[Late surgical results of operation in partial atrioventricular canal defect]

Twenty-three patients underwent repair of a partial atrioventricular canal defect and have been followed for a mean of 9.4 years. The patients were divided into two groups according to the management of mitral cleft. Mitral cleft was not repaired in seven patients and directly sutured or repaired by valvuloplasty using pericardium in sixteen patients. In seven patients untreated mitral cleft left, two patients have required mitral valve replacement because of progressive severe mitral regurgitation. In sixteen patients mitral cleft repaired, no patients have required re-operation. However, one patient using pericardium in valvuloplasty, mitral regurgitation was in progress recently due to calcification and degeneration of the pericardium. The peak flow velocity, pressure gradient, pressure half time, and valve area in the mitral valve were measured by echo-doppler study. We recognized no statistical difference among two groups about hemodynamic performance in the mitral valve.

1) As concerns post-operative mitral regurgitation, the mitral cleft should be repaired. 2) After mitral cleft closure, the mitral flow pattern was not disturbed. 3) Autologous pericardium should not be adapted for valvuloplasty, because calcification and degeneration of the pericardium may cause progressive incompetency of the mitral valve.