Atrioventricular septal defect complicated by right ventricular outflow tract obstruction. Analysis of risk factors regarding surgical repair.

Eighteen patients with complete atrioventricular septal defect (AVSD) were found to have either associated tetralogy (n = 15) or pulmonary atresia (n = 3). Their pre- and post-operative course was reviewed focusing attention on risk factors for complete repair. These included right ventricular (RV) hypoplasia, identified by cineangiographic volume determinations in two cases (11%) and inadequate pulmonary artery size in one patient. In the 2 cases with RV hypoplasia and in one case, in whom all chordae of the AV valve were connected to a single right ventricular papillary muscle (AVSD type Rastelli B), complete repair was not feasible. In addition, angiography revealed coronary artery variations in 5/18 (28%), which did not preclude surgical repair. Palliative surgery was undertaken in 10 patients and complete repair carried out in five. Six of 18 patients died, 2 among those after complete repair.