ABSTRACT
A 63-year-old woman presented with pseudoaneurysm formation due to rupture of the porcine aortic wall of the stentless bioprosthesis. She had undergone aortic root replacement using the full root technique with the 25-mm Prima Plus bioprosthesis for annuloaortic ectasia. Congestive heart failure, appearing 65 months after the first surgery, progressed rapidly. Multidetector computed tomography (CT) showed a pseudoaneurysm of the aortic root, and echocardiography revealed severe mitral regurgitation. At reoperation, a large pseudoaneurysm with a 20-mm horizontal tear was seen in the non-coronary sinus of the Prima Plus valve. A repeat aortic root replacement and mitral valve replacement with two mechanical valves were performed. The patient had an uneventful recovery. Histologic examination of the explanted porcine aortic root showed host mononuclear cells and macrophages between the well-stained and poorly stained areas, suggesting that the torn tissue had undergone host-mediated degeneration to some extent. Porcine aortic roots have excellent hemodynamic features, but ruptures in the aortic sinuses of the porcine aortic root have been reported in some cases. Careful follow up with CT or echocardiography is therefore needed after aortic root replacement with stentless bioprostheses.