Risk Factors for Mortality After the Norwood Procedure Using Right Ventricle to Pulmonary Artery Shunt

Background. The purpose of this study was to describe the experience with staged surgical reconstruction of the hypoplastic left heart syndrome (HLHS) with a right ventricle to pulmonary artery conduit and to identify the risk factors that influence late outcome. Methods. Between February 1998 and June 2007, 62 patients with HLHS underwent a Norwood procedure by using right ventricle to pulmonary artery conduit (median age, 9 days [range, 1 to 57]; median body weight 2.7 kg [range, 1.6 to 3.9 kg]). The subsequent 47 patients underwent a bidirectional Glenn procedure (stage 2). Thirty-two patients underwent a modified Fontan procedure (stage 3). Follow-up was complete (median, 32 months; range, 1 to 101). Results. Hospital mortality after the Norwood procedure was 8% (5 of 62 patients). Between stages, 9 patients died, 3 before stage 2 and 6 before stage 3. There was 1 late death after stage 3. Overall survival was 76% (47 of 62). The estimated 1-year and and 5-year survival rates were 80% and 73%, respectively. Using the any-mortality as the endpoint, prematurity (gestational age <37 weeks), body weight less than 2.5 kg at stage 1 operation, and tricuspid regurgitation 2+ or more were associated with mortality. Using Cox regression analysis, body weight less than 2.5 kg and tricuspid regurgitation 2+ or more were two independent factors associated with midterm survival. Conclusions. From 9 years of experience, despite good early survival after Norwood stage 1 palliation, low body weight and tricuspid valve regurgitation were still associated with worse outcome. More efforts should be made to improve the late results for patients with hypoplastic left heart syndrome.