Single Ventricle Patients Research Articles

Outcome of single-ventricle patients supported with extracorporeal membrane oxygenation

Background: Single ventricle heart disease can be left or right ventricle dominant congenital heart disease mostly associated with other risk factors like low birth weight, Preterm, chromosomal abnormality and all these risk factor associated with increase mortality. Methods: A retrospective chart review of paediatric patients from neonatal age to 14 years since 2012 to 2021, with supported by extracorporeal membrane oxygenation (ECMO) including both single ventricle heart physiology and biventricular heart, admitted in paediatric cardiac surgical intensive care unit in our hospital was conducted. All data were compared between single ventricle heart physiology and biventricular heart. Data was performed using commercially available software (SPSS), with statistical significance set p<0.05. Results: We enrolled total 124 patients who underwent ECMO cannulation. 68 children had single ventricle, while 56 being biventricular heart. Most children acquired ECMO cannulation in CICU 63 (50.8%). Male to female ratio was 74:50. 70.2% children got the ECMO cannulation when they had already been operated for surgical repair. Conclusions: Paediatric ECMO utilization in SV is valuable and recently its utilization has been increased in it with improve survival.

Abstract 4136819: Necrotizing Enterocolitis is More Common After Hybrid Stage 1 Palliation Than Norwood Without Clear Risk Factors

Background: Infants with congenital heart disease are at high risk of developing necrotizing enterocolitis (NEC), with increased morbidity and mortality compared to infants without heart disease who develop NEC. Shunted single ventricle patients are at even higher risk. The hybrid stage 1 palliation (HS1P) is an alternative to the Norwood procedure for high-risk single ventricle patients or as initial palliation for patients with future two ventricle repair, as bridge to transplant, or as destination therapy. Few small studies have shown similar or slightly higher rates of NEC after HS1P compared to after Norwood. Aims: To evaluate the incidence, risk factors, and outcomes of NEC in HS1P versus Norwood patients. Methods: This is a single-center retrospective cohort study of all neonates who underwent HS1P or Norwood procedure from 2011-2022. Demographic data and episodes of NEC (defined using modified Bell’s criteria) were collected. NEC incidences and risk factors were compared between HS1P and Norwood patients using Chi-square test. For HS1P patients, more extensive data were collected including planned and final physiologic outcomes (single ventricle palliation, biventricular repair, transplant, and destination) and primary patient risk factors that led to HS1P. Risk factors and clinical outcomes of HS1P patients with and without NEC were compared using standard univariate tests. Results: The cumulative incidence of NEC in the HS1P group was 53% versus 37% in the Norwood group (p=0.01) and HS1P patients had more NEC episodes than the Norwood group (median 2 vs 1, p=0.03). Suspected NEC (stage 1A/1B) accounted for 70-75% of NEC cases in both groups. Only two infants, both in the HS1P group, had surgical (stage 3B) NEC. We found no differences in baseline demographics between patients with and without NEC in both HS1P and Norwood groups. In the HS1P group, NEC was associated with longer hospital length of stay (LOS), (median 49 days vs 23 days, p<0.0001) and greater need for tube feeds at 1 year (32% of the NEC group exclusively orally fed versus 43% of the non-NEC group, p=0.03). Final physiologic outcome was not associated with development of NEC in the HS1P group (p=0.38). Conclusions: While the exact risk factors or predictors are not clear, NEC is more common after HS1P compared to Norwoods and is associated with longer hospital LOS and late feeding difficulty. Further studies to better understand the physiologic causes of NEC in the HS1P population are needed.

Comparison of Necrotizing Enterocolitis After Surgical Norwood versus Hybrid Stage 1 Palliation.

Hybrid stage 1 palliation (HS1P) is used as an alternative to the surgical Norwood for single ventricle patients and specific other conditions. Necrotizing enterocolitis (NEC) occurs in 5%-18% of infants after surgical Norwood, contributing to significant morbidity. We sought to compare the NEC incidences in HS1P versus Norwood patients. A single-center retrospective cohort study of all infants undergoing HS1P or Norwood over a 12-year period. Demographics, underlying cardiac diagnosis, surgical details, and NEC episodes were queried for each patient. The cumulative incidences of NEC between HS1P and Norwood patients were compared. A total of 305 infants were included; 200 Norwood and 105 HS1P. HS1P infants were more often premature (gestational age < 37weeks; 23.8% vs 1.5%) and had lower birth weight (mean 2.8 ± 0.66kg versus 3.3 ± 0.47kg) than their Norwood counterparts. Most infants who underwent the Norwood procedure had hypoplastic left heart syndrome (79.5%), with variable underlying cardiac diagnosis for those who underwent HS1P. Incidence of NEC was significantly higher in the HS1P group (53.3% versus 37.0%, p = 0.01), with increased risk independent of birth weight or underlying cardiac diagnosis (adjusted odds ratio 1.8, p = 0.03). Infants after HS1P had a median of 2 episodes of NEC (interquartile range [IQR] 1-3) versus 1 episode in the Norwood group (IQR 1-2). Infants after HS1P are at higher risk of NEC in comparison to infants after the Norwood procedure. More studies are needed to help predict which infants after HS1P are at highest risk for NEC.

HeartMate 3 Ventricular Assist Device in a Single-Ventricle and Single-Lung Patient Palliated With a Bidirectional Glenn.

We describe a 15 year old patient with failing second-stage single-ventricle palliation and left pulmonary artery thrombosis successfully supported with HeartMate 3 ventricular assist device and a Fontan completion as destination therapy.

Unstable right ventricular hypertension in pulmonary atresia and intact ventricular septum: a case report.

Arterial oxygen saturation in single ventricle patients is dependent on systemic cardiac output. Here, we describe a case of a newborn with single ventricle physiology and an unusual mechanism to explain poor cardiac output and cyanosis. This case highlights the importance of identifying and considering ventricular morphology and ventricular-ventricular interactions to understand clinical challenges.

Donor great vessel free arterial grafts for complex reconstruction during pediatric heart transplantation

ObjectivePrior studies suggest that prolonged donor heart warm ischemia time increases heart transplant mortality. Patients with single-ventricle heart disease requiring transplant with concomitant aortic arch or central pulmonary artery reconstruction present technical challenges that extend donor warm ischemia time using conventional techniques. Studies in larger pediatric and adult patients with single-ventricle anatomy have described the use of prosthetic material for concomitant great vessel reconstruction. We have used donor free arterial grafts to simplify concomitant great vessel reconstructions and reduce warm donor ischemia time in small patients with single-ventricle physiology undergoing heart transplant. The purpose of this study is to review our results in these patients. MethodsChildren with single-ventricle heart disease who underwent free donor arterial graft great vessel reconstruction at heart transplant were identified, divided into aortic arch and central pulmonary artery groups, and retrospectively reviewed. Warm and total ischemia times were recorded contemporaneously at transplant. ResultsFifteen pediatric patients with single-ventricle physiology underwent donor free arterial graft great vessel reconstructions (9 aortic arch, 6 pulmonary artery). Mean donor warm and total ischemia times for the entire cohort were 52.8 ± 10.7 and 341.7 ± 41.2 minutes. Two patients required postoperative extracorporeal membrane oxygenation. Hospital survival was 94% (1 death). There were no late deaths, and 2 patients had late retransplant. There were no early or late aortic or pulmonary artery obstructions, reinterventions, or complications at median follow-up of 14.2 years (interquartile range, 4.2-16.3 years). ConclusionsDonor free arterial grafts for concomitant great vessel reconstruction during heart transplant in small, single-ventricle patients reduces warm ischemia time, simplifies technical demands, and preserves growth potential.

Retrograde Flow to Aortic Root Predicts Inferior Cardiopulmonary Performance and Restrictive Lung Physiology in Fontan Circulation

BackgroundCardiac output in Fontan circulation depends on systemic venous pressure, pulmonary vascular resistance, and ventricular function. Because myocardial function is dependent on coronary perfusion, we studied whether retrograde flow to aortic root in the mitral/aortic atresia subgroup of hypoplastic left heart syndrome (HLHS) affects cardiopulmonary performance. MethodsWe studied 26 stable Fontan patients (14.4 ± 2.4 years) with right (RV, n = 17) and left (LV, n = 9) systemic ventricle morphology. All RV patients had HLHS and were subdivided according to postnatal flow to the hypoplastic ascending aorta being antegrade (HLHS-A) or retrograde (HLHS-R) due to valve atresia. Physical activity was assessed by questionnaire (LASERI, a questionnaire for Finnish children regarding physical activity), cardiopulmonary exercise test (1-minute ramp protocol), body composition (Biacorpus RX 4000), and muscle fitness (EUROFIT). These data were correlated with the postnatal aorta size and current branch pulmonary artery size index (McGoon index). ResultsPatients with HLHS-R seldom self-reported engagement in vigorous physical activity and had significantly lower cardiopulmonary performance (peak oxygen uptake [VO2peak]) than patients with LV morphology (P = 0.037), but not compared with patients with HLHS-A. Branch pulmonary artery size did not correlate with VO2peak. Patients with HLHS-R had most severe lung restrictions (forced vital capacity z-score –3 ± 0.9, P = 0.0073; forced expiratory volume in 1 second z-score –3.3 ± 1.1, P = 0.001). ConclusionsYoung Fontan patients with LV had better cardiopulmonary performance than patients with HLHS. Patients with HLHS-R were the least active and had the lowest VO2peak and most restrictive lungs. It is important to recognize postnatally single ventricle patients at high risk for inactivity to promote an active and healthy lifestyle.

Advances in understanding and managing pediatric heart failure and transplant.

This article highlights the most recent advances in a review of the current literature in the field of pediatric heart failure and transplantation. Diagnostically, the identification of new genetic factors has contributed to a deeper understanding of cardiomyopathy in children. Novel medications like sacubitril/valsartan and Sodium-Glucose cotransporter-2 (SGLT2) inhibitors, which are now standard in the adult population are being studied in pediatric population and offer new promise of pediatric heart failure treatment. Ventricular assist devices are more commonly used in cardiomyopathy patients and single ventricle patients as a bridge to transplant. Recent pediatric heart transplant society (PHTS) data demonstrated that waitlist survival improved significantly over the past decades (i) and new treatments such as daratumumab and eculizumab have been used in high-risk populations and demonstrate promising results. TEAMMATE trial is the first multicenter randomized clinical trial (RCT) in pediatric heart transplant (HT) to evaluate the safety and efficacy of everolimus (EVL) and low-dose tacrolimus (TAC) compared to standard-dose TAC and mycophenolate mofetil (MMF). It will provide valuable information about the safety and efficacy of EVL, TAC, and MMF (ii).Donor cell-free DNA has been used more in pediatric transplant recipients and has significantly decreased invasive EMB (iii). This past 5 years have witness dramatic progress in the field of pediatric heart failure and transplantation including more use of mechanical support in heart failure patients with various underlying etiology, especially use of mechanical support in single ventricle patients and the use of sacubitril/valsartan and SGLT2 inhibitors in the pediatric population. The problem of the highly sensitized transplant recipient remains, although novel therapeutics have been added to our toolbox of options to maintain healthy allograft function. Ongoing research aims to further enhance our understanding and management of pediatric heart failure, emphasizing the need for continued innovation in this complex field.

Quantitative plasma proteomic analysis in children after superior cavopulmonary anastomosis with pulmonary arteriovenous malformations.

Approximately 1000 children are born every year in the United States with one effective cardiac pumping chamber, or single ventricle heart disease. One of the early causes of mortality in this population is pulmonary arteriovenous malformations (PAVMs), which allow blood to bypass gas exchange in the lungs. PAVMs most frequently occur in children after superior cavopulmonary anastomosis (SCPA), a procedure that redirects venous blood from the upper body to the lungs. Because plasma proteins are in part responsible for directing angiogenesis, we hypothesized that differential protein concentrations would be observed in superior caval blood among children after SCPA according to PAVM status. We performed quantitative plasma proteomics from 11 children with PAVMs and in seven children without PAVMs; an additional 11 children with Fontan circulation were included as a reference. Among children with SCPA, there were no significant differences in the plasma proteomes for those with and without PAVMs. When comparing children with Fontan circulation to those with SCPA and PAVMs, 18 proteins exhibited differential expression (10 downregulated and eight upregulated) in superior caval plasma. These results suggest that factors other than, or in addition to, plasma proteins may be responsible for single ventricle patients' susceptibility to PAVMs after SCPA. IMPACT: What is the key message of your article? We did not identify significant differences in plasma proteins when comparing those children with and without pulmonary arteriovenous malformations (PAVMs) after superior cavopulmonary anastomosis (SCPA). What does it add to the existing literature? The etiology of PAVMs in this population is likely due to factors other than, or in addition to, differences in plasma proteins. What is the impact? Further studies are needed to identify causes of PAVMs among children after SCPA.

Deep Learning-Based Electrocardiogram Analysis Predicts Biventricular Dysfunction and Dilation in Congenital Heart Disease

BackgroundArtificial intelligence–enhanced electrocardiogram (AI-ECG) analysis shows promise to detect biventricular pathophysiology. However, AI-ECG analysis remains underexplored in congenital heart disease (CHD). ObjectivesThe purpose of this study was to develop and externally validate an AI-ECG model to predict cardiovascular magnetic resonance (CMR)-defined biventricular dysfunction/dilation in patients with CHD. MethodsWe trained (80%) and tested (20%) a convolutional neural network on paired ECG-CMRs (≤30 days apart) from patients with and without CHD to detect left ventricular (LV) dysfunction (ejection fraction ≤40%), RV dysfunction (ejection fraction ≤35%), and LV and RV dilation (end-diastolic volume z-score ≥4). Performance was assessed during internal testing and external validation on an outside health care system using area under receiver-operating curve (AUROC) and area under precision recall curve. ResultsThe internal and external cohorts comprised 8,584 ECG-CMR pairs (n = 4,941; median CMR age 20.7 years) and 909 ECG-CMR pairs (n = 746; median CMR age 25.4 years), respectively. Model performance was similar for internal testing (AUROC: LV dysfunction 0.87; LV dilation 0.86; RV dysfunction 0.88; RV dilation 0.81) and external validation (AUROC: LV dysfunction 0.89; LV dilation 0.83; RV dysfunction 0.82; RV dilation 0.80). Model performance was lowest in functionally single ventricle patients. Tetralogy of Fallot patients predicted to be at high risk of ventricular dysfunction had lower survival (P < 0.001). Model explainability via saliency mapping revealed that lateral precordial leads influence all outcome predictions, with high-risk features including QRS widening and T-wave inversions for RV dysfunction/dilation. ConclusionsAI-ECG shows promise to predict biventricular dysfunction/dilation, which may help inform CMR timing in CHD.

Diastolic dysfunction: assessment and implications on the single ventricle circulation.

Patients with a functionally single ventricle (SV) are palliated with a series of procedures leading to a Fontan circulation. Over the life span, a substantial proportion of SV patients develop heart failure that can arise from circulatory or ventricular failure. Diastolic dysfunction (DD) is an important determinant of adverse outcomes in SV patients. However, assessment and categorization of DD in the SV remains elusive. We review recent literature and developments in assessment of DD in the SV and its relation to clinical outcomes. DD is prevalent in the SV and associated with worse outcomes. Occult DD can be exposed with provocative testing by exercise or preload challenge during catheterization. Likewise, sensitivity to detect DD may be increased via assessment of atrial function and strain imaging. Recent studies revisiting previous concepts such as incoordinate diastolic wall motion show that these are associated with SV end-diastolic pressures and post-Fontan recovery, yielding accessible DD assessment. Emerging technologies such as ultrafast ultrasound (UFUS) can provide noninvasive assessment of myocardial stiffness, inefficient diastolic flow patterns and intraventricular pressure gradients, thereby yielding new tools and insights into diastolic myocardial and hemodynamic properties. Characterizing DD in the SV continues to have substantial limitations, necessitating synthesis of multiple parameters into an overall assessment, accounting for their change over time, and in the context of the patient's clinical status. New and emerging techniques may help advance DD assessment and the ability to track response to treatment of new targets.

A Comparison of Ductal Stenting and Surgical Shunts for Infants with Duct-Dependent Pulmonary Blood Flow: The Impact of Single Versus Biventricular Repair Pathways on Outcomes.

Ductal stenting (DS) is an alternative to the Blalock-Taussig-Thomas Shunt (BTTS) as initial palliation for congenital heart disease with duct-dependent pulmonary blood flow (DDBPF). We sought to analyze the impact of intended single ventricle (SV) and biventricular (BiV) repair pathways on the outcome of DS and BTTS in infants with DDPBF. A single-center, retrospective comparison of infants with DDPBF who underwent either DS (2012-2022) or BTTS procedures (2013-2017). Primary outcomes included all-cause mortality and risk of unplanned re-intervention. Participants were divided into four groups: 1.SV with DS, 2.SV with BTTS, 3.BiV with DS, and 4.BiV with BTTS. Fifty-one DS (SV 45%) and 86 BTTS (SV 49%) procedures were undertaken. For those who had DS, mortality was lower in the BiV compared to SV patients (BiV: 0/28, versus SV: 4/23, p = 0.04). Compared to BiV DS, BiV BTTS had a higher risk of combined death or unplanned re-intervention (HR 4.28; CI 1.25-14.60; p = 0.02). In SV participants, there was no difference for either primary outcome based on procedure type. DS was associated with shorter intensive care length of stay for SV participants (mean difference 5days, p = 0.01) and shorter intensive care and hospital stay for BiV participants (mean difference 11days for both outcomes, p = 0.001). There is a survival benefit for DS in BiV participants compared with DS in SV and BTTS in BiV participants. Ductal stenting is associated with a shorter intensive care and hospital length of stay.

Atrial septal interventions during and after hybrid stage I palliation of hypoplastic left heart syndrome.

Hybrid stage I palliation (HS1P) is an alternative approach for initial palliation in hypoplastic left heart syndrome (HLHS) patients. Unlike surgical stage I palliation where atrial septectomy is routinely performed, atrial septal intervention (ASI) during HS1P is variable. In this study, we described our experience with ASI in single ventricle (SV) patients who underwent HS1P and identified factors associated with need for ASI after HS1P. Data were retrospectively collected for all HLHS patients who underwent HS1P at our center over the past 12 years. We evaluated ASIs performed during the HS1P (intra-HS1P ASI) and ASIs performed during the period from HS1P to the subsequent surgical stage, either interval Norwood stage I or comprehensive stage II (post-HS1P ASI). Patient factors and procedural data were compared to identify factors associated with undergoing post-HS1P ASI and the impact of ASI on patient outcomes was evaluated. Of 50 SV patients included, 23 (46%) underwent intra-HS1P ASI and 26 (52%) underwent post-HS1P ASI. Need for post-HS1P ASI was lower among patients who had an intra-HS1P ASI as compared to those who did not (30% vs. 70%; p = 0.005). There were no significant differences in short or Midterm outcomes between patients who underwent intra-HS1P ASI or post-HS1P ASI and their counterparts. ASI is common both during and after HS1P but is generally well tolerated and type of ASI does not significantly impact overall patient outcomes. Our findings suggest that the current approach of individualizing management of ASI in the HS1P population is effective and safe.

Reducing Adverse Events Associated with Pediatric Cardiac Catheterization: A Quality Improvement Project Focusing on Decreasing Catheterization-Associated Blood Transfusions.

The objective of this study is to describe interventions and outcomes of a quality improvement (QI) project to reduce red blood cell transfusion (RBCT) within 72h of pediatric cardiac catheterization. Using Plan-Do-Study-Act (PDSA) methodology, we applied interventions including (1). Intraprocedural-to reduce hemodilution, blood loss, and excessive anticoagulation, (2). Standardization of institutional transfusion criteria, and (3). "Hard stop" requiring QI team consultation prior to elective post-catheterization RBCT. Primary outcome measures were frequency of RBCT from IMPACT quarterly reports and cases between transfusions (CBT). Length of stay (LOS) was the primary countermeasure. Characteristics of patients who did and did not receive RBCT were compared. 698 pediatric cardiac catheterizations occurred between 4/2017 and 8/2023. Intraprocedural interventions did not alter frequency of RBCT or CBT. Standardized transfusion guidelines followed by the "hard stop" decreased RBCT frequency from 10 to 1.9% and increased CBT without increasing LOS. Patients requiring RBCT were younger (medians 0.31 vs 2.4years), smaller (5.2 vs 11.8kg), and had longer procedures (2.24 vs 1.57h) all p < 0.001. Single ventricle patients were more likely to have RBCT than simple biventricular patients (14.1% vs 3.1%; RR = 4.57, 95% CI 2.29-10.4; p < 0.001). Procedure type (diagnostic vs. intervention) and starting hemoglobin concentration were comparable between groups. Programmatic adherence to standardized peri-procedural transfusion guidelines successfully decreased RBCT without compromising patient care or increasing LOS. Younger age, lower weight, procedure length, and single ventricle physiology were all associated with RBCT risk.

Structured Tube Weaning Using the Hunger Provocation Method in Infants with Single Ventricle Heart Defects: A Multicenter Study.

Despite improvement in hemodynamics, children with single ventricle heart disease remain on feeding tubes long after stage 2 palliation (S2P). Use of a hunger provocation method in a multidisciplinary team setting has been successful at weaning these children from feeding tubes. The objective of this study is to describe patient characteristics and outcomes in the single ventricle population who underwent a formal tube weaning process using a standardized hunger provocation method. Single ventricle patients after S2P from six centers were included. Patient data collected included baseline demographics, swallow evaluation results, and feeding characteristics such as percent oral intake at the start of tube wean. Tube wean data included tube weaning process and duration, interruptions to the tube wean, adverse events, and weights before, during, and after the tube wean. 94% (60 of 64) of patients achieved oral independence. The median time to tube wean was 12.5days. 62% of patients had transient weight loss during the tube wean. 61% of the cohort was taking less than 10% goal volumes by mouth with 90% of those patients successfully tube weaned. All patients with history of aspiration were successfully tube weaned. 75% of successfully weaned patients were above baseline weight at 1-month post-tube wean. The most common cause of tube wean interruption was contraction of a viral illness. Use of a standardized tube weaning process via hunger provocation method is both feasible and safe in the single ventricle population, resulting in successful feeding tube removal in a timely manner with minimal adverse effects.

Native aortic root thrombus leading to myocardial infarction in a single ventricle patient.

We report a 14-month-old male with hypoplastic left heart syndrome, mitral stenosis, and aortic stenosis with native aortic root thrombus. He developed a wide complex ventricular tachycardia and ST-segment elevation myocardial infarction with troponin I levels peaking at 388 ng/mL. He was treated safely with systemic alteplase with a resolution of his regional wall motion abnormality 18 hours later.

Angiographic tool to detect pulmonary arteriovenous malformations in single ventricle physiology.

Individuals with single ventricle physiology who are palliated with superior cavopulmonary anastomosis (Glenn surgery) may develop pulmonary arteriovenous malformations. The traditional tools for pulmonary arteriovenous malformation diagnosis are often of limited diagnostic utility in this patient population. We sought to measure the pulmonary capillary transit time to determine its value as a tool to identify pulmonary arteriovenous malformations in patients with single ventricle physiology. We defined the angiographic pulmonary capillary transit time as the number of cardiac cycles required for transit of contrast from the distal pulmonary arteries to the pulmonary veins. Patients were retrospectively recruited from a single quaternary North American paediatric centre, and angiographic and clinical data were reviewed. Pulmonary capillary transit time was calculated in 20 control patients and compared to 20 single ventricle patients at the pre-Glenn, Glenn, and Fontan surgical stages (which were compared with a linear-mixed model). Correlation (Pearson) between pulmonary capillary transit time and haemodynamic and injection parameters was assessed using angiograms from 84 Glenn patients. Five independent observers calculated pulmonary capillary transit time to measure reproducibility (intraclass correlation coefficient). Mean pulmonary capillary transit time was 3.3 cardiac cycles in the control population, and 3.5, 2.4, and 3.5 in the pre-Glenn, Glenn, and Fontan stages, respectively. Pulmonary capillary transit time in the Glenn population did not correlate with injection conditions. Intraclass correlation coefficient was 0.87. Pulmonary angiography can be used to calculate the pulmonary capillary transit time, which is reproducible between observers. Pulmonary capillary transit time accelerates in the Glenn stage, correlating with absence of direct hepatopulmonary venous flow.

Bilateral bidirectional cavopulmonary connection: a review of surgical techniques and clinical implications.

The presence of bilateral superior caval veins (bSCVs) could negatively influence the outcome of Fontan patients. In the setting of a bilateral bidirectional Glenn, the selective blood flow to the ipsilateral long with consequent flow stagnation in the connecting portion could lead to poor growth of the central portion of the pulmonary artery, potentially affecting the eligibility for Fontan completion and being associated with a higher incidence of thrombotic complications. Alternative surgical techniques have been described to perform a bidirectional cavopulmonary anastomosis in the presence of bSCVs aiming to achieve a balanced growth of the pulmonary bifurcation. The short-term results of these techniques such as the V- or Y-shape seem to be excellent; however, some anatomical settings could affect the feasibility of these techniques. The so-called "unifocalization" creates a configuration comparable to a "normal" bidirectional Glenn and could be a feasible alternative. However, the long-term results of this technique are not published yet. The positive effect of additional pulsatile pulmonary flow on pulmonary artery growth should be considered in case of bilateral bidirectional Glenn, despite the higher incidence of postoperative complications reported and the difficult calibration of the amount of additional flow. The role of computational fluid dynamic to simulate the surgical strategy in single ventricle patients is promising and could be worthwhile in the setting of bSCVs. In fact, the surgical techniques of bilateral bidirectional Glenn could be simulated testing their feasibility and allowing to identify the more favorable hemodynamic pattern, patient specific. This review article highlights the critical issues related to the presence of bSCVs in univentricular physiology, analyzing pros and cons of the different surgical techniques. Besides reviewing the literature, this manuscript focuses on the role of computational fluid simulation in identifying the most favorable surgical technique with an individualized approach, which could potentially improve the clinical outcome.

(292) - Clinical Deterioration in Stage 1 and 2 Single Ventricle Patients Awaiting Heart Transplant

(292) - Clinical Deterioration in Stage 1 and 2 Single Ventricle Patients Awaiting Heart Transplant

Rejection in the setting of combined Heart and Liver Transplantation

IntroductionEach year the number of combined heart-liver transplants (HLT) increases, with two distinct patient populations proceeding down this pathway. The first are patients with congenital heart disease (CHD), most commonly single ventricle patients palliated with Fontan. The second group are those with long standing congestive hepatopathy, amyloidosis, hemochromatosis, or alcohol induced myopathies and liver disease.One argument for HLT has been the low rate of rejection even among sensitized patients, with reported rejection rates ranging from 0% to 31%. Historically, those with CHD have been highly sensitized which in some cases may prevent or at least delay transplantation. As such, a recent consensus statement by Emamaulee et al. suggest that “there may be an immunological benefit to proceed with HLT with significantly fewer acute cellular and humoral rejection episodes”. The aim of this study is to demonstrate that HLT patients remain at risk for rejection and have required treatment for it. ResultsThere were 15 patients who underwent HLT from January 2017 to February 2022. Of the four patients who did not have CHD, none were considered sensitized, and all underwent induction with basiliximab per our institutional protocol. One of these had rejection. Rejection episodes were identified in four of the 11 CHD patients (36%) patients. ConclusionsIn our study of 15 HLT, including 11 CHD patients (73% denied transplant at ≥ 1 center) demonstrated a higher rate of rejection than previously reported. While theoretically, HLT may mitigate the likelihood of rejection, the risk still exists, and patients benefit from close monitoring commensurate with single organ transplant.