Systemic atrioventricular conduit for extracardiac bypass of hypoplastic systemic atrioventricular valve

The management of severe congenital mitral stenosis in infants andchildren is still controversial. We describe our experience with the use ofa systemic atrioventricular (SAV) extracardiac conduit to bypass ahypoplastic systemic atrioventricular valve. An SAV extracardiac conduithas been used in six patients (left atrium--left ventricle in five, rightatrium--right ventricle in one). One hospital death occurred due tomediastinitis and there were two late deaths, one due to progressivesubaortic stenosis and one sudden, possibly due to arrhythmia.Postoperative cardiac catheterization performed in five patients showedreduction of the transmitral gradient from a mean of 16 mmHg to a mean of 5mmHg. Calcification of the bioprosthetic valve occurred in two patients 31/2 years and 2 years respectively after the operation; one died fromconcomitant subaortic stenosis and one underwent conduit replacement.Although its long-term efficacy is limited, the SAV conduit seems the mostreliable surgical option for infants and children with hypoplastic systemicatrioventricular valves unsuited to conventional surgery.