A case report: Carpentier-Edwards porcine bioprosthesis malfunction due to the stent dehiscence at 17 years after the implantation in the mitral position

A 53-year-old female had undergone mitral valve replacement with Carpentier-Edwards (C-E) porcine bioprosthesis for mitral valve regurgitation at the other hospital in November, 1981. Postoperative clinical course was uneventful, since she was referred from the other hospital in 1990. In December, 1997, she had sudden complaint of shortness of breath on effort, and the chest X-ray showed pulmonary congestion and increase of cardio-thoracic ratio. Echocardiography and catheterization revealed severe mitral regurgitation due to bioprosthesis malfunction and aortic valve regurgitation. Combined mitral and aortic valve replacement was successfully performed with mechanical valves in February, 1998. The explanted C-E porcine bioprosthesis showed the commissural dehiscence from only one of the three stents without any leaflet perforation, commissural tear, pannus overgrowth, impaired leaflet mobility and leaflet deterioration or calcification. This case suggested the variety of malfunction of C-E porcine bioprosthesis and the limitation of its long-term durability.