Dr. Chandra is a board certified vascular surgeon who specializes in cutting edge approaches to aortic aneurysmal disease, peripheral vascular disease and limb salvage.
- Vascular Surgery
- Aortic Aneurysm
- Peripheral Arterial Disease
- Fenestrated and branched repair of the aorta
- Limb Salvage
- Critical Limb Ischemia
- Advanced endovascular surgery techniques
- Thoracic Aortic Aneurysms
- Carotid Artery Diseases
- Women's Health
- Peripheral Vascular Diseases
- Amputation prevention
- Aortic Diseases
- Intermittent Claudication
- Diabetic Foot Ulcers
- Mesenteric Vascular Occlusion
- Iliac Aneurysm
- Aortic Dissection
- Dissecting Aneurysm
- Peripheral Arterial Aneurysm and Dissection
- Popliteal aneurysm
- Suprarenal Aneurysm
- Ruptured Aneurysm
- Peripheral ARterial Embolism and Thrombosis
Clinical Associate Professor, Surgery - Vascular Surgery
Associate Program Director, Stanford Vascular Surgery Fellowship (2014 - Present)
Medical Student Clerkship Director, Stanford Vascular Surgery (2013 - Present)
Stanford South Asian Translational Heart Institute (SSATHI) Member, Stanford University (2013 - Present)
Clinical Competency Committee, Stanford Vascular Surgery (2013 - Present)
Program Evaluation Committee, Stanford Vascular Surgery (2014 - Present)
Honors & Awards
Excellence in Teaching Award, Stanford School of Medicine (2010)
Glasgow-Rubin Achievement Award, AMWA (2004)
Inductee, Alpha Omega Alpha (2004)
Boards, Advisory Committees, Professional Organizations
Member, Society for Vascular Surgery (2015 - Present)
Member, Western Vascular Surgery Society (2015 - Present)
Member, San Francisco Surgical Society (2014 - Present)
Member, Northern California Vascular Surgery Society (2015 - Present)
Board Certification: Vascular Surgery, American Board of Surgery (2014)
Fellowship:Stanford University (2013) CA
Board Certification: General Surgery, American Board of Surgery (2012)
Residency:Stanford University (2011) CA
Residency:Stanford University (2006) CA
Internship:Stanford University (2005) CA
Medical Education:University of Chicago Pritzker (2004) IL
Venita Chandra, Richard Vecchiotti, Ross Venook, Tatun Tarin, Joel Goldsmith. "United States Patent US8986188 B2 Dynamic and Adjustable Support Devices", The Board of Trustees of the Leland Stanford Junior University, Mar 24, 2015
Best Endovascular vs. Best Surgical Therapy in Patients With Critical Limb Ischemia
This study will compare the effectiveness of best available surgical treatment with best available endovascular treatment in adults with critical limb ischemia (CLI) who are eligible for both treatment options.
Global Registry for Endovascular Aortic Treatment (GREAT)
Prospective, observational Registry to obtain data on device performance and clinical outcomes.
PRESERVE-Zenith® Iliac Branch System Clinical Study
The PRESERVE-Zenith® Iliac Branch System Clinical Study is a clinical trial to study the safety and effectiveness of the Zenith® Branch Endovascular Graft-Iliac Bifurcation in combination with the Zenith® Connection Endovascular Stent/ConnectSX™ covered stent in the treatment of aorto-iliac and iliac aneurysms.
Study to Evaluate the Safety and Efficacy of CHAM* for the Treatment of Diabetic Foot Ulcers
A Multicenter, Randomized, Single-Blind Study with an Open-Label Extension Option to Further Evaluate the Safety and Efficacy of Cryopreserved Human Amniotic Membrane for the Treatment of Chronic Diabetic Foot Ulcers
Zenith(R) Low Profile AAA Endovascular Graft Clinical Study
The Zenith® Low Profile AAA Endovascular Graft Clinical Study is a clinical trial approved by US FDA to study the safety and effectiveness of the Zenith® Low Profile AAA Endovascular Graft to treat abdominal aortic, aorto-iliac, and iliac aneurysms.
Zenith® p-Branch® Endovascular Graft Pivotal Study
The Zenith® p-Branch® Pivotal Study is a clinical trial approved by FDA to study the safety and effectiveness of the Zenith® p-Branch® endovascular graft in combination with the Atrium iCAST™ covered stents in the treatment of abdominal aortic aneurysms.
Graduate and Fellowship Programs
Vascular Surgery (Fellowship Program)
Clinical Impact of a Wound Care Center on a Vascular Surgery Practice
MOSBY-ELSEVIER. 2018: E88–E89
View details for Web of Science ID 000433036700079
Long-term outcomes after repair of symptomatic abdominal aortic aneurysms.
Journal of vascular surgery
OBJECTIVES: Previous studies have reported increased perioperative mortality of nonruptured symptomatic abdominal aortic aneurysms (Sx-AAA) compared with asymptomatic elective AAA (E-AAA) repairs, but no long-term-outcomes have been reported. We sought to compare long-term outcomes of Sx-AAA and E-AAA after repair at a single academic institution.METHODS: Patients receiving AAA repair for Sx-AAA and E-AAA from 1995 through 2015 were included. Ruptured AAA and suprarenal or thoracoabdominal AAA were excluded. Demographics, comorbidities, and operative approach were collected. Long-term mortality was the primary outcome, determined by chart review or link to Social Security Death Index. Additionally, long-term mortality and reinterventions were compared after groups were matched with nearest neighbor propensity to reduce bias.RESULTS: AAA repair was performed for 1054 E-AAA (383 open repair [36%], 671 endovascular aneurysm repair [EVAR] [64%]), and 139 symptomatic aneurysms (60 open repair [43%], 79 EVAR [57%]). Age (73years vs 74years; P= .13) and aneurysm diameter were similar between Sx-AAA and E-AAA (6.0cm vs 5.8cm; P= .5). The proportion of women was higher for Sx-AAA (26% vs 16%; P= .003), as was the proportion of non-Caucasians (40% vs 29%; P= .009). After propensity matching, there were no differences between groups for patient characteristics, AAA diameter, treatment modality, or comorbidities, including hypertension, coronary artery disease, congestive heart failure, diabetes, hyperlipidemia, lung disease, diabetes, renal disease, and smoking history. Women were treated for Sx-AAA at significantly smaller aortic diameters; however, compared with men (5.1cm vs 6.3cm; P< .001). Perioperative mortality was 5.0% for Sx-AAA and 2.3% for E-AAA (P= .055). By life-table analysis, Sx-AAA had lower 5-year (62% vs 71%) and 10-year (39% vs 51%) survivals (P= .01) compared with E-AAA for the entire cohort. Similar trends were observed for 5-year and 10-year mortality after propensity matching (63% and 40% vs 71% and 52%; P= .05). When stratified by repair type 5-year and 10-year survivals trended lower after open surgery (68% and 42% Sx-AAA vs 84% and 59% E-AAA; P= .08) but not EVAR (59% and 40% Sx-AAA vs 61% and 49% E-AAA; P= .4). Aneurysm-related reinterventions were similar for Sx-AAA and E-AAA (15% vs 14%; P= .8). Reinterventions were more common after EVAR compared with open repair (22% vs 7%, Sx-AAA P= .015; 20% vs 4% E-AAA; P= .007).CONCLUSIONS: Patients with Sx-AAA had lower long-term survival and similar aneurysm-related reinterventions compared with patients with E-AAA undergoing repair. Women also underwent repair for Sx-AAA at a significantly smaller size when compared with men, which emphasizes the role of gender in AAA symptomatology. Differences in long-term survival may be only partially explained by measured patient, aneurysm, and operative factors, and may reflect unmeasured social factors or suggest inherent differences in pathophysiology of Sx-AAAs.
View details for DOI 10.1016/j.jvs.2018.02.036
View details for PubMedID 29705087
Controversies and evidence for cardiovascular disease in the diverse Hispanic population
JOURNAL OF VASCULAR SURGERY
2018; 67 (3): 960–69
Hispanics account for approximately 17% of the U.S.They are one of the fastest growing racial/ethnic groups, second only to Asians. This heterogeneous population has diverse socioeconomic conditions, making the prevention, diagnosis, and management of vascular disease difficult. This paper discusses the cultural, racial, and social aspects of the Hispanic community in the United States and assesses how they affect vascular disease within this population. Furthermore, it explores risk factors, medical and surgical treatments, and outcomes of vascular disease in the Hispanic population; generational evolution of these conditions; and the phenomenon called the Hispanic paradox.A systematic search of the literature was performed to identify all English-language publications from 1991 to 2014 using PubMed, which draws from the National Institutes of Health and U.S. National Library of Medicine, with the words "cardiovascular disease," "prevalence," "vascular," and "Hispanic." An additional search was performed using "cardiovascular disease and Mexico," "cardiovascular disease and Cuba," "cardiovascular disease and Puerto Rico," and "cardiovascular disease and Latin America" as well as for complications, management, outcomes, surgery, vascular disease, and Hispanic paradox. The resulting publications were queried for generational data (spanning multiple well-defined age groups) regarding cardiovascular disease, and cross-references were obtained from their bibliographies. Results are segmented by country of origin.Compared with non-Hispanic whites, Hispanics face higher risks of cardiovascular diseases because of a high prevalence of high blood pressure, obesity, diabetes mellitus, and ischemic stroke. However, the incidence of peripheral arterial disease and carotid disease appears to be significantly lower than in whites. The Hispanic paradox (lower mortality in spite of higher cardiovascular risk factors) may relate to challenges in ascribing life expectancy and cause of death in this diverse population. Low socioeconomic status and high prevalence of concomitant diseases negatively influence the outcomes of all patients, independent of being Hispanic.Understanding the cultural diversity in Hispanics is important in terms of targeting preventive measures to modify cardiovascular risk factors, which affect development and outcomes of vascular disease. The available literature regarding vascular disease in the Hispanic population is limited, and further longitudinal study is warranted to improve health care delivery and outcomes in this group.
View details for DOI 10.1016/j.jvs.2017.06.111
View details for Web of Science ID 000425912200044
View details for PubMedID 28951154
Retrograde Pedal Access-Cutting Edge or Comical?
Vascular and endovascular surgery
Retrograde pedal access is a technique utilized with increasing frequency by many interventionists to address patients with advanced multilevel peripheral artery disease and significant comorbidities. This approach to revascularization is being used both in patients who fail traditional antegrade access and in some patients thought to be poor candidates for antegrade approach. However, the lack of randomized controlled trial data, or long-term results, coupled with the associated potential risks including dissection, spasm, and thrombosis have rendered retrograde pedal access a controversial topic. This article details the pros and cons associated with the debate surrounding retrograde pedal access and highlights the current literature and remaining questions regarding outcomes of this technique.
View details for DOI 10.1177/1538574418780055
View details for PubMedID 29932023
Percutaneous Septectomy in Chronic Dissection with Abdominal Aortic Aneurysm Creates Uniluminal Neck for EVAR.
Cardiovascular and interventional radiology
The intent of this report is to describe the technical details and rationale of endovascular septectomy using a wire saw maneuver in cases of chronic aortic dissection and associated infra-renal aortic aneurysm to allow standard endovascular abdominal aortic graft placement; preliminary clinical experience is also retrospectively reviewed.Between June 2013 and June 2016, four consecutive patients (mean age 55.3 years; range 52-58 years) with chronic type B aortic dissection and isolated infra-renal abdominal aortic aneurysm (AAA) underwent endovascular aneurysm repair (EVAR) following guidewire septectomy to create a suitable proximal aortic landing zone. Technical success was evaluated by angiography performed at the end of the procedure. Procedural safety was determined by assessing any major adverse events through 30 days of follow-up. Endoleaks and longer-term efficacy were evaluated.Four patients with chronic aortic dissections had associated AAA with a mean maximum diameter of 60 ± 13 mm (range 50-77 mm). All underwent guidewire saw septectomy to facilitate EVAR. Following successful septectomy, standard abdominal bifurcated endografts were implanted uneventfully. No major adverse events and no endoleaks were noted on CT angiographic examinations through 30 days following the procedure. Also, no rupture, re-intervention or endoleak has been noted during follow-up at a mean of 21.8 ± 15 months (range 4-39 months).Guidewire saw septectomy is a technique that has the potential to create an anatomically suitable proximal neck for successful EVAR management of AAA in select patients with associated chronic aortic dissection.
View details for DOI 10.1007/s00270-017-1668-3
View details for PubMedID 28493108
Gender-Related Differences in Iliofemoral Arterial Anatomy among Abdominal Aortic Aneurysm Patients.
Annals of vascular surgery
Gender-related differences in iliofemoral anatomy are critically important for delivery of modern EVAR devices, however remains poorly characterized in the context of other patient-specific factors. The goal of the present study was to provide a detailed quantification of anatomic differences in iliofemoral anatomy between genders while controlling for height, weight, and vascular comorbidities.Fifty women with computed tomography angiograms for evaluation of abdominal aortic aneurysm between 2000 and 2012 were selected and matched to an equal nonpaired cohort of males with similar age, body mass indices (BMIs), and prevalence of vascular comorbidities (e.g., coronary artery disease, peripheral vascular disease). A 3-dimensional workstation was used to measure outer and inner diameters at anatomic reference locations at the common iliac (CIA), external iliac (EIA), and common femoral (CFA) arteries. Iliac aneurysms were excluded from analysis. Multivariate analysis-of-covariance models were employed for evaluating CIA, EIA, and CFA diameters as dependent variables.Luminal diameters were significantly smaller at the CIA (8.8 vs. 11.8 mm, P < 0.001), EIA (7.0 vs. 8.4 mm, P < 0.001), and CFA (6.7 vs. 9.5 mm, P < 0.001) arteries between men and women despite similar BMIs (27.7 vs. 27.5, P = 0.20). Similar statistically significant differences were found between men and women when comparing adventitial diameters (P < 0.001), however not when comparing degrees of stenosis (defined as outer diameter minus inner diameter [P = 0.96]). Female gender was negatively correlated with luminal diameter at the CIA (-2.34 [-3.72 to -0.96]; coef. [95% CI]), EIA (-0.95 [-1.8 to -0.04]), and CFA (-2.61 [-3.51 to -1.71]) arteries. Weight (per 10 kg) was positively correlated with luminal diameters measured at the CIA (0.41 [0.12-0.68]) and CFA (0.35 [0.16-0.53]). No independent relationships between height, vascular comorbidities, and arterial diameters were identified. 24% (n = 12) of females compared to only 14% (n = 7) of males in this study would have been ineligible for EVAR with current devices due to poor iliac access criteria.Women have significantly smaller iliofemoral arterial systems compared to men, even after controlling for height, weight, and other comorbidities that are known to affect vascular anatomy. This quantifiable difference in arterial anatomy is important to consider when deciding between various open versus endovascular treatment strategies for women.
View details for DOI 10.1016/j.avsg.2017.01.025
View details for PubMedID 28479440
Management and outcomes of symptomatic abdominal aortic aneurysms during the past 20 years.
Journal of vascular surgery
2017; 66 (6): 1679–85
We compared the management of patients with symptomatic, unruptured abdominal aortic aneurysms (AAAs) treated at a tertiary care center between two decades. This 20-year period encapsulated a shift in surgical approach to aortic aneurysms from primarily open to primarily endovascular, and we sought to determine the effect of this shift in the evaluation, treatment, and clinical outcomes of patients with symptomatic AAA.We reviewed 1429 consecutive patients with unruptured AAAs treated at a tertiary care hospital by six staff surgeons between 1995 and 2004 (era 1) and between 2005 and 2014 (era 2). Of those patients, 160 (11%) were symptomatic from their aneurysm and were included in our study. Patient demographics, operative approach, and outcomes were analyzed and compared for each period.Era 1 included 75 patients (71% men; average age, 73.1 ± 10.0 years) treated for symptomatic AAA (91.9% infrarenal, 4.0% juxtarenal, and 4.0% pararenal); of these, 68% were treated with open repair and 32.0% were treated with an endovascular repair. Perioperative mortality during this period was 5.3% (7.8% for the open cohort and 0% for the endovascular cohort). Era 2 included 85 patients (72.9% men; average age 72.0 ± 9.5 years) treated for symptomatic AAA (90.1% infrarenal, 7.5% juxtarenal, and 2.4% pararenal); of these, 29% were treated open and 71% underwent endovascular repair. Perioperative mortality was 5.9% (8.0% for the open cohort and 5.0% for the endovascular cohort). Era 2 had a significantly higher rate of endovascular repair compared with era 1 (71% vs 32%; P < .0001) and a trend toward decreased long-term mortality. The length of stay for era 2 was significantly reduced compared with era 1 (4 days vs 6 days; P = .005).To our knowledge, this is the largest single-institution cohort of symptomatic AAAs, which comprise 10% to 11% of overall aneurysms. As expected, we found a significant shift over time in the approach to these patients from a primarily open to a primarily endovascular technique. The modern era was also associated with decreased lengths of stay and fewer gastrointestinal and wound complications but no significant differences in overall perioperative mortality.
View details for DOI 10.1016/j.jvs.2017.04.033
View details for PubMedID 28619644
Predictive models for mortality after ruptured aortic aneurysm repair do not predict futility and are not useful for clinical decision making
JOURNAL OF VASCULAR SURGERY
2016; 64 (6): 1617-1622
The clinical decision-making utility of scoring algorithms for predicting mortality after ruptured abdominal aortic aneurysms (rAAAs) remains unknown. We sought to determine the clinical utility of the algorithms compared with our clinical decision making and outcomes for management of rAAA during a 10-year period.Patients admitted with a diagnosis rAAA at a large university hospital were identified from 2005 to 2014. The Glasgow Aneurysm Score, Hardman Index, Vancouver Score, Edinburgh Ruptured Aneurysm Score, University of Washington Ruptured Aneurysm Score, Vascular Study Group of New England rAAA Risk Score, and the Artificial Neural Network Score were analyzed for accuracy in predicting mortality. Among patients quantified into the highest-risk group (predicted mortality >80%-85%), we compared the predicted with the actual outcome to determine how well these scores predicted futility.The cohort comprised 64 patients. Of those, 24 (38%) underwent open repair, 36 (56%) underwent endovascular repair, and 4 (6%) received only comfort care. Overall mortality was 30% (open repair, 26%; endovascular repair, 24%; no repair, 100%). As assessed by the scoring systems, 5% to 35% of patients were categorized as high-mortality risk. Intersystem agreement was poor, with κ values ranging from 0.06 to 0.79. Actual mortality was lower than the predicted mortality (50%-70% vs 78%-100%) for all scoring systems, with each scoring system overestimating mortality by 10% to 50%. Mortality rates for patients not designated into the high-risk cohort were dramatically lower, ranging from 7% to 29%. Futility, defined as 100% mortality, was predicted in five of 63 patients with the Hardman Index and in two of 63 of the University of Washington score. Of these, surgery was not offered to one of five and one of two patients, respectively. If one of these two models were used to withhold operative intervention, the mortality of these patients would have been 100%. The actual mortality for these patients was 60% and 50%, respectively.Clinical algorithms for predicting mortality after rAAA were not useful for predicting futility. Most patients with rAAA were not classified in the highest-risk group by the clinical decision models. Among patients identified as highest risk, predicted mortality was overestimated compared with actual mortality. The data from this study support the limited value to surgeons of the currently published algorithms.
View details for DOI 10.1016/j.jvs.2016.07.121
View details for Web of Science ID 000390044000011
View details for PubMedID 27871490
SPY technology as an adjunctive measure for lower extremity perfusion
JOURNAL OF VASCULAR SURGERY
2016; 64 (1): 195-201
Lack of a reliable outcome measure often leads to excessive or insufficient interventions for critical limb ischemia (CLI). SPY technology (Novadaq Technologies Inc, Bonita Springs, Fla), widely adapted by plastic and general surgeons, uses laser-assisted fluorescence angiography (LAFA) to assess tissue perfusion. We sought to determine the role of SPY as an alternative, perhaps more reliable outcome measure for vascular interventions.All patients undergoing elective or urgent revascularization for claudication and CLI were prospectively recruited from June 2012 to August 2014. LAFA using SPY technology was performed before and after revascularization procedures under a standard Institutional Review Board-approved protocol. Quantitative measures of perfusion at plantar surfaces were analyzed and compared with ankle-brachial index.A total of 93 patients with claudication or CLI underwent LAFA before and after a revascularization procedure in the study period. The mean preoperative ankle-brachial index increased from 0.60 to 0.84 (P < .001) after a revascularization procedure. Plantar perfusion as measured by LAFA also improved significantly after intervention. Ingress, defined as the rate at which fluorescence intensity increases on the plantar surface during LAFA, increased from 7.1 to 12.4 units/s (P < .001). Peak perfusion, defined as the difference between the baseline and the peak of fluorescence intensity, increased from 97.1 and 143.9 units (P < .001). Egress, defined as the rate at which intensity diminishes after reaching peak perfusion, increased from 1.0 to 1.9 units/s (P = .035). Procedure-related digital embolization was also observed in several patients despite lack of an angiographic finding.This is the largest prospective study evaluating SPY technology in peripheral vascular interventions. Our study shows that SPY is a valuable tool in visualizing real-time procedural outcomes and providing additionally useful information on regional tissue perfusion. Further investigation is warranted to standardize outpatient use and to determine threshold values that predict wound healing.
View details for DOI 10.1016/j.jvs.2016.01.039
View details for Web of Science ID 000378562900027
View details for PubMedID 26994959
- Unplanned reoperations after vascular surgery JOURNAL OF VASCULAR SURGERY 2016; 63 (3): 731-737
- Association of an Endovascular-First Protocol for Ruptured Abdominal Aortic Aneurysms With Survival and Discharge Disposition JAMA SURGERY 2015; 150 (11): 1058-1065
Impact of Renal Artery Angulation on Procedure Efficiency During Fenestrated and Snorkel/Chimney Endovascular Aneurysm Repair
JOURNAL OF ENDOVASCULAR THERAPY
2015; 22 (4): 594-602
To determine the impact of renal artery angulation on time to successful renal artery cannulation and procedure efficiency during fenestrated and snorkel/chimney endovascular aneurysm repair (EVAR).The imaging and procedure logs of 77 patients (mean age 74.2 years; 63 men) who underwent complex EVAR (24 fenestrated, 53 snorkel/chimney) from 2009 to 2013 were reviewed. Renal artery angulation was measured on preoperative computed tomographic angiography scans. Time to renal artery cannulation was retrieved from the EVAR procedure logs and compared to preoperative renal artery angulation and other metrics of procedure efficiency (eg, procedure time, fluoroscopy time, blood loss, etc). In all, 111 renal arteries were available for renal artery angulation measurement (39 fenestrated, 72 snorkel/chimney); 22 renal cannulations were inappropriate for the comparative analyses due to concomitant visceral artery stenting (n=15), combined procedures (n=6), or unsuccessful cannulation (n=1).For patients undergoing fenestrated EVAR, mean renal artery angulation was -28°±21° (range +37° to -60°), not significantly different (p=0.66) from patients receiving snorkel/chimney grafts (mean -30°±19°, range +22° to -65°). Comparative analysis using median renal artery angulation (-30° for both groups) demonstrated that renal artery cannulation during fenestrated EVAR was performed significantly faster in arteries with less downward (≥ -30°) angulation (16.0 vs 32.8 minutes, p=0.04), whereas cannulation in snorkel/chimneys was faster in arteries with greater downward (< -30°) angulation (10.9 vs 17.3 minutes, p=0.05). Fenestrated EVAR cases involving less downward (≥ -30°) renal artery angulation were also associated with shorter overall procedure time (187.7 vs 246.2 minutes, p=0.01) and decreased fluoroscopy time (70.3 vs 98.2 minutes, p=0.04). Immediate renal function decline, procedural complications, and postoperative issues were not associated with renal artery angulation.Procedural efficiency may be optimized by considering renal artery angulation as one of several objective variables used in the selection of an appropriate endovascular strategy. The fenestrated approach is more efficient with less downward angulation to the renal arteries, while the snorkel/chimney strategy is facilitated by more downward renal artery angulation.
View details for DOI 10.1177/1526602815590119
View details for Web of Science ID 000358119200019
Aortoiliac Elongation after Endovascular Aortic Aneurysm Repair
ANNALS OF VASCULAR SURGERY
2015; 29 (5): 891-897
Aortoiliac elongation after endovascular aortic aneurysm repair (EVAR) is not well studied. We sought to assess the long-term morphologic changes after EVAR and identify potentially modifiable factors associated with such a change.An institutional review board-approved retrospective review was conducted for 88 consecutive patients who underwent EVAR at a single academic center from 2003 to 2007 and who also had at least 2 follow-up computed tomography angiograms (CTAs) available for review up to 5 years after surgery. Standardized centerline aortic lengths and diameters were obtained on Aquarius iNtuition 3D workstation (TeraRecon Inc., San Mateo, CA) on postoperative and all-available follow-up CTAs. Relationships to aortic elongation were determined using Wilcoxon rank-sum test or linear regression (Stata version 12.1, College Station, TX). Changes in length over time were determined by mixed-effects analysis (SAS version 9.3, Cary, NC).The study cohort was composed of mostly men (88%), with a mean age of (76 ± 8) and a mean follow-up of 3.2 years (range, 0.4-7.5 years). Fifty-seven percent of patients (n = 50) had devices with suprarenal fixation and 43% (n = 38) had no suprarenal fixation. Significant lengthening was observed over the study period in the aortoiliac segments, but not in the iliofemoral segments. Aortoiliac elongation over time was not associated with sex (P = 0.3), hypertension (P = 0.7), coronary artery disease (P = 0.3), diabetes (P = 0.3), or tobacco use (P = 0.4), but was associated with the use of statins (P = 0.03) and the presence of chronic obstructive pulmonary disease (P = 0.02). Significant aortic lengthening was associated with increased type I endoleaks (P = 0.03) and reinterventions (P = 0.03). Over the study period, 4 different devices were used; Zenith (Cook Medical Inc., Bloomington, IN), Talent (Medtronic, Minneapolis, MN), Aneuryx (Medtronic), and Excluder (W. L. Gore and Associates Inc., Flagstaff, AZ). After adjusting for differences in proximal landing zone, significant differences in aortic lengthening over time were observed by device type (P = 0.02).Significant aortoiliac elongation was observed after EVAR. Such morphologic changes may impact long-term durability of EVAR, warranting further investigation into factors associated with these morphologic changes.
View details for DOI 10.1016/j.avsg.2014.12.041
View details for Web of Science ID 000356994400003
View details for PubMedID 25757989
Novel Approach to a Giant External Iliac Vein Aneurysm Secondary to Posttraumatic Femoral Arteriovenous Fistula
VASCULAR AND ENDOVASCULAR SURGERY
2015; 49 (5-6): 148-151
We describe a case of a 55-year-old male with a remote history of a gunshot wound to the left thigh who presented with a 1-year history of worsening high-output congestive heart failure, left lower extremity edema, and left lower abdominal discomfort. Diagnostic evaluation included a computed tomographic angiography (CTA) that demonstrated a fistulous communication between the left superficial femoral artery (SFA) and vein (SFV) as well as a 7.2-cm external iliac vein aneurysm. Given his symptomatology, an endovascular repair of his AVF was recommended, followed by antithrombotic therapy for his aneurysm. Three-month postoperative CTA confirmed AVF exclusion as well as a significant decrease in maximal diameter of the left external iliac vein aneurysm now measuring 24 mm. This case is the first reported successful mid-term repair of a iliac venous aneurysm in the setting of a traumatic arteriovenous fistula using an endovascular approach.
View details for DOI 10.1177/1538574415602781
View details for Web of Science ID 000361529700008
View details for PubMedID 26335991
Gastrointestinal Mucormycosis Requiring Surgery in Adults with Hematologic Malignant Tumors: Literature Review
2015; 16 (2): 194-202
Gastrointestinal mucormycosis is associated with high mortality rates. Appropriate and early antifungal therapy and prompt surgical intervention are essential.Case report and literature review.Nineteen case reports were reviewed describing adults with hematologic malignant tumors who developed intestinal mucormycosis and underwent surgery. The overall survival rate was 50%.Intestinal mucormycosis is an infection associated with a high mortality rate although adults with underlying hematologic malignant have improved outcomes compared with other groups.
View details for DOI 10.1089/sur.2013.232
View details for Web of Science ID 000352360400015
View details for PubMedID 25405775
Cheese wire fenestration of a chronic juxtarenal dissection flap to facilitate proximal neck fixation during EVAR.
Annals of vascular surgery
2015; 29 (1): 124 e1-5
To describe successful endovascular repair of a complex chronic aortoiliac dissection facilitated by a unique endovascular fenestration technique at the proximal neck.A 57-year-old man presented with disabling lower extremity claudication and a remote history of medically treated type B aortic dissection. Computed tomographic angiography demonstrated a complex dissection with 7.1-cm false lumen aneurysmal dilatation and significant true lumen compression within bilateral iliac aneurysms and no suitable proximal infrarenal neck free of dissection.Using intravascular ultrasound, guidewires were introduced into true and false lumens. A 9F sheath was placed on the right side, and a 20-ga Chiba needle was positioned at the level of the celiac artery and oriented toward the dissection flap. The needle was advanced to puncture the flap, and a 0.014-in wire was then snared from the true to the false lumen. Shearing of the dissection flap in the juxtarenal segment was performed using a "cheese wire" technique, whereby both ends of the guidewire were pulled caudally in a sawing motion down through the infrarenal neck and into the aneurysm sac. Angiography confirmed absence of residual dissection and perfusion of the visceral vessels via the true lumen. Given the newly created infrarenal neck, standard endovascular aortic repair (EVAR) was performed and antegrade and retrograde false lumen flow was obliterated from the visceral vessels. Postoperative imaging confirmed aneurysm exclusion, no endoleak, and patent bilateral common iliac arteries with resolution of claudication symptoms and normal ankle-brachial indices.Endovascular management of false lumen aneurysms in the setting of chronic dissection is limited by the ability of stent grafts to obtain adequate proximal or distal fixation. Endovascular fenestration of these chronic flaps facilitates generation of suitable landing zones, thereby serving as a useful adjunct to standard EVAR.
View details for DOI 10.1016/j.avsg.2014.07.025
View details for PubMedID 25192823
- Cheese Wire Fenestration of a Chronic Juxtarenal Dissection Flap to Facilitate Proximal Neck Fixation during EVAR ANNALS OF VASCULAR SURGERY 2015; 29 (1)
- Gastrointestinal Mucormycosis Initially Manifest as Hematochezia from Arterio-Enteric Fistula DIGESTIVE DISEASES AND SCIENCES 2014; 59 (12): 2905-2908
- Comparison of fenestrated endografts and the snorkel/chimney technique 28th Annual Meeting of the Western-Vascular-Society MOSBY-ELSEVIER. 2014: 849–56
- Thoracic outlet syndrome in high-performance athletes 28th Annual Meeting of the Western-Vascular-Society MOSBY-ELSEVIER. 2014: 1012–17
The "Terrace Technique"-Totally Endovascular Repair of a Type IV Thoracoabdominal Aortic Aneurysm.
Annals of vascular surgery
2014; 28 (6): 1563 e11-6
As an alternative to branched or fenestrated aortic stent grafts, the "snorkel" or "chimney graft" strategy is a feasible endovascular option, particularly for juxtarenal aneurysms. When more than 2 visceral vessels require revascularization, however, the summative displacement of the main body endograft theoretically increases gutter formation with subsequent endoleak. The "terrace" strategy, or "sandwich", stacks the snorkel grafts into separate layers, and we describe a case using 4 snorkel grafts during endovascular aneurysm repair of a type IV thoracoabdominal aortic aneurysm (TAAA).A 76-year-old man with prohibitive operative risk has been followed for years with an asymptomatic TAAA that grew to 6.2 cm. Endovascular strategy consisted of celiac and superior mesenteric artery snorkel stents deployed and molded adjacent to a 36-mm proximal thoracic cuff (Cook TX2).Through the proximal thoracic endograft, both renals were then accessed, and in this second layer, or "terrace configuration," bilateral renal snorkels were deployed and molded adjacent to a 36-mm bifurcated abdominal stent-graft system (Cook Zenith). "Quadruple kissing" balloon angioplasty was then performed to mold the lower part of the devices. Operative time was 4 hr, the patient was extubated immediately and recovered quickly on the floor, being discharged in 3 days. Postoperative imaging at 6 months, 1 year, and 2 years have revealed patent aortic components without evidence of stent-graft migration or significant endoleak. The terrace snorkel stents were all patent to the celiac, superior mesenteric, and right renal arteries, while the left renal artery stent shows some stent compression.In select high-risk patients opting for an all-endovascular approach of type IV TAAAs, up to 4 snorkel grafts can be deployed in a "terrace" or "sandwich" configuration to successfully revascularize all visceral branches and provide aneurysm exclusion. Long-term follow-up is necessary to understand the overall success of this strategy.
View details for DOI 10.1016/j.avsg.2014.03.010
View details for PubMedID 24704581
Monitoring of fetal radiation exposure during pregnancy
William J. Von Liebig Forum at the Rapid Session of the Vascular Annual Meeting of the Society-for-Vascular-Surgery (SVS) / Peripheral-Vascular-Surgery-Society Session
MOSBY-ELSEVIER. 2013: 710–14
One unique concern of vascular surgeons and trainees is radiation exposure associated with increased endovascular practice. The safety of childbearing is a particular worry for current and future women in vascular surgery. Little is known regarding actual fetal radiation exposure. This multi-institutional study aimed to evaluate the radiation dosages recorded on fetal dosimeter badges and compare them to external badges worn by the same cohort of women.All women who declared pregnancy with potential radiation exposure were required to wear two radiation monitors at each institution, one outside and the other inside the lead apron. Maternal (external) and fetal monitor dosimeter readings were analyzed. Maternal radiation exposures prior to, during, and postpregnancy were also assessed to determine any associated behavior modification.Eighty-one women declared pregnancy from 2008 to 2011 and 32 had regular radiation exposure during pregnancy. Maternal whole-body exposures ranged from 21-731 mrem. The average fetal dosimeter recordings for the cohort rounded to zero. Only two women had positive fetal dosimeter recordings; one had a single recording of 3 mrem and the other had a single recording of 7 mrem. There was no significant difference between maternal exposures prior to, during, and postpregnancy.Lack of knowledge of fetal radiation exposure has concerned many vascular surgeons, prompting them to wear double lead aprons during pregnancy, and perhaps prevented numerous other women from entering the field. Our study showed negligible radiation exposure on fetal monitoring suggesting that with the appropriate safety precautions, these concerns may be unwarranted.
View details for DOI 10.1016/j.jvs.2013.01.052
View details for Web of Science ID 000323616800019
View details for PubMedID 23591191
Preoperative embolization of replaced right hepatic artery prior to pancreaticoduodenectomy
JOURNAL OF SURGICAL ONCOLOGY
2012; 106 (4): 509-512
Aberrancy of the hepatic arterial anatomy is common. Because of its course directly adjacent to the head of the pancreas, a replaced right hepatic artery (RHA) is vulnerable to invasion by peri-pancreatic malignancies. Division of the RHA at the time of pancreaticoduodenectomy, however, may result in hepatic infarction and/or bilioenteric anastomotic complications. We report two cases of patients undergoing preoperative embolization of tumor encased replaced RHAs to allow for sufficient collateralization prior to pancreaticoduodenectomy.
View details for DOI 10.1002/jso.23082
View details for Web of Science ID 000307550900026
View details for PubMedID 22374866
Cost Impact of Extension Cuff Utilization During Endovascular Aneurysm Repair
21st Annual Winter Meeting of the Peripheral-Vascular-Surgery-Society
ELSEVIER SCIENCE INC. 2012: 86–92
Modular stent-graft systems for endovascular aneurysm repair (EVAR) most often require two to three components, depending on the device. Differences in path lengths and availability of main body systems often require additional extensions for appropriate aneurysm exclusion. These additional devices usually result in added expenses and can affect the financial viability of an EVAR program within a hospital. The purpose of this study was to analyze the use of extensions during EVAR, focusing on incidence, clinical impact, and financial impact, as well as determining the associated cost differences between two- and three-component EVAR device systems.We reviewed available clinical data, images, and follow-up of 218 patients (203 males and 15 females, mean age: 74 ± 9 years) who underwent elective EVAR at a single academic center from 2004 to 2007. Patients were divided into two groups: patients undergoing EVAR using the standard number of pieces, that is, no extensions used (group A, n = 98), and those needing proximal or distal extensions during the index procedure (group B, n = 120).Both groups were similar in terms of demographics; preoperative characteristics, including aneurysm morphology; as well as intraoperative, postoperative, and midterm outcomes. Overall, 30-day operative mortality was 1.4%, with a mean follow-up of 24 months. Group A patients underwent repair with two-piece modular devices 41% of the time and three-piece systems 59% of the time, whereas group B patients underwent repair with two-piece modular systems 82% of the time and three-piece modular systems 18% of the time. The number of additional extensions per patient ranged from one to four (median: one piece). There was a 30% cost increase in overall mean device-related cost when using extensions versus the standard number of pieces (group A: $13,220 vs. group B: $17,107, p < 0.01).Clinical midterm aneurysm-related outcomes after EVAR in patients who required additional extensions was comparable with those treated with the standard number of pieces. An increased number of extensions led to increased costs and could have potentially been minimized with appropriate preoperative planning or device selection. Consideration should be made toward per-case pricing instead of per-piece pricing to further improve cost efficiency without compromising long-term patient outcomes.
View details for DOI 10.1016/j.avsg.2011.10.003
View details for Web of Science ID 000298325900011
View details for PubMedID 22176878
Early results of a highly selective algorithm for surgery on patients with neurogenic thoracic outlet syndrome
25th Annual Meeting of the Western-Vascular-Society
MOSBY-ELSEVIER. 2011: 1698–1705
Neurogenic thoracic outlet syndrome (nTOS) encompasses a wide spectrum of disabling symptoms that are often vague and difficult to diagnose and treat. We developed and prospectively analyzed a treatment algorithm for nTOS utilizing objective disability criteria, thoracic outlet syndrome (TOS)-specific physical therapy, radiographic evaluation of the thoracic outlet, and selective surgical decompression.Patients treated for nTOS from 2000-2009 were reviewed (n = 93). In period 1, most patients were offered surgery with documentation of appropriate symptoms. A prospective observational study began in 2007 (period 2) and was aimed at determining which patients benefited most from surgical intervention. Evaluation began with a validated mini-QuickDASH (QD) quality-of-life scale (0-100, 100 = worse) and duplex imaging of the thoracic outlet. Patients then participated in TOS-specific physical therapy (PT) for 2 to 4 months and were offered surgery based on response to PT and improvement in symptoms.Thirty-four patients underwent first rib resection in period 1 (68% female, mean age 39, 18% athletes, 15% workers comp). In operated patients undergoing duplex imaging, 47% showed compression of their thoracic outlet arterial flow on provocative positioning. Based on subjective improvement of symptoms, 56% of patients at 1 year had a positive outcome. In period 2 during the prospective cohort, 59 consecutive patients were evaluated for nTOS (64% female, mean age 36, 32% athletes, 12% workers comp) with a mean pre-PT QD disability score of 55.1. All patients were prescribed PT, and 24 (41%) were eventually offered surgical decompression based on compliance with PT, interval improvement on QD score, and duplex compression of the thoracic outlet. Twenty-one patients underwent surgery (SURG group) consisting of first rib resection, middle and anterior scalenectomy, and brachial plexus neurolysis. There were significant differences between the SURG and non-SURG cohorts with respect to age, participation in competitive athletics, history of trauma, and symptom improvement with PT. At 1-year follow-up, 90% of patients expressed symptomatic improvement with the mean post-op QD disability score decreasing to 24.9 (P = .005) and 1-year QD scores improving down to 20.5 (P = .014).This highly-selective algorithm for nTOS surgery leads to improvement in overall success rates documented subjectively and objectively. Compliance with TOS-specific PT, improvement in QD scores after PT, young age, and competitive athletics are associated with improved surgical outcomes. Long-term follow-up will be necessary to document sustained symptom relief and to determine who the optimal surgical candidates are.
View details for DOI 10.1016/j.jvs.2011.05.105
View details for Web of Science ID 000297823400022
View details for PubMedID 21803527
Long-term impact of a preclinical endovascular skills course on medical student career choices
25th Annual Meeting of the Western-Vascular-Society
MOSBY-ELSEVIER. 2011: 1193–1200
Surging interest in the 0 + 5 integrated vascular surgery (VS) residency and successful recruitment of the top students in medical school requires early exposure to the field. We sought to determine the impact of a high-fidelity simulation-based preclinical endovascular skills course on medical student performance and ultimate career specialty choices.Fifty-two preclinical medical students enrolled in an 8-week VS elective course from 2007 to 2009. Students completed a baseline and postcourse survey and performed a renal angioplasty/stent procedure on an endovascular simulator (pretest). A curriculum consisting of didactic teaching covering peripheral vascular disease and weekly mentored simulator sessions concluded with a final graded procedure (posttest). Long-term follow-up surveys 1 to 3 years after course completion were administered to determine ultimate career paths of participants as well as motivating factors for career choice.Objective and subjective performance measured on the simulator and through structured global assessment scales improved in all students from pre- to posttest, particularly with regard to technical skill and overall procedural competency (P < .001). Prior to enrolling in the course, 9% of the students expressed high interest in VS, and after completing the course, this response nearly tripled in terms of seriously considering VS as a career option (P = .03). Overall interest postcourse in VS and procedural-based surgical specialties was nearly 90%. In long-term follow-up, 25% were still strongly considering integrated VS residencies, with other top career choices including surgical subspecialties (64%), radiology (10%), and cardiology (6%). Most respondents indicated major reasons for continued interest in VS were the ability to practice endovascular procedures on the simulator (92%) and mentorship from VS faculty (70%).Basic endovascular skills can be efficiently introduced through a simulation-based curriculum and lead to improved novice performance. Early exposure of preclinical medical students provides an effective teaching and recruitment tool for procedural-based fields, particularly surgical subspecialties. Mentored exposure to endovascular procedures on the simulator positively impacts long-term medical student attitudes toward vascular surgery and ultimate career choices.
View details for DOI 10.1016/j.jvs.2011.04.052
View details for Web of Science ID 000295562800042
View details for PubMedID 21723068
A comparison of laparoscopic and robotic assisted suturing performance by experts and novices
2010; 147 (6): 830-839
Surgical robotics has been promoted as an enabling technology. This study tests the hypothesis that use of the robotic surgical system can significantly improve technical ability by comparing the performance of both experts and novices on a complex laparoscopic task and a robotically assisted task.Laparoscopic experts (LE) with substantial laparoscopic and robotic experience (n = 9) and laparoscopic novices (LN) (n = 20) without any robotic experience performed sequentially 10 trials of a suturing task using either robotic or standard laparoscopic instrumentation fitted to the ProMIS surgical simulator. Objective performance metrics provided by ProMIS (total task time, instrument pathlength, and smoothness) and an assessment of learning curves were analyzed.Compared with LNs, the LEs demonstrated significantly better performance on all assessment measures. Within the LE group, there was no difference in smoothness (328 +/- 159 vs 355 +/- 174; P = .09) between robot-assisted and standard laparoscopic tasks. An improvement was noted in total task time (113 +/- 41 vs 132 +/- 55 sec; P < .05) and instrument pathlengths (371 +/- 163 vs 645 +/- 269 cm; P < .05) when using the robot. This advantage in terms of total task time, however, was lost among the LEs by the last 3 trials (114 +/- 40 vs 118 +/- 49 s; P = .84), while instrument pathlength remained better consistently throughout all the trials. For the LNs, performance was significantly better in the robotic trials on all 3 measures throughout all the trials.The ProMIS surgical simulator was able to distinguish between skill levels (expert versus novice) on robotic suturing tasks, suggesting that the ProMIS is a valid tool for measuring skill in robot-assisted surgery. For all the ProMIS metrics, novices demonstrated consistently better performance on a suturing task using robotics as compared to a standard laparoscopic setup. This effect was less evident for experts who demonstrated improvements only in their economy of movement (pathlength), but not in the speed or smoothness of performance. Robotics eliminated the early learning curve for novices, which was present when they used standard laparoscopic tools. Overall, this study suggests that, when performing complex tasks such as knot tying, surgical robotics is most useful for inexperienced laparoscopists who experience an early and persistent enabling effect. For experts, robotics is most useful for improving economy of motion, which may have implications for the highly complex procedures in limited workspaces (eg, prostatectomy).
View details for DOI 10.1016/j.surg.2009.11.002
View details for Web of Science ID 000278532300011
View details for PubMedID 20045162
Surgical robotics and image guided therapy in pediatric surgery: emerging and converging minimal access technologies.
Seminars in pediatric surgery
2006; 15 (4): 267-275
Minimal access surgery (MAS) is now commonplace in the armamentarium of the pediatric surgeon, and is being applied to a growing list of pediatric surgical diseases. Robot-assisted surgery and image guided therapy (IGT) have evolved as innovative minimal access approaches, and hold the promise of advancing MAS far beyond what is currently possible. The aims of this article are to describe the currently available robotic, and image guided therapy systems, review their present and potential applications, and discuss the future directions of these converging technologies.
View details for PubMedID 17055957