Jeffrey Yang

All Publications

• Progression of Aortic Dilation in Patients with Tetralogy of Fallot with Pulmonary Atresia and Major Aortopulmonary Collateral Arteries. Pediatric cardiology Punn, P., Mainwaring, R. D., Yang, J. K., Olson, I., Jacobs, N. M., Ma, M., Punn, R., Arunamata, A. 2026

  Abstract

  Patients with tetralogy of Fallot, pulmonary atresia and major aortopulmonary collateral arteries (TOF/PA/MAPCAs) demonstrate enlarged aortic dimensions. Although aortic z-scores derived from normal populations are widely used, these have limited utility in a population where dilation is nearly universal. The objectives of the study were to determine the range of values of aortic dilation across pediatric patients with TOF/PA/MAPCAs, characterize the trajectory of aortic growth before and after surgical intervention, and report the incidence of important aortic complications at long-term follow-up. We performed a retrospective evaluation of pediatric TOF/PA/MAPCAs patients repaired only at our institution over 20 years (2003-2023). Aortic dimension measurements were performed on up to 3 echocardiograms for each patient: initial echocardiogram (before any intervention), intermediate echocardiogram (< 30 days before complete repair), and post-operative echocardiogram (≥ 1 year following complete repair). Last available echocardiogram was also reviewed. Degree of aortic regurgitation and rates of aortic growth were assessed and compared by surgical strategy. 224 patients were included in the study, 73 (33%) underwent staged repair with a surgical aortopulmonary window and/or bilateral unifocalization to central shunt before eventual complete repair. All aortic dimension z-scores on the initial and intermediate echocardiograms were classified as severely dilated. There was a statistically significant increase in aortic annulus (p = 0.006) and ST junction (p < 0.001) z-scores between the initial and intermediate echocardiograms, with a significant decrease in all aortic dimension z-scores by the post-operative echocardiogram, returning to initial z-score values. Growth rates (mm/year) between the initial and intermediate echocardiograms compared to the intermediate and post-operative echocardiograms were greater for aortic annulus (8.9 ± 12.1 vs. 1.7 ± 3.2, p < 0.001), root (10.6 ± 9.3 vs. 2.3 ± 3.1, p < 0.001), and ST junction (9.1 ± 8.7 vs. 2.0 ± 3.3, p < 0.001), and did not differ by surgical strategy (staged vs. single-stage complete repair). Aortic dimension z-scores continued to significantly decrease at long-term follow-up (median follow-up time 8.5 years [IQR 3.8-13 years]). Only 4 patients in the cohort had more than mild aortic regurgitation at the post-operative echocardiogram (2 moderate, 2 severe), and all 4 patients eventually required surgical intervention on the aortic valve and ascending aorta within the long-term follow-up time frame. Our study demonstrated severely dilated z-scores for all aortic measurements across time, with an increase in growth rates before complete repair and return to initial values over a year following septation with continued decrease at long-term follow-up. These results support that progressive aortic dilation after complete repair does not occur, and despite severe aortic dilation, the incidence of requiring major aortic intervention for patients with TOF/PA/MAPCAs at long-term follow-up remains low. These findings may serve as the foundation for establishing normative reference values specific to this population, and could facilitate the development of new z-score equations that more accurately reflect expected aortic dimensions. Improved characterization of the longitudinal findings in this population better equips us to counsel families, and provides helpful clinical guidance for interval surveillance evaluations.

  View details for DOI 10.1007/s00246-026-04414-w

  View details for PubMedID 42560516

  View details for PubMedCentralID 5812349

• Indications for continuous electroencephalography and frequency of electrographic seizure detection in a pediatric and neonatal cardiovascular intensive care unit. Epilepsia Segal, J. B., Yang, J. K., Silverman, A., Darji, H., He, Z., Campen, C. J. 2025

  Abstract

  OBJECTIVE: Seizures are a recognized complication of critical cardiovascular illness in infants and children. We assessed the diagnostic yield of continuous video-electroencephalography (cEEG) in a pediatric and neonatal cardiovascular intensive care unit (CVICU) by the symptoms and risk factors prompting cEEG evaluation.METHODS: This retrospective case series included all consecutive cEEGs in patients ≤21years old performed in one CVICU over 38months. cEEG indications were categorized as (1) index symptoms of concern and/or (2) clinical risk factors. Index symptoms were divided into (1) vital sign symptoms (i.e., heart rate, blood pressure, oxygen, respiration, or temperature) and (2) non-vital sign symptoms (i.e., mental status, abnormal movements, eye findings, weakness, or failed extubation). Indications for cEEG were extracted by manual chart review. The presence of seizures was established electrographically from neurophysiologist reports.RESULTS: There were 605 cEEGs from 411 patients. The median study was 26h (25%-75%, interquartile range=20-41h). Seizures were detected in 57 of 605 (9%) cEEGs overall; in 34 of 356 (10%) cEEGs obtained for risk factors alone (odds ratio [OR] =1.03, 95% confidence interval [CI] = .60-1.82, p=.90), 0 of 104 (0%) for isolated vital sign changes (p<.001), 10 of 101 (10%) for symptoms not involving vital signs (OR=1.06, 95% CI = .52-2.09, p=.88), and in 13 of 44 (30%) for both vital sign and non-vital sign symptoms (OR=4.93, 95% CI=2.45-9.77, p<.001). On univariate analysis, symptoms involving gaze deviation, abnormal limb movements, or intermittent oxygen desaturation, and the risk factors of preexisting epilepsy, recent neurosurgery, acute stroke, and cardiac air embolism were associated with seizures (p<.05).SIGNIFICANCE: There were zero electrographic seizures in cEEGs obtained for isolated vital sign changes, whereas cEEGs obtained for the combination of vital sign changes and other non-vital sign symptoms were five times more likely to detect electrographic seizures than cEEGs obtained based on risk factors alone.

  View details for DOI 10.1111/epi.18253

  View details for PubMedID 39760979

• Extended Rhythm Monitoring to Assess for Ventricular Arrhythmias After Transcatheter Pulmonary Valve Replacement With the Harmony Valve. Circulation. Cardiovascular interventions Yang, J. K., Wattenbarger, L., Taylor, A. C., Chubb, H., Romfh, A. W., Peng, L. F., Ceresnak, S. R., Dubin, A. M., McElhinney, D. B. 2024: e014381

  Abstract

  Varying rates of nonsustained ventricular tachycardia (NSVT) have been reported early after transcatheter pulmonary valve replacement (TPVR) with the Harmony valve, but data regarding rhythm outcomes beyond hospital discharge are limited. This study aims to characterize ventricular arrhythmias after Harmony TPVR from implant through mid-term follow-up.Ventricular arrhythmia data from postimplant telemetry and follow-up extended rhythm monitoring (ERM) were analyzed after Harmony TPVR.Fifty-four patients with tetralogy of Fallot (n=39), valvar pulmonary stenosis (n=10), or pulmonary atresia with intact ventricular septum (n=5) were studied; 22% had prior NSVT and 24% were on prior rhythm medication. On postimplant telemetry, 27 patients (50%) had NSVT, including 1 who had torsade de pointes, but most had <5 episodes. Pre-TPVR NSVT or rhythm medications, diagnosis other than tetralogy, and substantial device contact with the myocardium were associated with more frequent NSVT on telemetry. Ten patients (19%) were started on a new antiarrhythmic medication. On discharge ERM, 37% of patients had NSVT, most with <5 episodes and only 13% with NSVT beyond 5 days post-discharge. On follow-up ERM, 14% of patients had a single episode of NSVT and 1 had 5 episodes. During follow-up, antiarrhythmic medications were discontinued in 8 of 10 patients and no patients died or had sustained ventricular tachycardia.NSVT and ventricular ectopy were common early after TPVR but were infrequent in most cases and diminished rapidly after discharge. The incidence of NSVT on follow-up ERM was similar to preimplant incidence. Few patients had antiarrhythmic medications initiated, and most were discontinued on follow-up. There were no major arrhythmic events after discharge.

  View details for DOI 10.1161/CIRCINTERVENTIONS.124.014381

  View details for PubMedID 39727055

• Mitigating Alarm Fatigue and Improving the Bedside Experience by Reducing Non-actionable Alarms. The Journal of pediatrics Yang, J. K., Su, F., Graber-Naidich, A., Hedlin, H., Madsen, N., DeSousa, C., Feehan, S., Graves, A., Palmquist, A., Cable, R., Kipps, A. K. 2024: 114278

  Abstract

  To assess whether conditional bedside alarm triggers can reduce the frequency of non-actionable alarms without compromising patient safety and enhance nursing and family satisfaction.Single center, quality improvement initiative in an acute care cardiac unit (ACCU) and pediatric intensive care unit (PICU). Following the 4-week pre-intervention baseline period, bedside monitors were programmed with hierarchical time delay and conditional alarm triggers. Bedside alarms were tallied for 4 weeks each in the immediate post intervention period and 2-year follow-up. The primary outcome was alarms per monitored patient day. Nurses and families were surveyed pre- and post-intervention.A total of 1509 patients contributed to 2034, 1968, and 2043 monitored patient days which were evaluated in the baseline, follow-up, and 2-year follow-up periods, respectively. The median number of alarms per monitored patient day decreased by 75% in the PICU (p<0.001) and 82% in the ACCU (p<0.001) with sustained effect at 2-year follow-up. No increase of rapid response calls, emergent transfers, or code events occurred in either unit. Nursing surveys reported an improved capacity to respond to alarms and fewer perceived non-actionable alarms. Family surveys, however, did not demonstrate improved sleep quality.Implemented changes to bedside monitor alarms decreased total alarm frequency in both the acute care cardiac unit and pediatric intensive care unit, improving the care provider experience without compromising safety.

  View details for DOI 10.1016/j.jpeds.2024.114278

  View details for PubMedID 39216620

• Intraoperative and Postoperative Hemodynamic Predictors of Acute Kidney Injury in Pediatric Heart Transplant Recipients. Journal of pediatric intensive care Hollander, S. A., Chung, S., Reddy, S., Zook, N., Yang, J., Vella, T., Navaratnam, M., Price, E., Sutherland, S. M., Algaze, C. A. 2024; 13 (1): 37-45

  Abstract

  Acute kidney injury (AKI) is common after pediatric heart transplantation (HT) and is associated with inferior patient outcomes. Hemodynamic risk factors for pediatric heart transplant recipients who experience AKI are not well described. We performed a retrospective review of 99 pediatric heart transplant patients at Lucile Packard Children's Hospital Stanford from January 1, 2015, to December 31, 2019, in which clinical and demographic characteristics, intraoperative perfusion data, and hemodynamic measurements in the first 48 postoperative hours were analyzed as risk factors for severe AKI (Kidney Disease: Improving Global Outcomes [KDIGO] stage ≥ 2). Univariate analysis was conducted using Fisher's exact test, Chi-square test, and the Wilcoxon rank-sum test, as appropriate. Multivariable analysis was conducted using logistic regression. Thirty-five patients (35%) experienced severe AKI which was associated with lower intraoperative cardiac index ( p  = 0.001), higher hematocrit ( p  < 0.001), lower body temperature ( p  < 0.001), lower renal near-infrared spectroscopy ( p  = 0.001), lower postoperative mean arterial blood pressure (MAP: p  = 0.001), and higher central venous pressure (CVP; p  < 0.001). In multivariable analysis, postoperative CVP >12 mm Hg (odds ratio [OR] = 4.27; 95% confidence interval [CI]: 1.48-12.3, p  = 0.007) and MAP <65 mm Hg (OR = 4.9; 95% CI: 1.07-22.5, p  = 0.04) were associated with early severe AKI. Children with severe AKI experienced longer ventilator, intensive care, and posttransplant hospital days and inferior survival ( p  = 0.01). Lower MAP and higher CVP are associated with severe AKI in pediatric HT recipients. Patients, who experienced AKI, experienced increased intensive care unit (ICU) morbidity and inferior survival. These data may guide the development of perioperative renal protective management strategies to reduce AKI incidence and improve patient outcomes.

  View details for DOI 10.1055/s-0041-1736336

  View details for PubMedID 38571984

  View details for PubMedCentralID PMC10987224

• Mitigating Alarm Fatigue and Improving the Care Provider, Patient, and Family Experience Through Reduction in Non-Actionable Bedside Alarms Yang, J. K., Su, F., DeSousa, C., Graber, A., Hedlin, H., Feehan, S., Graves, A., Palmquist, A., Madsen, N., Cable, R., Kipps, A. LIPPINCOTT WILLIAMS & WILKINS. 2022: A13205

  View details for DOI 10.1161/circ.146.suppl_1.13205

  View details for Web of Science ID 001839809400048

• Ventricular arrhythmias following transcatheter pulmonary valve replacement with the harmony TPV25 device. Catheterization and cardiovascular interventions : official journal of the Society for Cardiac Angiography & Interventions Taylor, A., Yang, J., Dubin, A., Chubb, M. H., Motonaga, K., Goodyer, W., Giacone, H., Peng, L., Romfh, A., McElhinney, D., Ceresnak, S. 2022

  Abstract

  BACKGROUND: Transcatheter pulmonary valve replacement (TPVR) with the Harmony valve (Medtronic, Inc.) was recently approved to treat postoperative native outflow tract pulmonary regurgitation. While the 22mm Harmony valve Early Feasibility Study demonstrated ventricular tachycardia (VT) in only 5% of patients, little is known about ventricular arrhythmias after TPVR with the larger 25mm valve (TPV25).METHODS: A single center review was performed of patients with TPV25 implant from 2020 to 2021. Demographic, cardiac, procedural, and postimplant cardiac telemetry data were collected and compared between patients who did and did not have peri-implant ventricular arrhythmia.RESULTS: Thirty patients underwent TPV25 at a median age of 30 years. On postimplant telemetry, VT events were documented in 12 patients (40%); 11 nonsustained VT (NSVT) (median 3 episodes per patient and 6 beats per episode, maximum 157 episodes) and 1 sustained VT (3%), with Torsades de Pointes secondary to a short coupled premature ventricular contraction (PVC). VT events were associated with annular valve positioning (p<0.001) and increased postimplant PVC burden (p<0.0001), but there was no association between VT and other demongraphic, historical, or procedural factors. The frequency of NSVT events fell from 3/hfrom 0 to 12h postimplant to 0.5/hr from 12 to 24h (p<0.001).CONCLUSION: VT occurred commonly (40%) in the first 24h after TPV25 implant, with self-limited NSVT in 11 of 12 patients and 1 patient with cardiac arrest secondary to Torsades de Pointes. VT only occurred with annular valve positioning. Larger, longer-term studies are needed to determine risk factors for and natural history of post-TPVR VT.

  View details for DOI 10.1002/ccd.30393

  View details for PubMedID 36198126

• VENTRICULAR ARRHYTHMIAS FOLLOWING TRANSCATHETER PULMONARY VALVE REPLACEMENT WITH THE HARMONY(C) TPV 25 DEVICE Taylor, A., Yang, J., Dubin, A., Chubb, M., Motonaga, K., Goodyer, W., Giacone, H., Peng, L. F., Romfh, A. W., McElhinney, D. B., Ceresnak, S. R. ELSEVIER SCIENCE INC. 2022: 1362

  View details for Web of Science ID 000781026601461

• Impact of a clinical pathway on acute kidney injury in patients undergoing heart transplant. Pediatric transplantation Algaze, C. A., Margetson, T. D., Sutherland, S. M., Kwiatkowski, D. M., Maeda, K., Navaratnam, M., Samreth, S. P., Price, E. P., Zook, N. B., Yang, J. K., Hollander, S. A. 2021: e14166

  Abstract

  BACKGROUND: To evaluate the impact of a clinical pathway on the incidence and severity of acute kidney injury in patients undergoing heart transplant.METHODS: This was a 2.5-year retrospective evaluation using 3years of historical controls within a cardiac intensive care unit in an academic children's hospital. Patients undergoing heart transplant between May 27, 2014, and April 5, 2017 (pre-pathway) and May 1, 2017, and November 30, 2019 (pathway) were included. The clinical pathway focused on supporting renal perfusion through hemodynamic management, avoiding or delaying nephrotoxic medications, and providing pharmacoprophylaxis against AKI.RESULTS: There were 57 consecutive patients included. There was an unadjusted 20% reduction in incidence of any acute kidney injury (p=.05) and a 17% reduction in Stage 2/3 acute kidney injury (p=.09). In multivariable adjusted analysis, avoidance of Stage 2/3 acute kidney injury was independently associated with the clinical pathway era (AOR -1.3 [95% CI -2.5 to -0.2]; p=.03), achieving a central venous pressure of or less than 12mmHg (AOR -1.3 [95% CI -2.4 to -0.2]; p=.03) and mean arterial pressure above 60mmHg (AOR -1.6 [95% CI -3.1 to -0.01]; p=.05) in the first 48h post-transplant, and older age at transplant (AOR - 0.2 [95% CI -0.2 to -0.06]; p=.002).CONCLUSIONS: This report describes a renal protection clinical pathway associated with a reduction in perioperative acute kidney injury in patients undergoing heart transplant and highlights the importance of normalizing perioperative central venous pressure and mean arterial blood pressure to support optimal renal perfusion.

  View details for DOI 10.1111/petr.14166

  View details for PubMedID 34727417

• Intraoperative and Postoperative Hemodynamic Predictors of Acute Kidney Injury in Pediatric Heart Transplant Recipients JOURNAL OF PEDIATRIC INTENSIVE CARE Hollander, S. A., Chung, S., Reddy, S., Zook, N., Yang, J., Vella, T., Navaratnam, M., Price, E., Sutherland, S. M., Algaze, C. A. 2021

  View details for DOI 10.1055/s-0041-1736336

  View details for Web of Science ID 000704825900002

• Early Functional Status After Surgery for Congenital Heart Disease: A Single-Center Retrospective Study. Pediatric critical care medicine : a journal of the Society of Critical Care Medicine and the World Federation of Pediatric Intensive and Critical Care Societies Han, B., Yang, J. K., Ling, A. Y., Ma, M., Kipps, A. K., Shin, A. Y., Beshish, A. G. 2021

  Abstract

  OBJECTIVES: The objective of this study is to investigate the change in functional status in infants, children, and adolescents undergoing congenital heart surgery using the Functional Status Scale.DESIGN: A single-center retrospective study.SETTING: A 26-bed cardiac ICU in a free-standing university-affiliated tertiary children's hospital.PATIENTS: All patients 0-18 years who underwent congenital heart surgery from January 1, 2014, to December 31, 2017.INTERVENTIONS: None.MEASUREMENTS AND MIN RESULTS: The primary outcome variable was change in Functional Status Scale scores from admission to discharge. Additionally, two binary outcomes were derived from the primary outcome: new morbidity (change in Functional Status Scale ≥ 3) and unfavorable functional outcome (change in Functional Status Scale ≥ 5); their association with risk factors was assessed using modified Poisson regression. Out of 1,398 eligible surgical encounters, 65 (4.6%) and 15 (1.0%) had evidence of new morbidity and unfavorable functional outcomes, respectively. Higher Surgeons Society of Thoracic and the European Association for Cardio-Thoracic Surgery score, single-ventricle physiology, and longer cardiopulmonary bypass time were associated with new morbidity. Longer hospital length of stay was associated with both new morbidity and unfavorable outcome.CONCLUSIONS: This study demonstrates the novel application of the Functional Status Scale on patients undergoing congenital heart surgery. New morbidity was noted in 4.6%, whereas unfavorable outcome in 1%. There was a small change in the total Functional Status Scale score that was largely attributed to changes in the feeding domain. Higher Society of Thoracic and the European Association for Cardio-Thoracic Surgery score, single-ventricle physiology, and longer cardiopulmonary bypass times were associated with new morbidity, whereas longer hospital length of stay was associated with both new morbidity and unfavorable outcome. Further studies with larger sample size will need to be done to confirm our findings and to better ascertain the utility of Functional Status Scale on this patient population.

  View details for DOI 10.1097/PCC.0000000000002838

  View details for PubMedID 34593740

• Non-Contact Video-Based Neonatal Respiratory Monitoring. Children (Basel, Switzerland) Rossol, S. L., Yang, J. K., Toney-Noland, C., Bergin, J., Basavaraju, C., Kumar, P., Lee, H. C. 2020; 7 (10)

  Abstract

  Respiratory rate (RR) has been shown to be a reliable predictor of cardio-pulmonary deterioration, but standard RR monitoring methods in the neonatal intensive care units (NICU) with contact leads have been related to iatrogenic complications. Video-based monitoring is a potential non-contact system that could improve patient care. This iterative design study developed a novel algorithm that produced RR from footage analyzed from stable NICU patients in open cribs with corrected gestational ages ranging from 33 to 40 weeks. The final algorithm used a proprietary technique of micromotion and stationarity detection (MSD) to model background noise to be able to amplify and record respiratory motions. We found significant correlation-r equals 0.948 (p value of 0.001)-between MSD and the current hospital standard, electrocardiogram impedance pneumography. Our video-based system showed a bias of negative 1.3 breaths and root mean square error of 6.36 breaths per minute compared to standard continuous monitoring. Further work is needed to evaluate the ability of video-based monitors to observe clinical changes in a larger population of patients over extended periods of time.

  View details for DOI 10.3390/children7100171

  View details for PubMedID 33036226

• Pectoral Nerve Blocks Decrease Postoperative Pain and Opioid Use After Pacemaker or Implantable Cardioverter-Defibrillator Placement in Children. Heart rhythm Yang, J. K., Char, D. S., Motonaga, K. S., Navaratnam, M., Dubin, A. M., Trela, A., Hanisch, D. G., McFadyen, G., Chubb, H., Goodyer, W., Ceresnak, S. R. 2020

  Abstract

  BACKGROUND: Pectoral nerve blocks (PECS) can reduce intra-procedural anesthetic requirements and postoperative pain. Little is known on the utility of PECS in reducing pain and narcotic use after pacemaker (PM) or implantable cardioverter defibrillator (ICD) placement in children.OBJECTIVE: To determine whether PECS can decrease postoperative pain and opioid use after PM or ICD placement in children.METHODS: A single center, retrospective review of pediatric patients undergoing transvenous PM or ICD placement between 2015-2020 was performed. Patients with recent cardiothoracic surgery or neurologic/developmental deficits were excluded. Demographics, procedural variables, postoperative pain, and postoperative opioid usage were compared between patients who underwent PECS and those who underwent conventional local anesthetic (CONTROL).RESULTS: A total of 74 patients underwent PM or ICD placement with 20 patients (27%) undergoing PECS. There were no differences between PECS and CONTROL with regard to age, weight, gender, type of device placed, presence of congenital heart disease, type of anesthesia, procedural time or complication rates. Patients who underwent PECS had lower pain scores at 1, 2, 6, 18, and 24-hours compared to CONTROL. PECS patients had a lower mean cumulative pain score [PECS 1.5 (95%-CI 0.8-2.2) vs CONTROL 3.1 (95%-CI 2.7-3.5); P<0.001] and lower total opioid use [PECS 6.0 MME/m2 (95%-CI 3.4-8.6) vs CONTROL 15.0 MME/m2 (95%-CI 11.8-18.2); P=0.001] over the 24-hours post-implant.CONCLUSIONS: Pectoralis nerve blocks reduce postoperative pain scores and lower total opioid usage after ICD or PM placement. PECS should be considered at the time of transvenous device placement in children.

  View details for DOI 10.1016/j.hrthm.2020.03.009

  View details for PubMedID 32201270

• Global Spinal Alignment in Cervical Kyphotic Deformity: The Importance of Head Position and Thoracolumbar Alignment in the Compensatory Mechanism. Neurosurgery Mizutani, J., Verma, K., Endo, K., Ishii, K., Abumi, K., Yagi, M., Hosogane, N., Yang, J., Tay, B., Deviren, V., Ames, C. 2018; 82 (5): 686-694

  Abstract

  Previous studies have evaluated cervical kyphosis (C-kypho) using cervical curvature or chin-brow vertical angle, but the relationship between C-kypho and global spinal alignment is currently unknown.To elucidate global spinal alignment and compensatory mechanisms in primary symptomatic C-kypho using full-spine radiography.In this retrospective multicenter study, symptomatic primary C-kypho patients (Cerv group; n = 103) and adult thoracolumbar deformity patients (TL group; n = 119) were compared. We subanalyzed Cerv subgroups according to sagittal vertical axis (SVA) values of C7 (SVAC7 positive or negative [C7P or C7N]). Various Cobb angles (°) and SVAs (mm) were evaluated.SVAC7 values were -20.2 and 63.6 mm in the Cerv group and TL group, respectively (P < .0001). Various statistically significant compensatory curvatures were observed in the Cerv group, namely larger lumbar lordosis (LL) and thoracic kyphosis. The C7N group had significantly lower SVACOG (center of gravity of the head) and SVAC7 (32.9 and -49.5 mm) values than the C7P group (115.9 and 45.1 mm). Sagittal curvatures were also different in T4-12, T10-L2, LL4-S, and LL. The value of pelvic incidence (PI)-LL was different (C7N vs C7P; -2.2° vs 9.9°; P < .0003). Compensatory sagittal curvatures were associated with potential for shifting of SVAC7 posteriorly to adjust head position. PI-LL affected these compensatory mechanisms.Compensation in symptomatic primary C-kypho was via posterior shifting of SVAC7, small T1 slope, and large LL. However, even in C-kypho patients, lumbar degeneration might affect global spinal alignment. Thus, global spinal alignment with cervical kyphosis is characterized as head balanced or trunk balanced.

  View details for DOI 10.1093/neuros/nyx288

  View details for PubMedID 28591781

• Interventional magnetic resonance imaging guided carotid embolectomy using a novel resonant marker catheter: demonstration of preclinical feasibility. Biomedical microdevices Yang, J. K., Cote, A. M., Jordan, C. D., Kondapavulur, S., Losey, A. D., McCoy, D., Chu, A., Yu, J. F., Moore, T., Stillson, C., Settecase, F., Alexander, M. D., Nicholson, A., Cooke, D. L., Saeed, M., Barry, D., Martin, A. J., Wilson, M. W., Hetts, S. W. 2017; 19 (4): 88

  Abstract

  To assess the visualization and efficacy of a wireless resonant circuit (wRC) catheter system for carotid artery occlusion and embolectomy under real-time MRI guidance in vivo, and to compare MR imaging modality with x-ray for analysis of qualitative physiological measures of blood flow at baseline and after embolectomy. The wRC catheter system was constructed using a MR compatible PEEK fiber braided catheter (Penumbra, Inc, Alameda, CA) with a single insulated longitudinal copper loop soldered to a printed circuit board embedded within the catheter wall. In concordance with IACUC protocol (AN103047), in vivo carotid artery navigation and embolectomy were performed in four farm pigs (40-45 kg) under real-time MRI at 1.5T. Industry standard clots were introduced in incremental amounts until adequate arterial occlusion was noted in a total of n=13 arteries. Baseline vasculature and restoration of blood flow were confirmed via MR and x-ray imaging, and graded by the Thrombolysis in Cerebral Infarction (TICI) scale. Wilcoxon signed-rank tests were used to analyze differences in recanalization status between DSA and MRA imaging. Successful recanalizations (TICI 2b/3) were compared to clinical rates reported in literature via binomial tests. The wRC catheter system was visible both on 5° sagittal bSSFP and coronal GRE sequence. Successful recanalization was demonstrated in 11 of 13 occluded arteries by DSA analysis and 8 of 13 by MRA. Recanalization rates based on DSA (0.85) and MRA (0.62) were not significantly different from the clinical rate of mechanical aspiration thrombectomy reported in literature. Lastly, a Wilcoxon signed rank test indicated no significant difference between TICI scores analyzed by DSA and MRA. With demonstrated compatibility and visualization under MRI, the wRC catheter system is effective for in vivo endovascular embolectomy, suggesting progress towards clinical endovascular interventional MRI.

  View details for DOI 10.1007/s10544-017-0225-9

  View details for PubMedID 28948399

  View details for PubMedCentralID PMC5896013

• In vitro clearance of doxorubicin with a DNA-based filtration device designed for intravascular use with intra-arterial chemotherapy. Biomedical microdevices Aboian, M. S., Yu, J. F., Gautam, A., Sze, C. H., Yang, J. K., Chan, J., Lillaney, P. V., Jordan, C. D., Oh, H. J., Wilson, D. M., Patel, A. S., Wilson, M. W., Hetts, S. W. 2016; 18 (6): 98

  Abstract

  To report a novel method using immobilized DNA within mesh to sequester drugs that have intrinsic DNA binding characteristics directly from flowing blood. DNA binding experiments were carried out in vitro with doxorubicin in saline (PBS solution), porcine serum, and porcine blood. Genomic DNA was used to identify the concentration of DNA that shows optimum binding clearance of doxorubicin from solution. Doxorubicin binding kinetics by DNA enclosed within porous mesh bags was evaluated. Flow model simulating blood flow in the inferior vena cava was used to determine in vitro binding kinetics between doxorubicin and DNA. The kinetics of doxorubicin binding to free DNA is dose-dependent and rapid, with 82-96 % decrease in drug concentration from physiologic solutions within 1 min of reaction time. DNA demonstrates faster binding kinetics by doxorubicin as compared to polystyrene resins that use an ion exchange mechanism. DNA contained within mesh yields an approximately 70 % decrease in doxorubicin concentration from solution within 5 min. In the IVC flow model, there is a 70 % drop in doxorubicin concentration at 60 min. A DNA-containing ChemoFilter device can rapidly clear clinical doses of doxorubicin from a flow model in simple and complex physiological solutions, thereby suggesting a novel approach to reduce the toxicity of DNA-binding drugs.

  View details for DOI 10.1007/s10544-016-0124-5

  View details for PubMedID 27778226

  View details for PubMedCentralID PMC5441460

• Endovascular MR-guided Renal Embolization by Using a Magnetically Assisted Remote-controlled Catheter System. Radiology Lillaney, P. V., Yang, J. K., Losey, A. D., Martin, A. J., Cooke, D. L., Thorne, B. R., Barry, D. C., Chu, A., Stillson, C., Do, L., Arenson, R. L., Saeed, M., Wilson, M. W., Hetts, S. W. 2016; 281 (1): 219-28

  Abstract

  Purpose To assess the feasibility of a magnetically assisted remote-controlled (MARC) catheter system under magnetic resonance (MR) imaging guidance for performing a simple endovascular procedure (ie, renal artery embolization) in vivo and to compare with x-ray guidance to determine the value of MR imaging guidance and the specific areas where the MARC system can be improved. Materials and Methods In concordance with the Institutional Animal Care and Use Committee protocol, in vivo renal artery navigation and embolization were tested in three farm pigs (mean weight 43 kg ± 2 [standard deviation]) under real-time MR imaging at 1.5 T. The MARC catheter device was constructed by using an intramural copper-braided catheter connected to a laser-lithographed saddle coil at the distal tip. Interventionalists controlled an in-room cart that delivered electrical current to deflect the catheter in the MR imager. Contralateral kidneys were similarly embolized under x-ray guidance by using standard clinical catheters and guidewires. Changes in renal artery flow and perfusion were measured before and after embolization by using velocity-encoded and perfusion MR imaging. Catheter navigation times, renal parenchymal perfusion, and renal artery flow rates were measured for MR-guided and x-ray-guided embolization procedures and are presented as means ± standard deviation in this pilot study. Results Embolization was successful in all six kidneys under both x-ray and MR imaging guidance. Mean catheterization time with MR guidance was 93 seconds ± 56, compared with 60 seconds ± 22 for x-ray guidance. Mean changes in perfusion rates were 4.9 au/sec ± 0.8 versus 4.6 au/sec ± 0.6, and mean changes in renal flow rate were 2.1 mL/min/g ± 0.2 versus 1.9 mL/min/g ± 0.2 with MR imaging and x-ray guidance, respectively. Conclusion The MARC catheter system is feasible for renal artery catheterization and embolization under real-time MR imaging in vivo, and quantitative physiologic measures under MR imaging guidance were similar to those measured under x-ray guidance, suggesting that the MARC catheter system could be used for endovascular procedures with interventional MR imaging. (©) RSNA, 2016.

  View details for DOI 10.1148/radiol.2016152036

  View details for PubMedID 27019290

  View details for PubMedCentralID PMC5047126

• Block Copolymer Membranes for Efficient Capture of a Chemotherapy Drug. ACS macro letters Chen, X. C., Oh, H. J., Yu, J. F., Yang, J. K., Petzetakis, N., Patel, A. S., Hetts, S. W., Balsara, N. P. 2016; 5 (8): 936-941

  Abstract

  We introduce the use of block copolymer membranes for an emerging application, "drug capture". The polymer is incorporated in a new class of biomedical devices, referred to as ChemoFilter, which is an image-guided temporarily deployable endovascular device designed to increase the efficacy of chemotherapy-based cancer treatment. We show that block copolymer membranes consisting of functional sulfonated polystyrene end blocks and a structural polyethylene middle block (S-SES) are capable of capturing doxorubicin, a chemotherapy drug. We focus on the relationship between morphology of the membrane in the ChemoFilter device and efficacy of doxorubicin capture measured in vitro. Using small-angle X-ray scattering and cryogenic scanning transmission electron microscopy, we discovered that rapid doxorubicin capture is associated with the presence of water-rich channels in the lamellar-forming S-SES membranes in aqueous environment.

  View details for DOI 10.1021/acsmacrolett.6b00459

  View details for PubMedID 27547493

  View details for PubMedCentralID PMC4989249

• In Vitro Capture of Small Ferrous Particles with a Magnetic Filtration Device Designed for Intravascular Use with Intraarterial Chemotherapy: Proof-of-Concept Study. Journal of vascular and interventional radiology : JVIR Mabray, M. C., Lillaney, P., Sze, C. H., Losey, A. D., Yang, J., Kondapavulur, S., Liu, D., Saeed, M., Patel, A., Cooke, D., Jun, Y. W., El-Sayed, I., Wilson, M., Hetts, S. W. 2016; 27 (3): 426-32.e1

  Abstract

  To establish that a magnetic device designed for intravascular use can bind small iron particles in physiologic flow models.Uncoated iron oxide particles 50-100 nm and 1-5 µm in size were tested in a water flow chamber over a period of 10 minutes without a magnet (ie, control) and with large and small prototype magnets. These same particles and 1-µm carboxylic acid-coated iron oxide beads were likewise tested in a serum flow chamber model without a magnet (ie, control) and with the small prototype magnet.Particles were successfully captured from solution. Particle concentrations in solution decreased in all experiments (P < .05 vs matched control runs). At 10 minutes, concentrations were 98% (50-100-nm particles in water with a large magnet), 97% (50-100-nm particles in water with a small magnet), 99% (1-5-µm particles in water with a large magnet), 99% (1-5-µm particles in water with a small magnet), 95% (50-100-nm particles in serum with a small magnet), 92% (1-5-µm particles in serum with a small magnet), and 75% (1-µm coated beads in serum with a small magnet) lower compared with matched control runs.This study demonstrates the concept of magnetic capture of small iron oxide particles in physiologic flow models by using a small wire-mounted magnetic filter designed for intravascular use.

  View details for DOI 10.1016/j.jvir.2015.09.014

  View details for PubMedID 26706187

  View details for PubMedCentralID PMC4769113

• Development and Validation of Endovascular Chemotherapy Filter Device for Removing High-Dose Doxorubicin: Preclinical Study. Journal of medical devices Patel, A. S., Saeed, M., Yee, E. J., Yang, J., Lam, G. J., Losey, A. D., Lillaney, P. V., Thorne, B., Chin, A. K., Malik, S., Wilson, M. W., Chen, X. C., Balsara, N. P., Hetts, S. W. 2014; 8 (4): 0410081-410088

  Abstract

  To develop a novel endovascular chemotherapy filter (CF) able to remove excess drug from the blood during intra-arterial chemotherapy delivery (IAC), thus preventing systemic toxicities and thereby enabling higher dose IAC. A flow circuit containing 2.5 mL of ion-exchange resin was constructed. Phosphate-buffered saline (PBS) containing 50 mg doxorubicin (Dox) was placed in the flow model with the hypothesis that doxorubicin would bind rapidly to resin. To simulate IAC, 50 mg of doxorubicin was infused over 10 min into the flow model containing resin. Similar testing was repeated with porcine serum. Doxorubicin concentrations were measured over 60 min and compared to controls (without resin). Single-pass experiments were also performed. Based on these experiments, an 18F CF was constructed with resin in its tip. In a pilot porcine study, the device was deployed under fluoroscopy. A control hepatic doxorubicin IAC model (no CF placed) was developed in another animal. A second CF device was created with a resin membrane and tested in the infrarenal inferior vena cava (IVC) of a swine. In the PBS model, resin bound 76% of doxorubicin in 10 min, and 92% in 30 min (P < 0.001). During IAC simulation, 64% of doxorubicin bound in 10 min and 96% in 60 min (P < 0.001). On average, 51% of doxorubicin concentration was reduced during each pass in single pass studies. In porcine serum, 52% of doxorubicin bound in 10 min, and 80% in 30 min (P < 0.05). CF device placement and administration of IAC were successful in three animals. No clot was present on the resin within the CF following the in vivo study. The infrarenal IVC swine study demonstrated promising results with up to 85% reduction in peak concentration by the CF device. An endovascular CF device was developed and shown feasible in vitro. An in vivo model was established with promising results supporting high-capacity rapid doxorubicin filtration from the blood that can be further evaluated in future studies.

  View details for DOI 10.1115/1.4027444

  View details for PubMedID 25653735

  View details for PubMedCentralID PMC4298098