AORTIC VALVE RE-REPLACEMENT USING A NOVEL TWO-PIECE BIOPROSTHESIS IN A CALF MODEL

Abstract

Purpose: To evaluate the feasibility of using a prototype two-piece bioprosthetic valve with a detachable sewing ring for aortic re-replacement in a calf model. Methods: Using a proprietary surgical technique, we implanted a prototype two-piece bioprosthetic aortic valve in a 76-kg juvenile calf with the aid of cardiopulmonary bypass. Five months post aortic valve replacement, a second surgery was performed and one valve component (the prosthetic aortic leaflets) was removed from the second valve component (the detachable sewing ring), which was left attached to the native aortic annulus. New prosthetic aortic leaflets were then attached using the same proprietary technique. Results: After both procedures, the calf recovered uneventfully. During the 5 months between operations, he gained 80 kg. Renal, hepatic and hematologic data were within normal limits. On postoperative day 5 after the second operation, the animal was electively killed according to the study protocol. Conclusion: The prototype two-piece bioprosthetic valve with the detachable sewing ring permitted easy and quick re-replacement of the prosthetic aortic valve leaflets without removal of the original sewing ring from the native aortic valve annulus. This experience proves that replacement of an aortic valve prosthesis in the bovine model is safe and feasible. This finding may contribute to more rigorous requirements for in situ animal valve testing.