Truncus arteriosus with single pulmonary artery: influence of pulmonary vascular obstructive disease on early and late operative results.

Nineteen patients with truncus arteriosus and single pulmonary artery had corrective operations at the Mayo Clinic from 1969 to 1983. At operation, their ages ranged from 4 months to 20 years (mean 8.1 years). The preoperative pulmonary resistance divided by 2 was used to predict the degree of pulmonary vascular obstructive disease at operation. The influence of elevated pulmonary resistance and the intraoperative postrepair ratio of pulmonary artery to left ventricular pressure on operative and late mortality were examined. The outcome of patients with single pulmonary artery was compared with the outcome of 148 patients with truncus arteriosus and two pulmonary arteries operated on during the same period. Patients with a single pulmonary artery had an operative mortality similar to that of patients with two pulmonary arteries (32 versus 28%, p greater than 0.05). Late mortality was, however, significantly greater (p less than 0.001) for patients with a single pulmonary artery. Elevated ratios of intraoperative postrepair pulmonary artery to left ventricular pressure were associated with significantly higher (p less than 0.02) operative and late mortality, but elevated preoperative pulmonary resistance was not (p greater than 0.10). Truncus arteriosus with single pulmonary artery is associated with poor postoperative survival, and although elevated pulmonary resistances preoperatively did not predict outcome, elevated intraoperative postrepair pulmonary artery to left ventricular pressure ratios were associated with increased operative and late survival, suggesting a deleterious role of pulmonary hypertension.