Intracorporeal LVAD implantation in pediatric patients: A single-center 10 years' experience.

BACKGROUND: Mechanical cardiac support is currently an effective strategy to reduce morbidity and mortality in pediatric patients. However, solid evidence regarding the feasibility of intracorporeal devices in children still needs to be provided. We report our 10-year experience with intracorporeal left ventricular assist devices (LVAD) in children. MATERIALS AND METHODS: We included all patients undergoing intracorporeal, continuous-flow LVAD implantation between 2012 and 2022. Baseline and postoperative data were collected from the institutional database. RESULTS: Seven HeartWare and 4 HeartMate3 were implanted in 11 patients (median age 13.9 years, median body surface area - BSA - 1.42 m2, IQR 1.06-1.68). The most frequent indication to LVAD implant was dilated cardiomyopathy (72.7%). All candidates underwent a thorough preoperative advanced imaging. Three-dimensional reconstructions and implant fit simulation were performed when BSA was <1.2 m2, weight <30 kg, or internal transverse thoracic diameter <20 cm. There was no operative death. The most common postoperative complication was surgical re-exploration due to bleeding (27.3%). One patient died of severe neurological complications after about 3 months of hospitalization. No late deaths or unplanned re-hospitalizations occurred in the remaining 10, 6 of whom were discharged home. There were no major complications at the follow-up. All survivors underwent successful heart transplantation. CONCLUSIONS: Intracorporeal LVAD implantation proved to be a potentially feasible and safe option in young teenagers and children whose BSA was >1.0 m2. In borderline cases, the 3D reconstruction with implant fit simulation can effectively help to identify those patients who can safely undergo intrathoracic LVAD implantation.

Tricuspid Valve Repair Can Restore the Prognosis of Patients with Hypoplastic Left Heart Syndrome and Tricuspid Valve Regurgitation: A Meta-analysis.

To date, evidence supporting the efficacy of tricuspid valve (TV) repair in interrupting the progression of systemic right ventricular (RV) adverse remodeling in hypoplastic left heart syndrome (HLHS) is conflicting. We conducted a systematic review and meta-analysis of scientific literature to assess the impact of TV repair in effectively modifying the prognosis of patients with HLHS. We conducted a systematic review of PubMed, Web of Science, and Scopus databases. A random-effect meta-analysis was performed and transplant-free survival, freedom from TV regurgitation, and TV reoperation data were reconstructed using the published Kaplan-Meier curves. Nine studies were included, comprising 203 HLHS patients undergoing TV repair and 323 HLHS controls. The estimated transplant-free survival at 1, 5, and 10 years of follow-up was 75.5% [95% confidence interval (CI) = 67.6-84.3%], 63.6% [95% CI = 54.6-73.9%], and 61.9% [95% CI = 52.7-72.6%], respectively. Transplant-free survival was comparable to HLHS peers without TV regurgitation (p = 0.59). Five-year freedom from recurrence of TV regurgitation and freedom from TV reoperation was 57% [95% CI = 46.7-69.7%] and 63.6% [95% CI = 54.5-74.3%], respectively. Younger age and TV repair at the time of Norwood operation increased the risk of TV regurgitation recurrence and the need for TV reoperation. Our meta-analysis supports the efficacy of TV repair in favorably modifying the prognosis of patients with HLHS and TV regurgitation, reestablishing a medium-term transplant-free survival which is comparable to HLHS peers. However, durability of surgery and long-term fate of TV and RV performance are still unclear.

Correlations between the alpha-Gal antigen, antibody response and calcification of cardiac valve bioprostheses: experimental evidence obtained using an alpha-Gal knockout mouse animal model.

Introduction: Preformed antibodies against αGal in the human and the presence of αGal antigens on the tissue constituting the commercial bioprosthetic heart valves (BHVs, mainly bovine or porcine pericardium), lead to opsonization of the implanted BHV, leading to deterioration and calcification. Murine subcutaneous implantation of BHVs leaflets has been widely used for testing the efficacy of anti-calcification treatments. Unfortunately, commercial BHVs leaflets implanted into a murine model will not be able to elicit an αGal immune response because such antigen is expressed in the recipient and therefore immunologically tolerated. Methods: This study evaluates the calcium deposition on commercial BHV using a new humanized murine αGal knockout (KO) animal model. Furtherly, the anti-calcification efficacy of a polyphenol-based treatment was deeply investigated. By using CRISPR/Cas9 approach an αGal KO mouse was created and adopted for the evaluation of the calcific propensity of original and polyphenols treated BHV by subcutaneous implantation. The calcium quantification was carried out by plasma analysis; the immune response evaluation was performed by histology and immunological assays. Anti-αGal antibodies level in KO mice increases at least double after 2 months of implantation of original commercial BHV compared to WT mice, conversely, the polyphenols-based treatment seems to effectively mask the antigen to the KO mice's immune system. Results: Commercial leaflets explanted after 1 month from KO mice showed a four-time increased calcium deposition than what was observed on that explanted from WT. Polyphenol treatment prevents calcium deposition by over 99% in both KO and WT animals. The implantation of commercial BHV leaflets significantly stimulates the KO mouse immune system resulting in massive production of anti-Gal antibodies and the exacerbation of the αGal-related calcific effect if compared with the WT mouse. Discussion: The polyphenol-based treatment applied in this investigation showed an unexpected ability to inhibit the recognition of BHV xenoantigens by circulating antibodies almost completely preventing calcific depositions compared to the untreated counterpart.

Late left ventricular myocardial remodeling after pulmonary artery banding for end-stage dilated cardiomyopathy in infants: an imaging study.

BACKGROUND: Understanding the macroscopic biventricular changes induced by pulmonary artery banding (PAB) in children with dilated cardiomyopathy (DCM) represents the first step to unraveling the regenerative potential of the myocardium. We herein investigated the phases of left ventricular (LV) rehabilitation in PAB responders, using a systematic echocardiographic and cardiac magnetic imaging (CMRI) surveillance protocol. METHODS: We prospectively enrolled all patients with DCM treated with PAB from September-2015 at our institution. Among 9 patients, 7 positively responded to PAB and were selected. Transthoracic 2D echocardiography was performed before PAB; and 30, 60, 90, and 120 days after PAB; and at the last available follow-up. CMRI was performed before PAB (whenever possible) and one year after PAB. RESULTS: In PAB responders, LV ejection fraction showed a modest 10% increase 30-60 days after PAB, followed by its almost complete normalization after 120  days (median of 20[10-26]% vs 56[44.5-63.5]%, at baseline and 120 days after PAB, respectively). Parallelly, the LV end-diastolic volume decreased from a median of 146(87-204)ml/m2 to 48(40-50)ml/m2. At the last available follow-up (median of 1.5 years from PAB), both echocardiography and CMRI showed a sustained positive LV response, although myocardial fibrosis was detected in all patients. CONCLUSIONS: Echocardiography and CMRI show that PAB can promote a LV remodeling process, which starts slowly and can culminate in the normalization of LV contractility and dimensions 4 months later. These results are maintained up to 1.5 years. However, CMRI showed residual fibrosis as evidence of a past inflammatory injury whose prognostic significance is still uncertain.

Overshoot of the Respiratory Exchange Ratio during Recovery from Maximal Exercise Testing in Young Patients with Congenital Heart Disease.

INTRODUCTION: The overshoot of the respiratory exchange ratio (RER) after exercise is reduced in patients with heart failure. AIM: The present study aimed to investigate the presence of this phenomenon in young patients with congenital heart disease (CHD), who generally present reduced cardiorespiratory fitness. METHODS: In this retrospective study, patients with CHD underwent a maximal cardiopulmonary exercise testing (CPET) assessing the RER recovery parameters: the RER at peak exercise, the maximum RER value reached during recovery, the magnitude of the RER overshoot and the linear slope of the RER increase after the end of the exercise. RESULTS: In total, 117 patients were included in this study. Of these, there were 24 healthy age-matched control subjects and 93 young patients with CHD (transposition of great arteries, Fontan procedure, aortic coarctation and tetralogy of Fallot). All patients presented a RER overshoot during recovery. Patients with CHD showed reduced aerobic capacity and cardiorespiratory efficiency during exercise, as well as a lower RER overshoot when compared to controls. RER magnitude was higher in the controls and patients with aortic coarctation when compared to those with transposition of great arteries, previous Fontan procedure, and tetralogy of Fallot. The RER magnitude was found to be correlated with the most relevant cardiorespiratory fitness and efficiency indices. CONCLUSIONS: The present study proposes new recovery indices for functional evaluation in patients with CHD. Thus, the RER recovery overshoots analysis should be part of routine CPET evaluation to further improve prognostic risk stratifications in patients with CHD.

Decellularized cryopreserved human pericardium: a validation study towards tissue bank practice.

Pericardial patches are currently used as reconstructive material in cardiac surgery for surgical treatment of cardiac septal defects. Autologous pericardial patches, either treated with glutaraldehyde or not, can be used as an alternative to synthetic materials or xenograft in congenital septal defects repair. The availability of an allogenic decellularized pericardium could reduce complication during and after surgery and could be a valid alternative. Decellularization of allogenic tissues aims at reducing the immunogenic reaction that might trigger inflammation and tissue calcification over time. The ideal graft for congenital heart disease repair should be biocompatible, mechanically resistant, non-immunogenic, and should have the ability to growth with the patients. The aim of the present study is the evaluation of the efficacy of a new decellularization protocol of homologous pericardium, even after cryopreservation. The technique has proven to be suitable as a tissue bank procedure and highly successful in the removal of cells and nucleic acids content, but also in the preservation of collagen and biomechanical properties of the human pericardium.

Ventricular morphology of single-ventricle hearts has a significant impact on outcomes after Fontan palliation: a meta-analysis.

OBJECTIVES: A conclusive interpretation of the role of ventricular dominance in outcomes after Fontan palliation has not been formulated yet. We conducted a systematic review and meta-analysis of scientific literature to give an insight into the impact of ventricular morphology in single-ventricle palliation, focusing on its influence on survival, morbidities, ventricular performance and functional capacity. METHODS: A systematic review of PubMed, Web of Science and Scopus databases was performed. A random-effect meta-analysis was conducted, and survival data were reconstructed using the published Kaplan-Meier survival curves. RESULTS: Twenty-seven studies were selected, for a total of 4529 left-dominant versus 4844 right-dominant patients. Estimated survival at 1, 5, 10, 20 and 30 years of follow-up was 0.99 [95% confidence interval (CI) = 0.98-0.99], 0.95 [95% CI = 0.94-0.96], 0.92 [95% CI = 0.91-0.93], 0.86 [95% CI = 0.84-0.88] and 0.68 [95% CI = 0.65-0.83] for left-dominant patients and 0.94 [95% CI = 0.93-0.95], 0.89 [95% CI = 0.88-0.9], 0.85 [95% CI = 0.83-0.87], 0.69 [95% CI = 0.63-0.75] and 0.59 [95% CI = 0.5-0.69] for right-dominant patients, respectively. Survival was statistically lower for right-dominant patients (P < 0.001), with an hazard ratio for the mortality of 2.38 (2.03-2.80); also, they displayed significantly longer hospital stay, worse ventricular function, larger ventricular volumes and a higher incidence of moderate or severe atrioventricular valve regurgitation when compared to left-dominant patients. CONCLUSIONS: According to our meta-analysis, the morphology of the dominant ventricle has a significant impact on outcomes after Fontan palliation. Right-dominant patients experience an inferior long-term survival when the anatomical right ventricle is included in the systemic circulation.

Pulmonary Artery Banding for Dilated Cardiomyopathy in Children: Returning to the Bench from Bedside.

Current treatment paradigms for end-stage dilated cardiomyopathy (DCM) in children include heart transplantation and mechanical support devices. However, waitlist mortality, shortage of smaller donors, time-limited durability of grafts, and thrombo-hemorrhagic events affect long-term outcomes. Moreover, both these options are noncurative and cannot preserve the native heart function. Pulmonary artery banding (PAB) has been reinvented as a possible "regenerative surgery" to retrain the decompensated left ventricle in children with DCM. The rationale is to promote positive ventricular-ventricular interactions that result in recovery of left ventricular function in one out of two children, allowing transplantation delisting. Although promising, global experience with this technique is still limited, and several surgical centers are reluctant to adopt PAB since its exact biological bases remain unknown. In the present review, we summarize the clinical, functional, and molecular known and supposed working mechanisms of PAB in children with DCM. From its proven efficacy in the clinical setting, we described the macroscopic geometrical and functional changes in biventricular performance promoted by PAB. We finally speculated on the possible underlying molecular pathways recruited by PAB. An evidence-based explanation of the working mechanisms of PAB is still awaited to support wider adoption of this surgical option for pediatric heart failure.

Pulmonary valve preservation during tetralogy of Fallot repair: midterm functional outcomes and risk factors for pulmonary regurgitation.

OBJECTIVES: Many centres have recently adopted pulmonary valve (PV) preservation (PVP) during tetralogy of Fallot (ToF) repair. We sought to identify the midterm functional outcomes and risk factors for pulmonary regurgitation after this procedure. METHODS: All patients undergoing PVP during transatrial-transpulmonary repair for ToF with PV stenosis at our institution between January 2007 and December 2020 were reviewed. RESULTS: Overall, 73 patients were included. At the index surgery, the body surface area was 0.31 ± 0.04 m2, the age was 4.9 ± 2.9 months and the preoperative PV z-score was -3.02 ± 1.11. At a mean follow-up of 5.3 ± 2.7 years, the fractional area change of the right ventricle (RV) was 47.1 ± 5.2%, and the tricuspid annular plane systolic excursion z-score was -3.31 ± 1.89%. The 5-year freedom from moderate/severe PV regurgitation was 61.3% [95% confidence interval (CI): 48, 73%]. There was a significant correlation between RV function and moderate/severe PR at follow-up (R2: 0.08; P = 0.03). A comparison with a group of patients undergoing a transannular patch procedure (N = 33) showed superior outcomes for patients with PVP. The preoperative PV z-score and the degree of PR at discharge were risk factors for the early development of moderate/severe PR at follow-up [hazard ratio (HR): 0.64; 95% CI: 0.48, 0.86, P = 0.01 and HR: 2.31; 95% CI: 1.00, 5.36, P = 0.04, respectively]. A preoperative PV annulus z-score ≤ -2.85 was found to be predictive for moderate/severe PR at 5 years after PVP (HR: 2.56; 95% CI: 1.31, 5.01, P = 0.002). CONCLUSIONS: A pulmonary valve preservation strategy during tetralogy of Fallot repair should always be attempted. However, a preoperative PV annulus z-score < -2.85 and moderate/severe regurgitation upon discharge are risk factors for midterm pulmonary regurgitation.

Hybrid approach for management of end-stage heart failure in complex congenital heart disease.

Management of end-stage heart failure (ESHF) in children with congenital heart disease is challenging. We report a step-by-step hybrid procedure (transcatheter pulmonary valve and left mechanical assist device implantations) in a child with ESHF after repair of tetralogy of Fallot, as an effective bridge to transplant strategy.

Surgery for Anomalous Aortic Origin of a Coronary Artery (AAOCA) in Children and Adolescents: A Meta-Analysis.

We conducted a systematic review and meta-analysis of the literature to assess the outcomes of surgery for the anomalous aortic origin of a coronary artery in children and young adults (<30 years). Thirteen publications were selected, including a total of 384 patients. Unroofing of the intramural segment was adopted in 92% (95% CI: 81%-98%) of cases, with pooled early and late mortality of 0% (95% CI: 0%-0.3%) and 0.1% (95% CI: 0%-1%), respectively. Reoperation for aortic regurgitation was anecdotal. Surgical management of anomalous aortic origin of coronary arteries can be achieved with excellent results in pediatric patients, but concerns remain about the durability of surgery.

Protective continuous ventilation strategy during cardiopulmonary bypass in children undergoing surgery for congenital heart disease: a prospective study.

OBJECTIVES: The aim of this study was to evaluate if a 'protective' (low-tidal/low-frequency) ventilation strategy can shorten the postoperative ventilation time and minimize acute lung injury in children with congenital heart disease (CHD) undergoing repair with cardiopulmonary bypass (CPB). METHODS: This is a single-centre prospective, interventional study, including children with CHD under the age of 5 years, undergoing open-heart surgery with a CPB >60 min, in hypothermia, haemodynamically stable, and without evident genetic abnormalities. Assist-control ventilation (tidal volume of 4 ml/kg, 10 breaths/min, positive end-expiratory pressure 5 cmH2O and FiO2 0.21) was applied in a cohort of patients during CPB. We compared clinical outcomes and in fully ventilated versus non-ventilated (control) patients. Propensity score was used to weigh ventilated and control groups to correct for the effect of other confounding clinical variables. Clinical and ventilation parameters and lung inflammatory biomarkers in tracheal aspirates were measured. The primary outcome was the postoperative intubation time of more or less than 48 h. RESULTS: We included 140 children (53 ventilated, 87 non-ventilated) with different CHD. There were no deaths or adverse events in ventilated patients. Using a weighted generalized linear model, we found no sufficient evidence for an effect of intraoperative ventilation on postoperative intubation time [estimate 0.13 (95% confidence interval, -0.08; 0.35), P = 0.22]. CONCLUSIONS: Continuous low-tidal/low-frequency mechanical ventilation during CPB is safe and harmless. However, no significant advantages were found when compared to non-ventilated patients in terms of postoperative ventilation time.

Surgical management of failing Fontan circulation: results from 30 cases with 285 patient-years follow-up.

OBJECTIVES: Fontan patients are known to suffer from clinical attrition over the years, which has been characterized as Fontan failure. We sought to evaluate the clinical outcomes of such Fontan patients undergoing surgical management in a 25-year, single-centre experience. METHODS: A retrospective single-centre analysis of patients undergoing surgical treatment for failing Fontan between 1995 and 2020, including any reoperations when ventricular function was preserved, or a heart transplant (HTx), when ventricular contractility was impaired. We analysed survival, indications for surgery and early and late complication rates. RESULTS: We collected 30 patients (mean age 24.7 years) who required surgery after a mean time of 19.3 years from the original Fontan procedure: Fontan conversion in 21 (70%, extracardiac conduit in 19, lateral tunnel in 2), a HTx in 4 (13.3%) and other reoperations in 5 (16.7%). The most common indications for surgery were tachyarrhythmias (63.3%) and severe right atrial dilatation (63.3%). Overall survival at the 1-, 5-, 10- and 20-year follow-up examinations were 75.9% [95% confidence interval (CI): 91.4-60.4%], 75.9% (95% CI: 91.4-60.4%), 70% (95% CI: 78-52%) and 70% (95% CI: 78-52%), respectively. The most frequent complications were postoperative tachyarrhythmias (50%) and late Fontan-associated liver disease (56.5%). HTx and Fontan conversion provided comparably good outcomes compared to other reoperations (P = 0.022). CONCLUSIONS: Surgery for failing Fontan can be performed effectively with overall good long-term survival. However, early and late morbidities are still a significant burden. Because other reoperations performed when patients presented with contraindications for a HTx have carried high mortality, close clinical follow-up is mandatory, and an earlier indication for Fontan conversion or a HTx is advisable to optimize outcomes.

Three-dimensional Printing for Hybrid Closure of Complex Muscular Ventricular Septal Defects.

The identification and surgical closure of apical complex muscular ventricular septal defects remains a difficult problem because of their location in the ventricular septum distal to the moderating band. Three-dimensional reconstruction can help the surgeon to better understand the location and structure of congenital cardiac defects. We report the case of a child with multiple apical complex muscular ventricular septal defects closed through a hybrid approach with the aid of a 3-dimensional printed model.

Effectiveness of Repair of Aortic Coarctation in Neonates: A Long-Term experience.

To evaluate early and long-term results of surgical treatment of aortic coarctation (CoAo) in neonates. This is a retrospective clinical review of neonates with CoAo, who underwent surgery between 1995 and 2019. Data were retrieved from our institutional database, to identify preoperative and postoperative characteristics. Statistical analysis was performed by means of relative risk ratio and Cox and logistic multivariate analysis. 218 consecutive neonates (M/F: 129/89, median age 11 days, IQR 7-17 days) were included; 202 (92.7%) had a left thoracotomy; 178 underwent extended end-to-end anastomosis (EEEA, 81.6%). Hypoplastic aortic arch (HAA) was present in 102 patients (46.8%); complex cardiac anomalies in 85 (39%). Significant postoperative complications occurred in 20 (9.2%). Thirty-day mortality was 2.3% (most in complex types). At a median follow-up of 10.4 years (IQR 5.6-15.0 years; FU completeness 95.9%), there were 8 late deaths (3.7%), all associated to complex CoAo. Among 196 survivors, 177 (93.2%) were in NYHA class I; re-interventions on aortic arch occurred in 9.2% (2.0% were surgical). Freedom from mortality and re-intervention on aorta at 10 years were 94.3% and 96.7%, respectively. Surgical repair of CoAo in newborns without CPB in our series was safe and low-risk, with excellent early and late outcomes.

Surgical strategies for the management of end-stage heart failure in infants and children: A 15-year experience with a patient-tailored approach.

End-stage heart failure (ESHF) in pediatric age is an ongoing challenge. Heart transplantation is the final option, but its long-term outcomes are still suboptimal in children. An alternative patient-tailored surgical protocol to manage ESHF in children is described. Retrospective, single-center analysis of pediatric patients admitted to our institution between April 2004 and February 2021 for ESHF. Our current protocol is as follows: (a) Patients <1 year with isolated left ventricular dysfunction due to dilated cardiomyopathy underwent pulmonary artery banding (PAB). (b) Patients <10 years and <20 kg, who did not meet previous criteria were managed with Berlin Heart EXCOR. (c) Patients >10 years or >20 kg, underwent placement of intracorporeal Heartware. Primary outcomes were survival, transplant incidence, and postoperative adverse events. A total of 24 patients (mean age 5.3 ± 5.9 years) underwent 26 procedures: PAB in 6 patients, Berlin Heart in 11, and Heartware in 7. Two patients shifted from PAB to Berlin Heart. Overall survival at 1-year follow-up and 5-year follow-up was 78.7% (95%CI = 62%-95.4%) and 74.1% (95%CI = 56.1%-92.1%), respectively. Berlin Heart was adopted in higher-risk settings showing inferior outcomes, whereas a PAB enabled 67% of patients to avoid transplantation, with no mortality. An integrated, patient-tailored surgical strategy, comprehensive of PAB and different types of ventricular assist devices, can provide satisfactory medium-term results for bridging to transplant or recovery. The early postoperative period is critical and requires strict clinical vigilance. Selected infants can benefit from PAB that has demonstrated to be a safe bridge to recovery.

Perioperative Glial Fibrillary Acidic Protein Is Associated with Long-Term Neurodevelopment Outcome of Infants with Congenital Heart Disease.

BACKGROUND: Brain injury, impaired brain maturation, and long-term neurodevelopmental disorders are common in infants with congenital heart diseases (CHD). We aimed to assess whether plasma glial fibrillary acidic protein (GFAP) can predict neurodevelopmental anomalies in CHD infants operated on cardiopulmonary bypass (CPB). METHODS: We measured plasma GFAP in 38 infants at multiple CPB phases. Cognitive, neuropsychological, and psychopathological functioning were assessed 5.7 ± 2.2 years after surgery. We identified an impaired global neurodevelopmental index (NDI) when at least two domains were abnormal. The relationships between NDI, GFAP, and clinical variables were explored with non-supervised feature selection methods and modeled with a nested non-linear logistic regression. RESULTS: Intelligence quotient scores were within the normal range in 84% of children, whereas 58% showed an abnormal NDI, with the greatest impairments in the psychopathological area. The plasma GFAP peak was 0.95 (0.44-1.57) ng/mL, and it was correlated with age, weight, duration of surgery phases, and CPB minimum temperature. In the regression model, the GFAP peak was associated with an impaired NDI with a possible flexible point toward NDI impairment at 0.49 ng/mL, keeping constant ICU stay, CPB duration, CHD anatomy, weight, and CPB minimum temperature. CONCLUSION: GFAP is a promising early marker of abnormal long-term neuropsychological development.

Surgery for Anomalous Aortic Origin of Coronary Arteries: Technical Safeguards and Pitfalls.

Anomalous aortic origin of a coronary artery (AAOCA) is reported as the second leading cause of sudden cardiac death in otherwise healthy young individuals. Several surgical studies have reported a shallow operative risk, describing repair as safe and effective with short or medium-term follow-up. However, surgical repair can also be associated with a high risk of complications. Numerous repair techniques have been described in the literature, but each technique's indications and limitations are often not well-understood or understated. Since explicit technical knowledge of the most appropriate surgical technique is highly desirable, we sought to thoroughly and clearly outline the safeguards and pitfalls of the most common surgical techniques used to repair AAOCA.