Surgical treatment of complete atrioventricular canal defect with an endocardial cushion prosthesis.

In order to obtain better operative results with less postoperative atrioventricular valve regurgitation, we have developed a new method of repair for the complete atrioventricular canal with a composite prosthetic patch called an endocardial cushion prosthesis, in which horizontal wings are attached to a vertical patch on both sides to compensate for the defective atrioventricular valve tissue. Ten patients ranging in age from 8 months to 8 years (mean 28.9 months) have been operated on with this technique since 1975. All patients except one showed severe preoperative pulmonary hypertension (over 50 mm Hg) in mean pulmonary artery pressure. Six patients had trivial-to-moderate mitral regurgitation before surgery. Nine patients survived the operation (operative mortality 10%). Postoperative mitral regurgitation was found in three of seven patients who underwent cardiac catheterization and angiocardiographic examination at an average of 4.4 months after surgery. The grades of mitral regurgitation were trivial in all. Mild-to-moderate tricuspid regurgitation was observed in five patients and there was a correlation between the grades of tricuspid regurgitation and pulmonary/systemic peak pressure ratio (r = .757, p less than .05). This method appears to be advantageous in preventing postoperative mitral regurgitation with low operative mortality. However, tricuspid regurgitation was not well avoided among the patients with persisting pulmonary hypertension.