Michael Ma, MD is an Assistant Professor of Cardiothoracic Surgery in the Division of Pediatric Cardiac Surgery at Stanford University. His practice encompasses all aspects of congenital heart disease, with an emphasis on neonates, complex biventricular repair, pulmonary artery reconstruction, and heart failure. Dr. Ma’s translational research lab utilizes biomechanical engineering principles to optimize existing and develop de novo surgical and endovascular therapies in the ongoing treatment of complex heart defects.

Clinical Focus

  • Neonatal Cardiac Surgery
  • Pediatric Cardiac Surgery
  • Thoracic and Cardiac Surgery

Academic Appointments

Professional Education

  • Board Certification: American Board of Thoracic Surgery, Thoracic and Cardiac Surgery (2017)
  • Board Certification: American Board of Thoracic Surgery, Congenital Cardiac Surgery (2021)
  • Board Certification, American Board of Thoracic Surgery, Congenital Cardiac Surgery (2021)
  • Fellowship: Stanford University Dept of Cardiothoracic Surgery (2018) CA
  • Residency: Stanford University Dept of Cardiothoracic Surgery (2016) CA
  • Medical Education: Columbia University College of Physicians and Surgeons (2010) NY
  • BS, Stanford University, Chemical Engineering (2003)

Current Research and Scholarly Interests

Our lab aims to understand the biomechanics that govern a wide spectrum of congenital heart defects, and how those biomechanics change with contemporary operative repair strategies. We simulate operations virtually via CFD, and in ex vivo and in vivo animal models, and analyze how the changes we make alter fluid flow, pressure, and stresses throughout the system. We hope that these experiments can impact and optimize existing techniques that translate quickly to the operating room.

Clinical Trials

  • Comparison of Methods of Pulmonary Blood Flow Augmentation in Neonates: Shunt Versus Stent (The COMPASS Trial) Recruiting

    COMPASS is a prospective multicenter randomized interventional trial. Participants with ductal-dependent pulmonary blood flow will be randomized to receive either a systemic-to-pulmonary artery shunt or ductal artery stent. Block randomization will be performed by center and by single vs. two ventricle status. Participants will be followed through the first year of life.

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  • The Medtronic Harmony™ Transcatheter Pulmonary Valve Clinical Study Not Recruiting

    The purpose of this study is to further evaluate the safety and effectiveness of the Harmony™ TPV system. The Pivotal/CAS phases of the study have transitioned into a post-approval study to confirm the long-term functionality of transcatheter implantation of the Medtronic Harmony TPV.

    Stanford is currently not accepting patients for this trial.

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All Publications

  • Simulation-Based Design of Bicuspidization of the Aortic Valve. The Journal of thoracic and cardiovascular surgery Kaiser, A. D., Haidar, M. A., Choi, P. S., Sharir, A., Marsden, A. L., Ma, M. R. 2024


    Severe congenital aortic valve pathology in the growing patient remains a challenging clinical scenario. Bicuspidization of the diseased aortic valve has proven to be a promising repair technique with acceptable durability. However, most understanding of the procedure is empirical and retrospective. This work seeks to design the optimal gross morphology associated with surgical bicuspidization with simulations, based on the hypothesis that modifications to the free edge length cause or relieve stenosis.Model bicuspid valves were constructed with varying free edge lengths and gross morphology. Fluid-structure interaction simulations were conducted in a single patient-specific model geometry. The models were evaluated for primary targets of stenosis and regurgitation. Secondary targets were assessed and included qualitative hemodynamics, geometric height, effective height, orifice area and billow.Stenosis decreased with increasing free edge length and was pronounced with free edge length ≤1.3 times the annular diameter d. With free edge length 1.5d or greater, no stenosis occurred. All models were free of regurgitation. Substantial billow occurred with free edge length ≥1.7d.Free edge length ≥1.5d was required to avoid aortic stenosis in simulations. Cases with free edge length ≥1.7d showed excessive billow and other changes in gross morphology. Cases with free edge length 1.5-1.6d have a total free edge length approximately equal to the annular circumference and appeared optimal. These effects should be studied in vitro and in animal studies.

    View details for DOI 10.1016/j.jtcvs.2023.12.027

    View details for PubMedID 38211896

  • Ex Vivo Modeling of Atrioventricular Valve Mechanics in Single Ventricle Physiology. Annals of biomedical engineering Moye, S. C., Kidambi, S., Lee, J. Y., Cowles, T. H., Gilligan-Steinberg, S. D., Bryan, A. Y., Wilkerson, R., Woo, Y. J., Ma, M. R. 2023


    Single ventricle physiology (SVP) is used to describe any congenital heart lesion that is unable to support independent pulmonary and systemic circulations. Current treatment strategies rely on a series of palliation surgeries that culminate in the Fontan physiology, which relies on the single functioning ventricle to provide systemic circulation while passively routing venous return through the pulmonary circulation. Despite significant reductions in early mortality, the presence of atrioventricular valve (AVV) regurgitation is a key predictor of heart failure in these patients. We sought to evaluate the biomechanical changes associated with the AVV in SVP physiologies. Left and right ventricles were sutured onto patient-derived 3D-printed mounts and mounted into an ex vivo systemic heart simulator capable of reproducing Norwood, Glenn, Fontan and Late Fontan physiologies. We found that the tricuspid anterior leaflet experienced elevated maximum force, average force, and maximum yank compared to the posterior and septal leaflets. Between physiologies, maximum yank was greatest in the Norwood physiology relative to the Glenn, Fontan, and Late Fontan physiologies. These contrasting trends suggest that long- and short-term mechanics of AVV failure in single ventricle differ and that AVV interventions should account for asymmetries in force profiles between leaflets and physiologies.

    View details for DOI 10.1007/s10439-023-03178-1

    View details for PubMedID 36966247

    View details for PubMedCentralID 5371563

  • Williams Syndrome: Supravalvar Aortic, Aortic Arch, Coronary and Pulmonary Arteries: Is Comprehensive Repair Advisable and Achievable? Seminars in thoracic and cardiovascular surgery. Pediatric cardiac surgery annual Ma, M., Martin, E., Algaze, C., Collins, R. T., McElhinney, D., Mainwaring, R., Hanley, F. 2023; 26: 2-8


    Williams syndrome, and various elastin protein mediated arteriopathies, presents a clinical challenge to pediatric cardiovascular specialists. In the severest phenotypes, multilevel obstruction to the systemic and pulmonic arterial systems result in biventricular dysfunction which can be imminently life-threatening. As a longstanding, quaternary referral center for complex pulmonary arteriopathies and pediatric connective tissue disease, Stanford Medicine Children's Health has developed a sizeable experience managing these patients. This manuscript is a summary of our current strategies, with a focus on our surgical techniques, peri-procedural considerations on timing and staging of various interventions, and long-term results.

    View details for DOI 10.1053/j.pcsu.2022.12.003

    View details for PubMedID 36842795

  • Force Profiles of Single Ventricle Atrioventricular Leaflets in Response to Annular Dilation and Leaflet Tethering. Seminars in thoracic and cardiovascular surgery Kidambi, S., Moye, S. C., Lee, J., Cowles, T. H., Strong, E. B., Wilkerson, R., Paulsen, M. J., Woo, Y. J., Ma, M. R. 2022


    We sought to understand how leaflet forces change in response to annular dilation and leaflet tethering in single ventricle physiology. Explanted fetal bovine tricuspid valves were sutured onto image-derived annuli and ventricular mounts. Control valves (CV) were secured to a size-matched HLHS-type annulus and compared to: 1) normal tricuspid valves (NTV) secured to a size-matched saddle-shaped annulus, 2) HLHS-type annulus with leaflet tethering (LT), 3) HLHS-type annulus with annular dilation (DIL), or 5) a combined disease model with both dilation and tethering (DIS). The specimens were tested in a systemic heart simulator at various SVPs. Leaflet forces were measured using optical strain sensors sutured to each leaflet edge. Average force in the anterior leaflet was 43.2% lower in CV compared to NTV (p<0.001). LT resulted in a 6.6% increase in average forces on the anterior leaflet (p=0.04), 10.7% increase on the posterior leaflet (p=0.03), and 14.1% increase on the septal leaflet (p<0.001). In DIL, average septal leaflet forces increased relative to the control valves by 42.2% (p=0.01). In DIS, average leaflet forces increased by 54.8% in the anterior leaflet (p<0.001), 37.6% in the posterior leaflet (p=0.03), and 79.9% in the septal leaflet (p<0.001). The anterior leaflet experiences the highest forces in the normal tricuspid annulus under SVP conditions. Annular dilation resulted in an increase in forces on the septal leaflet and leaflet tethering resulted in an increase in forces across all 3 leaflets. Annular dilation and leaflet tethering combined resulted in the largest increase in leaflet forces across all 3 leaflets.

    View details for DOI 10.1053/j.semtcvs.2022.09.012

    View details for PubMedID 36455710

  • Evaluating predicted heart mass in adolescent heart transplantation. The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation Lee, J. Y., Zawadzki, R. S., Kidambi, S., Rosenthal, D. N., Dykes, J. C., Nasirov, T., Ma, M. 2022


    BACKGROUND: Predicted Heart Mass (PHM) has emerged as an attractive size matching metric in adult cardiac transplantation. However, since PHM was derived from a healthy adult cohort, its generalizability to the pediatric population is unclear. We hypothesize that PHM can be extended to older adolescents, and potentially broaden the donor pool available to this group.METHODS: The United Network for Organ Sharing database was retrospectively analyzed for patients aged 13 to 18 undergoing heart transplantation. Recipients were divided into quintiles (Q1-Q5) based on donor-to-recipient predicted heart mass ratios (PHMR). Primary end-point was graft survival at 5 years.RESULTS: Two thousand sixty-one adolescent heart transplant recipients between January 1994 and September 2019 were retrospectively analyzed. The median PHMR's for each quintile was 0.84 (0.59-0.92), 0.97 (0.92-1.02), 1.08 (1.02-1.14), 1.21 (1.14-1.30), and 1.44 (1.30-2.31). Kaplan-Meier survival curves demonstrated comparable survival across all quintiles of PHMR (p=0.9). Multivariate Cox regression showed no significant difference in graft failure of the outer quintiles when compared to the middle quintile (Q1: 1.04 HR, p=0.80; Q2: 1.02 HR, p=0.89; Q4: 1.19 HR, p=0.28; Q5: 1.02 HR, p=0.89). Significant covariates included transplant year (HR: 0.95, p < 0.0001), serum bilirubin (HR: 1.04, p=0.0004), ECMO at transplantation (HR: 2.85, p < 0.0001), and underlying diagnosis of dilated cardiomyopathy (vs congenital heart disease, HR: 0.66, p=0.0004).CONCLUSIONS: Matching by PHM is not associated with survival or risk in adolescent heart transplant recipients. Our results underscore the ongoing need to develop an improved size-matching method in pediatric heart transplantation.

    View details for DOI 10.1016/j.healun.2022.08.027

    View details for PubMedID 36210265

  • Weight Matching in Infant Heart Transplantation: A National Registry Analysis. The Annals of thoracic surgery Lee, J. Y., Kidambi, S., Zawadzki, R. S., Rosenthal, D. N., Dykes, J. C., Nasirov, T., Ma, M. 2022


    BACKGROUND: Infants account for a significant proportion of pediatric heart transplants, but also suffer from a high waitlist mortality. Donor oversizing by weight-based criteria is common practice in transplantation and is prevalent in this group. We sought to analyze the impact of oversizing on outcomes in infants.METHODS: Infant heart transplantations reported to the United Network for Organ Sharing from 01/1994 to 09/2019 were retrospectively analyzed. 2384 heart transplantation recipients were divided into quintiles (Q1-Q5) based on donor-to-recipient weight ratios (DRWR). Multivariate Cox regression was used to estimate the effect of DRWR. The primary endpoint of graft survival at one year.RESULTS: The median DRWR for each quintile was 0.90 (0.37 to 1.04), 1.17 (1.04 to 1.29), 1.43 (1.29 to 1.57), 1.74 (1.58 to 1.97), and 2.28 (1.97 to 5.00). Pairwise comparisons showed improved survival for Q3 and Q4 over each of the bottom two quintiles and the top quintile, respectively. Regression analyses found that Q3 and Q4 were protective against graft failure when compared to the bottom two quintiles, respectively. There was no difference in hazard amongst the top three quintiles. Significant covariates included primary diagnosis, ischemic time, serum bilirubin, transplant year, mechanical ventilation at transplantation, extracorporeal membrane oxygenation at transplantation. Gender, female-to-male transplantation, and mechanical circulatory support at transplantation were not significant in univariate analyses.CONCLUSIONS: Modest oversizing by DRWR (1.29 to 1.97) is associated with increased survival and lower risk in infant heart transplantation. Additional investigation is needed to establish best practices for size-matching in this population.

    View details for DOI 10.1016/j.athoracsur.2022.05.067

    View details for PubMedID 35835207

  • Biomechanical Analysis of the Ross Procedure in an Ex Vivo Left Heart Simulator. World journal for pediatric & congenital heart surgery Bryan, A. Y., Brandon Strong, E., Kidambi, S., Gilligan-Steinberg, S., Bennett-Kennett, R., Lee, J. Y., Imbrie-Moore, A., Moye, S. C., Hendrickx-Rodriguez, S., Wang, H., Dauskardt, R. H., Joseph Woo, Y., Ma, M. R. 2022; 13 (2): 166-174


    BACKGROUND: Neo-aortic pulmonary autografts often experience root dilation and valve regurgitation over time. This study seeks to understand the biomechanical differences between aortic and neo-aortic pulmonary roots using a heart simulator.METHODS: Porcine aortic, neo-aortic pulmonary, and pulmonary roots (n=6) were mounted in a heart simulator (parameters: 100 mm Hg, 37 °C, 70 cycles per minute, 5.0 L/min cardiac output). Echocardiography was used to study root distensibility (percentage change in luminal diameter between systole and diastole) and valve function. Leaflet motion was tracked with high-speed videography. After 30 min in the simulator, leaflet thickness (via cryosectioning), and multiaxial modulus (via lenticular hydrostatic deformation testing) were obtained.RESULTS: There were no significant differences between aortic and neo-aortic pulmonary leaflet motion, including mean opening velocity (218 vs 248 mm/s, P=.27) or mean closing velocity (116 vs 157 mm/s, P=.12). Distensibility was similar between aortic (8.5%, 1.56 mm) and neo-aortic pulmonary (7.8%, 1.12 mm) roots (P=.59). Compared to virgin controls, native pulmonic roots exposed to systemic pressure for 30 min had reduced leaflet thickness (630 vs 385 m, P=.049) and a reduced Young's modulus (3,125 vs 1,089 kPa, P=.077). In contrast, the aortic roots exposed to pressure displayed no significant difference in aortic leaflet thickness (1,317 vs 1,256 m, P=.27) or modulus (5,931 vs 3,631 kPa, P=.56).CONCLUSIONS: Neo-aortic pulmonary roots demonstrated equivalence in valve function and distensibility but did experience changes in biomechanical properties and morphology. These changes may contribute to long-term complications associated with the Ross procedure.

    View details for DOI 10.1177/21501351211070288

    View details for PubMedID 35238706

  • Relation Between Pulmonary Artery Pressures Measured Intraoperatively and at One-Year Catheterization After Unifocalization and Repair of Tetralogy with Major Aortopulmonary Collateral Arteries. Seminars in thoracic and cardiovascular surgery Ma, M., Peng, L. F., Zhang, Y., Wise-Faberowski, L., Martin, E., Hanley, F. L., McElhinney, D. B. 1800


    To assess the relationships between pulmonary artery (PA) pressure and the PA:aortic systolic pressure ratio measured intraoperatively and at surveillance catheterization in patients achieving complete unifocalization and repair for tetralogy of Fallot with major aortopulmonary collateral arteries (TOF/MAPCAs). This was a single-center retrospective cohort analysis of all patients who underwent complete repair of TOF/MAPCAs from 2002-2019 and received a postoperative surveillance catheterization at our center 6-24 months after surgery. Associations between intraoperative and catheter hemodynamic data were analyzed. 163 patients were included. Median systolic PA pressure was 30 (quartiles 26, 35) and 35 (28, 42) mmHg intraoperatively and at catherization respectively; systolic aortic pressure 90 (86, 100) and 84 (76, 92); and PA:aortic pressure ratio was 0.33 (0.28, 0.40) and 0.41 (0.34, 0.49). Moderate correlation was found between the intraoperative and catheter-based hemodynamics, with the majority of systolic PA pressures within 10mmHg and PA:Ao systolic ratios within 0.1. Changes in the ratio were influenced to a similar degree by differences in PA and aortic pressures. Surgical and/or catheter reinterventions were more common in patients with both higher intraoperative PA systolic pressure and PA:aortic systolic ratios and in those with greater discrepancy between intraoperative and catheterization values. PA systolic pressure and the PA:aortic systolic pressure ratio measured immediately after repair remain useful metrics for assessing the initial operative PA reconstruction, and as indicators of longer term hemodynamics. Initially elevated and subsequently discrepant PA systolic pressure and PA:aortic systolic pressure ratios were associated with higher rates of reintervention. (Figure 7).

    View details for DOI 10.1053/j.semtcvs.2022.01.004

    View details for PubMedID 35092847

  • Alternative to heart-lung transplantation for end-stage tetralogy of Fallot with major aortopulmonary collaterals: Simultaneous heart transplantation and pulmonary artery reconstruction. The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation Adamson, G. T., Profita, E. L., Quinonez, Z. A., McElhinney, D. B., Rosenthal, D. N., Ma, M. n. 2021

    View details for DOI 10.1016/j.healun.2021.02.003

    View details for PubMedID 33674153

  • Longevity of large aortic allograft conduits in Tetralogy with major aortopulmonary collaterals. The Annals of thoracic surgery Ma, M. n., Arunamata, A. n., Peng, L. F., Wise-Faberowski, L. n., Hanley, F. L., McElhinney, D. B. 2021


    Appropriate conduit selection for right ventricle (RV) to pulmonary artery (PA) connection has been extensively studied, with older implantation age, pulmonary (v. aortic) homografts, and true-sizing associated with increased longevity. Notably, patients with PA arborization abnormalities (ie MAPCAs) are reported to require earlier and more frequent conduit interventions. We aim to understand the behavior of large diameter aortic homografts in patients with MAPCAs, which are programmatically utilized at our institution.This is a single-center retrospective cohort study including all children < 12 years of age who underwent RV-PA connection using an aortic homograft ≥ 16mm diameter between 2002-2019, with a primary outcome of freedom from any RV-PA reintervention and a secondary outcome of freedom from surgical reintervention. Patients were grouped by absolute and indexed conduit sizes for further analysis.A total of 336 conduits were followed for a median of 3.0 years; transcatheter (n = 30) and/or surgical (n = 35) reintervention was performed on 64 conduits. Estimated freedom from reintervention and surgical replacement was 84% and 90% at 5 years. Younger age and smaller absolute conduit size were associated with earlier reintervention, but conduit z-score (median 3.5) was not assocated with outcome.The programmatic use of oversized aortic homograft RV-PA conduits in the surgical repair of MAPCAs provides a focused experience that demonstrates similar longevity to reported best alternatives. Secondarily, conduit oversizing may improve durability and enables an increased likelihood of non-operative reintervention.

    View details for DOI 10.1016/j.athoracsur.2021.01.054

    View details for PubMedID 33600790

  • Unifocalization and pulmonary artery reconstruction in patients with tetralogy of Fallot and major aortopulmonary collateral arteries who underwent surgery before referral. The Journal of thoracic and cardiovascular surgery Ma, M. n., Zhang, Y. n., Wise-Faberowski, L. n., Lin, A. n., Asija, R. n., Hanley, F. L., McElhinney, D. B. 2020


    The study objective was to characterize and analyze outcomes in patients with tetralogy of Fallot and major aortopulmonary collateral arteries who had undergone surgery elsewhere before referral (prereferral surgery).Patients with tetralogy of Fallot and major aortopulmonary collateral arteries who underwent surgery between 2001 and 2019 at our center were reviewed. Prereferral surgery and unoperated patients were compared, as were subsets of prereferral surgery patients who had undergone different types of prior procedures. Primary outcomes included complete repair with survival to 6 months, death, and perioperative metrics.Of 576 patients studied, 200 (35%) had undergone a wide range and number of prior operations elsewhere, including 92 who had pulmonary blood supply through a shunt and 108 who had a right ventricle pulmonary artery connection. Patients who underwent prereferral surgery with an existing right ventricle pulmonary artery connection had undergone more prereferral surgery procedures than those with a shunt and were more likely to have a right ventricle outflow tract pseudoaneurysm or pulmonary artery stent (all P < .001) at the time of referral. The cumulative incidences of complete repair and death were similar regardless of prereferral surgery status, but the cumulative incidence of complete repair with 6-month survival was higher (P = .002) and of death lower (P = .18) in patients who had prior right ventricle pulmonary artery connection compared with those who had received a prior shunt only.Our comprehensive management strategy for tetralogy of Fallot and major aortopulmonary collateral arteries can be applied with excellent procedural results in both unoperated patients and those who have undergone multiple and varied procedures elsewhere.

    View details for DOI 10.1016/j.jtcvs.2020.03.062

    View details for PubMedID 32444187

  • Corrected Transposition: Anatomic Repair Using the Hemi-Mustard Atrial Baffle and Bidirectional Superior Cavopulmonary Connection. Seminars in thoracic and cardiovascular surgery. Pediatric cardiac surgery annual Ma, M. n., Mainwaring, R. D., Hanley, F. L. 2019; 22: 51–56


    Anatomic repair for congenitally corrected transposition requires thoughtful surgical planning at both initial (neonatal or late) presentation, and during definitive repair. An algorithmic approach to the overall management of this lesion, with its many associated intracardiac anomalies, is presented. Modified atrial switch with bidirectional superior cavopulmonary connection is commonly utilized and demonstrates favorable results through a 20-year experience. Herein, technical considerations learned during the implementation of this strategy are described and emphasize the concept, in selected cases, of native pulmonary root preservation by translocation as an adjunct that is uniquely suited by adopting this approach.

    View details for PubMedID 31027564

  • Comprehensive Management of Major Aortopulmonary Collaterals in the Repair of Tetralogy of Fallot. Seminars in thoracic and cardiovascular surgery. Pediatric cardiac surgery annual Ma, M., Mainwaring, R. D., Hanley, F. L. 2018; 21: 75–82


    The heterogenous anatomy of Tetralogy of Fallot with major aortopulmonary collateral arteries has engendered a similar degree of diversity in its management and, ultimately, outcome. We summarize our comprehensive treatment paradigm for this lesion evolved over 15 years of experience through 458 patients and the results obtained. An updated analysis of 307 patients treated primarily at our institution is included. A review of recent literature, comparison of management strategies, and discussion of ongoing controversies are provided.

    View details for PubMedID 29425528

  • A novel inflow cannulation strategy for pediatric mechanical circulatory support in small left ventricles. journal of thoracic and cardiovascular surgery Ma, M., Yarlagadda, V. V., Rosenthal, D. N., Maeda, K. 2017

    View details for DOI 10.1016/j.jtcvs.2017.03.034

    View details for PubMedID 28416331

  • Long-Term Outcomes After Lung Transplantation in Children With Intellectual Disabilities. Pediatric transplantation Lee, J. Y., Mullis, D. M., Zawadzki, R. S., Nilkant, R., Kuhan, S., Kidambi, S., Sharir, A., Ma, M. 2024; 28 (5): e14807


    The United Network for Organ Sharing (UNOS) started recording data on intellectual disability status in 2008. This study aimed to characterize the long-term outcomes for children with intellectual disabilities (IDs) undergoing lung transplantation.All pediatric patients (under 18 years old) undergoing bilateral lung transplantation were identified using the UNOS database. The patients were grouped into the following categories: no cognitive delay, possible cognitive delay, and definite cognitive delay. The primary endpoint was graft survival at 3-year posttransplantation. Multivariate Cox proportional hazards modeling was used to estimate the independent effect of cognitive disability on graft survival.Five hundred four pediatric patients who underwent lung transplantation between March 2008 and December 2022 were retrospectively analyzed. 59 had a definite cognitive delay (12%), 23 had a possible delay (5%), and 421 had no delay (83%). When comparing these three groups, there was no significant difference in 60-day graft survival (p = 0.4), 3-year graft survival (p = 0.6), 3-year graft survival for patients who survived at least 60-day posttransplantation (p = 0.9), distribution of causes of death (p = 0.24), nor distribution treatment of rejection within 1-year posttransplantation (p = 0.06).Intellectual disability does not impact long-term outcomes after bilateral lung transplantation. Intellectual disability should not be a contraindication to bilateral lung transplantation on the basis of inferior graft survival.

    View details for DOI 10.1111/petr.14807

    View details for PubMedID 38923151

  • Effect of graft sizing in valve-sparing aortic root replacement for bicuspid aortic valve: The Goldilocks ratio. JTCVS techniques Choi, P. S., Sharir, A., Ono, Y., Shibata, M., Kaiser, A. D., Zhu, Y., Marsden, A. L., Woo, Y. J., Ma, M. R., Kim, J. B. 2024; 25: 1-7


    To investigate the effect of graft sizing on valve performance in valve-sparing aortic root replacement for bicuspid aortic valve.In addition to a diseased control model, 3 representative groups-free-edge length to aortic/graft diameter (FELAD) ratio <1.3, 1.5 to 1.64, and >1.7-were replicated in explanted porcine aortic roots (n = 3) using straight grafts sized respective to the native free-edge length. They were run on a validated ex vivo univentricular system under physiological parameters for 20 cycles. All groups were tested within the same aortic root to minimize inter-root differences. Outcomes included transvalvular gradient, regurgitation fraction, and orifice area. Linear mixed effects model and pairwise comparisons were employed to compare outcomes across groups.The diseased control had mean transvalvular gradient 10.9 ± 6.30 mm Hg, regurgitation fraction 32.5 ± 4.91%, and orifice area 1.52 ± 0.12 cm2. In ex vivo analysis, all repair groups had improved regurgitation compared with control (P < .001). FELAD <1.3 had the greatest amount of regurgitation among the repair groups (P < .001) and 1.5-1.64 the least (P < .001). FELAD <1.3 and >1.7 exhibited greater mean gradient compared with both control and 1.5 to 1.64 (P < .001). Among the repair groups, 1.5 to 1.64 had the largest orifice area, and >1.7 the smallest (P < .001).For a symmetric bicuspid aortic valve, performance after valve-sparing aortic root replacement shows a bimodal distribution across graft size. As the FELAD ratio departs from 1.5 to 1.64 in either direction, significant increases in transvalvular gradient are observed. FELAD <1.3 may also result in suboptimal improvement of baseline regurgitation.

    View details for DOI 10.1016/j.xjtc.2024.03.025

    View details for PubMedID 38899072

    View details for PubMedCentralID PMC11184666

  • SURGICAL OUTCOMES IN PATIENTS UNDERGOING A DOUBLE SWITCH OPERATION FOR CORRECTED TRANSPOSITION. The Annals of thoracic surgery Mainwaring, R. D., Felmly, L. M., Ho, D. Y., Arunamata, A., Algaze, C., Ma, M., Hanley, F. L. 2024


    BACKGROUND: Congenitally corrected transposition of the great arteries (CC-TGA) is a rare and complex form of congenital heart disease. Results of physiologic repair proved disappointing due to late right ventricular dysfunction and/or tricuspid regurgitation. The current study was performed to evaluate surgical outcomes in patients undergoing a double switch for CC-TGA.METHODS: This was a retrospective review of 121 patients who underwent a double switch over a two-decade time frame (2002-2023). The median age of patients was 32 months. Forty-nine of 121 patients (40%) had undergone left ventricular retraining prior to double switch.RESULTS: Sixty-seven patients underwent an arterial switch whereas 54 underwent a Rastelli procedure. There were four in-hospital deaths (3.3%) including three who had a Rastelli procedure (5.6%) and one who had an arterial switch (1.5%). At a median follow-up of 30 months, there have been four late deaths (two Rastelli and two arterial switch). Combined early and late mortality was 9.3% for the Rastelli and 4.5% for arterial switch. Combined mortality was 2.0% for patients who required left ventricular retraining versus 9.7% for those who did not. For the 117 patients discharged from the hospital, 93% have normal or low normal left ventricular function and 96% have mild or less neo-aortic insufficiency.CONCLUSIONS: Surgical outcomes in patients undergoing a double switch procedure have been excellent both in the short- and mid-term. However, the Rastelli procedure was associated with a more than two-fold increase in mortality risk compared with the arterial switch.

    View details for DOI 10.1016/j.athoracsur.2024.04.022

    View details for PubMedID 38750683

  • A prospective multicenter feasibility study of a miniaturized implantable continuous flow ventricular assist device in smaller children with heart failure. The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation Almond, C. S., Davies, R., Adachi, I., Richmond, M., Law, S., Tunuguntla, H., Mao, C., Shaw, F., Lantz, J., Wearden, P. D., Jordan, L. C., Ichord, R. N., Burns, K., Zak, V., Magnavita, A., Gonzales, S., Conway, J., Jeewa, A., Freemon, D. '., Stylianou, M., Sleeper, L., Dykes, J. C., Ma, M., Fynn-Thompson, F., Lorts, A., Morales, D., Vanderpluym, C., Dasse, K., Patricia Massicotte, M., Jaquiss, R., Mahle, W. T. 2024


    There is no FDA-approved left ventricular assist device (LVAD) for smaller children permitting routine hospital discharge. Smaller children supported with LVADs typically remain hospitalized for months awaiting heart transplant-a major burden for families and a challenge for hospitals. We describe the initial outcomes of the Jarvik 2015, a miniaturized implantable continuous flow LVAD, in the NHLBI-funded Pumps for Kids, Infants, and Neonates (PumpKIN) study, for bridge-to-heart transplant.Children weighing 8 to 30 kg with severe systolic heart failure and failing optimal medical therapy were recruited at 7 centers in the United States. Patients with severe right heart failure and single-ventricle congenital heart disease were excluded. The primary feasibility endpoint was survival to 30 days without severe stroke or non-operational device failure.Of 7 children implanted, the median age was 2.2 (range 0.7, 7.1) years, median weight 10 (8.2 to 20.7) kilograms; 86% had dilated cardiomyopathy; 29% were INTERMACS profile 1. The median duration of Jarvik 2015 support was 149 (range 5 to 188) days where all 7 children survived including 5 to heart transplant, 1 to recovery, and 1 to conversion to a paracorporeal device. One patient experienced an ischemic stroke on day 53 of device support in the setting of myocardial recovery. One patient required ECMO support for intractable ventricular arrhythmias and was eventually transplanted from paracorporeal biventricular VAD support. The median pump speed was 1600 RPM with power ranging from 1-4 Watts. The median plasma free hemoglobin was 19, 30, 19 and 30 mg/dL at 7, 30, 90 and 180 days or time of explant, respectively. All patients reached the primary feasibility endpoint. Patient-reported outcomes with the device were favorable with respect to participation in a full range of activities. Due to financial issues with the manufacturer, the study was suspended after consent of the eighth patient.The Jarvik 2015 LVAD appears to hold important promise as an implantable continuous flow device for smaller children that may support hospital discharge. The FDA has approved the device to proceed to a 22-subject pivotal trial. Whether this device will survive to commercialization remains unclear because of the financial challenges faced by industry seeking to develop pediatric medical devices. (Supported by NIH/NHLBI HHS Contract N268201200001I, 02954497).

    View details for DOI 10.1016/j.healun.2024.02.003

    View details for PubMedID 38713124

  • Mortality and morbidity after combined heart and liver transplantation in the failing Fontan: An updated dual center retrospective study. Clinical transplantation Vaikunth, S. S., Ortega-Legaspi, J. M., Conrad, D. R., Chen, S., Daugherty, T., Haeffele, C. L., Teuteberg, J., Mclean, R., MacArthur, J. W., Woo, Y. J., Maeda, K., Ma, M., Nasirov, T., Hoteit, M., Hilscher, M. B., Wald, J., Mandelbaum, T., Olthoff, K. M., Abt, P. L., Atluri, P., Cevasco, M., Mavroudis, C. D., Fuller, S., Lui, G. K., Kim, Y. Y. 2024; 38 (4): e15302


    As the adult Fontan population with Fontan associated liver disease continues to increase, more patients are being referred for transplantation, including combined heart and liver transplantation.We report updated mortality and morbidity outcomes after combined heart and liver transplant in a retrospective cohort series of 40 patients (age 14 to 49 years) with Fontan circulation across two centers from 2006-2022.The 30-day, 1-year, 5-year and 10-year survival rate was 90%, 80%, 73% and 73% respectively. Sixty percent of patients met a composite comorbidity of needing either post-transplant mechanical circulatory support, renal replacement therapy or tracheostomy. Cardiopulmonary bypass time > 283 min (4.7 h) and meeting the composite comorbidity were associated with mortality by Kaplan Meier analysis.Further study to mitigate early mortality and the above comorbidities as well as the high risk of bleeding and vasoplegia in this patient population is warranted.

    View details for DOI 10.1111/ctr.15302

    View details for PubMedID 38567883

  • A probabilistic neural twin for treatment planning in peripheral pulmonary artery stenosis. International journal for numerical methods in biomedical engineering Lee, J. D., Richter, J., Pfaller, M. R., Szafron, J. M., Menon, K., Zanoni, A., Ma, M. R., Feinstein, J. A., Kreutzer, J., Marsden, A. L., Schiavazzi, D. E. 2024: e3820


    The substantial computational cost of high-fidelity models in numerical hemodynamics has, so far, relegated their use mainly to offline treatment planning. New breakthroughs in data-driven architectures and optimization techniques for fast surrogate modeling provide an exciting opportunity to overcome these limitations, enabling the use of such technology for time-critical decisions. We discuss an application to the repair of multiple stenosis in peripheral pulmonary artery disease through either transcatheter pulmonary artery rehabilitation or surgery, where it is of interest to achieve desired pressures and flows at specific locations in the pulmonary artery tree, while minimizing the risk for the patient. Since different degrees of success can be achieved in practice during treatment, we formulate the problem in probability, and solve it through a sample-based approach. We propose a new offline-online pipeline for probabilistic real-time treatment planning which combines offline assimilation of boundary conditions, model reduction, and training dataset generation with online estimation of marginal probabilities, possibly conditioned on the degree of augmentation observed in already repaired lesions. Moreover, we propose a new approach for the parametrization of arbitrarily shaped vascular repairs through iterative corrections of a zero-dimensional approximant. We demonstrate this pipeline for a diseased model of the pulmonary artery tree available through the Vascular Model Repository.

    View details for DOI 10.1002/cnm.3820

    View details for PubMedID 38544354

  • Beating Heart Transplant Procedures Using Organs From Donors With Circulatory Death. JAMA network open Krishnan, A., Ruaengsri, C., Guenthart, B. A., Shudo, Y., Wang, H., Ma, M. R., MacArthur, J. W., Hiesinger, W., Woo, Y. J. 2024; 7 (3): e241828


    The use of ex vivo normothermic organ perfusion has enabled the use of deceased after circulatory death (DCD) donors for heart transplants. However, compared with conventional brain death donation, DCD heart transplantation performed with ex vivo organ perfusion involves an additional period of warm and cold ischemia, exposing the allograft to multiple bouts of ischemia reperfusion injury and may contribute to the high rates of extracorporeal membrane oxygenation usage after DCD heart transplantation.To assess whether the beating heart method of DCD heart transplantation is safe and whether it has an acceptable rate of extracorporeal membrane oxygenation use postoperatively.This case series includes 10 patients with end-stage heart failure undergoing DCD heart transplantation at a single academic medical center from October 1, 2022, to August 3, 2023. Data were analyzed from October 2022 to August 2023.Using a beating heart method of implantation of the donor allograft.The main outcome was primary graft dysfunction necessitating postoperative initiation of mechanical circulatory support. Survival and initiation of mechanical circulatory support were secondary outcomes.In this case series, 10 consecutive patients underwent DCD heart transplantation via the beating heart method. Ten of 10 recipients were male (100%), the mean (SD) age was 51.2 (13.8) years, and 7 (70%) had idiopathic dilated cardiomyopathy. Ten patients (100%) survived, and 0 patients had initiation of extracorporeal membrane oxygenation postoperatively. No other mechanical circulatory support, including intra-aortic balloon pump, was initiated postoperatively. Graft survival was 100% (10 of 10 patients), and, at the time of publication, no patients have been listed for retransplantation.In this study of 10 patients undergoing heart transplantation, the beating heart implantation method for DCD heart transplantation was safe and may mitigate ischemia reperfusion injury, which may lead to lower rates of primary graft dysfunction necessitating extracorporeal membrane oxygenation. These results are relevant to institutions using DCD donors for heart transplantation.

    View details for DOI 10.1001/jamanetworkopen.2024.1828

    View details for PubMedID 38466306

  • Impact of Congenital Heart Disease on the Outcomes of Very Low Birth Weight Infants. American journal of perinatology Chen, X., Bhombal, S., Kwiatkowski, D. M., Ma, M., Chock, V. Y. 2024


    OBJECTIVE: To investigate the association of congenital heart disease (CHD) with morbidity and mortality of very low birth weight (VLBW) infants.STUDY DESIGN: This matched case-control study included VLBW infants born at a single institution between 2001 and 2015. The primary outcome was mortality. Secondary outcomes included necrotizing enterocolitis, bronchopulmonary dysplasia (BPD), sepsis, retinopathy of prematurity, and intraventricular hemorrhage. These outcomes were assessed by comparing VLBW-CHDs with control VLBW infants matched by gestational age within a week, birth weight within 500g, sex, and birth date within a year using conditional logistic regression. Multivariable logistic regression analyzed differences in outcomes in the VLBW-CHD group between two birth periods (2001-2008 and 2009-2015) to account for changes in practice.RESULTS: In a cohort of 44 CHD infants matched with 88 controls, the mortality rate was 27% in infants with CHD and 1% in controls (p<0.0001). The VLBW-CHDs had increased BPD; (odds ratio [OR]: 7.70, 95% confidence interval [CI]: 1.96-30.29) and sepsis (OR: 10.59, 95% CI: 2.99-37.57) compared with the control VLBWs. When adjusted for preoperative ventilator use, the VLBW-CHDs still had significantly higher odds of BPD (OR: 6.97, 95% CI: 1.73-28.04). VLBW-CHDs also had significantly higher odds of both presumed and culture-positive sepsis as well as late-onset sepsis than their matched controls. There were no significant differences in outcomes between the two birth periods.CONCLUSION: VLBW-CHDs showed higher odds of BPD, sepsis, and mortality than VLBW infants without CHD. Future research should focus on the increased mortality and specific complications encountered by VLBW infants with CHD and implement targeted strategies to address these risks.KEY POINTS: · Incidence of CHD is higher in preterm infants than in term infants but the incidence of their morbidities is not well described.. · VLBW infants with CHD have higher odds of mortality, bronchopulmonary dysplasia, and sepsis.. · Future research is needed to implement targeted preventive responses..

    View details for DOI 10.1055/s-0044-1781460

    View details for PubMedID 38408479

  • Right Ventricular and Outflow Tract Functional Characteristics After Repair of Tetralogy of Fallot with Major Aortopulmonary Collaterals. Pediatric cardiology Long, Z. B., Punn, R., Zhang, Y., Arunamata, A. A., Asija, R., Ma, M., Hanley, F. L., McElhinney, D. B. 2024


    This study describes right ventricle (RV) characteristics and right ventricle to pulmonary artery (RV-PA) conduit function pre- and post-repair in patients with tetraology of Fallot with major aortopulmonary collaterals (TOF/MAPCAs). We reviewed patients who underwent single-stage, complete unifocalization, and repair of TOF/MAPCAs between 2006 and 2019 with available pre- and early postoperative echocardiograms. For a subset of patients, 6-12 month follow-up echocardiogram was available. RV and left ventricle (LV) characteristics and RV-PA conduit function were reviewed. Wilcoxon signed rank test and McNemar's test were used. 170 patients were reviewed, 46 had follow-up echocardiograms. Tricuspid valve annular plane systolic excursion (TAPSE) Z-scores were reduced from pre- (Z-score 0.01) to post-repair (Z-score -4.5, p < 0.001), improved but remained abnormal at follow-up (Z-score -4.0, p < 0.001). RV fractional area change (FAC) and LV ejection fraction were not significantly different before and after surgery. Conduit regurgitation was moderate or greater in 11% at discharge, increased to 65% at follow-up. RV-PA conduit failure (severe pulmonary stenosis or severe pulmonary regurgitation) was noted in 61, and 63% had dilated RV (diastolic RV area Z-score > 2) at follow-up. RV dilation correlated with the severe conduit regurgitation (p = 0.018). Longitudinal RV function was reduced after complete repair of TOF/MAPCAs, with decreased TAPSE and preserved FAC and LV ejection fraction. TAPSE improved but did not normalize at follow-up. Severe RV-PA conduit dysfunction was observed prior to discharge in 11% of patients and in 61% at follow-up. RV dilation was common at follow-up, especially in the presence of severe conduit regurgitation.

    View details for DOI 10.1007/s00246-024-03412-0

    View details for PubMedID 38360921

    View details for PubMedCentralID 6035101

  • Esophageal lung, pulmonary artery sling and congenital tracheal stenosis: A case report JOURNAL OF PEDIATRIC SURGERY CASE REPORTS Liang, N. E., Kim, G. S., Gugig, R., Ma, M., Coll, A., Sidell, D., Bruzoni, M. 2024; 101
  • Avoiding Obstructive Behavior. The Annals of thoracic surgery Choi, P. S., Ma, M. 2023

    View details for DOI 10.1016/j.athoracsur.2023.11.010

    View details for PubMedID 37952758

  • SDF4CHD: Generative Modeling of Cardiac Anatomies with Congenital Heart Defects. ArXiv Kong, F., Stocker, S., Choi, P. S., Ma, M., Ennis, D. B., Marsden, A. 2023


    Congenital heart disease (CHD) encompasses a spectrum of cardiovascular structural abnormalities, often requiring customized treatment plans for individual patients. Computational modeling and analysis of these unique cardiac anatomies can improve diagnosis and treatment planning and may ultimately lead to improved outcomes. Deep learning (DL) methods have demonstrated the potential to enable efficient treatment planning by automating cardiac segmentation and mesh construction for patients with normal cardiac anatomies. However, CHDs are often rare, making it challenging to acquire sufficiently large patient cohorts for training such DL models. Generative modeling of cardiac anatomies has the potential to fill this gap via the generation of virtual cohorts; however, prior approaches were largely designed for normal anatomies and cannot readily capture the significant topological variations seen in CHD patients. Therefore, we propose a type- and shape-disentangled generative approach suitable to capture the wide spectrum of cardiac anatomies observed in different CHD types and synthesize differently shaped cardiac anatomies that preserve the unique topology for specific CHD types. Our DL approach represents generic whole heart anatomies with CHD type-specific abnormalities implicitly using signed distance fields (SDF) based on CHD type diagnosis, which conveniently captures divergent anatomical variations across different types and represents meaningful intermediate CHD states. To capture the shape-specific variations, we then learn invertible deformations to morph the learned CHD type-specific anatomies and reconstruct patient-specific shapes. Our approach has the potential to augment the image-segmentation pairs for rarer CHD types for cardiac segmentation and generate cohorts of CHD cardiac meshes for computational simulation.

    View details for PubMedID 37961745

    View details for PubMedCentralID PMC10635288

  • Prenatal Diagnosis and Postnatal Management of a Fetal Pericardial Mass. NeoReviews Weigel, N., Hintz, S., Kaplinski, M., Barth, R., Balakrishnan, K., Panelli, D., Ma, M., Chitkara, R. 2023; 24 (10): e683-e689

    View details for DOI 10.1542/neo.24-10-e683

    View details for PubMedID 37777619

  • "Percutaneous" technique for direct external access to and stenting of obstructed pediatric ventricular assist device inflow cannula. JTCVS techniques Taylor, A., Lee, K. J., Felmly, L., Syed, A., Almond, C., Shuttleworth, P., Issapour, A., Babb, A., Ma, M., Martin, E. 2023; 21: 195-198

    View details for DOI 10.1016/j.xjtc.2023.07.024

    View details for PubMedID 37854820

    View details for PubMedCentralID PMC10580173

  • 20-Year Experience With Repair of Pulmonary Atresia or Stenosis and Major Aortopulmonary Collateral Arteries. Journal of the American College of Cardiology McElhinney, D. B., Asija, R., Zhang, Y., Jaggi, A., Shek, J., Peng, L. F., Boltz, M. G., Ma, M., Martin, E., Hanley, F. L. 2023; 82 (12): 1206-1222


    BACKGROUND: We have followed a consistent, albeit evolving, strategy for the management of patients with pulmonary atresia or severe stenosis and major aortopulmonary collateral arteries (MAPCAs) that aims to achieve complete repair with low right ventricular pressure by completely incorporating blood supply and relieving stenoses to all lung segments.OBJECTIVES: The purpose of this study was to characterize our 20-year institutional experience managing patients with MAPCAs.METHODS: We reviewed all patients who underwent surgery for MAPCAs and biventricular heart disease from November 2001 through December2021.RESULTS: During the study period, 780 unique patients underwent surgery. The number of new patients undergoing surgery annually was relatively steady during the first 15 years, then increased substantially thereafter. Surgery before referral had been performed in almost 40% of patients, more often in our recent experience than earlier. Complete repair was achieved in 704 patients (90%), 521 (67%) during the first surgery at our center, with a median right ventricular to aortic pressure ratio of 0.34 (25th, 75th percentiles: 0.28, 0.40). The cumulative incidence of mortality was 15% (95% CI: 12%-19%) at 10 years, with no difference according to era of surgery (P=0.53). On multivariable Cox regression, Alagille syndrome (HR: 2.8; 95%CI: 1.4-5.7; P=0.004), preoperative respiratory support (HR: 2.0; 95%CI: 1.2-3.3; P=0.008), and palliative first surgery at our center (HR: 3.5; 95%CI: 2.3-5.4; P< 0.001) were associated with higher risk of death.CONCLUSIONS: In a growing pulmonary artery reconstruction program, with increasing volumes and an expanding population of patients who underwent prior surgery, outcomes of patients with pulmonary atresia or stenosis andMAPCAs have continued to improve.

    View details for DOI 10.1016/j.jacc.2023.06.041

    View details for PubMedID 37704311

  • Comparing Apples to Apples: Exploring public reporting of congenital cardiac surgery outcomes based on common congenital heart operations. The Journal of thoracic and cardiovascular surgery Nathan, M., Gauvreau, K., White, O., Anderson, B. R., Bacha, E. A., Barron, D. J., Cleveland, J., Del Nido, P. J., Eghtesady, P., Galantowicz, M., Kennedy, A., Kohlsaat, K., Ma, M., Mattila, C., Van Arsdell, G., Gaynor, J. W. 2023


    We sought to simplify reporting of outcomes in congenital heart surgery that compares well-defined patient groups, accommodates multiple stakeholder needs while being easily understandable.We selected 19 commonly performed congenital heart surgeries ranging in complexity from repair of atrial septal defects (ASD) to the Norwood procedure. Strict inclusion/exclusion criteria ensured the creation of 19 well defined diagnosis/procedure cohorts. Preoperative, procedural, and postoperative data were collected for consecutive eligible patients from 9 centers between 1/1/2016 to 12/31/2021. Unadjusted operative mortality rates and hospital length of stay for each of the 19 diagnosis/procedure cohorts were summarized in aggregate and stratified by each center.Of 8572 eligible cases included, numbers in the 19 diagnosis/procedure cohorts ranged from 73 for tetralogy of Fallot repair after prior palliation to 1224 for ventricular septal defect (VSD) repairs for isolated VSD. In aggregate, the unadjusted mortality ranged from 0% for ASD repair to 28.4% for Hybrid Stage I. There was significant heterogeneity in case-mix and mortality for different diagnosis/procedure cohorts across centers (e.g., ASO/VSD n=7 to 42, mortality 0% to 7.4%; Norwood procedure n=16 to 122, mortality 5.3% to 25%).Reporting of institutional case volumes and outcomes within well-defined diagnosis/procedure cohorts can enable centers to benchmark outcomes, understand trends in mortality, and direct quality improvement. When made public, this type of report could provide parents with information on institutional volumes and outcomes and allow them to better understand the experience of each program with operations for specific congenital heart defects.

    View details for DOI 10.1016/j.jtcvs.2023.08.052

    View details for PubMedID 37689234

  • Short- and Mid-Term Results of Pulmonary Valve Replacement with the Inspiris Valve. The Annals of thoracic surgery Ragheb, D. K., Martin, E., Jaggi, A., Lui, G. K., Maskatia, S. A., Ma, M., Hanley, F. L., McElhinney, D. B. 2023


    BACKGROUND: Various bioprosthetic valves are used off-label for pulmonary valve replacement (PVR), but there is no consensus about whether a particular valve is best for this application. Recently, the Inspiris Valve was approved for aortic valve replacement, and surgeons have begun utilizing it for PVR. There is limited evidence about the performance of the Inspiris valve compared to other valves in the pulmonary position.METHODS: We reviewed all patients who underwent PVR with a size 19-27mm Inspiris or Mosaic valve from 2007-2022. Mid-term outcomes included freedom from moderate or severe pulmonary regurgitation (PR), a maximum Doppler gradient >36mmHg, and freedom from reintervention.RESULTS: A total of 225 consecutive patients who underwent PVR with a size 19-27mm Mosaic (n=163) or Inspiris (n=62) valve were included. There was no difference in baseline characteristics. Early postoperative gradients were low in both groups, but higher in the Mosaic cohort, and neither group had more than mild PR on discharge. On uni- and multivariable analysis, Inspiris valves were significantly more likely to develop moderate or greater PR over time. There was no significant difference between the valves in freedom from reintervention or from a maximum gradient >36mmHg.CONCLUSIONS: Early and short-term gradients were similar in patients undergoing PVR with Inspiris and Mosaic valves, but significant PR was more common in patients who received an Inspiris valve. These preliminary findings suggest that the durability of the Inspiris valve in the pulmonary position may not be superior to other bioprosthetic valves used for PVR.

    View details for DOI 10.1016/j.athoracsur.2023.07.049

    View details for PubMedID 37625611

  • An integrated program to expand donor utilization in pediatric heart transplantation: Case report of successful transplant with multiple donor risk factors. Pediatric transplantation Torpoco Rivera, D. M., Hollander, S. A., Almond, C., Profita, E., Dykes, J. C., Raissadati, A., Lee, J., Sacks, L. D., Kleiman, Z. I., Lee, E., Rosenthal, A., Rosenthal, D. N., Nasirov, T., Ma, M., Martin, E., Chen, S. 2023: e14584


    Pediatric heart transplantation (HT) continues to be limited by the shortage of donor organs, distance constraints, and the number of potential donor offers that are declined due to the presence of multiple risk factors.We report a case of successful pediatric HT in which multiple risk factors were mitigated through a combination of innovative donor utilization improvement strategies.An 11-year-old, 25-kilogram child with cardiomyopathy and pulmonary hypertension, on chronic milrinone therapy and anticoagulated with apixaban, was transplanted with a heart from a Hepatitis C virus positive donor and an increased donor-to-recipient weight ratio. Due to extended geographic distance, an extracorporeal heart preservation system (TransMedics™ OCS Heart) was used for procurement. No significant bleeding was observed post-operatively, and she was discharged by post-operative day 15 with normal biventricular systolic function. Post-transplant Hepatitis C virus seroconversion was successfully treated.Heart transplantation in donors with multiple risk factor can be achieved with an integrative team approach and should be taken into consideration when evaluating marginal donors in order to expand the current limited donor pool in pediatric patients.

    View details for DOI 10.1111/petr.14584

    View details for PubMedID 37470130

  • Outcomes After Development of Ventricular Arrhythmias in Single Ventricular Heart Disease Patients With Fontan Palliation. Circulation. Arrhythmia and electrophysiology Giacone, H. M., Chubb, H., Dubin, A. M., Motonaga, K. S., Ceresnak, S. R., Goodyer, W. R., Hanish, D., Trela, A. V., Boramanand, N., Lencioni, E., Boothroyd, D., Graber-Naidich, A., Wright, G., Haeffele, C., Hollander, S. A., McElhinney, D. B., Ma, M., Hanley, F. L., Chen, S. 2023: e011143


    With the advent of more intensive rhythm monitoring strategies, ventricular arrhythmias (VAs) are increasingly detected in Fontan patients. However, the prognostic implications of VA are poorly understood. We assessed the incidence of VA in Fontan patients and the implications on transplant-free survival.Medical records of Fontan patients seen at a single center between 2002 and 2019 were reviewed to identify post-Fontan VA (nonsustained ventricular tachycardia >4 beats or sustained >30 seconds). Patients with preFontan VA were excluded. Hemodynamically unstable VA was defined as malignant VA. The primary outcome was death or heart transplantation. Death with censoring at transplant was a secondary outcome.Of 431 Fontan patients, transplant-free survival was 82% at 15 years post-Fontan with 64 (15%) meeting primary outcome of either death (n=16, 3.7%), at a median 4.6 (0.4-10.2) years post-Fontan, or transplant (n=48, 11%), at a median of 11.1 (5.9-16.2) years post-Fontan. Forty-eight (11%) patients were diagnosed with VA (90% nonsustained ventricular tachycardia, 10% sustained ventricular tachycardia). Malignant VA (n=9, 2.0%) was associated with younger age, worse systolic function, and valvular regurgitation. Risk for VA increased with time from Fontan, 2.4% at 10 years to 19% at 20 years. History of Stage 1 surgery with right ventricular to pulmonary artery conduit and older age at Fontan were significant risk factors for VA. VA was strongly associated with an increased risk of transplant or death (HR, 9.2 [95% CI, 4.5-18.7]; P<0.001), with a transplant-free survival of 48% at 5-year post-VA diagnosis.Ventricular arrhythmias occurred in 11% of Fontan patients and was highly associated with transplant or death, with a transplant-free survival of <50% at 5-year post-VA diagnosis. Risk factors for VA included older age at Fontan and history of right ventricular to pulmonary artery conduit. A diagnosis of VA in Fontan patients should prompt increased clinical surveillance.

    View details for DOI 10.1161/CIRCEP.122.011143

    View details for PubMedID 37254747

  • Colocutaneous Fistula Following Pediatric Bivad Implantation, A Rare but Serious Complication Rangu, S., Murray, J., Shiu, A., Martin, E., Nasirov, T., Bruzoni, M., Chen, S., Rosenthal, D., Ma, M., Dykes, J. ELSEVIER SCIENCE INC. 2023: S447-S448
  • The Intra-Operative "Gross Pathology": An Approach to Determining Heart-Only Versus Heart-Liver Transplantation in Fontan Patients Rivera, D., Martin, E., Ma, M., Hollander, S., Bensen, R., Ebel, N., Zhang, K., Bonham, A., Gallo, A., Esquivel, C. O., Navaratnam, M., Rosenthal, D., Chen, S. ELSEVIER SCIENCE INC. 2023: S215
  • Racial Disparities in Pediatric Heart Transplantation: A National Registry Analysis Chan, K., Jacobs, N., Lee, J., Kidambi, S., Zawadzki, R., Kim, E., Dykes, J., Rosenthal, D., Ma, M. ELSEVIER SCIENCE INC. 2023: S37-S38
  • Evaluating the Impact of Donor-Recipient Race Mismatch on Graft Survival in Infant Heart Transplantation So, B. J., Lee, J., Kidambi, S., Dykes, J., Rosenthal, D., Ma, M. ELSEVIER SCIENCE INC. 2023: S383
  • Through the "Chimney": Berlin Heart Excor Pediatric Ventricular Assist Device Inflow Stenting via a Novel Direct Access to Inflow Tubing Taylor, A. C., Lee, K., Felmly, L. M., Issapour, A., Almond, C., Ma, M., Martin, E. ELSEVIER SCIENCE INC. 2023: S448
  • Use of the SherpaPak Cardiac Transport System for Infant and Pediatric Donor Hearts: An Initial Experience Profita, E. L., Lee, E., Ma, M., Martin, E., Hollander, S., Rosenthal, D., Almond, C., Nasirov, T. ELSEVIER SCIENCE INC. 2023: S187-S188
  • Serial Lung Perfusion Scintigraphy After Unifocalization and Repair of Tetralogy of Fallot With Major Aortopulmonary Collaterals. World journal for pediatric & congenital heart surgery Wise-Faberowski, L., Long, J., Ma, M., Nadel, H. R., Shek, J., Feinstein, J. A., Martin, E., Hanley, F. L., McElhinney, D. B. 2023: 21501351231162959


    BACKGROUND: In patients with tetralogy of Fallot and major aortopulmonary collaterals (MAPCAs), pulmonary blood supply is highly variable. Our approach to this condition emphasizes complete unifocalization of the pulmonary circulation, incorporating all lung segments and addressing stenoses out to the segmental level. Post-repair, we recommend serial lung perfusion scintigraphy (LPS) to assess short-term changes in pulmonary blood flow distribution.METHODS: We reviewed post-discharge and follow-up LPS performed through three years post-repair and analyzed serial changes in perfusion, risk factors for change, and the relationship between LPS parameters and pulmonary artery reintervention.RESULTS: Of 543 patients who had postoperative LPS results in our system, 317 (58%) had only a predischarge LPS available for review, while 226 had 1 (20%) or more (22%) follow-up scans within three years. Overall, pulmonary flow distribution prior to discharge was balanced, and there was minimal change over time; however, there was considerable patient-to-patient variation in both metrics. On multivariable mixed modeling, time after repair (P=.025), initial anatomy consisting of a ductus arteriosus to one lung (P<.001), and age at repair (P=.014) were associated with changes on serial LPS. Patients who had follow-up LPS were more likely to undergo pulmonary artery reintervention, but within that cohort, LPS parameters were not associated with reintervention risk.CONCLUSION: Serial LPS during the first year after MAPCAs repair is a noninvasive method of screening for significant post-repair pulmonary artery stenosis that occurs in a small but important minority of patients. In patients who received follow-up LPS beyond the perioperative period, there was minimal change over time in the population overall, but large changes in some patients and considerable variability. There was no statistical association between LPS findings and pulmonary artery reintervention.

    View details for DOI 10.1177/21501351231162959

    View details for PubMedID 36972512

  • Analysis of risk factors associated with extracorporeal membrane oxygenation after surgical repair of peripheral pulmonary artery stenoses. JTCVS open Felmly, L. M., Mainwaring, R. D., Algaze, C., Martin, E., Ma, M., Hanley, F. L. 2023; 13: 344-356


    Acute lung injury is a known complication of pulmonary artery reconstruction for peripheral pulmonary artery stenosis. Severe cases may require support with extracorporeal membrane oxygenation. The purpose of this study was to evaluate the characteristics of patients requiring extracorporeal membrane oxygenation after pulmonary artery reconstruction.This was a retrospective study of 150 patients who underwent surgical repair of peripheral pulmonary artery stenosis at our institution from 2002 to 2022. Underlying diagnoses included Williams syndrome (n = 44), Alagille syndrome (n = 43), elastin arteriopathy (n = 21), tetralogy of Fallot (n = 21), and other (n = 21). Characteristics of patients who required extracorporeal membrane oxygenation were compared with those who did not require extracorporeal membrane oxygenation.Eleven of the 150 patients undergoing pulmonary artery reconstruction (7.3%) required postoperative extracorporeal membrane oxygenation support (10 for acute lung injury and 1 for cardiac insufficiency). Four patients receiving extracorporeal membrane oxygenation had Williams syndrome, 3 patients had Alagille, and 4 patients had tetralogy of Fallot. Patients requiring extracorporeal membrane oxygenation had a higher preoperative right ventricle to aortic peak systolic pressure ratios (mean 1.14 vs 0.95), greater number of pulmonary artery ostial interventions (median, 23 vs 17), and longer duration of cardiopulmonary bypass (median, 597 vs 400 minutes). There were 3 in-hospital deaths (2.0%), 2 of whom required postoperative extracorporeal membrane oxygenation support.The data demonstrate multiple differences between patients who did and did not require extracorporeal membrane oxygenation after surgical repair of peripheral pulmonary artery stenosis. These results suggest that the preoperative extent of disease may predispose to the development of acute lung injury requiring extracorporeal membrane oxygenation support.

    View details for DOI 10.1016/j.xjon.2023.01.011

    View details for PubMedID 37063146

    View details for PubMedCentralID PMC10091391

  • Single-port robotic transcervical long-segment thoracic tracheal reconstruction: Cadaveric proof-of-concept study. JTCVS techniques Lui, N. S., Holsinger, F. C., Ma, M. R., Janus, J. R., Balakrishnan, K. 2022; 16: 231-236


    Slide tracheoplasty is the standard technique to repair congenital long-segment tracheal stenosis. This operation most commonly requires median sternotomy, which has drawbacks in young children. We hypothesized that a transcervical approach without sternotomy would be feasible if done with a single-port robotic system.This proof-of concept study was performed in 2 small adult cadavers using a single-port robotic surgical system via a small neck incision. Relevant information, including operative time and details of operative technique, were recorded.Long-segment slide tracheoplasty was completed successfully in 2 cadavers using a small neck incision and a single-port robotic surgical system. Strengths and pitfalls of the technique were identified, including technical refinements from the first attempt to the second. Operative time for robotic mobilization, incision, and anastomosis of the trachea was comparable to standard open approaches.Small-incision transcervical slide tracheoplasty, assisted by a single-port surgical robotic system, is feasible in a human cadaver. More work is needed to determine safety and applicability in live patients, particularly in children.

    View details for DOI 10.1016/j.xjtc.2022.08.025

    View details for PubMedID 36510525

    View details for PubMedCentralID PMC9735391

  • Criteria for Early Pacemaker Implantation in Patients With Postoperative Heart Block After Congenital Heart Surgery. Circulation. Arrhythmia and electrophysiology Duong, S. Q., Shi, Y., Giacone, H., Navarre, B., Gal, D., Han, B., Sganga, D., Ma, M., Reddy, C. D., Shin, A., Kwiatkowski, D. M., Dubin, A. M., Scheinker, D., Algaze, C. A. 2022: e011145


    Guidelines recommend observation for atrioventricular node recovery until postoperative days (POD) 7 to 10 before permanent pacemaker placement (PPM) in patients with heart block after congenital cardiac surgery. To aid in surgical decision-making for early PPM, we established criteria to identify patients at high risk of requiring PPM.We reviewed all cases of second degree and complete heart block (CHB) on POD 0 from August 2009 through December 2018. A decision tree model was trained to predict the need for PPM amongst patients with persistent CHB and prospectively validated from January 2019 through March 2021. Separate models were developed for all patients on POD 0 and those without recovery by POD 4.Of the 139 patients with postoperative heart block, 68 required PPM. PPM was associated with older age (3.2 versus 1.0 years; P=0.018) and persistent CHB on POD 0 (versus intermittent CHB or second degree heart block; 87% versus 58%; P=0.001). Median days [IQR] to atrioventricular node recovery was 2 [0-5] and PPM was 9 [6-11]. Of the 100 cases of persistent CHB (21 in the validation cohort), 59 (59%) required PPM. A decision tree model identified 4 risk factors for PPM in patients with persistent CHB: (1) aortic valve replacement, subaortic stenosis repair, or Konno procedure; (2) ventricular L-looping; (3) atrioventricular valve replacement; (4) and absence of preoperative antiarrhythmic agent (in POD 0 model only). The POD 4 model specificity was 0.89 [0.67-0.99] and positive predictive value was 0.94 [95% CI 0.81-0.98], which was stable in prospective validation (positive predictive value 1.0).A data-driven analysis led to actionable criteria to identify patients requiring PPM. Patients with left ventricular outflow tract surgery, atrioventricular valve replacement, or ventricular L-Looping could be considered for PPM on POD 4 to reduce risks of temporary pacing and improve care efficiency.

    View details for DOI 10.1161/CIRCEP.122.011145

    View details for PubMedID 36306332

  • Are There Still Reasons to Use Porcine Small Intestinal Submucosa? Journal of the American College of Cardiology Ma, M. 2022; 80 (11): 1069-1070

    View details for DOI 10.1016/j.jacc.2022.07.002

    View details for PubMedID 36075676

  • Commentary: The Devil in Z Details SEMINARS IN THORACIC AND CARDIOVASCULAR SURGERY Ma, M. 2022; 34 (3): 1010
  • Surgical repair of peripheral pulmonary artery stenosis: A 2-decade experience with 145 patients. The Journal of thoracic and cardiovascular surgery Felmly, L. M., Mainwaring, R. D., Collins, R. T., Lechich, K., Martin, E., Ma, M., Hanley, F. L. 2022


    BACKGROUND: Peripheral pulmonary artery stenosis (PPAS) is a relatively rare form of congenital heart disease often associated with Williams syndrome, Alagille syndrome, and elastin arteriopathy. This disease is characterized by stenoses at nearly all lobar and segmental ostia and results in systemic-level right ventricular pressures. The current study summarizes our experience with the surgical treatment of PPAS.METHODS: This was a retrospective review of 145 patients who underwent surgical repair of PPAS. This included 43 patients with Williams syndrome, 39 with Alagille syndrome, and 21 with elastin arteriopathy. Other diagnoses include tetralogy of Fallot with PPAS (n=21), truncus arteriosus (n=5), transposition (n=3), double-outlet right ventricle (n=2), arterial tortuosity syndrome (n=3), and other (n=8).RESULTS: The median preoperative right ventricle to aortic peak systolic pressure ratio was 1.01 (range, 0.50-1.60) which was reduced to 0.30 (range, 0.17-0.60) postoperatively. The median number of ostial repairs was 17 (range, 6-34) and median duration of cardiopulmonary bypass was 398minutes (range, 92-844). There were 3 in-hospital deaths (2.1%). The median duration of follow-up was 26months (range, 1-220) with 4 late deaths (2.9%). Eighty-two patients have subsequently undergone catheterization and 74 had a pressure ratio <0.50.CONCLUSIONS: The surgical treatment of PPAS resulted in a 70% reduction in right ventricular pressures. At 3years, freedom from death was 94% and 90% of those evaluated maintained low pressures. These results suggest that the surgical treatment of PPAS is highly effective in most patients.

    View details for DOI 10.1016/j.jtcvs.2022.07.037

    View details for PubMedID 36088147

  • Virtual Surgical Skills Training in a High School Summer Program. The Annals of thoracic surgery Bajaj, S. S., Patel, H. H., Fann, J. I., Ma, M., Lui, N. S. 2022


    BACKGROUND: The COVID-19 pandemic has disrupted components of traditional education with shifts toward virtual platforms. Here, we describe the virtual approach to basic surgical skills training during our high school program in the summers of 2020 and 2021.METHODS: Two 2-week sessions were held via Zoom with 99 students in 2020 and 198 students in 2021. Each student was sent surgical supplies and instruments. Interactive lectures were held each morning and basic surgical skills instruction each afternoon. After the session, survey links were distributed to students to complete an anonymous 37-item questionnaire regarding surgical skills confidence, simulation kit satisfaction, and technical difficulties.RESULTS: Of the 297 students, 270 (90.9%) completed the questionnaire, including 91 (91.9%) in 2020 and 179 (90.4%) in 2021. On a scale of 1 (fair) to 5 (excellent), students in 2020 and 2021 reported similar confidence in instrument handling (4-5: 90.0% vs 86.3%, p=0.38), suturing skin (4-5: 88.9% vs 82.8%, p=0.19), and thoracic aorta suturing (4-5: 73.3% vs 73.6%, p=0.97). Students reported greater confidence in 2020 on knot-tying (4-5: 98.9% vs 87.9%, p=0.002), coronary vessel suturing (4-5: 82.2% vs 65.5%, p<0.001), and valve model suturing (4-5: 68.5% vs 50.3%, p=0.005) than students in 2021. Students had similar satisfaction rates with the program (extremely or somewhat satisfied: 92.3% vs 86.0%, p=0.51) between 2020 and 2021.CONCLUSIONS: Virtual education carries the potential for basic surgical skills training for a more widespread audience with less access to direct surgical education. Further research is needed to optimize teaching finer surgical skills.

    View details for DOI 10.1016/j.athoracsur.2022.07.034

    View details for PubMedID 35934065

  • Subcutaneous Treprostinil Improves Surgical Candidacy for Next Stage Palliation in Single Ventricle Patients With High-Risk Hemodynamics. Seminars in thoracic and cardiovascular surgery Sullivan, R. T., Handler, S. S., Feinstein, J. A., Ogawa, M., Liu, E., Ma, M., Hopper, R. K., Norris, J., Hollander, S. A., Chen, S. 2022


    Single ventricle (SV) patients with pulmonary vascular disease (SV-PVD) are considered poor surgical candidates for Glenn or Fontan palliation. Given limited options for Stage 1 (S1) and Stage 2 (S2) SV patients with SV-PVD, we report on the use of subcutaneous treprostinil (TRE) to treat SV-PVD in this population. This single-center, retrospective cohort study examined SV patients who were not candidates for subsequent surgical palliation due to SV-PVD and were treated with TRE. The primary outcome was ability to progress to the next surgical stage; secondary outcomes included changes in hemodynamics after TRE initiation. Between 3/2014 and 8/2021, 17 SV patients received TRE for SV-PVD: 11 after S1 and 6 after S2 (median PVR 4.1 [IQR 3.2-4.8] WU*m2, and 5.0 [IQR 1.5-6.1] WU*m2, respectively). Nine of eleven (82%) S1 progressed to S2, and 2 (18%) underwent heart transplant (HTx). Three of six (50%) S2 progressed to Fontan, 1 underwent HTx and 2 are awaiting Fontan on TRE. TRE significantly decreased PVR in S1 patients with median post-treatment PVR of 2.0 (IQR 1.5-2.6) WU*m2. TRE can allow for further surgical palliation in select pre-Fontan patients with SV-PVD, obviating the need for HTx. Improvement in PVR was significant in S1 patients and persisted beyond discontinuation of therapy for most patients.

    View details for DOI 10.1053/j.semtcvs.2022.07.011

    View details for PubMedID 35931345

  • Innominate artery patency after direct cannulation in neonates. JTCVS techniques Choi, P. S., Nasirov, T., Hanley, F., Peng, L., McElhinney, D. B., Ma, M. 2022; 14: 171-176


    Objective: The study objective was to determine the short-term incidence of innominate artery stenosis for neonates who underwent direct innominate artery cannulation during the Norwood procedure.Methods: This is a retrospective, single-institution review of 92 patients who underwent the Norwood procedure with direct innominate artery cannulation from 2006 to 2017. The primary outcome was angiographic evidence of patency at pre-Glenn cardiac catheterization. Patient characteristics, intraoperative surgical and hemodynamic measurements, and postoperative neurologic findings were recorded.Results: At a median age of 5.0days, 92 neonates underwent the Norwood procedure with direct innominate artery cannulation. These patients underwent cardiac catheterization at a median of 3.0months after the index operation. In 5 of 92 patients with catheterization images available for review, there was angiographic evidence of mild innominate artery stenosis, and none had moderate or severe stenosis. Review of follow-up records did not reveal evidence of clinically significant stenosis or innominate artery reintervention.Conclusions: In neonates undergoing the Norwood procedure with direct innominate cannulation, innominate artery stenosis was uncommon and clinically significant stenosis did not occur.

    View details for DOI 10.1016/j.xjtc.2022.06.001

    View details for PubMedID 35967223

  • Commentary: Operating on fewer veins in vain. JTCVS open Ma, M. 2022; 10: 322-323

    View details for DOI 10.1016/j.xjon.2021.12.008

    View details for PubMedID 36004213

  • Identifying Predictors of Pediatric Heart Only versus Combined Heart-Liver Transplantation. Zhang, K., Chen, S., Syed, A., Gallo, A., Esquivel, C., Bonham, C., Hollander, S., Ma, M., Han, J., Ebel, N. WILEY. 2022: 476-477
  • Tetralogy of Fallot and Aortic Dissection: Implications in Management. JACC. Case reports Vaikunth, S. S., Chan, J. L., Woo, J. P., Bykhovsky, M. R., Lui, G. K., Ma, M., Romfh, A. W., Lamberti, J., Mastrodicasa, D., Fleischmann, D., Fischbein, M. P. 2022; 4 (10): 581-586


    We present the case of a 61-year-old man with tetralogy of Fallot postrepair and mechanical aortic valve replacement with an aortic root/ascending/arch aneurysm with chronic type A aortic dissection. He underwent uncomplicated aortic root and total arch replacement. Continued surveillance for aortic aneurysm is necessary in the tetralogy of Fallot population. (Level of Difficulty: Intermediate.).

    View details for DOI 10.1016/j.jaccas.2022.02.021

    View details for PubMedID 35615213

  • Surgical Repair of Supravalvar Aortic Stenosis in Association With Transverse and Proximal Descending Aortic Abnormalities. World journal for pediatric & congenital heart surgery Mainwaring, R. D., Collins, R. T., Ma, M., Martin, E., Arunamata, A., Algaze-Yojay, C., Hanley, F. L. 2022; 13 (3): 353-360


    BACKGROUND: Supravalvar aortic stenosis (SVAS) may be an isolated defect of the proximal ascending aorta. However, more severe cases have extension of the arteriopathy into the transverse and proximal descending aorta. The purpose of this study was to review our experience with SVAS with and without aortic arch arteriopathy.METHODS: This was a retrospective review of 58 patients who underwent surgical repair of SVAS. The median age at repair was 18 months. A total of 37 patients had Williams syndrome. A total of 31 (53%) patients had associated peripheral pulmonary artery stenosis and 23 (39%) had coronary artery ostial stenosis (CAOS).RESULTS: A total of 37 of 58 (64%) patients had surgical repair of SVAS without the need for arch intervention while 21 (36%) patients had repair of the distal aortic arch. There were 3 (5.2%) operative deaths, 2 of whom had aortic arch involvement and one without arch involvement. There were 2 deaths after discharge from the hospital. Patients who needed arch surgery were more likely to have severe arch gradients compared to those without arch involvement (71% vs 30%, P < .05), were more likely to undergo concomitant procedures for peripheral pulmonary artery stenosis or CAOS (90% vs 62%, P < .05), and to have Williams syndrome (86% vs 51%, P < .05).CONCLUSIONS: More than one-third of patients who had SVAS repair at our institution had procedures directed at the transverse or proximal descending aorta. Patients with arch involvement had more severe arch obstruction, required more concomitant procedures, and were more likely to have Williams syndrome.

    View details for DOI 10.1177/21501351221085975

    View details for PubMedID 35446223

  • Neurologic complications in en bloc pediatric heart-liver transplants Pan, J., Bensen, R., Ebel, N., Mendoza, J., Ma, M., Hollander, S., Gallo, A., Esquivel, C. O., Bonham, A. WILEY. 2022
  • Long-Term Outcomes of ECMO Post-Heart Transplant Iqbal, M. S., Wujcik, K. A., Nair, A., Yarlagadda, V., Ma, M. R., Hollander, S. A., Profita, E. ELSEVIER SCIENCE INC. 2022: S505-S506
  • Pediatric VAD Growth in the US: What Factors May Be Driving Growth Jumps? Iqbal, M. S., Sweat, K., Dykes, J. C., Murray, J., Ma, M., Martin, E., Rosenthal, D. N., Almond, C. S. ELSEVIER SCIENCE INC. 2022: S521-S522
  • Size Matching by Height, Body Surface Area, and Body Mass Index in Infant Heart Transplantation Lee, J., Kidambi, S., Rosenthal, D. N., Dykes, J. C., Ma, M. ELSEVIER SCIENCE INC. 2022: S53
  • Towards identifying predictors of pediatric heart only versus combined heart liver transplantation Zhang, K., Chen, S., Syed, A., Gallo, A., Esquivel, C., Bonham, A., Hollander, S. A., Ma, M., Han, J., Ebel, N. H. WILEY. 2022
  • Virtual Transcatheter Interventions for Peripheral Pulmonary Artery Stenosis in Williams and Alagille Syndromes. Journal of the American Heart Association Lan, I. S., Yang, W., Feinstein, J. A., Kreutzer, J., Collins, R. T., Ma, M., Adamson, G. T., Marsden, A. L. 2022: e023532


    Background Despite favorable outcomes of surgical pulmonary artery (PA) reconstruction, isolated proximal stenting of the central PAs is common clinical practice for patients with peripheral PA stenosis in association with Williams and Alagille syndromes. Given the technical challenges of PA reconstruction and the morbidities associated with transcatheter interventions, the hemodynamic consequences of all treatment strategies must be rigorously assessed. Our study aims to model, assess, and predict hemodynamic outcomes of transcatheter interventions in these patients. Methods and Results Isolated proximal and "extensive" interventions (stenting and/or balloon angioplasty of proximal and lobar vessels) were performed in silico on 6 patient-specific PA models. Autoregulatory adaptation of the cardiac output and downstream arterial resistance was modeled in response to intervention-induced hemodynamic perturbations. Postintervention computational fluid dynamics predictions were validated in 2 stented patients and quantitatively assessed in 4 surgical patients. Our computational methods accurately predicted postinterventional PA pressures, the primary indicators of success for treatment of peripheral PA stenosis. Proximal and extensive treatment achieved median reductions of 14% and 40% in main PA systolic pressure, 27% and 56% in pulmonary vascular resistance, and 10% and 45% in right ventricular stroke work, respectively. Conclusions In patients with Williams and Alagille syndromes, extensive transcatheter intervention is required to sufficiently reduce PA pressures and right ventricular stroke work. Transcatheter therapy was shown to be ineffective for long-segment stenosis and pales hemodynamically in comparison with published outcomes of surgical reconstruction. Regardless of the chosen strategy, a virtual treatment planning platform could identify lesions most critical for optimizing right ventricular afterload.

    View details for DOI 10.1161/JAHA.121.023532

    View details for PubMedID 35253446

  • Airway Characteristics of Patients With 22q11 Deletion Undergoing Pulmonary Artery Reconstruction Surgery: Retrospective Cohort 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 Sganga, D., Meister, K., Sidell, D. R., Wise-Faberowski, L., Shek, J., Ma, M., Martin, E., Hanley, F. L., McElhinney, D., Asija, R. 2022


    OBJECTIVES: We have previously shown that patients with a chromosome 22q11 microdeletion are at risk for prolonged respiratory failure after pulmonary artery reconstruction surgery compared with those with normal genotype. We sought to describe preexisting airway abnormalities in this patient population and examine relationships between airway abnormalities and outcomes.DESIGN: Single-center retrospective chart review from Society of Thoracic Surgery and Pediatric Cardiac Critical Care Consortium databases and the electronic medical record.SETTING: Lucile Packard Children's Hospital at Stanford from September 2017 to February 2019.PATIENTS: All patients undergoing pulmonary artery reconstruction surgery were considered for inclusion.INTERVENTIONS: We identified 127 patients meeting study inclusion criteria. Thirty-nine patients met specific criteria and underwent screening preoperative bronchoscopy including microdirect laryngoscopy and lower airway examination. Postoperative bronchoscopy was performed at the discretion of the intensive care team.MEASUREMENTS AND MAIN RESULTS: Airway abnormalities were detected in 25/26 of children (96%) with a chromosome 22q11 deletion who underwent preoperative bronchoscopy. Upper and lower airway pathologies were found in 19/25 (73%) and 21/25 (81%) patients, respectively, and it was common for patients to have more than one abnormality. Presence of 22q11 deletion was associated with longer duration of mechanical ventilation (9.1 vs 4.3 d; p = 0.001), use of noninvasive positive pressure support (13 vs 6 d; p = 0.001), and longer hospital stays (30 vs 14 d; p = 0.002). These outcomes were worse when compared with patients with known airway abnormalities who did not have 22q11 deletion.CONCLUSIONS: Preexisting upper and lower airway pathologies are common in patients with a chromosome 22q11 deletion who undergo pulmonary artery reconstruction surgery. Despite similar postoperative hemodynamics and outcomes as their counterparts without 22q11 deletion, 22q11 deletion is associated with more postoperative respiratory complications not entirely explained by preexisting airway abnormalities.

    View details for DOI 10.1097/PCC.0000000000002921

    View details for PubMedID 35213412

  • Commentary: A new Fontan commandment. The Journal of thoracic and cardiovascular surgery Ma, M. 2022

    View details for DOI 10.1016/j.jtcvs.2022.01.008

    View details for PubMedID 35125211

  • Neurologic complications in en bloc pediatric heart-liver transplants Pan, J., Bensen, R., Ebel, N., Mendoza, J., Ma, M., Hollander, S., Gallo, A., Esquivel, C., Bonham, A. WILEY. 2022: 80
  • Implantable Cardioverter Defibrillators in Infants and Toddlers: Indications, Placement, Programming, and Outcomes. Circulation. Arrhythmia and electrophysiology Zahedivash, A., Hanisch, D., Dubin, A. M., Trela, A., Chubb, H., Motonaga, K., Goodyer, W., Maeda, K., Reinhartz, O., Ma, M., Martin, E., Ceresnak, S. 2022: CIRCEP121010557


    Limited data exist regarding implantable cardioverter defibrillator (ICD) usage in infants and toddlers. This study evaluates ICD placement indications, procedural techniques, programming strategies, and outcomes of ICDs in infants and toddlers.This is a single-center retrospective review of all patients ≤3 years old who received an ICD from 2009 to 2021.Fifteen patients received an ICD at an age of 1.2 years (interquartile range [IQR], 0.1-2.4; 12 [80%] women; weight, 8.2 kg [IQR, 4.2-12.6]) and were followed for a median of 4.28 years (IQR, 1.40-5.53) or 64.2 patient-years. ICDs were placed for secondary prevention in 12 patients (80%). Diagnoses included 8 long-QT syndromes (53%), 4 idiopathic ventricular tachycardias/ventricular fibrillations (VFs; 27%), 1 recurrent ventricular tachycardia with cardiomyopathy (7%), 1 VF with left ventricular noncompaction (7%), and 1 catecholaminergic polymorphic ventricular tachycardia (7%). All implants were epicardial, with a coil in the pericardial space. Intraoperative defibrillation safety testing was attempted in 11 patients (73%), with VF induced in 8 (53%). Successful restoration of sinus rhythm was achieved in all tested patients with a median of 9 (IQR, 7.3-11.3) J or 0.90 (IQR, 0.68-1.04) J/kg. Complications consisted of 1 postoperative chylothorax and 3 episodes of feeding intolerance. VF detection was programmed to 250 (IQR, 240-250) ms with first shock delivering 10 (IQR, 5-15) J or 1.1 (IQR, 0.8-1.4) J/kg. Three patients (20%) received appropriate shocks for ventricular tachycardia/VF. No patient received an inappropriate shock. There were 2 (13%) ventricular lead fractures (at 2.6 and 4.2 years post-implant), 1 (7%) pocket-site infection, and 2 (13%) generator exchanges. All patients were alive, and 1 patient (7%) received a heart transplant.ICDs can be safely and effectively placed for sudden death prevention in infants and toddlers with good midterm outcomes.

    View details for DOI 10.1161/CIRCEP.121.010557

    View details for PubMedID 35089800

  • Ultrarapid Nanopore Genome Sequencing in a Critical Care Setting. The New England journal of medicine Gorzynski, J. E., Goenka, S. D., Shafin, K., Jensen, T. D., Fisk, D. G., Grove, M. E., Spiteri, E., Pesout, T., Monlong, J., Baid, G., Bernstein, J. A., Ceresnak, S., Chang, P. C., Christle, J. W., Chubb, H., Dalton, K. P., Dunn, K., Garalde, D. R., Guillory, J., Knowles, J. W., Kolesnikov, A., Ma, M., Moscarello, T., Nattestad, M., Perez, M., Ruzhnikov, M. R., Samadi, M., Setia, A., Wright, C., Wusthoff, C. J., Xiong, K., Zhu, T., Jain, M., Sedlazeck, F. J., Carroll, A., Paten, B., Ashley, E. A. 2022

    View details for DOI 10.1056/NEJMc2112090

    View details for PubMedID 35020984

  • Commentary: The hardest part of cardiothoracic surgery is getting to do it. The Journal of thoracic and cardiovascular surgery Ma, M. 1800

    View details for DOI 10.1016/j.jtcvs.2021.12.040

    View details for PubMedID 35012782

  • Biomechanical engineering comparison of four leaflet repair techniques for mitral regurgitation using a novel 3-dimensional-printed left heart simulator. JTCVS techniques Paulsen, M. J., Cuartas, M. M., Imbrie-Moore, A., Wang, H., Wilkerson, R., Farry, J., Zhu, Y., Ma, M., MacArthur, J. W., Woo, Y. J. 2021; 10: 244-251


    Mitral valve repair is the gold standard treatment for degenerative mitral regurgitation; however, a multitude of repair techniques exist with little quantitative data comparing these approaches. Using a novel ex vivo model, we sought to evaluate biomechanical differences between repair techniques.Using porcine mitral valves mounted within a custom 3-dimensional-printed left heart simulator, we induced mitral regurgitation using an isolated P2 prolapse model by cutting primary chordae. Next, we repaired the valves in series using the edge-to-edge technique, neochordoplasty, nonresectional remodeling, and classic leaflet resection. Hemodynamic data and chordae forces were measured and analyzed using an incomplete counterbalanced repeated measures design with the healthy pre-prolapse valve as a control.With the exception of the edge-to-edge technique, all repair methods effectively corrected mitral regurgitation, returning regurgitant fraction to baseline levels (baseline 11.9% ± 3.7%, edge-to-edge 22.5% ± 6.9%, nonresectional remodeling 12.3% ± 3.0%, neochordal 13.4% ± 4.8%, resection 14.7% ± 5.5%, P < 0.01). Forces on the primary chordae were minimized using the neochordal and nonresectional techniques whereas the edge-to-edge and resectional techniques resulted in significantly elevated primary forces. Secondary chordae forces also followed this pattern, with edge-to-edge repair generating significantly higher secondary forces and leaflet resection trending higher than the nonresectional and neochord repairs.Although multiple methods of degenerative mitral valve repair are used clinically, their biomechanical properties vary significantly. Nonresectional techniques, including leaflet remodeling and neochordal techniques, appear to result in lower chordal forces in this ex vivo technical engineering model.

    View details for DOI 10.1016/j.xjtc.2021.09.040

    View details for PubMedID 34977730

    View details for PubMedCentralID PMC8691825

  • Biomechanical engineering comparison of four leaflet repair techniques for mitral regurgitation using a novel 3-dimensional-printed left heart simulator JTCVS TECHNIQUES Paulsen, M. J., Cuartas, M., Imbrie-Moore, A., Wang, H., Wilkerson, R., Farry, J., Zhu, Y., Ma, M., MacArthur, J. W., Woo, Y. 2021; 10: 244-251
  • Left Subclavian Artery Isolation with Right Aortic Arch and D-Transposition of the Great Arteries. CASE (Philadelphia, Pa.) Hansen, K., Dhillon, G., Ma, M., Maskatia, S. A., Su, L., Vasanawala, S., Punn, R. 1800; 5 (6): 392-398

    View details for DOI 10.1016/

    View details for PubMedID 34993370

  • Commentary: Ross procedure in neonates and infants: Withstanding the litmus test of time. The Journal of thoracic and cardiovascular surgery Desai, M., Ma, M., Yerebakan, C. 2021

    View details for DOI 10.1016/j.jtcvs.2021.10.004

    View details for PubMedID 34756622

  • 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


    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

  • Commentary: Simplifying complex heart defects through modeling. JTCVS techniques Ma, M. 2021; 7: 203

    View details for DOI 10.1016/j.xjtc.2021.02.018

    View details for PubMedID 34318246

    View details for PubMedCentralID PMC8311673

  • Commentary: Simplifying complex heart defects through modeling JTCVS TECHNIQUES Ma, M. 2021; 7: 203
  • UNOS Match Runs for Pediatric Heart Transplant Organ Allocation-How Well Do They Sequence Patients Based on Medical Urgency? Sweat, K. R., Power, A., Dykes, J. C., Ma, M., Davies, R., Hollander, S. A., Profita, E., Rosenthal, D. N., Chen, C., Almond, C. S. ELSEVIER SCIENCE INC. 2021: S38
  • Waitlist Mortality for Children Listed for Heart Transplant in the United States: How are We Doing? Power, A., Sweat, K. R., Dykes, J. C., Ma, M., Chen, S., Schmidt, J., Kaufman, B. D., Hollander, S. A., Profita, E., Rosenthal, D. N., Chen, C., Almond, C. S. ELSEVIER SCIENCE INC. 2021: S37–S38
  • A Model to Evaluate Effect of Patient-Pump Mismatch on Thrombosis in a Pediatric Pulsatile Ventricular Assist Device Kidambi, S., Moye, S., Jahadi, O., Shad, R., Paul, S., Shiu, A., Ma, M. ELSEVIER SCIENCE INC. 2021: S442
  • Outcomes of Ventricular Assist Device Use in Children for Bridge to Heart Retransplantation Dykes, J. C., Ma, M., Murray, J., Hollander, S. A., Profita, E. L., Rosenthal, D. N., Chen, C., Almond, C. S. ELSEVIER SCIENCE INC. 2021: S89
  • Outcomes of Ventricular Assist Device Use for Bridge to Heart Transplant in Children with Single-Ventricle Heart Disease Murray, J., Dykes, J. C., Ma, M., Chen, S., Chen, C., Profita, E., Rosenthal, D. N., Almond, C. S. ELSEVIER SCIENCE INC. 2021: S120
  • Weight Matching in Infant Heart Transplantation: Analysis of the United Network for Organ Sharing Database Lee, J., Kidambi, S., Rosenthal, D., Nasirov, T., Dykes, J., Ma, M. ELSEVIER SCIENCE INC. 2021: S220
  • Evaluating Matching by Predicted Heart Mass in Adolescent Heart Transplantation: Analysis of the United Network for Organ Sharing Database Lee, J., Kidambi, S., Rosenthal, D., Nasirov, T., Dykes, J., Ma, M. ELSEVIER SCIENCE INC. 2021: S221
  • Atrial Cannulation in Pediatric Mechanical Circulatory Support Dykes, J. C., Rosenthal, D. N., Ma, M., Almond, C. S., Zafar, F., Peng, D. M., Power, A., Murray, J., Barnes, A. P., Gajarski, R. J., O'Connor, M. J., Maeda, K. ELSEVIER SCIENCE INC. 2021: S96
  • Recurrent fibrovascular granulation on PhotoFix® bovine pericardium causing systemic and pulmonary venous obstruction after repair of scimitar syndrome. Cardiology in the young Taylor, N. P., Long, Z. n., Arunamata, A. n., Ma, M. n. 2021: 1–2


    A young adult with late diagnosis of scimitar syndrome underwent infradiaphragmatic baffling of the scimitar vein to left atrium through an intra-atrial tunnel using PhotoFix® bovine pericardium with recurrent extensive fibrovascular granulation of the patch causing pulmonary and systemic venous obstruction leading to eventual explantation of the bovine pericardium.

    View details for DOI 10.1017/S1047951121000822

    View details for PubMedID 33682649

  • Commentary: The Devil in Z Details. Seminars in thoracic and cardiovascular surgery Ma, M. 2021

    View details for DOI 10.1053/j.semtcvs.2021.06.003

    View details for PubMedID 34118392

  • Compassionate Deactivation of Pediatric Ventricular Assist Devices: A Review of 14 Cases. Journal of pain and symptom management Hollander, S. A., Kaufman, B. D., Bui, C. n., Gregori, B. n., Murray, J. M., Sacks, L. n., Ryan, K. R., Ma, M. n., Rosenthal, D. N., Char, D. n. 2021


    Compassionate deactivation (CD) of ventricular assist device (VAD) support is a recognized option for children when the burden of therapy outweighs the benefits.To describe the prevalence, indications, and outcomes of CD of children supported by VADs at the end of life.Review of cases of CD at our institution between 2011-2020. To distinguish CD from other situations where VAD support is discontinued, patients were excluded from the study if they died during resuscitation (including ECMO), experienced brain or circulatory death prior to deactivation, or experienced a non-survivable brain injury likely to result in imminent death regardless of VAD status.Of 24 deaths on VAD, 14 (58%) were CD. Median age was 5.7 (IQR 0.6, 11.6) years; 6 (43%) had congenital heart disease; 4 (29%) were on a device that can be used outside of the hospital. CD occurred after 40 (IQR: 26, 75) days of support; none while active transplant candidates. CD discussions were initiated by the caregiver in 6 (43%) cases, with the remainder initiated by a medical provider. Reasons for CD were multifactorial, including end-organ injury, infection, and stroke. CD occurred with endotracheal extubation and/or discontinuation of inotropes in 12 (86%) cases, and death occurred within 10 (IQR: 4, 23) minutes of CD.CD is the mode of death in more than half of our VAD non-survivors and is pursued for reasons primarily related to noncardiac events. Caregivers and providers both initiate CD discussions. Ventilatory and inotropic support is often withdrawn at time of CD with ensuing death.

    View details for DOI 10.1016/j.jpainsymman.2021.01.125

    View details for PubMedID 33910026

  • Mid-Term Outcomes After Unifocalization Guided by Intraoperative Pulmonary Flow Study. World journal for pediatric & congenital heart surgery Goodman, A., Ma, M., Zhang, Y., Ryan, K. R., Jahadi, O., Wise-Faberowski, L., Hanley, F. L., McElhinney, D. B. 2021; 12 (1): 76–83


    BACKGROUND: Repair of tetralogy of Fallot (TOF) with major aortopulmonary collateral arteries (MAPCAs) requires unifocalization of pulmonary circulation, intracardiac repair with the closure of the ventricular septal defect, and placement of a right ventricle (RV) to pulmonary artery (PA) conduit. The decision to perform complete repair is sometimes aided by an intraoperative flow study to estimate the total resistance of the reconstructed pulmonary circulation.METHODS: We reviewed patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs to evaluate acute and mid-term outcomes after repair with and without flow studies and to characterize the relationship between PA pressure during the flow study and postrepair RV pressure.RESULTS: Among 579 patients who underwent unifocalization and PA reconstruction for TOF/MAPCAs, 99 (17%) had an intraoperative flow study during one (n = 91) or more (n = 8) operations to determine the suitability for a complete repair. There was a reasonably good correlation between mean PA pressure at 3 L/min/m2 during the flow study and postrepair RV pressure and RV:aortic pressure ratio. Acute and mid-term outcomes (median: 3.8 years) after complete repair in the flow study patients (n = 78) did not differ significantly from those in whom the flow study was not performed (n = 444). Furthermore, prior failed flow study was not associated with differences in outcome after subsequent intracardiac repair.CONCLUSIONS: The intraoperative flow study remains a useful adjunct for determining the suitability for complete repair in a subset of patients undergoing surgery for TOF/MAPCAs, as it is reasonably accurate for estimating postoperative PA pressure and serves as a reliable guide for the feasibility of single-stage complete repair.

    View details for DOI 10.1177/2150135120964427

    View details for PubMedID 33407027

  • Recent outcomes of the extracardiac Fontan procedure in patients with hypoplastic left heart syndrome ANNALS OF PEDIATRIC CARDIOLOGY Arunamata, A., Tacy, T. A., Kache, S., Mainwaring, R. D., Ma, M., Maeda, K., Punn, R. 2020; 13 (3): 186–93
  • Recent outcomes of the extracardiac Fontan procedure in patients with hypoplastic left heart syndrome. Annals of pediatric cardiology Arunamata, A., Tacy, T. A., Kache, S., Mainwaring, R. D., Ma, M., Maeda, K., Punn, R. 2020; 13 (3): 186-193


    To investigate patient-related factors, echocardiographic, and anatomic variables associated with immediate and long-term clinical outcomes after extracardiac Fontan procedure at our institution.Retrospective review of preoperative cardiac catheterizations and echocardiograms as well as medical records of all children with hypoplastic left heart syndrome (HLHS) who underwent Fontan between June 2002 and December 2018.Seventy-seven patients with HLHS were included (age 4 years [1.5-11.7]). Seventy patients (91%) received a nonfenestrated Fontan and 57 patients (74%) underwent Fontan without cardiopulmonary bypass (CPB). Presence of a Fontan fenestration (P = 0.69) and use of CPB (P = 0.79) did not differ between those with <2 weeks compared to those with ≥2 weeks of chest tube drainage. There were no differences in either pre- or intra-operative hemodynamics between patients who weighed <15 kg compared to those who weighed ≥15 kg at time of surgery; incidence of death, transplant, and transplant listing were similar between weight groups. Inferior vena cava (IVC) diameter z-score did not differ among patients with and without chylous chest tube drainage (P = 0.78), with and without development of protein losing enteropathy (P = 0.23), or death/heart transplant/transplant listing compared to survivors without transplant (P = 0.26).In HLHS patients undergoing Fontan, preoperative weight and IVC diameter appeared to have no influence on immediate postoperative outcomes. Performing the Fontan off CPB and with a fenestration also conferred no added clinical benefit. These observations should be considered when deciding optimal timing for Fontan completion.

    View details for DOI 10.4103/apc.APC_5_20

    View details for PubMedID 32863652

    View details for PubMedCentralID PMC7437630

  • A novel cross-species model of Barlow's disease to biomechanically analyze repair techniques in an exvivo left heart simulator. The Journal of thoracic and cardiovascular surgery Imbrie-Moore, A. M., Paulsen, M. J., Zhu, Y., Wang, H., Lucian, H. J., Farry, J. M., MacArthur, J. W., Ma, M., Woo, Y. J. 2020


    OBJECTIVE: Barlow's disease remains challenging to repair, given the complex valvular morphology and lack of quantitative data to compare techniques. Although there have been recent strides in exvivo evaluation of cardiac mechanics, to our knowledge, there is no disease model that accurately simulates the morphology and pathophysiology of Barlow's disease. The purpose of this study was to design such a model.METHODS: To simulate Barlow's disease, a cross-species exvivo model was developed. Bovine mitral valves (n=4) were sewn into a porcine annulus mount to create excess leaflet tissue and elongated chordae. A heart simulator generated physiologic conditions while hemodynamic data, high-speed videography, and chordal force measurements were collected. The regurgitant valves were repaired using nonresectional repair techniques such as neochord placement.RESULTS: The model successfully imitated the complexities of Barlow's disease, including redundant, billowing bileaflet tissues with notable regurgitation. After repair, hemodynamic data confirmed reduction of mitral leakage volume (25.9±2.9 vs 2.1±1.8mL, P<.001) and strain gauge analysis revealed lower primary chordae forces (0.51±0.17 vs 0.10±0.05N, P<.001). In addition, the maximum rate of change of force was significantly lower postrepair for both primary (30.80±11.38 vs 8.59±4.83N/s, P<.001) and secondary chordae (33.52±10.59 vs 19.07±7.00N/s, P=.006).CONCLUSIONS: This study provides insight into the biomechanics of Barlow's disease, including sharply fluctuating force profiles experienced by elongated chordae prerepair, as well as restoration of primary chordae forces postrepair. Our disease model facilitates further in-depth analyses to optimize the repair of Barlow's disease.

    View details for DOI 10.1016/j.jtcvs.2020.01.086

    View details for PubMedID 32249088

  • Angiographic Anatomy of Major Aortopulmonary Collateral Arteries and Association With Early Surgical Outcomes in Tetralogy of Fallot. Journal of the American Heart Association Adamson, G. T., McElhinney, D. B., Zhang, Y. n., Feinstein, J. A., Peng, L. F., Ma, M. n., Algaze, C. A., Hanley, F. L., Perry, S. B. 2020: e017981


    Background Due in part to the heterogeneity of the pulmonary circulation in patients with tetralogy of Fallot and major aortopulmonary collateral arteries (MAPCAs), research on this condition has focused on relatively basic anatomic characteristics. We aimed to detail pulmonary artery (PA) and MAPCA anatomy in a large group of infants, assess relationships between anatomy and early surgical outcomes, and consider systems for classifying MAPCAs. Methods and Results All infants ( <1 year of age) undergoing first cardiac surgery for tetralogy of Fallot/MAPCAs from 2001 to 2019 at Stanford University were identified. Preoperative angiograms delineating supply to all 18 pulmonary segments were reviewed for details of each MAPCA and the arborization and size of central PAs. We studied 276 patients with 1068 MAPCAs and the following PA patterns: 152 (55%) incompletely arborizing PAs, 48 (17%) normally arborizing PAs, 45 (16%) absent PAs, and 31 (11%) unilateral MAPCAs. There was extensive anatomic variability, but no difference in early outcomes according to PA arborization or the predominance of PAs or MAPCAs. Patients with low total MAPCA and/or PA cross-sectional area were less likely to undergo complete repair. Conclusions MAPCA anatomy is highly variable and essentially unique for each patient. Though each pulmonary segment can be supplied by a MAPCA, central PA, or both, all anatomic combinations are similarly conducive to a good repair. Total cross-sectional area of central PA and MAPCA material is an important driver of outcome. We elucidate a number of novel associations between anatomic features, but the extreme variability of the pulmonary circulation makes a granular tetralogy of Fallot/MAPCA classification system unrealistic.

    View details for DOI 10.1161/JAHA.120.017981

    View details for PubMedID 33283588

  • In Vivo Validation of Restored Chordal Biomechanics After Mitral Ring Annuloplasty in a Rare Ovine Case of Natural Chronic Functional Mitral Regurgitation. Journal of cardiovascular development and disease Wang, H. n., Paulsen, M. J., Imbrie-Moore, A. M., Tada, Y. n., Bergamasco, H. n., Baker, S. W., Shudo, Y. n., Ma, M. n., Woo, J. Y. 2020; 7 (2)


    Mitral valve chordae tendineae forces are elevated in the setting of mitral regurgitation (MR). Ring annuloplasty is an essential component of surgical repair for MR, but whether chordal forces are reduced after mitral annuloplasty has never been validated in vivo. Here, we present an extremely rare ovine case of natural, severe chronic functional MR, in which we used force-sensing fiber Bragg grating neochordae to directly measure chordal forces in the baseline setting of severe MR, as well as after successful mitral ring annuloplasty repair. Overall, our report is the first to confirm in vivo that mitral ring annuloplasty reduces elevated chordae tendineae forces associated with chronic functional MR.

    View details for DOI 10.3390/jcdd7020017

    View details for PubMedID 32429298

  • Unilateral branch pulmonary artery origin from a solitary arterial trunk with major aortopulmonary collaterals to the contralateral lung: anatomic and developmental considerations. Seminars in thoracic and cardiovascular surgery Adamson, G. T., Houyel, L. n., McElhinney, D. B., Maskatia, S. A., Ma, M. n., Hanley, F. L., Lopez, L. n. 2020


    In both truncus arteriosus communis (TAC) and tetralogy of Fallot (TOF), there is a rare phenotype that includes a single branch pulmonary artery (PA) arising from a solitary great artery and major aortopulmonary collaterals (MAPCAs) supplying the contralateral lung. We describe the intracardiac and great vessel anatomy of infants with this phenotype, consider rationale for classifying patients as TOF vs. TAC, and describe surgical outcomes. Our institution's surgical database was reviewed for patients with a single branch PA from a solitary arterial trunk and contralateral MAPCAs from 2007 to 2019. Demographic, imaging, and surgical data were collected and described. All 11 patients underwent complete repair with a median right ventricular to aortic pressure ratio of 0.36 (range 0.26-0.50). At 0.1-9.1 years after repair (median 0.8 years) there was approximately balanced left-right lung perfusion (median 52% to the right lung, range 34-74%). The MAPCA lungs exemplified the full spectrum of PA and MAPCA anatomy, from absent intrapericardial PAs with all single supply MAPCAs to a normally arborizing PA with all dual supply MAPCAs and present pulmonary valve leaflet tissue. All patients had a systemic semilunar valve with 3 thin and similarly sized leaflets and fibrous continuity with the tricuspid valve, and all had coronary origins and outflow tract morphology more consistent with TOF. It is appropriate to classify all patients with a single anomalous PA from a solitary arterial trunk and MAPCAs to the contralateral lung as TOF rather than TAC Type A3. All variants were amenable to surgical repair.

    View details for DOI 10.1053/j.semtcvs.2020.11.009

    View details for PubMedID 33181302

  • Outcomes in Patients with Alagille Syndrome and Complex Pulmonary Artery Disease. The Journal of pediatrics Luong, R. n., Feinstein, J. A., Ma, M. n., Ebel, N. H., Wise-Faberowski, L. n., Zhang, Y. n., Peng, L. F., Yarlagadda, V. V., Shek, J. n., Hanley, F. L., McElhinney, D. B. 2020


    To assess outcomes in a large cohort of patients with Alagille Syndrome (ALGS) who underwent pulmonary artery reconstruction surgery for complex PA disease.Patients with ALGS who underwent PA reconstruction surgery at Lucile Packard Children's Hospital Stanford were reviewed. Patients were examined as an overall cohort and based on the primary cardiovascular diagnosis: severe isolated branch PA stenosis, tetralogy of Fallot (TOF) without major aortopulmonary collateral arteries (MAPCAs), or TOF with MAPCAs RESULTS: Fifty-one patients with ALGS underwent PA surgery at our center: 22 with severe branch PA stenosis, 9 with TOF without MAPCAs, and 20 with TOF and MAPCAs. Forty-one patients (80%) achieved a complete repair. Five of the patients with TOF with MAPCAs (25%) had a complete repair at the first surgery, compared with 8 (89%) and 19 (86%) with TOF without MAPCAs and isolated branch PA stenosis, respectively. At a median follow-up of 1.7 years after the first surgery, 39 patients (76%) were alive, 36 with a complete repair and a median PA:aortic systolic pressure ratio of 0.38. Nine patients (18%), 8 with isolated branch PA stenosis, underwent liver transplantation.Most patients with ALGS and complex PA disease can undergo complete repair with low postoperative right ventricular pressure. Patients with TOF/MAPCAs had the worst outcome, with higher mortality and more frequent PA interventions compared with patients with TOF without MAPCAs or isolated branch PA stenosis. Complex PA disease is not a contraindication to liver transplantation in patients with ALGS.

    View details for DOI 10.1016/j.jpeds.2020.09.053

    View details for PubMedID 32980376

  • Comprehensive Ex Vivo Comparison of 5 Clinically Used Conduit Configurations for Valve-Sparing Aortic Root Replacement Using a 3-Dimensional-Printed Heart Simulator. Circulation Paulsen, M. J., Imbrie-Moore, A. M., Baiocchi, M. n., Wang, H. n., Hironaka, C. E., Lucian, H. J., Farry, J. M., Thakore, A. D., Zhu, Y. n., Ma, M. n., MacArthur, J. W., Woo, Y. J. 2020; 142 (14): 1361–73


    Many graft configurations are clinically used for valve-sparing aortic root replacement, some specifically focused on recapitulating neosinus geometry. However, the specific impact of such neosinuses on valvular and root biomechanics and the potential influence on long-term durability are unknown.Using a custom 3-dimenstional-printed heart simulator with porcine aortic roots (n=5), the anticommissural plication, Stanford modification, straight graft (SG), Uni-Graft, and Valsalva graft configurations were tested in series using an incomplete counterbalanced measures design, with the native root as a control, to mitigate ordering effects. Hemodynamic and videometric data were analyzed using linear models with conduit as the fixed effect of interest and valve as a fixed nuisance effect with post hoc pairwise testing using Tukey's correction.Hemodynamics were clinically similar between grafts and control aortic roots. Regurgitant fraction varied between grafts, with SG and Uni-Graft groups having the lowest regurgitant fractions and anticommissural plication having the highest. Root distensibility was significantly lower in SG versus both control roots and all other grafts aside from the Stanford modification (P≤0.01 for each). All grafts except SG had significantly higher cusp opening velocities versus native roots (P<0.01 for each). Relative cusp opening forces were similar between SG, Uni-Graft, and control groups, whereas anticommissural plication, Stanford modification, and Valsalva grafts had significantly higher opening forces versus controls (P<0.01). Cusp closing velocities were similar between native roots and the SG group, and were significantly lower than observed in the other conduits (P≤0.01 for each). Only SG and Uni-Graft groups experienced relative cusp closing forces approaching that of the native root, whereas relative forces were >5-fold higher in the anticommissural plication, Stanford modification, and Valsalva graft groups.In this ex vivo modeling system, clinically used valve-sparing aortic root replacement conduit configurations have comparable hemodynamics but differ in biomechanical performance, with the straight graft most closely recapitulating native aortic root biomechanics.

    View details for DOI 10.1161/CIRCULATIONAHA.120.046612

    View details for PubMedID 33017215

  • Postoperative Recovery of Left Ventricular Function following Repair of Large Ventricular Septal Defects in Infants. Journal of the American Society of Echocardiography : official publication of the American Society of Echocardiography Adamson, G. T., Arunamata, A., Tacy, T. A., Silverman, N. H., Ma, M., Maskatia, S. A., Punn, R. 2019


    INTRODUCTION: Early postoperative left ventricular (LV) dysfunction is observed following repair of large ventricular septal defects (VSDs), but the frequency and rate of recovery of LV function are unknown. This study aims to characterize the incidence and rate of recovery of postoperative LV dysfunction following repair of large VSDs and to improve understanding of LV mechanics before and after VSD repair.METHODS: Infants who underwent surgical repair of an isolated large VSD were included. Pre- and postoperative echocardiographic images were reviewed, and LV function was assessed by both conventional echocardiography and speckle-tracking strain analyses. Postoperative LV dysfunction was defined as an LV ejection fraction (LVEF)<50% using the 5/6 area-length method. Echocardiograms were reviewed to assess LVEF and LV volume through 1-year follow-up.RESULTS: Of 104 infants evaluated (median age, 0.31 [0.22, 0.56] years), all had normal preoperative LVEF and 39 (38%) had postoperative LV dysfunction. Follow-up echocardiograms were available in 31 (80%) patients, all of whom had LVEF>50% within 9months of surgery. Lower preoperative apical four-chamber longitudinal strain (A4LS) and greater LV end-diastolic volume indexed to body surface area1.38 were independently associated with postoperative LV dysfunction. An absolute preoperative A4LS < 16.7% (area under the curve=0.87; 95% CI, 0.78-0.95; P<.001) was most strongly associated with postoperative dysfunction.CONCLUSIONS: Infants with LV dysfunction following repair of large VSDs recover function within 9months. Preoperative A4LS can be helpful to detect subclinical LV dysfunction in the setting of a large hemodynamically significant VSD and guide postoperative expectations for providers and families.

    View details for DOI 10.1016/j.echo.2019.10.003

    View details for PubMedID 31866322

  • Redo Valve-Sparing Root Replacement for Delayed Cusp Derangement From Ventricular Septal Defect ANNALS OF THORACIC SURGERY Zhu, Y., Cohen, J. E., Ma, M., Woo, Y. 2019; 108 (5): E295–E296
  • Outcomes After Aortopulmonary Window for Hypoplastic Pulmonary Arteries and Dual-Supply Collaterals ANNALS OF THORACIC SURGERY Bauser-Heaton, H., Ma, M., McElhinney, D. B., Goodyer, W. R., Zhang, Y., Chan, F. P., Asija, R., Shek, J., Wise-Faberowski, L., Hanley, F. L. 2019; 108 (3): 820–27
  • Surgical results of unifocalization revision Mainwaring, R. D., Patrick, W. L., Rosenblatt, T. R., Ma, M., Kamra, K., Arunamata, A., Hanley, F. L. MOSBY-ELSEVIER. 2019: 534–44
  • Modeling conduit choice for valve-sparing aortic root replacement on biomechanics with a 3-dimensional-printed heart simulator JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY Paulsen, M. J., Kasinpila, P., Imbrie-Moore, A. M., Wang, H., Hironaka, C. E., Koyano, T. K., Fong, R., Chiu, P., Goldstone, A. B., Steele, A. N., Stapleton, L. M., Ma, M., Woo, Y. 2019; 158 (2): 392–403
  • Redo Valve-Sparing Root Replacement for Delayed Cusp Derangement from Ventricular Septal Defect. The Annals of thoracic surgery Zhu, Y., Cohen, J. E., Ma, M., Woo, Y. J. 2019


    A 28-year-old gentleman with ventricular septal defect (VSD), double-chambered right ventricle (DCRV) with associated right ventricular outflow tract obstruction, and anomalous right coronary artery (RCA) underwent resection of the DCRV, trans-aortic VSD repair, and unroofing of anomalous RCA. Two years later, he returned with delayed presentation of VSD flow funnel related aortic cusp prolapse and symptomatic severe aortic regurgitation. He underwent reoperative valve-sparing aortic root replacement and aortic cusp repair with an excellent outcome.

    View details for PubMedID 30986415

  • Outcomes After Aortopulmonary Window for Hypoplastic Pulmonary Arteries and Dual-Supply Collaterals. The Annals of thoracic surgery Bauser-Heaton, H., Ma, M., McElhinney, D. B., Goodyer, W. R., Zhang, Y., Chan, F. P., Asija, R., Shek, J., Wise-Faberowski, L., Hanley, F. L. 2019


    BACKGROUND: Our institutional approach to tetralogy of Fallot (TOF) with major aortopulmonary collateral arteries (MAPCAs) emphasizes early unifocalization and complete repair (CR). In the small subset of patients with dual-supply MAPCAs and confluent but hypoplastic central pulmonary arteries (PAs), our surgical approach is early creation of an aortopulmonary window (APW) to promote PA growth. Factors associated with successful progression to CR, and mid-term outcomes have not been assessed.METHODS: Clinical data were reviewed. PA diameters were measured off-line from angiograms prior to APW and on follow-up catheterization >1 month after APW but prior to any additional surgical interventions.RESULTS: From 11/01-3/18, 352 patients with TOF/MAPCAs underwent initial surgery at our center, 40 of whom had a simple APW with or without ligation of MAPCAs as the first procedure (median age 1.4 months). All PA diameters increased significantly on follow-up angiography. Ultimately, 35 patients underwent CR after APW. Nine of these patients (26%) underwent intermediate palliative operation between 5 and 39 months (median 8 months). There were no early deaths. The cumulative incidence of CR was 65% 1 year post-APW and 87% at 3 years. Repaired patients were followed for a median of 4.2 years after repair; the median PA:aortic pressure ratio was 0.39 (0.22-0.74).CONCLUSIONS: Most patients with TOF/MAPCAs and hypoplastic but normally arborizing PAs and dual-supply MAPCAs are able to undergo CR with low right ventricular pressure after APW early in life. Long-term outcomes were good, with acceptable PA pressures in most patients.

    View details for PubMedID 30980823

  • Outcomes After Initial Unifocalization to a Shunt in Complex Tetralogy of Fallot with MAPCAs. The Annals of thoracic surgery Bauser-Heaton, H. n., Ma, M. n., Wise-Faberowski, L. n., Asija, R. n., Shek, J. n., Zhang, Y. n., Peng, L. F., Sidell, D. R., Hanley, F. L., McElhinney, D. B. 2019


    Our approach to tetralogy of Fallot (TOF) with pulmonary atresia and major aortopulmonary collateral arteries (MAPCAs) emphasizes early single-stage unifocalization and intracardiac repair. However, a subset of patients with small native pulmonary arteries (PAs) and MAPCAs undergo unifocalization to a shunt rather than simultaneous intracardiac repair.Patients with TOF/MAPCAs who underwent unifocalization to a systemic-to-PA shunt by a single surgeon were reviewed. The decision to perform simultaneous intracardiac repair was based on an intraoperative flow study or empirical assessment of PA and MAPCA size.From 11/01-12/17, 57 patients with TOF/MAPCAs underwent unifocalization to a shunt at a median age of 6.9 months. Genetic abnormalities were documented in 60% of patients, including a chromosome 22q11 deletion in 25 and Alagille syndrome in 8. Twenty patients (35%) had undergone prior surgery elsewhere (n=16) and/or at our center (n=7). During a median follow-up of 5.4 years, 9 patients had additional surgery to revise the PA reconstruction before complete repair, and 38 patients underwent complete repair. Survival was 74±6% 5 years after unifocalization. At follow-up, the median PA:aortic systolic pressure ratio was 0.36 and was >0.50 in 2 patients.In patients with the smallest MAPCAs and PAs, single-stage unifocalization to a shunt followed by intracardiac repair yields an excellent outcome in most cases.

    View details for DOI 10.1016/j.athoracsur.2019.01.030

    View details for PubMedID 30772338

  • Use of a supramolecular polymeric hydrogel as an effective post-operative pericardial adhesion barrier. Nature biomedical engineering Stapleton, L. M., Steele, A. N., Wang, H. n., Lopez Hernandez, H. n., Yu, A. C., Paulsen, M. J., Smith, A. A., Roth, G. A., Thakore, A. D., Lucian, H. J., Totherow, K. P., Baker, S. W., Tada, Y. n., Farry, J. M., Eskandari, A. n., Hironaka, C. E., Jaatinen, K. J., Williams, K. M., Bergamasco, H. n., Marschel, C. n., Chadwick, B. n., Grady, F. n., Ma, M. n., Appel, E. A., Woo, Y. J. 2019; 3 (8): 611–20


    Post-operative adhesions form as a result of normal wound healing processes following any type of surgery. In cardiac surgery, pericardial adhesions are particularly problematic during reoperations, as surgeons must release the adhesions from the surface of the heart before the intended procedure can begin, thereby substantially lengthening operation times and introducing risks of haemorrhage and injury to the heart and lungs during sternal re-entry and cardiac dissection. Here we show that a dynamically crosslinked supramolecular polymer-nanoparticle hydrogel, with viscoelastic and flow properties that enable spraying onto tissue as well as robust tissue adherence and local retention in vivo for two weeks, reduces the formation of pericardial adhesions. In a rat model of severe pericardial adhesions, the hydrogel markedly reduced the severity of the adhesions, whereas commercial adhesion barriers (including Seprafilm and Interceed) did not. The hydrogels also reduced the severity of cardiac adhesions (relative to untreated animals) in a clinically relevant cardiopulmonary-bypass model in sheep. This viscoelastic supramolecular polymeric hydrogel represents a promising clinical solution for the prevention of post-operative pericardial adhesions.

    View details for DOI 10.1038/s41551-019-0442-z

    View details for PubMedID 31391596

  • Surgical Repair of Ebstein's Anomaly Utilizing A Bicuspidization Approach. The Annals of thoracic surgery Mainwaring, R. D., Rosenblatt, T. R., Lui, G. K., Ma, M. n., Hanley, F. L. 2019


    Ebstein's anomaly of the tricuspid valve is a rare and heterogeneous form of congenital heart defect. The purpose of this study was to review the surgical experience with Ebstein's anomaly at a single institution.This was a retrospective review of 47 patients with Ebstein's anomaly who were previously unrepaired and underwent surgical repair of the tricuspid valve. Our surgical approach repairs the leaflets at the pre-existing level and does not attempt to reposition the hingepoints at the anatomic annulus. The median age at surgery was 17 years (range 2 to 53 years). Pre-operatively, the median degree of tricuspid regurgitation was graded as moderate-to-severe and the median right ventricular function was slightly below normal.Forty-seven patients underwent surgical repair without any mortality. Forty-three of the 47 patients (91%) had a successful repair as evidenced by a decrease in the amount of tricuspid regurgitation to trace/mild. Four patients (9%) had an unsuccessful initial repair. Thirteen of the 47 (29%) underwent a concomitant bi-directional Glenn procedure. There were 8 patients (17%) who have required late re-operation. Seven of these 8 patients initially had undergone a successful repair but returned with recurrent tricuspid regurgitation. Six of the 8 late re-operations entailed a re-repair, while two (4%) required ; tricuspid valve replacement.The bicuspidization surgical technique resulted in 91% percent of patients undergoing a successful initial repair. These results suggest this technique may be a viable alternative to the "cone" procedure.

    View details for DOI 10.1016/j.athoracsur.2019.06.026

    View details for PubMedID 31394091

  • Surgical results of unifocalization revision. The Journal of thoracic and cardiovascular surgery Mainwaring, R. D., Patrick, W. L., Rosenblatt, T. R., Ma, M., Kamra, K., Arunamata, A., Hanley, F. L. 2018


    OBJECTIVE: Midline unifocalization has been developed for the surgical treatment of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. All patients will eventually require reoperation due to the presence of a conduit, and some may also require revision of the distal unifocalized bed. The purpose of this study was to evaluate the surgical results of unifocalization revision.METHODS: This was a retrospective review of 254 patients who underwent midline unifocalization for treatment of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. Forty-eight of 254 patients (18%) have subsequently undergone unifocalization revision. Thirty-two of these patients had previously undergone a single-stage complete repair, whereas 16 had a unifocalization and placement of a central shunt.RESULTS: For the 32 patients who previously underwent a complete repair, there have been no early or late deaths. The peak systolic pulmonary artery to aortic pressure ratio was 0.44±0.11 after the initial repair and increased to 0.82±0.18 before revision. The pressure ratio decreased to 0.41±0.09 after revision. Three of 32 patients (9%) have subsequently undergone a second unifocalization revision. The 16 patients who previously had a unifocalization/shunt underwent unifocalization revision and complete repair (n=14) and revision and repeat shunt (n=2). There was 1 operative mortality and 3 late deaths (25% total) in this cohort. Three (25%) of 12 survivors have subsequently undergone a second unifocalization revision.CONCLUSIONS: The data demonstrate that unifocalization revision can be performed with a successful outcome in a majority of patients. Patients who underwent an initial unifocalization/shunt had a higher failure rate than patients who were initially repaired.

    View details for PubMedID 30982588

  • Modeling conduit choice for valve-sparing aortic root replacement on biomechanics with a 3-dimensional-printed heart simulator. The Journal of thoracic and cardiovascular surgery Paulsen, M. J., Kasinpila, P., Imbrie-Moore, A. M., Wang, H., Hironaka, C. E., Koyano, T. K., Fong, R., Chiu, P., Goldstone, A. B., Steele, A. N., Stapleton, L. M., Ma, M., Woo, Y. J. 2018


    OBJECTIVE: The optimal conduit for valve-sparing aortic root replacement is still debated, with several conduit variations available, ranging from straight tubular grafts to Valsalva grafts. Benefits of neosinus reconstruction include enhanced flow profiles and improved hemodynamics. Curiously, however, some clinical data suggest that straight grafts may have greater long-term durability. In this study, we hypothesized that straight tubular grafts may help maintain the native cylindrical position of the aortic valve commissures radially, resulting in preserved leaflet coaptation, reduced stresses, and potentially improved valve performance.METHODS: Using 3D printing, a left heart simulator with a valve-sparing root replacement model and a physiologic coronary circulation was constructed. Aortic valves were dissected from fresh porcine hearts and reimplanted into either straight tubular grafts (n=6) or Valsalva grafts (n=6). Conduits were mounted into the heart simulator and hemodynamic, echocardiographic, and high-speed videometric data were collected.RESULTS: Hemodynamic parameters and coronary blood flow were similar between straight and Valsalva grafts, although the former were associated with lower regurgitant fractions, less peak intercommissural radial separation, preserved leaflet coaptation, decreased leaflet velocities, and lower relative leaflet forces compared with Valsalva grafts.CONCLUSIONS: Valsalva grafts and straight grafts perform equally well in terms of gross hemodyanics and coronary blood flow. Interestingly, however, the biomechanics of these 2 conduits differ considerably, with straight grafts providing increased radial commissural stability and leaflet coaptation. Further investigation into how these parameters influence clinical outcomes is warranted.

    View details for PubMedID 30745047

  • Repair of Ductus or Hemi-Truncus to One Lung and Major Aortopulmonary Collaterals to the Other Lung. The Annals of thoracic surgery Mainwaring, R. D., Rosenblatt, T. R., Patrick, W. L., Ma, M., Peng, L., Hanley, F. L. 2018


    BACKGROUND: There are patients born with pulmonary atresia and a ductus arteriosus or hemi-truncus to one lung and major aortopulmonary collateral arteries (MAPCAs) to the contralateral lung. The purpose of this study was to review our surgical results for this relatively rare subset of patients.METHODS: This was a retrospective review of 35 patients with ductus/hemi-truncus in association with pulmonary atresia with ventricular septal defect and MAPCAs. Our surgical algorithm is bifurcated into two strategies: 1) patients with "favorable" MAPCAs are candidates for single stage complete repair, and 2) patients with "unfavorable" MAPCAs undergo a staged approach. The median age at surgery was 3 months (range 1-7 months), and the mean number of MAPCAs was 3.1 ± 1.3.RESULTS: Twenty patients underwent a single stage complete repair. All 20 of these patients are alive with a right ventricle to aortic pressure ratio of 0.34 ± 0.07. The distribution of pulmonary blood flow by lung perfusion scan was 44% to the right and 56% to the left lung. Fifteen patients underwent a staged approach, including unifocalization of the MAPCAs to a central shunt. There were two interim deaths. Twelve patients have undergone complete repair with a right ventricle to aortic pressure ratio of 0.38 ± 0.07. There was one late death after complete repair. The distribution of pulmonary blood flow was 39% to the right and 61% to the left lung.CONCLUSIONS: The data demonstrate that 32 of 35 patients with ductus/hemi-truncus and MAPCAs ultimately achieved complete repair with relatively low pulmonary artery pressures.

    View details for PubMedID 29684371

  • An analysis of patients requiring unifocalization revision following midline unifocalization for pulmonary atresia with ventricular septal defect and major aortopulmonary collaterals. European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery Mainwaring, R. D., Patrick, W. L., Ma, M., Hanley, F. L. 2018


    OBJECTIVES: Midline unifocalization has been developed for the surgical treatment of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. All patients will eventually require reoperation because of the presence of a conduit, and some patients may also require revision of the distal unifocalized bed. The purpose of this study was to analyse the need for unifocalization revision following midline unifocalization.METHODS: This was a retrospective review of 241 patients who underwent midline unifocalization for the treatment of pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. Two hundred and four (85.4%) patients had a single-stage complete repair, whereas 37 patients had a unifocalization and placement of a central shunt. Seventy-eight patients have subsequently undergone reoperations at our institution, including 44 operations that required unifocalization revision. These 44 patients were compared with the 191 operative survivors who did not require revision.RESULTS: An analysis of risk factors for requiring unifocalization revision included the following: (i) single-stage complete repair versus unifocalization and shunt (14.7% vs 37.8%, P<0.001), (ii) right ventricle to aortic pressure ratio at the initial repair (0.33±0.07 vs 0.44±0.08, P<0.001) and (iii) absence of central pulmonary arteries (32.8% vs 13.4%, P<0.001).CONCLUSIONS: Data demonstrate that 44 of 241 (18%) patients who underwent midline unifocalization have subsequently required revision of their unifocalization. The need for unifocalization revision was associated with 3 factors, all of which were known at the time of discharge from the initial unifocalization. These data suggest that potentially higher risk patients should be monitored more closely than their lower risk counterparts.

    View details for PubMedID 29447337

  • Current status of domino heart transplantation. Journal of cardiac surgery Shudo, Y., Ma, M., Boyd, J. H., Woo, Y. J. 2017; 32 (3): 229-232


    Domino heart transplant, wherein the explanted heart from the recipient of an en-bloc heart-lung is utilized for a second recipient, represents a unique surgical strategy for patients with end-stage heart failure. With a better understanding of the potential advantages and disadvantages of this procedure, its selective use in the current era can improve and maximize organ allocation in the United States. In this report, we reviewed the current status of domino heart transplantation.

    View details for DOI 10.1111/jocs.13104

    View details for PubMedID 28219115

  • Recovery of a Missile Embolus From the Right Ventricle. Annals of thoracic surgery Marshall, C. D., Ma, M. R., Park, J., Sheckter, C. C., Massoudi, R. A., Ligman, C. M., Jou, R. M., Ogden, W. D. 2017; 103 (1): e69-e71


    Missile embolism is a clinical entity in which a projectile object enters a blood vessel and is carried to a distant part of the body. We present a case of the discovery of an iliac vein to right ventricle missile embolus in a young man, with successful extraction through a right atriotomy. We provide a historical overview of the literature concerning missile embolism, and we argue that whereas acute embolized projectiles should be removed in almost all cases, it may be reasonable to simply observe an asymptomatic chronic missile embolus.

    View details for DOI 10.1016/j.athoracsur.2016.06.107

    View details for PubMedID 28007279

  • Pulmonary Valve Repair for Patients With Acquired Pulmonary Valve Insufficiency ANNALS OF THORACIC SURGERY Said, S. M., Mainwaring, R. D., Ma, M., Tacy, T. A., Hanley, F. L. 2016; 101 (6): 2294-2301


    Pulmonary valve (PV) insufficiency is often an acquired condition after treatment for pulmonary stenosis. It is recognized that PV insufficiency has serious deleterious effects. Although surgical replacement of the PV is efficacious, artificial valves inevitably fail and require re-intervention. The purpose of this study was to summarize our experience with PV repair in patients with acquired PV insufficiency.This was a retrospective review of 16 patients with marked PV insufficiency who underwent PV repair. Thirteen of these patients were born with tetralogy of Fallot (TOF) and had undergone a previous transannular patch repair. Three patients were born with critical pulmonary stenosis and had a surgical valvotomy or balloon valvuloplasty.The 13 patients with TOF had resection of their previously placed transannular patch with re-approximation of the anterior commissure. All 13 patients experienced a marked reduction in the degree of pulmonary insufficiency. None of these patients have experienced any increase in insufficiency during follow-up. The 3 patients with critical pulmonary stenosis had a variety of pathologic findings identified at the surgical procedure. One patient had a large gap between a commissure and underwent closure of that commissure. The second and third patients had torn leaflets repaired with pericardial and Gore-Tex patches (Gore, Inc, Flagstaff, AZ). The degree of PV insufficiency was decreased to mild in all 3 patients. However, 2 of these 3 patients have subsequently had an increase in the degree of pulmonary insufficiency.Patients with TOF who underwent a previous transannular patch may be candidates for bicuspidization of their native PV, and the results of this procedure have been quite stable at follow-up. PV repair for torn leaflets was effective in the short term but was less stable over time.

    View details for DOI 10.1016/j.athoracsur.2016.01.035

    View details for Web of Science ID 000376502600043

    View details for PubMedID 27083251

  • Anatomic Factors Associated With Truncal Valve Insufficiency and the Need for Truncal Valve Repair. World journal for pediatric & congenital heart surgery Patrick, W. L., Mainwaring, R. D., Carrillo, S. A., Ma, M., Reinhartz, O., Petrossian, E., Selamet Tierney, E. S., Reddy, V. M., Hanley, F. L. 2016; 7 (1): 9-15


    Truncus arteriosus is a complex and heterogeneous form of congenital heart defect. Many of the risk factors from several decades ago, including late repair and interrupted aortic arch, have been mitigated through better understanding of the entity and improved surgical techniques. However, truncal valve dysfunction remains an important cause of morbidity and mortality. The purpose of this study was to evaluate the anatomic factors associated with truncal valve dysfunction and the need for truncal valve surgery.This was a retrospective review of 72 infants who underwent repair of truncus arteriosus at our institution. The median age at surgery was nine days, and the median weight was 3.1 kg. Preoperative assessment of truncal valve insufficiency by echocardiography revealed no or trace insufficiency in 30, mild in 25, moderate in 10, and severe in 7. The need for truncal valve surgery was dictated by the severity of truncal valve insufficiency.Sixteen (22%) of the 72 patients undergoing truncus arteriosus repair had concomitant truncal valve surgery. Anatomic factors associated with the need for truncal valve surgery included an abnormal number of truncal valve cusps (P < .005), presence of valve dysplasia (P < .005), and the presence of an anomalous coronary artery pattern (P < .005). Fifteen (94%) of the sixteen patients who underwent concomitant surgery had two or all three of these anatomic factors (sensitivity = 94%, specificity = 85%).This study demonstrates that the presence of specific anatomic factors was closely associated with the presence of truncal valve insufficiency and the need for concomitant truncal valve surgery. Preoperative evaluation of these anatomic factors may provide a useful tool in determining who should undergo concomitant truncal valve surgery.

    View details for DOI 10.1177/2150135115608093

    View details for PubMedID 26714988

  • Post-Transplant Hemodialysis Drastically Reduces One-Year Survival in Patients Entering Liver Transplantation without Renal Dysfunction. 9th Joint Meeting of the American-Society-of-Transplant-Surgeon/American-Society-of-Transplantation Ma, M., Brennan, T., Reyes, I., Tamura, M., Feng, S. WILEY-BLACKWELL. 2009: 261–261
  • Transplantation of hNT neurons into the ischemic cortex: Cell survival and effect on sensorimotor behavior JOURNAL OF NEUROSCIENCE RESEARCH Bliss, T. M., Kelly, S., Shah, A. K., Foo, W. C., Kohli, P., Stokes, C., Sun, G. H., Ma, M., Masel, J., Kleppner, S. R., Schallert, T., Palmer, T., Steinberg, G. K. 2006; 83 (6): 1004-1014


    Cell transplantation offers a potential new treatment for stroke. Animal studies using models that produce ischemic damage in both the striatum and the frontal cortex have shown beneficial effects when hNT cells (postmitotic immature neurons) were transplanted into the ischemic striatum. In this study, we investigated the effect of hNT cells in a model of stroke in which the striatum remains intact and damage is restricted to the cortex. hNT cells were transplanted into the ischemic cortex 1 week after stroke induced by distal middle cerebral artery occlusion (dMCAo). The cells exhibited robust survival at 4 weeks posttransplant even at the lesion border. hNT cells did not migrate, but they did extend long neurites into the surrounding parenchyma mainly through the white matter. Neurite extension was predominantly toward the lesion in ischemic animals but was bidirectional in uninjured animals. Extension of neurites through the cortex toward the lesion was also seen when there was some surviving cortical tissue between the graft and the infarct. Prolonged deficits were obtained in four tests of sensory-motor function. hNT-transplanted animals showed a significant improvement in functional recovery on one motor test, but there was no effect on the other three tests relative to control animals. Thus, despite clear evidence of graft survival and neurite extension, the functional benefit of hNT cells after ischemia is not guaranteed. Functional benefit could depend on other variables, such as infarct location, whether the cells mature, the behavioral tests employed, rehabilitation training, or as yet unidentified factors.

    View details for DOI 10.1002/jnr.20800

    View details for Web of Science ID 000237217100008

    View details for PubMedID 16496370

  • Transplanted human fetal neural stem cells survive, migrate, and differentiate in ischemic rat cerebral cortex PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Kelly, S., Bliss, T. M., Shah, A. K., Sun, G. H., Ma, M., Foo, W. C., Masel, J., Yenari, M. A., Weissman, I. L., Uchida, N., Palmer, T., Steinberg, G. K. 2004; 101 (32): 11839-11844


    We characterize the survival, migration, and differentiation of human neurospheres derived from CNS stem cells transplanted into the ischemic cortex of rats 7 days after distal middle cerebral artery occlusion. Transplanted neurospheres survived robustly in naive and ischemic brains 4 wk posttransplant. Survival was influenced by proximity of the graft to the stroke lesion and was negatively correlated with the number of IB4-positive inflammatory cells. Targeted migration of the human cells was seen in ischemic animals, with many human cells migrating long distances ( approximately 1.2 mm) predominantly toward the lesion; in naive rats, cells migrated radially from the injection site in smaller number and over shorter distances (0.2 mm). The majority of migrating cells in ischemic rats had a neuronal phenotype. Migrating cells between the graft and the lesion expressed the neuroblast marker doublecortin, whereas human cells at the lesion border expressed the immature neuronal marker beta-tubulin, although a small percentage of cells at the lesion border also expressed glial fibrillary acid protein (GFAP). Thus, transplanted human CNS (hCNS)-derived neurospheres survived robustly in naive and ischemic brains, and the microenvironment influenced their migration and fate.

    View details for DOI 10.1073/pnas.0404474101

    View details for Web of Science ID 000223276700056

    View details for PubMedID 15280535

    View details for PubMedCentralID PMC511061