Early degeneration of porcine xenograft valves in pediatric patients who have undergone apico-aortic bypass.

The glutaraldehyde-preserved stented porcine xenograft valve has been durable in adult patients with a low incidence of valve-related complications. In children, however, early degeneration and calcification of this valve is now being reported. The etiology of the early degeneration is still unclear but may be related to calcium metabolism, tissue fatigue, and host rejection. During the last 5 years at the Texas Heart Institute, 21 patients under 23 years of age underwent implantation of an apico-aortic conduit containing a porcine xenograft valve for treatment of severe forms of left ventricular outflow tract obstruction. Because of early failure, the valve was replaced in two patients (11.5%) within 3 years of implantation. Although early degeneration of the porcine valve might occur in some children, it may still be the preferred valve to use in young patients because anticoagulation is not required with its use.