Congenital: Hypoplastic Left Heart Syndrome
Hybrid strategy in neonates with ductal-dependent systemic circulation and multiple risk factorsThe study objective was to analyze outcomes of the hybrid strategy for ductal-dependent systemic circulation consisting of bilateral pulmonary artery banding with or without ductal stenting followed by delayed Norwood-type palliation or comprehensive stage II operation in high-risk neonates.
Combined Norwood and cavopulmonary shunt as the first palliation in late presenters with hypoplastic left heart syndrome and single-ventricle lesionsA primary cavopulmonary shunt as a component of the initial Norwood palliation could be an option in patients with hypoplastic left heart syndrome and single-ventricle lesions. We present our initial experience with this approach in carefully selected patients with unrestricted pulmonary blood flow and low pulmonary vascular resistance.
Commentary: The importance of operative timing in the era of coronavirus disease 2019 (COVID-19)The current worldwide coronavirus disease 2019 (COVID-19) pandemic has required all health care practitioners to consider the care of their patients in an entirely new light. This is especially paramount when determining the timing for any medical procedure, as providers must now, more than ever, appreciate the importance of critically evaluating what procedures are truly urgent and cannot be deferred to an elective basis. Despite the initial focus of the COVID-19 pandemic being directed toward adult patients, pediatric patients have also experienced a significant burden of this novel disease,1,2 and patients with congenital heart disease are certainly not exempt.
Commentary: “Murder on the Orient Express of pandemic: COVID was found guilty, but was it the murderer?”In Agatha Christie's novel Murder on the Orient Express, detective Hercule Poirot brilliantly resolves the murder of Mr Ratchett, a kidnapper, and proposes 2 possible solutions. The first is a plausible solution that fits with the scenario and saves the unfortunate group of murderers, who were looking for revenge. The second solution describes what happened but would have sent all of them to jail. The investigators adopted the first solution as the truth to save the entire family from prison.
Commentary: Adapting the practice of congenital heart surgery to the coronavirus disease 2019 (COVID-19) pandemicBezerra and colleagues1 report on an interesting case from São Paulo, Brazil, where, as of this writing in June 2020, coronavirus disease 2019 (COVID-19) is raging. This worldwide pandemic took clinicians by surprise and, as a consequence, there is a lot to catch up on, such as the different manifestations of this new disease, how it affects patients with congenital heart disease (CHD), and on how to prevent it. Writing from the one-time epicenter of the COVID-19 crisis in NYC, our team has unfortunately been confronted with patients with CHD infected with COVID-19 at different perioperative time periods, such as in asymptomatic patients coming from home for semielective surgery who tested positive on their polymerase chain reaction (PCR) nasal swab test, in a patient with cardiomyopathy on extracorporeal membrane oxygenation support who required a ventricular assist device while still positive, and in postoperative patients after Fontan and after truncus arteriosus repair (after testing negative on their preoperative PCR tests).
COVID-19 as a confounding factor in a child submitted to staged surgical palliation of hypoplastic left heart syndrome: One of the first reports of SARS-CoV-2 infection in patients with congenital heart diseaseIn December 2019, in the province of Wuhan, China, authorities identified an outbreak of pneumonia caused by a novel coronavirus, colloquially referred at COVID-19. The virus has now spread worldwide, reaching pandemic proportions.1 Although adult patients with cardiovascular comorbidities are at increased risk of progressing with the severe form of the disease,2 it is not known whether the same holds true for children with congenital heart disease (CHD). Furthermore, both the incidence of infection and severity of disease seem to be much lower in children than in adults.
Commentary: Diastolic dysfunction following biventricular conversion: When physiology beats anatomyA child was born with borderline left ventricle, mitral, and aortic valves. He underwent first-stage palliation followed by Glenn. Before Fontan, he was considered for biventricular conversion. Subsequently, he underwent 3 operations toward achieving that goal. Those entailed atrial septal defect closure, takedown of Damus–Kaye–Stansel, septal myectomy, resection of endocardial fibroelastosis (EFE), aortic commissurotomy, ascending aorta patch, mitral valve repair followed by replacement, pulmonary artery patch, and takedown of Glenn with superior vena cava patch.
Flow disturbances and the development of endocardial fibroelastosisEndothelial-to-mesenchymal transition (EndMT) has been identified as the underlying mechanism of endocardial fibroelastosis (EFE) formation. The purpose of this study was to determine whether hemodynamic alterations due to valvar defects promote EndMT and whether age-specific structural changes affect ventricular diastolic compliance despite extensive surgical resection of EFE tissue.
Commentary: Is this a bridge too far?No one would argue against the notion that tricuspid valve regurgitation is a potentially big problem in some patients with hypoplastic left heart syndrome. It is a risk factor for early death and surgical intervention on the tricuspid valve might be necessary in up to 25% of all patients with hypoplastic left heart syndrome in the first 10 years of life. The underlying mechanisms leading to the regurgitant valve are variable and likewise a variety of repair techniques have been reported. These techniques have met with only fair success for the most part.
Commentary: Why do some patients with hypoplastic left heart syndrome have endocardial fibroelastosis?Those who treat patients diagnosed with so-called hypoplastic left heart syndrome are well aware that the syndrome is made up of several phenotypic entities.1 This important fact, however, is not always appreciated by those seeking to establish the genetic cues predisposing toward development of the lesion.2 If we are to establish the reasons that some infants are born with the syndrome, it will be optimal if we can agree on the phenotypic variables to be included. In this regard, at least in the clinical setting, there is now agreement that one of the required features is the integrity of the ventricular septum, and the presence of concordant ventriculoarterial connections.
Commentary: Myocardial regeneration with stem cells—Hope was never the problem!In the last few decades, the discovery of the regenerative potential of the myocardium has led to experimental and clinical research efforts with significant resource utilization.1,2 Since the first administration of intracoronary and intramyocardial stem cells in adult ischemic heart disease, numerous attempts have followed with different sources and routes for cardiac stem cell therapy.3,4 While the safety of myocardial stem cells therapy was being confirmed in long-term clinical trials, their efficacy remained limited.
Commentary: The hourglass tricuspid valve annuloplasty during a Norwood procedure—Bridging the gapRapid advances have been made in stage 1 Norwood palliation for hypoplastic left heart syndrome, with hospital survival now approaching 93%.1 Tricuspid valve regurgitation (TR) and right ventricular dysfunction, however, continue to carry very high early and medium-term mortalities.2 TR significant enough to warrant intervention is observed in 25% of children with hypoplastic left heart syndrome.3 Significant TR is associated with a worse survival at 1 year,3 and successful repair can result in equivalent survival at 5 years.
The interannular bridge: A new technique for the management of tricuspid regurgitation in hypoplastic left heart syndromeFor patients with hypoplastic left heart syndrome (HLHS), it is essential to control moderate to severe tricuspid regurgitation (TR) so that the Norwood procedure can be tolerated. Because of the vulnerability and future growth potential of the valve leaflet, it is difficult to adopt a conventional procedure for immobilizing the leaflets and annulus. We report here a case in which we used the interannular bridge technique to control central TR in an infant with HLHS who had undergone the Norwood procedure.
Commentary: Cross my heart and stick a needle in it—I hope to liveIn this issue of the Journal, Burkhart and colleagues1 report results of a phase I trial designed to assess safety and feasibility of epicardial injections of umbilical cord blood–derived mononuclear cells in 10 patients with hypoplastic left heart syndrome at the time of stage II (Glenn) palliation.1 If we accept the premise that delivery of the right cell types in the right amount to the young infant myocardium will provide durable and clinically relevant benefit, then this work is important. Burkhart and colleagues1 have developed and refined a method of umbilical cord blood harvest and processing that provides a reliable product at the time of the Glenn palliation—a significant achievement resulting from years of determined hard work.
Autologous stem cell therapy for hypoplastic left heart syndrome: Safety and feasibility of intraoperative intramyocardial injectionsStaged surgical palliation for hypoplastic left heart syndrome results in an increased workload on the right ventricle serving as the systemic ventricle. Concerns for cardiac dysfunction and long-term heart failure have generated interest in first-in-infant, cell-based therapies as an additional surgical treatment modality.
Commentary: Mechanical ventilation: A toxic assetDisuse muscle atrophy, delirium, opioid addiction, benzodiazepine dependence, agitation, antibiotic-resistant infection, and microbiome derangement are among compounding iatrogenic expenses that start accruing, like debt on a high-interest loan, on admission to the postoperative intensive care unit (ICU). Recognizing the rapidly compounding dangers of ICU care, an “ICU liberation” philosophy is gaining traction in adult and pediatric settings, with coordinated attention to reducing sedation, performing early extubation, and encouraging mobility, aiming to pre-empt the cascade of iatrogenic complications that derails recovery for patients in the ICU.
Commentary: Faster recovery after complex neonatal cardiac surgeryEarly extubation in congenital cardiac surgery reduces the complications associated with prolonged intubation, avoiding the consequences of sedation and the effects of positive-pressure ventilation.1 Early extubation has a greater success rate in children with greater body weights and those undergoing shorter surgical procedures.2 Delayed extubation is considered an indicator of poor outcomes in most quality control programs. In the Society of Thoracic Surgeons database, early extubation after Fontan operation or repairing tetralogy of Fallot is mostly discussed.
Outcomes related to immediate extubation after stage 1 Norwood palliation for hypoplastic left heart syndromeImmediate extubation may have outcome benefits when judiciously instituted after neonatal congenital cardiac surgery. We sought to evaluate the outcomes of immediate extubation specifically in neonates undergoing stage 1 Norwood palliation of hypoplastic left heart syndrome.
Composite polytetrafluoroethylene homograft with external stent as valved pulmonary conduit: All hat and no cattle?Finding a reliable valved cardiac conduit for newborn infants and infants has been an elusive goal for decades. Homograft conduit narrowing and progressive valve incompetence are troublesome expectations, and many interventions will be avoided when better solutions emerge. Important progress has been made in tissue engineering, and recipient endothelium-lined conduit is an implantable reality,1 but work remains before a valve scaffold that sustains competence and supports renewable cellular architecture is a practical reality.
Pathology of valved venous homografts used as right ventricle-to-pulmonary artery conduits in congenital heart disease surgeryAlthough valved venous homografts (VVHs) are used for establishing right ventricle-to-pulmonary artery continuity in some complex heart defects, the tissue changes that occur in situ have not been described. We review the gross and microscopic changes observed in explanted VVH conduits and their effects on functionality.