Severe intermittent intraprosthetic regurgitation after mitral valve replacement with subvalvular preservation.

Preservation of the subvalvular apparatus during mitral valve replacement preserves left ventricular function and improves long-term survival. Complications of subvalvular preservation include left ventricular outflow tract obstruction and prosthesis impingement. We report a case of severe intermittent intraprosthetic mitral regurgitation detected by transesophageal echocardiography after mitral valve replacement by a bileaflet mechanical prosthesis with subvalvular preservation. Intravalvular prosthetic valve regurgitation was caused by remnants of the subvalvular apparatus, which were shown at reoperation to interfere with prosthetic leaflet motion and which were excised. Postoperative transesophageal echocardiography showed neither abnormal mitral regurgitation nor residual mass. The use of intraoperative transesophageal echocardiography could enable the detection of this rare complication.