Analysis of early results of partial atrioventricular (AV) canal deformity correction in 101 patients and of late results of these plus 131 patients treated earlier has focused on factors affecting operative risk. Age at operation and heart size had possible relevance and the degree of disability held borderline significance. Operative mortality was 5.6%; estimated late survival of the remaining patients at 5, 10, and 15 years was 96.5%, 95.3%, and 93.8%. Preoperative cardiac enlargement was the only significant factor related to the late result.
Mitral valvular deformity, which figures importantly in the causes of early and late failures, is difficult to evaluate because of the lack of quantitative methods of assessment. Accurate repair of the mitral valve cleft is required; determination of residual severe mitral regurgitation after repair is desirable to permit mitral replacement at the time.