Mortality and morbidity after combined heart and liver transplantation in the failing Fontan: An updated dual center retrospective study.

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

An integrated program to expand donor utilization in pediatric heart transplantation: Case report of successful transplant with multiple donor risk factors.

BACKGROUND: 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. METHODS: We report a case of successful pediatric HT in which multiple risk factors were mitigated through a combination of innovative donor utilization improvement strategies. RESULTS: 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. CONCLUSIONS: 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.

Weight Matching in Infant Heart Transplantation: A National Registry Analysis.

BACKGROUND: Infants account for a significant proportion of pediatric heart transplantation 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 January 1994 to September 2019 were retrospectively analyzed. 2384 heart transplantation recipients were divided into quintiles (Q1-Q5) on the basis of donor-to-recipient weight ratio (DRWR). Multivariate Cox regression was used to estimate the effect of DRWR. The primary end point was graft survival at 1 year. RESULTS: The median DRWR for each quintile was 0.90 (0.37-1.04), 1.17 (1.04-1.29), 1.43 (1.29-1.57), 1.74 (1.58-1.97), and 2.28 (1.97-5.00). Pairwise comparisons showed improved survival for Q3 and Q4 over each of the bottom 2 quintiles and the top quintile. Regression analyses found that Q3 and Q4 were protective against graft failure compared with the bottom 2 quintiles. There was no difference in hazard among the top 3 quintiles. Significant covariates included primary diagnosis, ischemia time, serum bilirubin level, transplantation year, mechanical ventilation at transplantation, and extracorporeal membrane oxygenation at transplantation. Sex, female-to-male transplantation, and mechanical circulatory support at transplantation were not significant in univariate analyses. CONCLUSIONS: Modest oversizing by DRWR (1.29-1.97) 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.

Evaluating predicted heart mass in adolescent heart transplantation.

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.

Innominate artery patency after direct cannulation in neonates.

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 5.0 days, 92 neonates underwent the Norwood procedure with direct innominate artery cannulation. These patients underwent cardiac catheterization at a median of 3.0 months 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.

Complete repair for Scimitar syndrome with transitional atrioventricular canal.

We describe an extremely rare case of a 15-year-old female, who underwent a complete repair for transitional atrioventricular canal with Scimitar syndrome by a two-patch technique including translocation of the Scimitar vein. This surgical technique offered superior patch shapes in order to better repair both anomalies.

Neonatal right mini thoracotomy for repair of critical pulmonary stenosis.

Over the last few decades, due to evolving surgical techniques and medical management, there has been a significant decrease in the rate of mortality and complications for neonates born with critical pulmonary valve stenosis. Median sternotomy is the standard approach; however, this longitudinal midline incision is invasive and leaves a significant scar. A right mini thoracotomy approach to this surgical repair decreases recovery time and the chance of possible future psychological distress from a visible median sternotomy scar. This is the first article to describe a right mini thoracotomy approach for critical pulmonary stenosis during the neonatal period.

Single Ventricular Assist Device Support for the Failing Bidirectional Glenn Patient.

BACKGROUND: Given poor outcomes, strategies to improve ventricular assist devices (VADs) for single-ventricle patients with bidirectional Glenn (BDG) palliation are needed. METHODS: This retrospective review describes an institutional experience with VAD support for patients with BDG from April 2011 to January 2019. Surgical strategies, complications, and causes of death are described. Survival to heart transplantation for various strategies are compared. RESULTS: A total of 7 patients with BDG (weights, 5.6 to 28.8 kg; ages, 7 months to 11 years) underwent VAD implantation. Three patients underwent implantation of Berlin Heart EXCOR devices (Berlin Heart, Inc, Spring, TX), 2 had HeartWare HVADs (Medtronic, Minneapolis, MN) implanted, and 2 patients underwent implantation of paracorporeal continuous flow devices. Four patients underwent ventricular inflow cannulation, and 3 underwent atrial inflow cannulation. At the time of VAD implantation, the BDG was left intact in 3 patients, taken down in 3 patients, and created de novo in 1 patient. Over a total of 420 VAD support days, 2 patients survived to heart transplantation, 1 patient with HeartWare ventricular cannulation and intact BDG (after 174 days) and another with Berlin Heart atrial cannulation and BDG take-down (after 72 days). There were 3 deaths within 2 weeks of VAD implantation (2 from respiratory failure, 1 from infection) and 2 deaths after 30 days as a result of strokes. CONCLUSIONS: The surgical strategy and postoperative management of VAD with BDG are still evolving. Successful support can be achieved with (1) both pulsatile and continuous flow pumps, (2) atrial or ventricular cannulation, and (3) with or without BDG take-down. Surgical strategy should be determined by individual patient anatomy, physiology, and condition.

Aortic or Pulmonary Valved Homograft Right Ventricle to Pulmonary Artery Conduit in the Norwood Procedure.

BACKGROUND: Several modifications of the Norwood procedure utilizing valved right ventricle to pulmonary artery conduits have recently been reported. Our group has been using aortic or pulmonary valved homografts combined with PTFE tube grafts for now 16 years. METHODS: In this report, we review our technique in detail and describe any changes that have occurred over the years. We provide detailed illustrations of our preferred surgical technique, report outcome data, and compare it to the other conduit options available. RESULTS: Between 2006 and 2015, 130 stage I Norwood procedures were performed at our institution, 100 of them using valved conduits. Our technique is described and illustrated in detail. Early mortality was 15%. Postoperative percutaneous intervention on the conduit was required in 29% of cases. CONCLUSIONS: While a randomized trial comparing different valved conduits is lacking, we believe a composite conduit made from homograft aortic or pulmonary valves and PTFE tube grafts is an excellent choice in stage I Norwood procedure.

Analysis of achieving an "ideal" outcome following midline unifocalization.

OBJECTIVE: Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries is a complex form of congenital heart disease. Midline unifocalization has been developed for the surgical treatment of this condition. There are 3 outcome measures that determine long-term success: patients are alive, patients have achieved complete repair (i.e. ventricular septal defect closure), and patients have a relatively low right ventricle-to-aortic pressure ratio (<0.45). However, to date, no studies have combined these 3 outcome measures to analyze the likelihood of achieving an ideal outcome. METHODS: This was a retrospective review of 255 patients who underwent midline unifocalization for pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. The median age at unifocalization was 4.5 months. RESULTS: Two hundred thirty-five (92%) patients were alive at a mean follow-up of 5.3 years. Two hundred and seventeen (85%) patients underwent single-stage complete repair, and 38 (15%) had an initial unifocalization and shunt. Twenty-four of the 38 palliated patients have subsequently undergone repair. Thus 241 (94%) patients ultimately achieved complete repair. Of the 241 patients who were repaired, 219 (86%) had a right ventricle-to-aortic peak systolic pressure ratio <0.45. Combining these outcome measures, 77% of patients achieved an ideal outcome at one month, 73% at 6 months, 76% at one year, and 80% at 4 years. CONCLUSIONS: Most (80%) patients can achieve all 3 measures of favorable outcome at 4 years following midline unifocalization. We speculate that this will be a favorable portend for the future of these patients.

An Alternative Approach by HeartWare Ventricular Assist Device in Hypertrophic Cardiomyopathy.

Hypertrophic cardiomyopathy is known to be difficult to support by left ventricular assist device because of the small ventricular cavity and inadequate drainage. Therefore, instead of cannulating on the left ventricular apex, a HeartWare ventricular assist device (HeartWare, Framingham, MA) was connected to the left atrium through right atrium onto atrial septum using ringed Gore-Tex (W.L. Gore & Associates, Flagstaff, AZ) interposition graft. The patient has been discharged home after ventricular assist device implant and underwent successful heart transplant after 111 days of support without any complications including any thromboembolic events. This new transatrial left atrial cannulation technique can be an alternative approach for ventricular assist device cannulation in hypertrophic cardiomyopathy. It can be safely performed with the HeartWare ventricular assist device.

Biatrial connection of partial anomalous pulmonary venous return.

We describe an extremely rare case of partial anomalous pulmonary venous return in a 3-year-old boy with an abnormal connection between the right upper pulmonary vein and the right middle pulmonary vein, which created biatrial communication hemodynamically. Patch closure on the orifice of the right upper pulmonary vein was performed to avoid distortion or kinking of the right pulmonary veins and the connection.

Is Continuous Flow Superior to Pulsatile Flow in Single Ventricle Mechanical Support? Results from a Large Animal Pilot Study.

Durable mechanical support in situations of physiologic single ventricle has been met with little success so far, particularly in small children. We created an animal model to investigate whether pulsatile or continuous flow would be superior. Three 1 month old sheep (10-16 kg) were instrumented. Via sternotomy and with cardiopulmonary bypass, a large ventricular septal defect and atrial septal defect were created. The left ventricle was cannulated using a Berlin Heart inflow cannula. This was connected sequentially to a continuous flow device (Thoratec HeartMate X, Pleasanton, CA) and to a pulsatile device (Berlin Heart Excor, The Woodlands, TX). Outflow was via a Y-graft to both aorta and pulmonary artery, striving for equal flow to both. Atrial filling pressures were controlled with volume infusions over a wide range. Under comparable loading conditions, significantly higher maximum flow was obtained by HeartMate X than by Excor (4.95 ± 1.27 L/min [range, 3.84-6.34 L/min] for HeartMate X vs. 1.80 ± 0.85 L/min [range, 1.01-2.7 L/min] for Excor; p < 0.05). Judging from this limited animal study, in single ventricle scenarios, continuous flow devices may achieve higher pump flows than pulsatile devices when provided with similar filling pressures. Their clinical use should be investigated. More extensive experimental studies are needed.

Hemodynamic monitoring of large animal chronic studies after median sternotomy: experiences with different telemetric physiological devices.

Telemetric physiological monitoring systems (TPMS) have enabled accurate continuous measurement of animal blood pressures and flows. However, few studies describe approaches for use of TPMS in the great vessels or inside the heart. We describe our initial experiences using two types of TPMSs. Twelve lambs (20-37 kg) underwent sternotomy. Two lambs were not instrumented and were killed at 14 days to confirm normal sternal wound healing (sham group, n = 2). Ten lambs underwent placement of either standard indwelling pressure-monitoring catheter and perivascular-flow-probe (CFP group, n = 3) or TPMS implantation (TPMS group, n = 7). The TPMS used were EG1-V3S2T-M2 (EG1, n = 5; Transonic Endogear Inc.) and Physio Tel Digital L21 (PTD, n = 2; Data Sciences Inc.). Two deaths because of respiratory problems occurred in TPMS group, attributed to lung compression by the implanted device. In TPMS group, more consistent trends of blood pressures and flows were recorded, and management of animals was easier and less labor-intensive. Comparing the two TPMSs, the initiation and renewal costs for each case was $28 K vs. $20 K and $1,700 vs. $0, (PTD versus EG1, respectively). In conclusion, TPMS implantation was feasible via median sternotomy in lambs. Telemetric physiological monitoring systems significantly improve reliability of hemodynamic monitoring in chronic survival animal study. EG1 was less costly than PTD.

Innominate artery cannulation and antegrade cerebral perfusion for aortic arch reconstruction in infants and children.

PURPOSE: Innominate artery cannulation has been widely adopted as a means to perform aortic arch reconstruction with continuous cerebral perfusion in the newborn. Although this technique has been subsequently utilized in infants and children, there is currently no data regarding the safety or efficacy in these older children. The purpose of this study was to review our experience with innominate artery cannulation for aortic arch reconstruction in patients beyond the neonatal period. METHODS: This was a retrospective review of 42 infants and children who underwent aortic arch reconstruction using the technique of innominate artery cannulation with continuous cerebral perfusion. Of these procedures, 29 (69%) were primary arch reconstructions, while 13 (31%) were aortic arch reoperations. The median age at surgery was 8 months, and 22 patients underwent concomitant intracardiac repairs. RESULTS: There was no operative mortality in this cohort of 42 patients undergoing aortic arch reconstruction. There was also no overt evidence of neurologic injury. Specifically, none of the patients demonstrated a neurologic deficit, clinical seizure, or unexpected delay in regaining a normal state of consciousness. The median duration of antegrade cerebral perfusion was 34 minutes. The median duration of hospital stay was 11 days. No patient required reoperation on the aortic arch with a median of 45-month follow-up. CONCLUSIONS: Innominate artery cannulation is a safe and effective technique for aortic arch reconstruction in nonneonates. We conclude that antegrade cerebral perfusion is a useful technique for aortic arch reconstruction in this patient population.

Fetal cardiac intervention: improved results of fetal cardiac bypass in immature fetuses using the TinyPump device.

OBJECTIVE: Fetal cardiac surgery is a potential innovative treatment for certain congenital heart defects that have significant mortality and morbidity in utero or after birth, but it has been limited by placental dysfunction after fetal cardiac bypass. We have used the TinyPump device for fetal cardiac bypass in sheep fetuses at 90 to 110 days gestation. METHODS: Ten mixed-breed pregnant ewes were used over a period of 6 months, and 10 fetuses were placed on bypass for 30 minutes. Five fetuses with a mean gestational age of 104 ± 4.5 days and mean weight of 1.4 ± 0.4 kg were placed on bypass using the TinyPump device, and 5 fetuses with a mean gestational age of 119 ± 4.5 days and mean weight of 3.4 ± 0.4 kg were placed on bypass using the roller head pump. The fetuses were monitored for up to 3 hours after bypass or until earlier demise. RESULTS: Progressive respiratory and metabolic acidosis developed in all fetuses. The TinyPump group had a lower gestational age and weight compared with the roller head pump group. However, the rate of postbypass deterioration in the TinyPump group, as measured with blood gases, was noted to be significantly slower compared with the roller head pump group. CONCLUSIONS: We demonstrate the feasibility of the TinyPump device for fetal cardiac bypass in a fetal sheep model. The TinyPump group showed improved results compared with the roller head group despite more immature fetuses. The TinyPump device seems to be a promising device for future studies of fetal cardiac bypass in immature fetal sheep and in primates.

Anomalous aortic origin of a coronary artery: medium-term results after surgical repair in 50 patients.

BACKGROUND: Anomalous aortic origin of a coronary artery (AAOCA) is a rare congenital heart defect that has been associated with myocardial ischemia and sudden death. Controversies exist regarding the diagnosis, treatment, and long-term recommendations for patients with AAOCA. The purpose of this study is to evaluate the medium-term results of surgical repair for AAOCA. METHODS: From January 1999 through August 2010, 50 patients underwent surgical repair of AAOCA. The median age at surgery was 14 years (range, 5 days to 47 years). Thirty-one patients had the right coronary originate from the left sinus of Valsalva, 17 had the left coronary originate from the right sinus, and 2 had an eccentric single coronary ostium. Twenty six of the 50 patients had symptoms of myocardial ischemia preoperatively, and 14 patients had associated congenital heart defects. Repair was accomplished by unroofing in 35, reimplantation in 6, and pulmonary artery translocation in 9. RESULTS: There was no operative mortality. The median time of follow-up has been 5.7 years. Two patients were lost to follow-up, and 1 patient required heart transplantation 1 year after AAOCA repair. In the remaining 47 postoperative patients, all have remained free of cardiac symptoms and no one has experienced a sudden death event. CONCLUSIONS: The surgical treatment of AAOCA is safe and appears to be highly effective in eliminating ischemic symptoms. These medium-term results are encouraging and suggest that many patients may be able to resume normal activities.