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 5 days, p = 0.01) and shorter intensive care and hospital stay for BiV participants (mean difference 11 days 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.

Optimal timing of bridging annuloplasty and patch augmentation for heterotaxy syndrome associated with functional single ventricles.

OBJECTIVE: Although the challenging prognosis of functional single ventricles with common atrioventricular valves due to complex morphology and uncontrollable regurgitation by valvuloplasty has been highlighted, reports on when and how these extremely complicated atrioventricular valves should be repaired are few. This study investigated the timing and risk factors for valve intervention in these patients. METHODS: Between April 2006 and March 2023, 40 patients with heterotaxy syndrome associated with functional single ventricles underwent surgery. Valve intervention was performed in 14 of the 40 patients with moderate or severe atrioventricular valve regurgitation. RESULTS: The timing of the first valve intervention varied, with four, five, three, and two patients undergoing valve intervention before the cavopulmonary shunt, simultaneously with the cavopulmonary shunt, before total cavopulmonary connection, and simultaneously with total cavopulmonary connection, respectively. Mechanical valve replacements were performed in three patients. Among the 14 patients undergoing valve intervention, four died. Three of the four patients underwent valvuloplasty before the cavopulmonary shunt, including two who could undergo the cavopulmonary shunt but died after the procedure. Eight of the fourteen patients completed total cavopulmonary connection. The cumulative survival rate was not significantly different between the 14 patients who underwent and 26 who did not undergo intervention (hazard ratio, 2.52; 95% confidence interval, 0.56-11.24; P = 0.23). CONCLUSION: Our surgical strategies provide a chance for the next staged repair of common atrioventricular valves in patients with both heterotaxy and valvular regurgitation. Including patch augmentation, advanced valve intervention is possible at or after the cavopulmonary shunt.

FibroScan as a surveillance marker post-cavopulmonary anastomosis for single-ventricle physiology.

Purpose: Single-ventricle physiology encompasses a group of congenital cardiac malformations with only one functional ventricle. The Fontan procedure is the final palliation of this pathway and has its complications. One of these is Fontan-associated liver disease (FALD). It is known that all patients with Fontan will have FALD, due to the physiology of the Fontan circuit, and only the severity will vary. The pathophysiology of hepatic damage in FALD is unique and not easily detectable by routine non-invasive investigations. Therefore, this study is aimed to identify if FibroScan can be used as a surveillance marker to detect and assess the progression of FALD. Methods: Patients who attended the Cardiothoracic and Vascular Surgery Outpatient Department (OPD) for follow-up post-cavopulmonary anastomosis (bidirectional Glenn and Fontan) were enrolled in this study. They underwent routine examinations and tests, and in addition a FibroScan was performed. Results: FibroScan showed that the liver stiffness measurement (LSM) was increased in all patients who had undergone Fontan and a couple of patients who had undergone bidirectional (BD) Glenn. The LSM was 12.29 (± 3.59) kPa in patients post-Fontan and 6.64 (± 4.24) kPa in patients post-BD Glenn. This raised LSM was not associated with a parallel rise in liver enzymes or other laboratory markers associated with liver function. This emphasizes the suitability of FibroScan as an early and non-invasive surveillance tool for monitoring the progression of hepatic venous congestion and FALD. Conclusion: We have found that LSM via FibroScan can effectively be a surveillance or screening test for FALD. Serial FibroScans can be used to monitor the progress of liver disease. Raised LSM may also have a role in predicting the morbidity for completion of Fontan post-BD Glenn operation. Large-scale studies are needed to validate our findings.

Impact of veno-venous collaterals on outcome after the total cavopulmonary connection.

OBJECTIVE: To evaluate the prevalence of veno-venous collaterals (VVCs) after total cavopulmonary connection (TCPC) and analyze their impact on outcomes. METHODS: Patients undergoing TCPC between 1994 and 2022 were evaluated. VVCs were identified using angiograms of cardiac catheterizations and their impact on outcomes was analyzed. RESULTS: A total of 635 patients were included. Median age at TCPC was 2.3 (interquartile ranges (IQR): 1.8-3.3) years. The most frequent diagnosis was hypoplastic left heart syndrome in 173 (27.2%) patients. Prior bidirectional cavopulmonary shunt was performed in 586 (92.3%) patients at a median age of 5.3 (3.6-9.9) months. VVCs were found in 94 (14.8%) patients at a median of 2.8 (0.1-11.8) years postoperatively. The prevalence of VVCs was similar between the dominant right and left ventricle (14.7 vs. 14.9%, p = 0.967). Mean pulmonary artery pressure (16.2 vs. 16.0 mmHg, p = 0.902), left atrial pressure (5.5 vs. 5.7 mmHg, p = 0.480), transpulmonary gradient (4.0 vs. 3.8 mmHg, p = 0.554) and oxygen saturation (81.4 vs. 82.6%, p = 0.103) before TCPC were similar between patients with and without VVCs. The development of VVCs did not affect survival after TCPC (p = 0.161). Nevertheless, VVCs were a risk for the development of plastic bronchitis (PB, p < 0.001). Interventional closure of VVCs was performed in 60 (9.4%) patients at a median of 8.9 (0.6-15.1) years after TCPC, and improvement of oxygen saturation was observed in 66% of the patients. CONCLUSIONS: The prevalence of VVCs after TCPC was 15%. VVCs had no impact on survival following TCPC but were associated with a high prevalence of PB.

The utility of novel STE parameters in echocardiographic assessment of single ventricle after Fontan palliation.

Background and aims of the study A functionally single ventricle (FSV) refers to a group of congenital heart defects that are not amenable for biventricular correction. The Fontan operation is utilized as surgical treatment for most of FSV patients. The evaluation of FSV function is extremely difficult due to its unique pathophysiology. This study aimed to explore the efficacy of speckle tracking echocardiography (STE) parameters measured at rest and during exercise for comprehensive assessment of univentricular heart. METHODS: We enrolled 37 patients with a functionally single ventricle after the Fontan operation, hospitalized in the Department of Congenital Heart Defects between years 2019 and 2021.The echocardiographic stress tests were performed in the Echocardiography Laboratory of the Congenital Heart Defects Department. The study was conducted on a bicycle ergometer in a semi-recumbent position. The parameters obtained by speckle tracking echocardiography (STE): the longitudinal strain of the FSV free wall (Ɛ) and the longitudinal strain of myocardial layers: subendocardial, medial and subepicardial were analyzed. A transmural longitudinal strain gradient (TG) was calculated as the difference between longitudinal deformation of the subendocardial and subepicardial layers. Current results of cardiac magnetic resonance imaging (CMR) and cardio-pulmonary test (CPET) were also incorporated. Demographic data, past interventions, pharmacological treatment and comorbidities were extracted from medical records. RESULTS: Ɛ at rest and during exercise were not related to the parameters of physical capacity obtained on CPET nor to the CMR results. The transmural strain gradient was dependent on physical performance parameter- peak oxygen uptake- and related to the FSV ejection fraction calculated by magnetic resonance imaging. CONCLUSIONS: The transmural strain gradient and FSV free wall strain are readily measurable and suitable for evaluating single ventricle function. The TG is positively correlated with peak oxygen uptake during the cardiopulmonary test and with the ejection fraction derived from cardiac magnetic resonance imaging. The applicability of these findings in patients undergoing the Fontan procedure warrants further exploration.

Outcomes of heart transplantation in children with previously palliated hypoplastic left heart syndrome.

OBJECTIVES: Paediatric heart transplantation in children who fail multistage palliation for hypoplastic left heart syndrome is associated with challenges related to immune, clinical or anatomic risk factors. We review current outcomes and risk factors for survival following heart transplantation in this challenging patient population. METHODS: The United Network for Organ Sharing transplantation database was merged with Paediatric Health Information System database to identify children who received heart transplantation following prior palliation for hypoplastic left heart syndrome. Multivariable Cox analysis of outcomes and factors affecting survival was performed. RESULTS: Our cohort included 849 children between 2009 and 2021. The median age was 1044 days (interquartile range 108-3535), and the median weight was 13 kg (interquartile range 7-26). Overall survival at 10 years following heart transplantation was 71%, with most of the death being perioperative. On multivariable analysis, risk factors for survival included Black race (hazard ratio = 1.630, P = 0.0253), blood type other than B (hazard ratio = 2.564, P = 0.0052) and male donor gender (hazard ratio = 1.367, P = 0.0483). Recipient age, the use of ventricular assist device or extracorporeal membrane oxygenation were not significantly associated with survival. Twenty-four patients underwent retransplantation, and 10-year freedom from retransplantation was 98%. Rejection before hospital discharge and within 1 year from transplantation was 20% and 24%, respectively, with infants having lower rejection rates. CONCLUSIONS: Compared with existing literature, the number of children with prior hypoplastic left heart syndrome palliation who receive heart transplantation has increased in the current era. Survival following transplantation in this patient population is acceptable. Most of the death is perioperative. Efforts to properly support these patients before transplantation might decrease early mortality and improve overall survival.

Hybrid stage 1 palliation with simultaneous off-pump ventricular assist device placement in neonates with high-risk single ventricle anatomy: Initial experience.

Background: Infants with single ventricle heart disease and severe atrioventricular valve regurgitation have poor outcomes following conventional staged palliation. As such, ventricular assist device (VAD) placement along with hybrid stage 1 palliation has been proposed as a bridge to heart transplant. We present a novel surgical technique for VAD implantation concurrent with hybrid stage 1 that avoids cardiopulmonary bypass. Methods: We performed a retrospective review of our institutional experience with this novel surgical technique. Results: Three patients (weight, 2.7-3.5 kg; age, 3 to 5 days) underwent hybrid stage 1 with VAD placement, consisting of bilateral 3.5-mm expandable polytetrafluoroethylene (PTFE) pulmonary artery bands, a ductal stent, a 6-mm Berlin Heart outflow cannula onto the main pulmonary trunk with a 10-mm graft, a 6-mm Berlin Heart outflow cannula onto the right atrium, and a 10-mL Berlin Heart pump. In patients with severe aortic arch hypoplasia or coarctation, a 4-mm PTFE graft was sewn from the VAD outflow graft to the innominate artery to protect coronary and cerebral perfusion. Procedures were performed off bypass with minimal blood product use. Patients were extubated on postoperative days 2, 2, and 5. There were no procedural complications. All patients were transferred out of the intensive care unit and demonstrated appropriate weight gain. Anticoagulation strategy was bivalirudin and antiplatelet therapy. The patients underwent transplantation after 149 days, 157 days, and 288 days of support. Conclusions: Off-pump single ventricle VAD placement is technically feasible and can be done at the time of hybrid stage 1 palliation with minimal operative morbidity as a bridge to transplant.

Ventricular Septation of the Double-Inlet Ventricle: Over Three Decades of Follow-Up.

There is renewed interest in septation of the double-inlet ventricle as an alternative to Fontan palliation. We examined our septation experience with over 30 years of follow-up. We retrospectively reviewed patients with double-inlet ventricle from 1990 to 2011. Patients with two adequate atrioventricular valves, a volume-overloaded ventricle, and no significant subaortic obstruction were septation candidates. Of 98 double-inlet ventricle patients, 9 (9.2%) underwent attempted septation via a one-stage (n = 2, 22.2%) or two-stage (n = 7, 77.8%) approach. Ages at primary septation were 7.5 and 20.2 months. In the staged group, median age at the first and second stage was 8.3 months [range 4.1-14.7] and 22.4 months [range 11.4-195.7], respectively. There were no operative mortalities. Median follow-up was 18.8 years [range 0.4-32.9] and 30-year transplant-free survival was 77.8% ± 13.9%. Both single stage patients are alive and in sinus rhythm; 1 underwent bilateral outflow tract obstruction repair 27 years later. Of 7 patients planned for two-stage septation, there was 1 interval mortality and 1 deferred the second stage. Five patients underwent the second stage; 1 required early reintervention for a residual neo-septal defect and 1 underwent right atrioventricular valve replacement 28 years later. Three patients required a pacemaker preoperatively (n = 1) or after partial septation (n = 2). At latest follow-up, 7 patients have normal biventricular function and no significant valvulopathy. All remain NYHA functional class I. Select double-inlet ventricles may be septated with excellent long-term outcomes. Reconsideration of this strategy is warranted to avoid the sequelae of Fontan circulation.

Contemporary Management of the Failing Fontan.

Adult patients with congenital heart disease have now surpassed the pediatric population due to advances in surgery and improved survival. One such complex congenital heart disease seen in adult patients is the Fontan circulation. These patients have complex physiology and are at risk for several complications, including thrombosis of the Fontan pathway, pulmonary vascular disease, heart failure, atrial arrhythmias, atrioventricular valve regurgitation, and protein-losing enteropathy. This review discusses the commonly encountered phenotypes of Fontan circulatory failure and their contemporary management.

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 12.5 days. 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.

Stenting of the Patent Ductus Arteriosus.

Since PDA stenting was first attempted in the early 1990s, significant technical advancements have improved outcomes and some centers have even transitioned to exclusive PDA stenting for all infants with duct-dependent pulmonary circulation. In addition to its use in infants with duct-dependent pulmonary circulation, PDA stenting has also been adapted as a percutaneous palliative option for suprasystemic pulmonary arterial hypertension and as a component of the hybrid procedure. In this article, the authors aim to review indications and outcomes for PDA stenting, describe the procedure, and discuss future directions.

Digital twinning of cardiac electrophysiology for congenital heart disease.

In recent years, blending mechanistic knowledge with machine learning has had a major impact in digital healthcare. In this work, we introduce a computational pipeline to build certified digital replicas of cardiac electrophysiology in paediatric patients with congenital heart disease. We construct the patient-specific geometry by means of semi-automatic segmentation and meshing tools. We generate a dataset of electrophysiology simulations covering cell-to-organ level model parameters and using rigorous mathematical models based on differential equations. We previously proposed Branched Latent Neural Maps (BLNMs) as an accurate and efficient means to recapitulate complex physical processes in a neural network. Here, we employ BLNMs to encode the parametrized temporal dynamics of in silico 12-lead electrocardiograms (ECGs). BLNMs act as a geometry-specific surrogate model of cardiac function for fast and robust parameter estimation to match clinical ECGs in paediatric patients. Identifiability and trustworthiness of calibrated model parameters are assessed by sensitivity analysis and uncertainty quantification.

Risk Factors for Death or Transplant After Stage 2 Palliation for Single Ventricle Heart Disease.

Background: For infants with single ventricle heart disease, the time after stage 2 procedure (S2P) is believed to be a lower risk period compared with the interstage period; however, significant morbidity and mortality still occur. Objectives: This study aimed to identify risk factors for mortality or transplantation referral between S2P surgery and the first birthday. Methods: Retrospective cohort analysis of infants in the National Pediatric Cardiology Quality Improvement Collaborative who underwent staged single ventricle palliation from 2016 to 2022 and survived to S2P. Multivariable logistic regression and classification and regression trees were performed to identify risk factors for mortality and transplantation referral after S2P. Results: Of the 1,455 patients in the cohort who survived to S2P, 5.2% died and 2.3% were referred for transplant. Overall event rates at 30 and 100 days after S2P were 2% and 5%, respectively. Independent risk factors for mortality and transplantation referral included the presence of a known genetic syndrome, shunt type at stage 1 procedure (S1P), tricuspid valve repair at S1P, longer time to extubation and reintubation after S1P, ≥ moderate tricuspid regurgitation prior to S2P, younger age at S2P, and the risk groups identified in the classification and regression tree analysis (extracorporeal membrane oxygenation after S1P and longer S2P cardiopulmonary bypass time without extracorporeal membrane oxygenation). Conclusions: Mortality and transplantation referral rates after S2P to 1 year of age remain high ∼7%. Many of the identified risk factors after S2P are similar to those established for interstage factors around the S1P, whereas others may be unique to the period after S2P.

Reprint of: How He Did It - The James S. Tweddell Approach to Single Ventricle Palliation in Patients With Hypoplastic Left Heart Syndrome.

This article will detail Dr. James Tweddell's operative technique and considerations for 26 all three stages of SVP in patients with HLHS. This will include the Norwood Procedure with 27 Right-Ventricle-to-Pulmonary-Artery Conduit (Sano Modification), Bidirectional Glenn 28 (Superior Cavopulmonary Connection), and Extracardiac, Fenestrated Fontan Completion (Total 29 Cavopulmonary Connection). These techniques are the culmination of over 20 years of experience 30 and represent the final techniques he employed at both Children's Hospital of Wisconsin and 31 Cincinnati Children's Hospital Medical Center.

Surgical pulmonary arterioplasty at bidirectional cavopulmonary anastomosis leads to favorable pulmonary hemodynamics at final stage palliation.

Objective: Pulmonary arterioplasty (PA plasty) at bidirectional cavopulmonary anastomosis (BDCA) is associated with increased morbidity, but outcomes to final stage palliation are unknown. We sought to determine the influence of PA plasty on pulmonary artery growth and hemodyamics at Fontan. Methods: We retrospectively reviewed clinical data and outcomes for BDCA patients from 2006 to 2018. PA plasty was categorized by extent (type 1-4), as previously described. Outcomes included pulmonary artery reintervention and mortality before final palliation. Results: Five hundred eighty-eight patients underwent BDCA. One hundred seventy-nine patients (30.0%) underwent concomitant PA plasty. Five hundred seventy (97%) patients (169 [94%] PA plasty) survived to BDCA discharge. One hundred forty out of 570 survivors (25%) required PA/Glenn reintervention before final stage palliation (59 out of 169 [35%]) PA plasty; 81 out of 401 (20%) non-PA plasty; P < .001). Twelve-, 24-, and 36-month freedom from reintervention after BDCA was 80% (95% CI, 74-86%), 75% (95% CI, 69-82%), and 64% (95% CI, 57-73%) for PA plasty, and 95% (95% CI, 93-97%), 91% (95% CI, 88-94%), and 81% (95% CI, 76-85%) for non-PA plasty (P < .001). Prefinal stage mortality was 37 (6.3%) (14 out of 169 PA plasty; 23 out of 401 non-PA plasty; P = .4). Five hundred four (144 PA plasty and 360 non-PA plasty) patients reached final stage palliation (471 Fontan, 26 1.5-ventricle, and 7 2-ventricular repair). Pre-Fontan PA pressure and pulmonary vascular resistance were 10 mm Hg (range, 9-12 mm Hg) and 1.6 mm Hg (range, 1.3-1.9 mm Hg) in PA plasty and 10 mm Hg (range, 8-12 mm Hg) and 1.5 mm Hg (range, 1.3-1.9 mm Hg) in non-PA plasty patients, respectively (P = .29, .6). Fontan hospital mortality, length of stay, and morbidity were similar. Conclusions: PA plasty at BDCA does not confer additional mortality risk leading to final palliation. Despite increased pulmonary artery reintervention, there was reliable pulmonary artery growth and favorable pulmonary hemodynamics at final stage palliation.

Survival benefits of the wait-and-grow approach in small babies (≤2000 g) requiring heart surgery.

Objective: The best approach to minimize the observed higher mortality of newborn infants with low birth weight who require congenital heart surgery is unclear. This retrospective study was designed to review outcomes of newborn infants weighing <2000 g who have undergone cardiovascular surgery to identify patient parameters and clinical strategies for care associated with higher survival. Methods: A retrospective chart review of 103 patients who underwent cardiovascular surgery from 2010 to 2021 who were identified as having low birth weight (≤2000 g). Patients who underwent only patent ductus arteriosus ligation or weighing >3500 g at surgery were excluded. Results: Median age was 24 days and weight at the time of surgery was 1920 g. Twenty-six (25%) operative mortalities were recorded. Median follow-up period was 2.7 years. The 1- and 3-year overall Kaplan-Meier survival estimate was 72.4% ± 4.5% and 69.1% ± 4.6%. The 1-year survival of patients who had a weight increase >300 g from birth to surgery was far superior to the survival of those who did not achieve such a weight gain (81.4% ± 5.6% vs 64.0% ± 6.7%; log-rank P = .04). By multivariable Cox-hazard regression analysis, the independent predictor of 1-year mortality was genetic syndrome (hazard ratio, 3.54; 95% CI, 1.67-7.82; P < .001), whereas following a strategy of increasing weight from birth to surgery resulted in lower mortality (hazard ratio, 0.49; 95% CI, 0.24-0.90; P = .02). Conclusions: A strategy of wait and grow for newborn infants with very low birth weight requiring heart surgery results in better survival than immediate surgery provided that the patient's condition allows for this waiting period.