Hybrid approach in hypoplastic left heart syndrome
- Correspondence to Dr Dietmar Schranz, Pediatric Heart Center, Justus-Liebig University Clinic, Feulgenstr. 12, Giessen 30385, Germany;
Hypoplastic left heart syndrome (HLHS), morphologically subdivided in mitral and/or aortic atresia or stenosis, accounts for 2–3% of all congenital heart defects and is a fatal congenital heart defect if untreated.1 Early postnatal survival requires a patent ductus arteriosus (DA) to provide systemic blood flow from the RV to aorta and an atrial septal defect to allow mixing of oxygenated pulmonary venous and deoxygenated systemic venous blood flow. Neonates that present with HLHS are clinically stable as long as the parallel pulmonary and systemic circulations are balanced, although the postnatal decrease in pulmonary vascular resistance may result in clinical decompensation. In about 6% of HLHS patients, the atrial septum is intact at birth, and up to 22% have a severely restrictive atrial septum,2 which results in a critically ill neonate. In prenatally undetected HLHS, neonates are often admitted in cardiogenic shock because of severe obstruction of the DA.
Surgical options are based on a three-staged procedure or heart transplantation. The three-stage Norwood procedure includes: Stage I with separation of systemic and pulmonary arterial flow using either a Blalock–Taussig shunt or a right ventricular to pulmonary artery conduit; Stage II with systemic venous flow from the superior vena cava directed to the pulmonary artery (and the shunt or conduit taken down); Stage III with a complete Fontan procedure directing the inferior vena caval flow to the pulmonary artery. Newer Hybrid approaches use a combination of surgical and transcatheter approaches for correction of HLHS. Despite significant advances in the surgical and intensive care for newborns with HLHS, decision making remains challenging for parents and physicians with a choice of the classical surgical Norwood procedure; a Hybrid surgical-interventional approach; heart transplantation or compassionate therapy after intense and repetitive communication about the choices and prognosis.
Lloyd et al3 draw attention to …