World Journal for Pediatric and Congenital Heart Surgery

The 18^th International Conference on Pediatric Mechanical Circulatory Support Systems and Pediatric Cardiopulmonary Perfusion was held in Milwaukee, WI, USA, on May 9 and 10, 2024. The conference was hosted by the Herma Heart Institute of Children's Wisconsin at the Pfister Hotel in downtown Milwaukee. This communication provides the highlights of the proceedings.

The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) registry collects data and adjudicates adverse events on pediatric patients receiving mechanical circulatory support at participating centers. To date, the registry includes over 1500 patients from 48 centers. Data collected has been used for research publications, quality improvement projects, and the regulatory support of several ventricular assist devices. While this dataset is large and adjudicated, the registry has real limitations that may limit the interpretation of findings. A full understanding of potential biases and limitations allows researchers and clinicians to make meaningful conclusions from the patient population. This report reviews the strengths and limitations of the ACTION registry to ensure optimal utility among pediatric patients receiving mechanical circulatory support. It also suggests potential areas for improvement to facilitate best care of this vulnerable population.

Background: In newly emerging economy countries, the shortage of pediatric donor hearts and poor healthcare infrastructure poses a significant challenge. Although mechanical circulatory support (MCS) has been proven effective in enhancing heart transplant waiting list outcomes, economic barriers hinder its widespread adoption. Methods: A single-center retrospective study reviewed children under 10 kg on the heart transplant (HTx) list from 2012 to 2023. Elective or priority status was assigned based on their clinical condition at the time of transplant. In cases of clinical decompensation, centrifugal pump and extracorporeal membrane oxygenation, transitioned to the Berlin Heart EXCOR (BHE) pediatric ventricular assist device (VAD) was employed. Pre- and post-HTx outcomes were analyzed with descriptive statistics, Cox regression, and competing survival risks. Results: Out of 81 infants on the HTx list, 61.7% (50/81) were in critical condition. The median wait time was 224 days, and 34% (28/81) died while waiting. Out of 37 transplanted patients, 6 (16%) had graft dysfunction, and 10 (27%) had acute renal injury. Survival to discharge was 84% (31/37). Patients who received the BHE exhibited higher chances of receiving a transplant (hazard ratio: 2.3; 95% confidence interval: 1.2-4.6; P = .01). Priority status or MCS use did not significantly impact mortality post-transplant. Conclusion: Advanced MCS technologies can potentially reduce the mortality risk on the pediatric HTx waitlist. The findings highlight the significant waiting time for HTx and the critical role of the BHE in improving outcomes in children, particularly those under 10 kg. The results advocate for the adoption of ventricular assist devices as a viable interim solution to bridge critically ill children to HTx, ultimately enhancing their chances of survival despite limited donor heart availability.

The declining birth rate and aging population are becoming increasingly serious social issues in Japan. In this report, we summarize the current congenital heart surgery and pediatric perfusion practices in Japan and Vietnam. In addition we report the rapid growth and development of congenital heart surgery in Vietnam made possible by medical education support provided by Japan over the past decade.

Background: Patients with congenital heart disease (CHD) are increasingly surviving to adulthood. Given their age- and condition-specific needs, the optimal postoperative setting for these patients is not yet determined. This study aims to evaluate the utility of an adult-specific order set in improving clinical outcomes for these patients in a pediatric cardiovascular intensive care unit (ICU). Methods: Adults with CHD (ACHD) admitted to the cardiovascular ICU following cardiac surgery at a pediatric tertiary care center were identified for a retrospective cohort study. Health care delivery metrics and clinical outcomes of participants who received the adult-specific order set were compared with control patients admitted prior to the intervention. Categorical outcomes were compared using the χ² test of independence or Fisher exact test, and continuous outcomes were assessed using the t test. Results: A total of 130 ACHD patients received the intervention, with no significant differences observed in clinical outcomes when compared with 89 controls. While there was additionally no reduction in hospital-related mortality (2.3% vs 7.8%, RR 0.3; P = .1), clinician ordering behaviors were better aligned with best-practices following the intervention. Among patients with moderate or greater anatomic complexity, a post hoc analysis demonstrated reduced in-hospital mortality from those who received the adult order set. Conclusions: The implementation of an adult-specific order set in a pediatric care setting did not improve clinical outcomes for all ACHD patients. Patients with moderate and greater anatomic complexity did see a mortality benefit, suggestive that targeted electronic tools may most benefit those who have the highest risk.

Background: Epicardial pacing systems, rather than transvenous systems, are utilized in pediatric patients who are too small to undergo transvenous access and/or have complex congenital heart disease (CHD) anatomically precluding a transvenous system. Longitudinal performance studies indicate that epicardial leads have higher failure rates when compared with transvenous leads but there are limited data on lead measurement changes in the acute phase after implantation. The objective of this study was to assess epicardial lead performance in the acute postimplant period and at one-year follow-up. Methods: This is a retrospective single center study of children and adult patients with CHD undergoing epicardial bipolar pacing lead and generator implantation between January 2012 and June 2022. We empirically selected 2 V as a critical lead threshold. Results: There were 256 leads implanted in 127 patients (mean age 6.1 ± 9.8 years), including 201/256 (79%) leads in patients with CHD. At the time of implant, 47/256 leads (18%) had a lead threshold of ≥2 V. Of those, 42 of 47 (89%) had recorded threshold values on postoperative day 1 (POD1) and 37 of 42 (88%) had decreased to a more acceptable threshold that was <2 V. For patients with an implant threshold of ≥2 V; impedance >1000 ohms, presence of CHD, perioperative or acute postop status, and location of the lead (atrial vs ventricular) did not significantly impact the odds of having a persistently high threshold (≥2 V) on POD1. Conclusion: Epicardial pacing lead thresholds generally improve in the immediate postop period and in our experience most leads with a high implant threshold improved to <2 V by POD1.

Cardiopulmonary bypass (CPB) is essential for the conduct of open-heart procedures. While lifesaving, CPB can be associated with significant end-organ injuries believed to result from inflammatory responses triggered by the extracorporeal surfaces encountering cellular elements in the blood stream. In this review, we discuss the role of interleukin-6 (IL-6) and the potential for Tocilizumab, an anti-IL-6 receptor antibody, in mitigating these effects. We compare the inflammatory responses in CPB and cytokine storm, a clinical condition in which Tocilizumab has been effectively implemented. Finally, we examine why corticosteroids, used to reduce the morbidity of CPB, may not effectively reduce IL-6 levels.

Coronary artery complications following the arterial switch operation (ASO) for transposition of the great arteries have become increasingly relevant as those affected are exposed to the comorbidities of later years. A scoping review was undertaken to explore the incidence, clinical features, and management of the long-term coronary complications after the ASO. The selection criteria yielded 73 articles They recorded few long-term coronary artery complications following the ASO, which were difficult to recognize as most affected patients’ symptoms were absent or nonspecific. In patients with suspected coronary artery involvement, coronary angiography or computed tomography provided confirmation, with significant stenosis generally managed by percutaneous trans-catheter interventions.

We present a case of a three-month-old male who presented with a cervical esophageal duplication cyst requiring early surgical intervention. The patient presented with feeding difficulties, poor weight gain, and respiratory distress. Due to the position of the cervical esophageal duplication cyst and airway compression, this unique case required a multidisciplinary surgical approach involving both otolaryngology and cardiothoracic surgery.

Permanent pacemaker placement is often indicated in newborns with congenital complete heart block (CCHB). The disproportionate size between commercially available devices and the neonate can lead to delayed intervention and high postoperative complication rates. Recently, Medtronic developed a Pediatric Implantable Pulse Generator (IPG); a very small single chamber pacemaker requiring a bipolar lead. This case report describes a minimally invasive approach for the implantation of this Pediatric IPG shortly after birth in a 2.32 kg neonate with CCHB.

We present a case study of neotricuspidization of the aortic valve with neocusp suturing based on templates similar to those used in the Ozaki procedure but adapted for infants. This is an alternative for patients when valve reconstruction is impossible or risky. A good postoperative hemodynamic outcome was obtained, but it is necessary to evaluate this approach on the basis of long-term results.

Transposition of the great arteries (TGA) with a rare form of ventricular septal defect (VSD) needs careful attention when choosing the optimal strategy for repair. A neonate with TGA and an atypical VSD, which extended from the perimembranous to the juxta-arterial regions, underwent the arterial switch procedure. The large VSD was successfully closed via a trans-tricuspid combined with a trans-aortic valve approach concomitantly with the arterial switch maneuver. Surgeons need to be aware aware that the types of VSD are diverse in TGA.

Cardiac disease in young children can be unrecognized until symptoms are unmasked by a precipitating event, such as an infection. We present a case of anomalous left coronary artery from the pulmonary artery causing clinically significant disease in a four-month-old male with concomitant mitral regurgitation and pulmonary coccidioidomycosis who required modification of his surgical management due to the infection. This case highlights how timely diagnosis and perioperative management and recovery can be affected by concurrent infections in patients with congenital heart disease.

The authors present an exceptionally rare case of a newborn in whom total anomalous pulmonary venous return (TAPVR) had been diagnosed prenatally and in whom genetic testing after neonatal cardiac repair confirmed a missense variant of the FBN1 gene consistent with Marfan syndrome as well as a PRKDC gene mutation associated with severe combined immunodeficiency. To the authors’ knowledge, this is the first reported case with this unique combination. Neonatal TAPVR repair was undertaken with a good postoperative outcome and survival until the last follow-up.

We present a unique case of progressive neoaortic root and neoascending aortic dilatation, with poly-valvar regurgitation in a patient with Marfan syndrome and hypoplastic left heart syndrome palliated to Fontan procedure. This progressive dilation and valvar dysfunction necessitated a modified Bentall procedure and tricuspid valve repair. Our case highlights the impact of both a primary and secondary aortopathy complicating the Fontan procedure and the need for mechanical aortic valve replacement.