Surgical treatment of non-critical right ventricular outflow tract obstruction with intact ventricular septum in patients over one year of age.

Between March 1966 and May 1982, 257 patients with clinically noncritical right ventricular outflow tract obstruction with intact ventricular septum (RVOTO/IVS) underwent elective open-heart correction, with an overall early mortality of 3.9%. Age ranged from 13 months to 48 years (mean 6.6 +/- 6.5 - median 5). We describe three different anatomical types, for which a standardized surgical approach is suggested. When one or more of the following features--small right ventricular cavity; rigid infundibular stenosis; hypoplastic pulmonary annulus and trunk; dysplastic cusps--were present, the mortality (10.6%) was significantly higher than in isolated valvular stenosis (2.2%) or in valvular plus dynamic infundibular stenosis or isolated low-lying stenosis (2.5%). In a series of 159 consecutive patients operated upon since September 1974 the cumulative early mortality was 1.3%. Late results on 202 patients (mean follow-up period of 25.6 +/- 22.6 months) are good in 90.6% and fair in 8.9% of the cases. One patient died of encephalitis 2 years after the operation. We believe that a more precise characterization of the underlying lesions and a more liberal use of different surgical techniques to minimize residual gradients, iatrogenic pulmonary incompetence and impairment of right ventricular contractility, may decrease early mortality and improve overall results.