Results of stage I palliation of single ventricle with hypoplastic left heart complex managed with a beating heart strategy.

Background: Neonates born with hypoplastic left heart syndrome (HLHS) or complex (HLHC), who undergo stage I palliation with Norwood operation or Damus-Kaye-Stansel (DKS), still carry substantial mortality and morbidity even in the modern era of cardiac surgery. Mortality varies from 10% up to 40% in some Institutions, remaining still one of the highest in pediatric cardiac surgery. In order to reduce mortality and morbidity, we have developed a strategy of selective cerebro-myocardial perfusion (sCMP), allowing to perform the entire operation on the beating heart. The aim of the presents report is to describe our results with such an innovative approach. Methods: Between December 2016 to December 2024, 12 consecutive patients underwent Norwood-Brawn/double-barrel DKS stage I palliation for single ventricle (SV) palliation associated with ascending aorta and severe arch hypoplasia. All patients were managed with a 3.5 mm modified Blalock-Taussig (mBT) shunt, except one 5-month infant who had a 4 mm shunt. The operation was performed under mild hypothermia with selective constant coronary and cerebral perfusion provided by 2 separate pump rotors. Results: There were 6 male and 6 female patients, with a median age of 4.5 days [interquartile range (IQR), 2.75-5.25 days] and median body weight of 3.2 kg (IQR, 3.075-3.55 kg). Median cardiopulmonary bypass (CPB) time was 200 min (166-306 min), the median time of myocardial perfusion 80 min (67.5-90 min), the median time of cerebral perfusion time was 160 min (150-176.25 min) and the median time of splanchnic ischemia during cerebro-myocardial perfusion was 47 (40.75-53.5 min). In the series only 2 patients required veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) for failure to wean from bypass. The mean peak troponin T (TnT) was 5,973 (IQR, 1,775.5-8,971) ng/L, while the mean peak lactate level was 8.9 (5.55-11.95) mmol/L. Acute kidney injury, requiring a transient period of peritoneal dialysis was observed in 9 of 12 (75%) patients, while no patients developed liver dysfunction. Postoperative death occurred in 2 patients affected by one of the most severe forms of HLHS (mitro-aortic atresia) due to cardiac dysfunction and failure to wean from VA ECMO support. There was one interstage mortality (between stage I and II) due to progressive heart failure and sepsis. During a median follow-up of 52 months (13-73 months) all late survival were in good clinical conditions without signs of cardiac dysfunction and trivial systemic valve regurgitation. Nine patients completed II stage and six of them stage III palliation of the univentricular heart. Conclusions: The present experience suggests that a strategy of cerebro-myocardial perfusion is safe, versatile, and feasible in high-risk neonates with HLHC. Encouraging outcomes were noted in terms of cardiac and neurological function, with limited end-organ morbidity.