Factors influencing early outcome of Norwood procedure for hypoplastic left heart syndrome.

OBJECTIVE [corrected] The operative outcome of the Norwood procedure for hypoplastic left heart syndrome is still not satisfactory. Conflicting reports concern factors associated with early Norwood procedure mortality and the reasons for the instability after surgery are not sufficiently understood. The purpose of this study was to determine some perioperative factors influencing early (30 days) outcome. METHODS We retrospectively analyzed a group of 30 consecutive children with hypoplastic left heart syndrome (aged 5-39 days) who underwent Norwood procedure in 1997 and 1998. The following factors were considered and statistically analyzed: operative age, birth weight, operative weight, serum level of bilirubin, aminotransferases, creatinine, urea, arterial blood gasses, anatomic subgroups, ascending aorta and arch size, systemic to pulmonary modified right Blalock-Taussig shunt size, cardiopulmonary circulatory arrest time, cardiopulmonary bypass time, and delayed chest closure. Eighteen patients underwent hemi-Fontan procedure with one late death and the modified Fontan operation was performed in 16 of them (one late death). RESULTS The early mortality was 37%. Seven deaths (64%) occurred during the first 24 h after operation. There was a significant difference between survivals and non-survivals in: birth weight (P=0.047), operative age (P=0.016), preoperative serum level of bilirubin (P=0.044), and cardiopulmonary circulatory arrest time (P=0.006). The other assessed factors were not found to be predictors of early mortality. All 16 survivals followed up are in New York Heart Association class I or II. CONCLUSIONS Anatomic and functional status of the patient, as well as procedural factors are related to Norwood operation early mortality. High mortality in hypoplastic left heart syndrome after stage I surgery indicates the necessity of assessing all factors which may determine further improvement in the outcome.