Hypoplastic Left Heart Syndrome and Aortic Atresia-Mitral Stenosis Variant: Role of Myocardial Protection Strategy and Impact of Ventriculo-coronary Connections After Stage I Palliation
BACKGROUND To evaluate the developing surgical technique of a modified Norwood procedure using a right ventricle-to-pulmonary artery shunt, we analyzed data obtained from 73 infants who underwent first-stage palliation for hypoplastic left heart syndrome between 1998 to 2002 at three centers in Japan. METHODS Procedures performed included an aortopulmonary neoaortic reconstruction and a nonvalved polytetrafluoroethylene shunt between a small right ventriculotomy and a distal stump of the main pulmonary artery. The size of the shunt used was 4 mm in 6 patients, 5 mm in 41, and 6 mm in 26. Continuous cerebral perfusion was used in all patients and an additional descending aortic perfusion was used in 39. Postoperative management was basically the same as that for infants undergoing other types of operations. RESULTS There were 61 hospital survivors (84%), including 5 of 6 patients weighing less than 2 kg, with 8 late deaths. Risk factors for hospital mortality include preoperative treatment without ventilatory support and surgeon's experience (first 10 cases). Three patients underwent a primary Fontan operation at 5, 9, and 10 months of age, with one late death. Forty-one patients underwent the bidirectional Glenn shunt after a mean interval of 6.9 months, and 19 of them completed the Fontan operation at median age of 2.1 years. Overall survivals were 65% at 1 year and 63% at 2 years. CONCLUSIONS Improved survival for patients after first-stage palliation of hypoplastic left heart syndrome is reproducible for many centers by an application of the modified Norwood procedure with the right ventricle-to-pulmonary artery shunt.