SURGICAL REPAIR OF THE HYPOPLASTIC LEFT-HEART SYNDROME

The outlook for newborns with hypoplastic left heart syndrome has been dramatically altered in the past decade with the successful applicati on of staged reconstructive techniques. Once considered a uniformly fa tal condition, refinements in operative technique and perioperative ca re have been largely responsible for this improved survival. The first stage in the reconstructive process, the Norwood procedure, continues to carry the most significant risk. The Norwood procedure must provid e: unobstructed systemic and coronary blood flow from the right ventri cle; unobstructed pulmonary venous return across the atrial septum; an d sufficient pulmonary blood flow without significant volume overload. Although the postoperative management of these patients must achieve the proper ratio of systemic and pulmonary vascular resistance, a prop erly performed reconstruction should result in a largely uncomplicated recovery. The second stage procedure, the hemi-Fontan operation, is p erformed between 4 and 6 months of age. This step results in removal o f the ventricular volume overload imposed by the systemic shunt and th e connection of the superior vena cava to the pulmonary arteries. Augm enting the central pulmonary arteries, avoiding conduction disturbance s, and constructing a potential connection for the inferior vena cava to the pulmonary arteries are essential components of this procedure. The Fontan procedure is performed at approximately 1.5-2 years of age. Inferior vena cava return is channeled to the pulmonary arteries thro ugh the previously constructed atriocaval connection to complete the s eparation of the pulmonary and systemic circulations. Although the cur rent techniques have resulted in substantial improvements in the quant ity and quality of survival, efforts to refine each stage of the proce ss continue to evolve with increasing follow-up and evaluation.