizes, which were as significant as flow-dependent or size-dependent changes. We conclude that comparisons of valve performance should adjust for variations in flow rate and for interpatient differences with the use of repeated-measures designs.(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 2225438

• HEMODYNAMIC COMPARISON OF HANCOCK AND CARPENTIER-EDWARDS MITRAL BIOPROSTHETIC VALVES CIRCULATION Khan, S., Mitchell, R. S., Derby, G. C., Oyer, P. E., Miller, D. C. 1990; 82 (5): 75-81

  View details for Web of Science ID A1990EJ51000011

• Surgical management of acute aortic dissection complicated by stroke. Circulation Fann, J. I., Sarris, G. E., Miller, D. C., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Shumway, N. E. 1989; 80 (3): I257-63

  Abstract

  Although patients with acute type A aortic dissection are best managed by emergency surgical intervention, preoperative stroke is known to be an independent predictor of late mortality and is considered by some to be a contraindication to operation because of the risk of precipitating hemorrhagic cerebral infarction and poor long-term outcome. In a series of 272 consecutive, unselected patients with aortic dissection undergoing surgical treatment during a 25-year span (1963-1987), 128 (47 +/- 3% [+/- 70% confidence level (CL)]) had an acute type A dissection. A total of seven patients with acute type A dissection (2.6 +/- 1% of all patients, 5.5 +/- 2% of the acute type A cohort) developed a new stroke preoperatively. Thirteen (4.8 +/- 1%) patients had a diminished or absent carotid pulse, only four (31 +/- 13%) of whom sustained a stroke. One patient died in the immediate postoperative period due to severe brain injury, yielding an operative mortality rate of 14 +/- 14%. Two patients had persistent neurological deficits and died within 4 months of operation; the actuarial survival estimate at 1 year was 57 +/- 19% (mean +/- SEM). One patient recovered function of one upper extremity (preoperative left hemiparesis compounded by paraplegia) but died 6 years later. The remaining three long-term survivors (43 +/- 19%) had major resolution of their neurological deficits and are clinically well 2-8 years postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 2766534

• SURGICAL-MANAGEMENT OF ACUTE AORTIC DISSECTION COMPLICATED BY STROKE CIRCULATION Fann, J. I., Sarris, G. E., Miller, D. C., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Shumway, N. E. 1989; 80 (3): 257-263

  View details for Web of Science ID A1989AR92500030

• INHIBITION OF ACCELERATED CARDIAC ALLOGRAFT ARTERIOSCLEROSIS BY FISH OIL JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Sarris, G. E., Mitchell, R. S., Billingham, M. E., Glasson, J. R., CAHILL, P. D., Miller, D. C. 1989; 97 (6): 841-855

  Abstract

  Accelerated coronary arteriosclerosis remains the most important factor limiting long-term survival of heart transplant recipients, and dietary fish oil supplementation with omega-3 polyunsaturated fatty acids has been suggested to have a protective effect against coronary disease in epidemiologic studies and to inhibit arteriosclerosis in animal experiments. Therefore we tested the hypothesis that fish oil administration inhibits the development of allograft coronary arteriosclerosis by using a heterotopic heart transplant model. Three groups of Lewis rats (n = 10 each) received heterotopic heart transplants from Brown-Norway donors and were treated with cyclosporine intraperitoneally on a tapering schedule. Group 1 received fish oil daily by gavage (2 ml/kg/day; Emulsified Super MaxEpa, Twin Labs, Ronkonkona, N.Y.). Group 2 received an equal amount of safflower oil, as well as aspirin (1 mg/kg/day) and dipyridamole (3 mg/kg/day). Group 3 received safflower oil only. All rats were put to death 110 days later, at which time there was no statistically significant difference in graft function as assessed by palpation (scale 0 to 4, mean = 3.7 +/- 0.5 [+/- standard deviation]; analysis of variance: p = 0.72) or in microscopic grade of rejection (scale, 0 = none to 3 = severe, mean 2.1 +/- 0.6; analysis of variance: p = 0.68) between any of the groups. The coronary arteries were histologically scored for the degree of arteriosclerosis (scale, 0 = normal to 3 = occluded), and a mean grade of coronary disease was calculated for each heart. The fish oil-treated group had significantly less severe allograft coronary arteriosclerosis (analysis of variance: p = 0.005) than did groups 2 and 3 (mean grade 0.23 +/- 0.22 versus 1.04 +/- 0.75 and 0.96 +/- 0.55 (p less than 0.05, Scheffe F test), whereas groups 2 and 3 had similar degrees of coronary disease (p = no significant difference). These data demonstrate that fish oil supplementation inhibited accelerated coronary arteriosclerosis in this cyclosporine-treated heart allograft rat model, whereas antiplatelet agents in these doses were ineffective. Although the mechanism of this protective effect remains incompletely understood, it does not appear to involve enhanced immunosuppression. Fish oil and specific omega-3 polyunsaturated fatty acids should be further investigated as potentially useful agents to ameliorate accelerated allograft coronary arteriosclerosis in other animal species and perhaps eventually in man.

  View details for PubMedID 2657223

• REGIONAL VARIABILITY OF PROSTACYCLIN BIOSYNTHESIS ARTERIOSCLEROSIS Fann, J. I., CAHILL, P. D., Mitchell, R. S., Miller, D. C. 1989; 9 (3): 368-373

  Abstract

  To investigate the regional variability in arterial and venous endothelial prostacyclin (PGI2) biosynthesis, we obtained 1-cm segments of carotid arteries, external jugular veins, femoral arteries and veins, iliac arteries and veins, inferior venae cavae (IVC), and aortas from 17 dogs. Vessel luminal PGI2 production was measured in the basal state by radioimmunoassay of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha). A total of 90 arterial specimens (57, 19, and 14 segments, respectively, of femoral/carotid arteries, iliac arteries, and aorta) and 41 venous specimens (15, 10, and 16 segments, respectively, of femoral/jugular veins, iliac veins, and IVC) were analyzed. Overall, arterial endothelial 6-keto-PGF1 alpha was higher than venous (8.1 +/- 0.5 ng/ml vs. 4.9 +/- 0.7 ng/ml, p less than 0.0004); 6-keto-PGF1 alpha levels were greater in the arteries than in their corresponding veins [femoral/carotid arteries (6.3 +/- 0.4 ng/ml) vs. femoral/jugular vein (2.1 +/- 0.4 ng/ml), p less than 0.0002; iliac arteries (9.3 +/- 1.0 ng/ml) vs. iliac veins (4.8 +/- 0.9 ng/ml), p less than 0.005; aorta (14.0 +/- 1.6 ng/ml) vs. IVC (7.5 +/- 1.4 ng/ml), p less than 0.006].(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 2655571

• THE VASCULAR WAR OF 1988 JAMA-JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION Wexler, L., Ginsburg, R., Mitchell, R. S., MEHIGAN, J. T. 1989; 261 (3): 418-419

  View details for Web of Science ID A1989R767700031

  View details for PubMedID 2521257

• MEASUREMENT OF HEME CATABOLISM IN SHEEP UNDERGOING ECMO Fischer, A. F., Shochat, S. J., Mitchell, R. S., Chapman, S., Sheehan, A., Stevenson, D. K. SLACK INC. 1989: A202–A202

  View details for Web of Science ID A1989R585101185

• EFFECTS OF ASPIRIN, DIPYRIDAMOLE, AND COD LIVER OIL ON ACCELERATED MYOINTIMAL PROLIFERATION IN CANINE VENOARTERIAL ALLOGRAFTS ANNALS OF SURGERY DeCampli, W. M., Kosek, J. C., Mitchell, R. S., Handen, C. E., Miller, D. C. 1988; 208 (6): 746-754

  Abstract

  The effects of the administration of aspirin (ASA), dipyridamole (DPM), and cod liver oil (CLO) on graft patency rate and degree of intimal hyperplasia were investigated in a canine, hypercholesterolemic veno-arterial allograft model in an attempt to modify this immunologically mediated vascular injury. The drug regimens were ASA 1 mg/kg/day, DPM 10 mg/kg/day, combined ASA and DPM (ASA + DPM), and CLO (1.8 g/day eicosapentanoic acid [EPA] and 1.2 g/day docosahexanoic acid [DHA]), and control. The early angiographic patency rate (1-3 weeks) was 81% +/- 10% (+/- 70% confidence limits); the 90-day overall patency rate was 60% +/- 4% (87/144), with no statistically significant differences among the groups (range 46 +/- 10-71 +/- 9%). Qualitatively, there was no difference in luminal thrombus, intimal hemorrhage, or lesion eccentricity. Considering the relatively short time of graft implantation, an extensive amount of microscopic disease was observed; quantitatively, the mean intimal thickness was 515 +/- 17 microgram overall but was not statistically different between the groups. The fraction of potential lumenal area occupied by intimal thickening was 0.37 +/- 0.01 but again did not differ significantly between the groups. These doses of ASA, DPM, ASA + DPM, and CLO did not alter graft occlusion or retard the marked degree of subintimal myointimal cell hyperplasia that was generated in this hypercholesterolemic canine veno-arterial allograft preparation. Possible explanations for these negative findings include inadequate dosage or form of omega-3 fatty acids and the antiplatelet drugs administered, excessive variability in graft response due to uncharacterized immunologic histocompatibility, and the possible influence of non-platelet-mediated mechanisms. Nevertheless, this preparation is attractive as a reproducible model of accelerated (immunologically mediated) experimental arteriosclerosis.

  View details for PubMedID 3196097

• INHIBITION OF VEIN GRAFT INTIMAL THICKENING BY EICOSAPENTANOIC ACID - REDUCED THROMBOXANE PRODUCTION WITHOUT CHANGE IN LIPOPROTEIN LEVELS OR LOW-DENSITY LIPOPROTEIN RECEPTOR DENSITY JOURNAL OF VASCULAR SURGERY CAHILL, P. D., Sarris, G. E., Cooper, A. D., Wood, P. D., Kosek, J. C., Mitchell, R. S., Miller, D. C. 1988; 7 (1): 108-118

  Abstract

  Marine lipids containing omega-3 fatty acids (chiefly, eicosapentanoic acid [EPA] and docosahexanoic acid [DHA]) may inhibit the development of atherosclerotic vascular disease, but the mechanisms responsible for this putative beneficial effect are unknown. We investigated the effects of EPA and DHA in a canine model of accelerated vein graft arteriosclerosis during a 3-month period. Twenty-five dogs were divided into three dietary groups: group I (control), group II (2.5% cholesterol), and group III (2.5% cholesterol plus 2 gm EPA/day [as MaxEPA]). The effects of EPA on vein graft intimal thickening, platelet and vascular prostaglandin metabolism, lipid and lipoprotein receptor metabolism, and hematologic parameters were assessed. Cholesterol feeding caused a significant 54% increase in graft intimal thickness compared with control animals (124.9 +/- 50.4 vs 81.2 +/- 32.4 micron; p = 0.013), which was prevented by supplementation with EPA in group III (56.9 +/- 30.0 micron; p = 0.001 vs group II). Intimal thickness in group III was not significantly different from that of control. EPA supplementation was also associated with a 38% decline in serum thromboxane levels from 457.0 +/- 129.3 pg/0.1 ml in group II to 283.5 +/- 96.9 pg/0.1 ml in group III (p = 0.007). The alterations in lipoprotein metabolism associated with cholesterol feeding were not affected by EPA: in both groups II and III, serum cholesterol and high-density lipoproteins and liver cholesterol content were elevated and hepatic low-density lipoproteins (LDL) receptor content was reduced. There were no differences between the three groups in terms of vein graft or native vessel prostacyclin production, hematocrit, platelet count, or coagulation parameters. In this canine model, dietary supplementation with marine omega-3 fatty acids reduced the extent and magnitude of accelerated vein graft intimal thickening induced by hypercholesterolemia; moreover, this beneficial effect was associated with lower serum thromboxane production and appeared to be independent of alterations in lipoprotein metabolism or LDL receptor density.

  View details for PubMedID 3336117

• PROSTHETIC VALVE PERFORMANCE - HOW IMPORTANT IS VALVE TYPE - REPLY JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Mitchell, R. S. 1987; 94 (3): 455-456

  View details for Web of Science ID A1987J949600027

• PRIMARY CARDIAC NEOPLASMS - EARLY AND LATE RESULTS OF SURGICAL-TREATMENT IN 42 PATIENTS JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY DEIN, J. R., Frist, W. H., Stinson, E. B., Miller, C., Baldwin, J. C., Oyer, P. E., Jamieson, S., Mitchell, R. S., Shumway, N. E. 1987; 93 (4): 502-511

  Abstract

  Forty-two patients underwent resection of primary cardiac neoplasms at Stanford University Medical Center and the Palo Alto Veterans Administration Medical Center between 1961 and 1986. A total of 27 atrial myxomas, seven benign nonmyxomatous tumors, and eight malignant tumors were resected. The mean age was 47 years (range 8 to 79) in 27 female and 15 male patients. The clinical presentations included congestive heart failure in 24 patients, palpitations in nine, neurologic symptoms in six, recurrent cardiac tamponade in three, vasculitis in two, and chest pain in two. Thirty-one of 34 benign lesions were completely resected, although one patient required cardiac transplantation to resect completely an "inoperable" benign tumor. All gross tumor was resected in four of eight patients with malignant lesions. All patients survived operation, but three with malignant disease died within 30 days. Late outcome was known for 41 of 42 (98%) patients. Total follow-up for the series was 200.1 patient-years, for an average of 4.7 years (range 1 month to 18 years). Excellent early and late results were obtained in patients with benign lesions, as there was no known tumor recurrence even if resection was incomplete. Effective palliation and local control of disease is possible with extensive resection of malignant primary tumors, but more effective adjuvant therapy will be necessary to improve long-term prognosis.

  View details for Web of Science ID A1987G751000003

  View details for PubMedID 3560997

• PHARMACOLOGICAL, HEMATOLOGICAL, AND PHYSIOLOGICAL-EFFECTS OF A NEW THROMBOXANE SYNTHETASE INHIBITOR (CGS-13080) DURING CARDIOPULMONARY BYPASS IN DOGS ANNALS OF THORACIC SURGERY DeCampli, W. M., Goodwin, D., Kosek, J. C., Handen, C. E., Mitchell, R. S., Miller, D. C. 1986; 42 (6): 690-696

  Abstract

  The hematological and pharmacological effects of a new thromboxane synthetase inhibitor, CGS-13080 (imidazo[1,5-alpha]pyridine-5-hexanoic acid), were investigated during cardiopulmonary bypass in a blinded, randomized manner in dogs. Compared with placebo, CGS-13080 suppressed thrombin-stimulated platelet thromboxane B2 production by 90% during cardiopulmonary bypass (p less than .001), an effect that persisted for two hours after stopping the infusion. In the CGS-13080-treated group, plasma 6-keto-prostaglandin F1 alpha levels significantly increased over time (p less than .03) and were somewhat higher when compared with those in the placebo-treated group. This observation suggests that an "endoperoxide shunt" may have occurred. In the control group, an inverse correlation between platelet count and level of thromboxane B2 per platelet following in vitro thrombin stimulation (r = .5, p less than .001) was apparent, but there was no correlation between these two variables (r = .18, p less than .10) in the CGS-13080-treated group. No adverse hemodynamic or other effects attributable to CGS-13080 occurred during or immediately following cardiopulmonary bypass. These results suggest that CGS-13080 is an effective inhibitor of thromboxane B2 production during cardiopulmonary bypass in dogs and has no adverse physiological effects.

  View details for Web of Science ID A1986F174300017

  View details for PubMedID 3789860

• INVASIVE CALCIFIC CONSTRICTIVE PERICARDITIS SIMULATING A LEFT-VENTRICULAR MASS AMERICAN HEART JOURNAL Schwartz, A. B., Mitchell, R. S., Higgins, C. B., Lipton, M. J., KLAUSNER, S. C. 1986; 112 (4): 861-863

  View details for Web of Science ID A1986E308500035

  View details for PubMedID 3766392

• A RECONSIDERATION OF CEREBRAL PERFUSION IN AORTIC-ARCH REPLACEMENT ANNALS OF THORACIC SURGERY Frist, W. H., Baldwin, J. C., Starnes, V. A., Stinson, E. B., Oyer, P. E., Miller, D. C., Jamieson, S. W., Mitchell, R. S., Shumway, N. E. 1986; 42 (3): 273-281

  Abstract

  Ten patients underwent aortic arch replacement for aneurysmal disease from 1970 to 1985 using a simplified cardiopulmonary bypass (CPB) technique with partial brachiocephalic perfusion, low CPB flow (30 to 50 ml/kg/min), moderate systemic cooling (26 degrees to 28 degrees C), and topical hypothermic myocardial protection. The arterial line from a single pump head has a Y shape to perfuse the femoral artery (20F cannula) and either the innominate or left carotid artery (14F). Of the 10 patients (mean age, 58 years) with arch aneurysm (6 atherosclerotic, 2 dissections, and 2 degenerative), 3 had previously undergone major cardiovascular operations. Concomitant procedures included aortic valve replacement in 4 and coronary artery bypass grafting in 3. Eight patients survived the procedure, and 1 died three weeks after operation of a ruptured abdominal aneurysm. Among the survivors, CPB time was 119 +/- 36 minutes (+/- standard deviation), myocardial ischemia time was 79 +/- 32 minutes, and intraoperative blood requirement was 5.9 +/- 3.4 units. There were no postoperative strokes. Neurological complications were only minor and included an asymptomatic miosis and ulnar nerve paresthesias in 1 patient and transient vocal cord palsy in another. Applicable in most patients undergoing elective resection of degenerative and atherosclerotic arch aneurysms and in selected patients with arch dissections, this simplified technique of brachiocephalic perfusion without circulatory arrest provides an attractive and safe alternative; the potential advantages are technical simplicity, reduced CPB and operating times, and satisfactory cerebral protection.

  View details for Web of Science ID A1986E046200010

  View details for PubMedID 3489444

• VALVULAR-VENTRICULAR INTERACTION - IMPORTANCE OF THE MITRAL APPARATUS IN CANINE LEFT-VENTRICULAR SYSTOLIC PERFORMANCE CIRCULATION Hansen, D. E., CAHILL, P. D., DeCampli, W. M., HARRISON, D. C., Derby, G. C., Mitchell, R. S., Miller, D. C. 1986; 73 (6): 1310-1320

  Abstract

  As the mitral valvular apparatus tenses during systole, forces transmitted along the chordae tendineae to the left ventricular chamber may influence left ventricular performance. To test this hypothesis, 10 dogs anesthetized with fentanyl were studied during cardiopulmonary bypass. The importance of the mitral apparatus in left ventricular systolic function was assessed independent of load by means of the slope of the contractile state-dependent left ventricular peak isovolumetric pressure-volume relationship (Emax), which was measured at constant heart rate and aortic pressure with a micromanometer inside a left ventricular intracavitary balloon before and immediately after all chordae tendineae were severed. Herniation of the balloon was prevented by a disk secured to the mitral anulus. Emax decreased from 11.97 +/- 3.35 (+/- SD) to 6.38 +/- 0.96 mm Hg/ml (p less than .001) with chordal severing. The volume intercept (Vo) was unchanged. Fluoroscopic studies of the balloon contour in eight additional dogs revealed dyskinesia in the area of the papillary muscle insertion and substantial alterations in chamber geometry during systole after the chordae were severed. Accordingly, we conclude that global left ventricular systolic performance is impaired when chordal attachments of the mitral valve are disrupted. Changes in left ventricular geometry or loss of inward force normally transmitted to the left ventricular wall as the valve tense may underlie these changes. These findings suggest that postoperative left ventricular dysfunction after mitral valve replacement may be attributable, in part, to excision of the native mitral apparatus at the time of surgery and support efforts to spare chordae during mitral valve surgery.

  View details for Web of Science ID A1986C525700028

  View details for PubMedID 3698258

• SIGNIFICANT PATIENT-RELATED DETERMINANTS OF PROSTHETIC VALVE PERFORMANCE JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Mitchell, R. S., Miller, D. C., Stinson, E. B., Oyer, P. E., Jamieson, S. W., Baldwin, J. C., Shumway, N. E. 1986; 91 (6): 807-817

  Abstract

  With rare exception, the bulk of out knowledge concerning the performance of any particular valve substitute originates from one institution; thus, if valve-related complications are more a function of the patient substrate undergoing operation than the prosthesis per se, the usefulness of inter-institutional comparisons would be severely limited. To address this question, the outcome of 2,719 patients after mitral or aortic valve replacement over 12,955 patient-years of follow-up was analyzed by time-dependent multivariate statistical methods with respect to thromboembolic events, anticoagulant-related hemorrhage, valve failure, fatal valve failure, all valve-related morbidity and mortality, necessity for reoperation, and late survival. Many patient-related factors were significant predictors of the probability of certain patient groups for sustaining these valve-related complications. Hence, comparisons of results of valve performance from different institutions may be misleading unless patient populations are comparable.

  View details for Web of Science ID A1986C716600001

  View details for PubMedID 3713234

• TIMING OF ABNORMAL INTERVENTRICULAR SEPTAL MOTION AFTER CARDIOPULMONARY BYPASS OPERATIONS - LACK OF INJURY PROVED BY PREOPERATIVE, INTRAOPERATIVE, AND POSTOPERATIVE ECHOCARDIOGRAPHY JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Schnittger, I., Keren, A., Yock, P. G., Allen, M. D., Modry, D. L., Zusman, D. R., Mitchell, R. S., Miller, D. C., Popp, R. L. 1986; 91 (4): 619-623

  Abstract

  Abnormal interventricular septal motion after cardiopulmonary bypass is a widely known occurrence. The cause and exact timing of this phenomenon remain unclear. We have studied 21 patients prospectively with preoperative, intraoperative, and postoperative two-dimensional and M-mode echocardiograms. Intraoperative studies were obtained with the pericardium closed and open and after completion of procedures performed with cardiopulmonary bypass. Fourteen patients had coronary artery bypass graft operations alone. Six patients had valve replacement with or without coronary bypass, and one patient had removal of a left atrial myxoma. All patients had normal interventricular septal motion before the operation, and none had abnormal septal motion intraoperatively. Four to eight days postoperatively, the septum still thickened normally in all patients, with five patients having normal, nine patients abnormal, and seven patients paradoxical interventricular septal motion. Studies in 11 patients 1 to 4 months postoperatively showed no change from the early postoperative study. The pericardium was left open postoperatively in all patients. Six patients were studied a few hours after sternal closure and all had abnormal interventricular septal motion. We conclude that abnormal interventricular septal motion after cardiac operations is not due to injury of the septum, adhesion formation, or loss of pericardial constraint. Closure of the chest wall itself, with the pericardium left open, is associated with this abnormality.

  View details for Web of Science ID A1986A823600019

  View details for PubMedID 3959582

• IMPORTANCE OF THE ANTERIOR AND POSTERIOR MITRAL CHORDAE ON GLOBAL LEFT-VENTRICULAR SYSTOLIC FUNCTION Hansen, D. E., CAHILL, P. D., DeCampli, W. M., HARRISON, D. C., HANDEN, C., Derby, G., Mitchell, R. S., Miller, D. C. ELSEVIER SCIENCE INC. 1986: A249–A249

  View details for Web of Science ID A1986A165000992

• PROSTHETIC GRAFT INFECTION - LIMITATIONS OF INDIUM WHITE BLOOD-CELL SCANNING JOURNAL OF VASCULAR SURGERY Brunner, M. C., Mitchell, R. S., Baldwin, J. C., James, D. R., Olcott, C., MEHIGAN, J. T., McDougall, I. R., Miller, D. C. 1986; 3 (1): 42-48

  Abstract

  The lack of a rapid, noninvasive, and accurate method to confirm or rule out prosthetic graft infection continues to constitute a compelling and vexing clinical problem. A host of adjunctive diagnostic techniques has been used in the past, but early promising results subsequently have usually not yielded acceptable sensitivity (reflecting false negatives) and specificity (reflecting false positive) data. White blood cell (WBC) indium 111 scanning has recently been added to this list. The utility and accuracy of 111In WBC scans were assessed by retrospective review of WBC scan results in 70 patients undergoing evaluation for possible prosthetic graft infection over a 7-year period. Operative and autopsy data (mean follow-up, 18 months for survivors with negative scans) were used to confirm the 22 positive, 45 negative, and three equivocal WBC scans. The false positive rate (+/- 70% confidence limits) was 36% +/- 6% (n = 8) among the 22 patients with positive scans (44% +/- 6% [11 of 25] if the three equivocal scans are included as false positive), yielding a specificity of 85% +/- 5% and an overall accuracy rate of 88% +/- 4% (80% +/- 5% and 84% +/- 5%, respectively, if the three equivocal cases are considered as false positive). All three patients with equivocal scans ultimately were judged not to have prosthetic graft infection. As implied by the high accuracy rate, the sensitivity of the test was absolute (100% [14 of 14]); there were no false negative results. (ABSTRACT TRUNCATED AT 250 WORDS)

  View details for Web of Science ID A1986AYC3400005

  View details for PubMedID 3079840

• Acute and chronic aortic dissections--determinants of long-term outcome for operative survivors. Circulation Haverich, A., Miller, D. C., Scott, W. C., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Shumway, N. E. 1985; 72 (3): II22-34

  Abstract

  A total of 135 survivors of surgical treatment of aortic dissection was followed for up to 15 years after surgery. Actuarial survival rates were 82 +/- 4% at 5 years and 64 +/- 6% at 10 years. There were no significant differences in long-term survival rates of patients in four subsets based on type and acuity of dissections. The incidence of late reoperation (dissection-related) was 13 +/- 4% at 5 years and 23 +/- 6% at 10 years; again, there was no significant difference among patients with different types or acuity of dissection. Multiple variables were investigated by multivariate discriminant analysis. Significant independent risk factors for late death included stroke, chronic renal dysfunction, remote myocardial infarction, and operation in the early years of this study. Younger age, site of intimal tear (arch), and cardiac tamponade portended a significantly higher likelihood of late reoperation. Except for stroke, no complication of the dissection or intraoperative factor significantly influenced late survival. Patients in whom the intimal tear was located in the aortic arch had the highest probability of late reoperation. Thus, dissection type, acuity, and distal extent, whether or not the tear was resected or concomitant aortic valve replacement performed, and a host of patient-related characteristics had no significant influence on the generally excellent long-term prognosis after surgical treatment. Indefinite surveillance of the remaining natural aorta is imperative (with reoperation when indicated) to attain such results.

  View details for PubMedID 3928189

• Effect of early postoperative volume loading on left ventricular systolic function (including left ventricular ejection fraction determined by myocardial marker) after myocardial revascularization. Circulation Miller, D. C., Daughters, G. T., Derby, G. C., Mitchell, R. S., Ingels, N. B., Stinson, E. B., Alderman, E. L. 1985; 72 (3): II207-15

  Abstract

  The effects of early volume loading in terms of isovolumetric-phase and ejection-phase indexes of left ventricular systolic function were studied in 12 patients 5 hr after myocardial revascularization, with myocardial markers used to measure left ventricular volume directly and with simultaneous transmural left ventricular pressure measurements by micromanometers. Volume loading (increasing transmural left ventricular end-diastolic pressure from 11 +/- 4 to 15 +/- 5 mm Hg) induced a significant 14% increase in left ventricular end-diastolic volume index (LVEDVI), which was associated (as expected) with significant (p less than .005) augmentation of stroke work (+26%), left ventricular pressure-volume loop area (+35%), and stroke volume index (+22%) and with increments in left ventricular dP/dt and mean velocity of circumferential fiber shortening despite a simultaneous increase in left ventricular afterload. In contrast to previous radionuclide studies, however, left ventricular ejection fraction increased significantly (+9%) and the left ventricular end-systolic pressure-volume ratio did not fall. The relative change in ejection fraction was directly proportional to the increment in LVEDVI (r = .54, p = .03) and inversely related to the change in left ventricular end-systolic volume index (r = -.71, p = .0005). Patients who demonstrated a small or no increase in ejection fraction generally had a larger simultaneous increase in afterload, but one patient exhibited exhaustion of preload reserve. Ejection fraction, as an ejection-phase index of left ventricular performance, is highly dependent on afterload; therefore, interpretation of postoperative changes in ejection fraction must be undertaken only with strict caution.(ABSTRACT TRUNCATED AT 250 WORDS)

  View details for PubMedID 3896554

• Operative risk of mitral valve replacement: discriminant analysis of 1329 procedures. Circulation Scott, W. C., Miller, D. C., Haverich, A., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Jamieson, S. W., Baldwin, J. C., Shumway, N. E. 1985; 72 (3): II108-19

  Abstract

  The influence of 34 variables on the operative mortality rate for isolated mitral valve replacement (MVR) was assessed by univariate and multivariate logistic regression analysis. The physiologic lesions were classified as stenosis (20%, operative mortality rate 8 +/- 1%), regurgitation (44%, operative mortality rate 13 +/- 2%), and mixed (34%, operative mortality rate 8 +/- 1%). Functional class (NYHA), previous myocardial infarction, and hepatic dysfunction were powerful independent clinical determinants of operative mortality (p less than .001), along with age at operation and emergency operation (p = .001, p = .04). Concomitant coronary artery bypass grafting or tricuspid annuloplasty, angina, ischemic etiology, and physiologic lesion were not significant independent determinants of operative risk. Interestingly, year of operation, prosthetic valve dysfunction, and previous cardiac surgery had no important effect on operative mortality. Early operative risk for MVR was related to preoperative cardiac and hepatic function. Prior myocardial infarction substantially increased the risk even if the mitral valve disease was not ischemic in origin. Increased operative mortality rate in the subgroup with mitral regurgitation was related to advanced left ventricular failure and myocardial infarction rather than the etiology of the mitral regurgitation. These clinical factors coupled with more refined measurements of left ventricular systolic pump function (independent of loading conditions) should permit more intelligent decision making regarding the optimal timing of MVR, at least in terms of early operative risk.

  View details for PubMedID 4028353

• WHEN IS DOPPLER-DETERMINED VALVE AREA BETTER THAN THE GORLIN FORMULA SEGAL, J., LERNER, D. J., ALDERMAN, E. L., MILLER, D. C., MITCHELL, R. S., POPP, R. L. AMER HEART ASSOC. 1985: 145

  View details for Web of Science ID A1985ARW1100581

• VALVE-REPLACEMENT IN PATIENTS WITH NATIVE VALVE ENDOCARDITIS - WHAT REALLY DETERMINES OPERATIVE OUTCOME ANNALS OF THORACIC SURGERY DAGOSTINO, R. S., Miller, D. C., Stinson, E. B., Mitchell, R. S., Oyer, P. E., Jamieson, S. W., Baldwin, J. C., Shumway, N. E. 1985; 40 (5): 429-438

  Abstract

  The influence of 27 variables on operative mortality and late complications (defined as residual or recurrent endocarditis or late bland periprosthetic leak) was determined using discriminant analysis for 108 patients undergoing valve replacement for native valve endocarditis at Stanford University Medical Center from March, 1964, to January, 1983. Congestive heart failure was the indication for valve replacement in 86% of patients. Aortic valve replacement was required in 68% and mitral valve replacement, in 26%. Patients were arbitrarily defined as having active (58%) or healed (42%) endocarditis. Follow-up included 515 patient-years and extended to a maximum of 19 years. Operative mortality was 15 +/- 4%, and 17 patients had late complications (linearized rate, 3.3% per patient-year). Seven variables were significantly related to operative mortality in the univariate analysis, but only organism (Staphylococcus aureus versus all others, p = 0.0302) was a significant independent predictor of operative mortality. For late complications, only 2 of 7 significant univariate covariates proved to be significant independent determinants: organisms on valve culture or gram stain and the presence of annular abscess. Patients with S. aureus endocarditis not showing prompt response to antibiotic treatment must be considered for early operation. Similarly, timely operative intervention for patients with annular abscess will be essential in decreasing late valve infections and perivalvular leaks.

  View details for Web of Science ID A1985AUP5300004

  View details for PubMedID 4062397

• PERCUTANEOUS TRANS-LUMINAL LASER ANGIOPLASTY FOR TREATMENT OF PERIPHERAL VASCULAR-DISEASE - CLINICAL-EXPERIENCE WITH 16 PATIENTS RADIOLOGY Ginsburg, R., Wexler, L., Mitchell, R. S., Profitt, D. 1985; 156 (3): 619-624

  Abstract

  Percutaneous transluminal laser angioplasty of the peripheral arteries was performed in 16 patients with pain at rest, objective evidence of severe peripheral ischemia, conditions requiring amputation, and/or medical contraindications to surgery. In 14 patients the ipsilateral femoral artery was entered in an antegrade direction using the Seldinger technique, base-line angiograms taken, and laser angioplasty performed using argon ions transported to the target site by a 400-mu quartz fiber. Patency was established in 50% of cases and correlated directly with both total energy delivered and time and power per exposure: the lower the energy, the higher the patency rate. Complications included spasm, pain, and mechanical or laser perforation. The authors conclude that while percutaneous transluminal laser angioplasty of peripheral arteries using argon radiation is possible in man, its clinical value has not been established.

  View details for Web of Science ID A1985ANZ9200008

  View details for PubMedID 3161118

• DETERMINANTS OF OPERATIVE MORTALITY FOR PATIENTS UNDERGOING AORTIC-VALVE REPLACEMENT - DISCRIMINANT-ANALYSIS OF 1,479 OPERATIONS JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Scott, W. C., Miller, D. C., Haverich, A., Dawkins, K., Mitchell, R. S., Jamieson, S. W., Oyer, P. E., Stinson, E. B., Baldwin, J. C., Shumway, N. E. 1985; 89 (3): 400-413

  Abstract

  The influence of 35 preoperative and intraoperative characteristics on operative mortality risk after 1,479 isolated aortic valve replacement procedures (1967 to 1981) was investigated utilizing univariate and multivariate logistic regression analyses. Mean age at operation was 58 +/- 13 years; 72% of patients were men. Physiology was classified as aortic stenosis (58%), regurgitation (30%), or both (9%). The overall operative mortality rate was 7% +/- 1%, but there were substantial differences in operative mortality rates among physiological subgroups (aortic regurgitation, 10% +/- 2%; aortic stenosis, 6% +/- 1%; stenosis/regurgitation, 5% +/- 2%). Independent determinants of operative mortality rate in the entire group were advanced New York Heart Association functional class, renal dysfunction, physiological subgroup, atrial fibrillation, and older age. In the aortic regurgitation subgroup, functional class, atrial fibrillation, and operative year were independent predictors. In the aortic stenosis subgroup, the significant determinants were functional class, renal dysfunction, age, prosthetic valve dysfunction, and absence of angina. Concomitant coronary bypass grafting, previous operation, endocarditis, and ascending aortic replacement had no independent predictive effect on operative mortality rate. Thus, the early results of aortic valve replacement can be related to several specific variables describing the functional and physiological status of the patient. Operative mortality rate is not independently related to previous operation or concomitant operative procedures. Specific differences in risk factors exist among the various physiological subgroups, probably reflecting the pathophysiology of the different hemodynamic lesions. This information should provide for a more rational approach to aortic valve replacement, at least in terms of early risk/benefit deliberations.

  View details for Web of Science ID A1985ADH6100009

  View details for PubMedID 3974275

• EFFECT OF EARLY POSTOPERATIVE VOLUME LOADING ON LEFT-VENTRICULAR SYSTOLIC FUNCTION (INCLUDING LEFT-VENTRICULAR EJECTION FRACTION DETERMINED BY MYOCARDIAL MARKER) AFTER MYOCARDIAL REVASCULARIZATION CIRCULATION Miller, D. C., Daughters, G. T., Derby, G. C., Mitchell, R. S., Ingels, N. B., Stinson, E. B., Alderman, E. L. 1985; 72 (3): 207-215

  View details for Web of Science ID A1985APY7900032

• ACUTE AND CHRONIC AORTIC DISSECTIONS - DETERMINANTS OF LONG-TERM OUTCOME FOR OPERATIVE SURVIVORS CIRCULATION Haverich, A., Miller, D. C., Scott, W. C., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Shumway, N. E. 1985; 72 (3): 22-34

  View details for Web of Science ID A1985APY7900005

• OPERATIVE RISK OF MITRAL-VALVE REPLACEMENT - DISCRIMINANT-ANALYSIS OF 1329 PROCEDURES CIRCULATION Scott, W. C., Miller, D. C., Haverich, A., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Jamieson, S. W., Baldwin, J. C., Shumway, N. E. 1985; 72 (3): 108-119

  View details for Web of Science ID A1985APY7900017

• SEVERING THE CHORDAE TENDINEAE REDUCES LEFT-VENTRICULAR SYSTOLIC PERFORMANCE IN DOGS Hansen, D. E., DeCampli, W. M., Mitchell, R. S., Derby, G. C., Miller, D. C. LIPPINCOTT WILLIAMS & WILKINS. 1985: 485–85

  View details for Web of Science ID A1985ARW1101940

• CRITICAL-EVALUATION OF 111-IN-WHITE CELL SCAN FOR DIAGNOSING PROSTHETIC GRAFT INFECTION McDougall, I. R., Brunner, M. C., Mitchell, R. S., Baldwin, J. C., James, D. R., Olcott, C., MEHIGAN, J. T., Miller, D. C. LIPPINCOTT-RAVEN PUBL. 1985: P18–P18

  View details for Web of Science ID A1985ARV0700035

• Independent determinants of operative mortality for patients with aortic dissections. Circulation Miller, D. C., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Jamieson, S. W., Shumway, N. E. 1984; 70 (3): I153-64

  Abstract

  A 20 year (1963 to 1982) surgical experience including 175 consecutive patients with aortic dissections was analyzed by logistic discriminant analyses to identify predictors of high operative risk. The patient population had characteristics similar to those in large autopsy series. Sixty-nine percent had type A and 58% had acute dissections. The intimal tear was located in the ascending aorta in 60% of the patients, the descending aorta in 27%, and the transverse arch in 13%. The overall operative mortality rate was 23 +/- 3%. The operative mortality rates were substantially lower between 1977 and 1982: mortality in patients with acute type A dissections, 7 +/- 5%; in those with chronic type A, 11 +/- 7%; in those with acute type B, 13 +/- 12%; and in those with chronic type B, 11 +/- 11%. After preliminary univariate screening, the following factors were determined to be significant independent predictors of operative mortality (in rank order of declining predictive power): type A patients (n = 121), renal dysfunction, tamponade, renal/visceral ischemia, and operative date; type B patients (n = 54), rupture, renal/visceral ischemia, and age; all patients (n = 175), renal dysfunction, renal/visceral ischemia, site of tear (ascending less than descending less than arch), tamponade, operative date, and pulmonary disease. Interestingly, several variables had no important bearing on operative mortality, including type (acute vs chronic) of dissection, age, previous operation, rupture, stroke, paraplegia, Marfan's syndrome, concomitant aortic valve replacement and/or coronary artery bypass grafting, site of tear, and whether or not the tear was resected in type A patients; emergency operation, hypertension, previous cardiac symptoms, paraplegia, site of tear, and resection of tear in type B patients; and, when all patients were considered together, age, sex, cardiac symptoms, prior operation, stroke, paraplegia, acute myocardial infarction, acute aortic regurgitation, Marfan's syndrome, and tear resection. These data allow calculation of any individual patient's operative risk and document that the operative mortality rate today is relatively low for all patients with aortic dissections, irrespective of type or acuity. Earlier surgical referral of patients with acute type A or acute type B dissection before irreversible major end-organ ischemia and/or infarction is probably in part responsible for the substantially improved results since 1977.

  View details for PubMedID 6235061

• Dobutamine and dopamine after cardiac surgery: greater augmentation of myocardial blood flow with dobutamine. Circulation Fowler, M. B., Alderman, E. L., Oesterle, S. N., Derby, G., Daughters, G. T., Stinson, E. B., Ingels, N. B., Mitchell, R. S., Miller, D. C. 1984; 70 (3): I103-11

  Abstract

  Left ventricular hemodynamics, dimensions and coronary sinus blood flows were measured simultaneously after infusions of dobutamine and dopamine. Ten patients were studied 6, 10 to 15, and 24 hr after cardiopulmonary bypass surgery. The dose of each drug was adjusted to increase cardiac output by 25%. Heart rate was held constant with atrial pacing. Dobutamine and dopamine increased peak left ventricular dP/dt from baseline values by 72% vs 58% during the early study, 77% vs 78% in the intermediate study, and 95% vs 79% in the late study (all NS, difference between drugs). Similarly, there were no significant differences in hemodynamic response or in cardiac dimensions after the two drugs in any period. Both drugs increased myocardial oxygen uptake during the intermediate and late studies (32% vs 33% and 34% vs 25%). With dobutamine this increase was matched by a similar increase in coronary blood flow; however, failure of the expected increase in coronary blood flow with dopamine suggested coronary constriction. Although dobutamine and dopamine have similar hemodynamic effects, dobutamine has the advantage of not limiting the increase in coronary blood flow associated with increased oxygen demand.

  View details for PubMedID 6744557

• DOBUTAMINE AND DOPAMINE AFTER CARDIAC-SURGERY - GREATER AUGMENTATION OF MYOCARDIAL BLOOD-FLOW WITH DOBUTAMINE CIRCULATION Fowler, M. B., Alderman, E. L., Oesterle, S. N., Derby, G., Daughters, G. T., Stinson, E. B., Ingels, N. B., Mitchell, R. S., Miller, D. C. 1984; 70 (3): 103-111

  View details for Web of Science ID A1984TF85700018

• LYMPHOMA OF THE HEART CATHETERIZATION AND CARDIOVASCULAR DIAGNOSIS WONG, D. W., GUTHANER, D. F., Gordon, E. P., Mitchell, R. S. 1984; 10 (4): 377-384

  Abstract

  A case of malignant lymphoma involving the heart is reported. The patient presented with symptoms of cardiac decompensation. The echocardiographic findings of an echogenic mass arising from the pulmonary valve as well as demonstration of soft tissue density diffusely infiltrating the heart and mediastinum was confirmed by computer tomography and angiography. Although the findings on the noninvasive studies were highly indicative of tumor involvement, the temporal association of the symptoms to a motor vehicle accident lead to the erroneous diagnosis of intracardiac and mediastinal hematoma.

  View details for Web of Science ID A1984TM41100010

  View details for PubMedID 6386175

• THROMBOEMBOLIC RISK AND DURABILITY OF THE HANCOCK BIOPROSTHETIC CARDIAC-VALVE EUROPEAN HEART JOURNAL Oyer, P. E., Stinson, E. B., Miller, D. C., Jamieson, S. W., Mitchell, R. S., Shumway, N. E. 1984; 5: 81-85

  View details for Web of Science ID A1984ACF9100015

  View details for PubMedID 6519106

• DEGENERATIVE AND ATHEROSCLEROTIC ANEURYSMS OF THE THORACIC AORTA - DETERMINANTS OF EARLY AND LATE SURGICAL OUTCOME JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY MORENOCABRAL, C. E., Miller, D. C., Mitchell, R. S., Stinson, E. B., Oyer, P. E., Jamieson, S. W., Shumway, N. E. 1984; 88 (6): 1020-1032

  Abstract

  To identify significant predictors of early and late mortality, multivariate discriminant analyses were applied to the clinical outcome of 175 consecutive patients with thoracic aortic aneurysms operated upon over a 20 year span. Only atherosclerotic and degenerative aneurysms were included; the patients were segregated into two groups according to location of the aneurysm. The ascending aortic aneurysm group consisted of 124 patients, 85% of whom required concomitant aortic valve replacement. There were 51 patients in the descending aortic aneurysm group. Mean follow-up was 4.9 years (maximum of 19 years), with a total of 860 patient-years of follow-up. Multivariate analyses revealed that surgical priority and advanced age were independent determinants of hospital mortality in the ascending group; for the descending group, surgical priority and the presence of congestive heart failure were the strongest predictors of hospital mortality. Late mortality in the ascending group correlated with advanced age. Hypertension and the presence of preoperative congestive heart failure were independent determinants of late mortality in the descending group. Several variables did not have any independent bearing on hospital or late mortality, including etiology and location of the aneurysm, previous myocardial infarction, chronic lung disease, and concomitant aortic valve replacement. High-risk subgroups of patients with thoracic aortic aneurysms can be identified by these variables. Aggressive medical plus surgical management and operation prior to aneurysm rupture is necessary to improve both early and long-term survival rates.

  View details for Web of Science ID A1984TV42000015

  View details for PubMedID 6503314

• PERFORMANCE-CHARACTERISTICS OF THE STARR-EDWARDS MODEL 1260 AORTIC-VALVE PROSTHESIS BEYOND 10 YEARS JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Miller, D. C., Oyer, P. E., Mitchell, R. S., Stinson, E. B., Jamieson, S. W., Baldwin, J. C., Shumway, N. E. 1984; 88 (2): 193-207

  Abstract

  The Starr-Edwards non-cloth-covered silicone ball (Model 1260) aortic valve prosthesis has been widely used for over 15 years and remains a standard against which newer values are compared. To define more completely the performance characteristics of this prosthesis, this study (including 449 patients) analyzed the long-term function of this specific valve over a cumulative total of 2,896 patient-years (pt-yrs) of follow-up which extended beyond 13 years. Expressed in both actuarial (% [+/- standard error of the mean] free at 10 years) and linearized (%/pt-yr) terms, respectively, valve-related complications occurred at the following rates: thromboembolism, 76 +/- 3 and 2.7; anticoagulant-related hemorrhage, 74 +/- 3 and 3.1; prosthetic valve endocarditis, 92 +/- 2 and 0.9; reoperation, 90 +/- 2 and 1.1; valve failure, 82 +/- 2 and 2.2; all valve-related morbidity and mortality, 51 +/- 3 and 6.0; and valve-related death, 88 +/- 2 and 1.3. Thirteen percent of hospital and 18% of late deaths were due to valve-related causes. No case of structural failure was documented. This prosthesis has an admirable structural durability record out to 13 years, and its long-term performance is satisfactory, albeit not optimal. Despite the indestructable design and construction of this mechanical valve substitute, 12% +/- 2% of patients had died of valve-related complications by 10 years, and fully 49% +/- 3% had had some form of serious valve-related complication. The long-term data reported herein can be used for analytical comparison when follow-up of patients with newer mechanical prostheses and tissue bioprostheses reaches 10 years to elucidate whether or not these newer valves truly represent improvements and which type of valve substitute proffers the most possible net benefit to the patient.

  View details for Web of Science ID A1984TE45900006

  View details for PubMedID 6748713

• INDEPENDENT DETERMINANTS OF OPERATIVE MORTALITY FOR PATIENTS WITH AORTIC DISSECTIONS CIRCULATION Miller, D. C., Mitchell, R. S., Oyer, P. E., Stinson, E. B., Jamieson, S. W., Shumway, N. E. 1984; 70 (3): 153-164

  View details for Web of Science ID A1984TF85700025

• INDEPENDENT DETERMINANTS OF OPERATIVE MORTALITY FOR PATIENTS WITH AORTIC DISSECTIONS Miller, D. C., Oyer, P. E., Mitchell, R. S., Stinson, E. B., Jamieson, S. W., Shumway, N. E. AMER HEART ASSOC. 1983: 15–15

  View details for Web of Science ID A1983RJ59300069

• Ten to fifteen year reassessment of the performance characteristics of the Starr-Edwards Model 6120 mitral valve prosthesis. journal of thoracic and cardiovascular surgery Miller, D. C., Oyer, P. E., Stinson, E. B., Reitz, B. A., Jamieson, S. W., Baumgartner, W. A., Mitchell, R. S., Shumway, N. E. 1983; 85 (1): 1-20

  View details for PubMedID 6848878

• ANEURYSM OF THE DIVERTICULUM OF THE DUCTUS-ARTERIOSUS IN THE ADULT - SUCCESSFUL SURGICAL-TREATMENT IN 5 PATIENTS AND REVIEW OF THE LITERATURE JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Mitchell, R. S., Seifert, F. C., Miller, D. C., Jamieson, S. W., Shumway, N. E. 1983; 86 (3): 400-408

  Abstract

  Sixteen aneurysms of the diverticulum of the ductus arteriosus in adults have been previously reported. Ten patients died of rupture of the aneurysm or died at surgical exploration. Only one previous patient underwent successful aneurysmectomy. Five new cases of aneurysm of the adult ductal diverticulum, all diagnosed preoperatively and successfully repaired, are presented. All five patients are alive 6 to 33 months postoperatively. Our experience with these patients suggests several important features of these aneurysms: (1) Diagnosis may be difficult and may require multiple-view aortography or computed tomographic (CT) scanning to differentiate from tumor. (2) The operative approach, either left thoracotomy or median sternotomy, may be determined by the necessity for concomitant procedures. (3) Unlike true atherosclerotic aneurysms of the aortic arch, these aneurysms can be repaired effectively by aneurysmorrhaphy. (4) Because of their critical location and the high incidence of complications in reported cases, aneurysms greater than 3 cm in diameter, those producing symptoms, or those showing progressive enlargement should be surgically resected.

  View details for Web of Science ID A1983RG46200010

  View details for PubMedID 6604198

• DISCRIMINANT-ANALYSIS OF THE CHANGING RISKS OF CORONARY-ARTERY OPERATIONS - 1971-1979 JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Miller, D. C., Stinson, E. B., Oyer, P. E., Jamieson, S. W., Mitchell, R. S., Reitz, B. A., Baumgartner, W. A., Shumway, N. E. 1983; 85 (2): 197-213

  Abstract

  The risk of perioperative myocardial infarction (PMI) and operative mortality (OM) associated with coronary artery bypass grafting (CABG) has declined since the introduction of this procedure 15 years ago. Rigorous scientific investigation of the reasons for this trend has been hindered by the complex interactions between changing indications for operation, criteria for patient selection, and management methods. Using univariate and multivariate logistic regression analyses, we investigated the effects of 42 variables on PMI and OM for two cohorts undergoing CABG between 1971 and 1975 (Group A) and 1977 and 1979 (Group B). According to previously identified risk factors, Group B patients were at higher potential risk than those in Group A. Nevertheless, the PMI and OM rates declined from 8.7% +/- 0.9% to 4.6% +/- 0.7% (p = 0.005) and from 2.4% +/- 0.5% to 1.2% +/- 0.4% (p = 0.07), respectively. In calendar year 1979 (N = 438), the PMI and OM rates were 2.8% +/- 0.8% and 0.7% +/- 0.4%. More importantly, the independent determinants of PMI and OM for the two time intervals were distinctly different. Factors which affected the PMI rate in Group A were no longer determinants of PMI in Group B; with the exception of emergency operation and, to a modest extent, congestive heart failure (CHF), predictors of OM in Group A were not determinants of OM in Group B. Thus the adverse impact of multiple patient-related and disease-related determinants of PMI and OM has been neutralized over this decade by the real improvements in patient management. The specific factors and management concepts responsible for these superior results in sicker patients remain uncharacterized; however, in general terms, more sophisticated medical, anesthetic, and nursing management and more refined surgical expertise have essentially nullified the concept of high-risk candidates. Furthermore, the more propitious early results being attained currently may translate directly into parallel long-term improvements in functional benefit and survival.

  View details for Web of Science ID A1983QC22500005

  View details for PubMedID 6600507

• PULMONARY-ARTERY SURGICAL ANEURYSMORRHAPHY - WHERE DO WE GO FROM HERE AMERICAN HEART JOURNAL FINCH, E. L., Mitchell, R. S., GUTHANER, D. F., FOWLES, R. F., Miller, D. C. 1983; 106 (3): 614-618

  View details for Web of Science ID A1983RE66300042

  View details for PubMedID 6881048

• 10 TO 15 YEAR REASSESSMENT OF THE PERFORMANCE-CHARACTERISTICS OF THE STARR-EDWARDS MODEL 6120 MITRAL-VALVE PROSTHESIS JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Miller, D. C., Oyer, P. E., Stinson, E. B., Reitz, B. A., Jamieson, S. W., Baumgartner, W. A., Mitchell, R. S., Shumway, N. E. 1983; 85 (1): 1-20

  View details for Web of Science ID A1983PY87000001

• Diagnosis of arterial prosthetic graft infection by indium-111 oxine white blood cell scans. Circulation Mckeown, P. P., Miller, D. C., Jamieson, S. W., Mitchell, R. S., Reitz, B. A., Olcott, C., MEHIGAN, J. T., SILBERSTEIN, R. J., McDougall, I. R. 1982; 66 (2): I130-4

  Abstract

  Early and accurate diagnosis of infected prosthetic arterial grafts is difficult, despite the application of diverse diagnostic modalities. Delay in making the diagnosis is largely responsible for the high amputation and mortality rates associated with this complication. In nine patients with suspected graft infections, indium-111 white blood cell scanning was useful and accurate. Graft infection was proved in five cases and ruled out in three. One false-positive scan was due to a sigmoid diverticular abscess overlying the graft. Indium-111 white blood cell scans may improve the accuracy of diagnosing infected prosthetic grafts, which may result in better limb and patient salvage rates.

  View details for PubMedID 7083531

• DIAGNOSIS OF ARTERIAL PROSTHETIC GRAFT INFECTION BY IN-111 OXINE WHITE BLOOD-CELL SCANS CIRCULATION Mckeown, P. P., Miller, D. C., Jamieson, S. W., Mitchell, R. S., Reitz, B. A., Olcott, C., MEHIGAN, J. T., SILBERSTEIN, R. J., McDougall, I. R. 1982; 66 (2): 130-134

  View details for Web of Science ID A1982NY67800024

• COMPREHENSIVE ASSESSMENT OF THE SAFETY, DURABILITY, CLINICAL-PERFORMANCE, AND HEALING CHARACTERISTICS OF A DOUBLE VELOUR KNITTED DACRON ARTERIAL PROSTHESIS VASCULAR SURGERY Mitchell, R. S., Miller, D. C., Billingham, M. E., MEHIGAN, J. T., Olcott, C., Stinson, E. B. 1980; 14 (3): 197-212

  View details for Web of Science ID A1980KE87600007