Hypoplastic Left Heart Syndrome

Abstract

Hypoplastic left heart syndrome (HLHS) is one of the most challenging forms of congenital heart disease to treat. Management of this condition consumes a substantial amount of energy, time, and bed capacity in many congenital heart centers in the Western world today. Simply defined, HLHS is a congenital malformation in which the left ventricle is inadequate and nonviable in its capacity to perform the function of systemic perfusion. The current conventional strategy of staged reconstruction involves the principles of right ventricular recruitment for systemic perfusion, aortic arch reconstruction, and a 2-step process of channeling systemic venous return directly to the pulmonary vasculature absent the use of a ventricular pump (bidirectional Glenn and Fontan operations). Initially promoted by Norwood in the early 1980s, the management protocol continues to evolve, leading to the survival of thousands of children who would otherwise succumb to this lethal condition. Article see p 638 The current management scheme offers the promise of creating survival for HLHS, truly a modern-day medical miracle; however, pitfalls exist at every step along the way. Overall mortality is one of the highest for any of the forms of congenital heart disease treated today. At best, only 2 of 3 neonates born with HLHS will live through completion of all 3 stages of surgery.1 First-stage surgical reconstruction is a technical challenge. Modifications to the style of delivery of pulmonary blood flow in the neonate (Blalock-Taussig shunt versus right ventricle–to–pulmonary artery conduit) were rigorously investigated in a landmark randomized clinical trial and were found to have only a small impact on early survival, with equalization of outcome by 18 months of age.2 Mortality between the first and second stages is still inexplicably and unacceptably high. For the survivors of surgery, the goal of creating a normal duration and quality of life …