Surgical Treatment of Left Atrioventricular Fistula due to Mitral Annular Abscess after Mitral Valve Replacement for Active Endocarditis

Mitral valve annular abscess with fistula is a life-threatening complication of mitral valve endocarditis. Surgical treatment is yet to be established, and operative mortality rate remains high. In the present case, severe mitral regurgitation due to left ventricular atrium fistula was diagnosed using echocardiography 3 months after the patient underwent mitral valve replacement for active mitral valve endocarditis. The fistula was found at the posterior site of the mitral valve annulus. Severe destruction of the annulus had caused the prosthetic valve to become unstable. Surgical procedures involved resection of weakened tissue of the annulus, fistula closure with a bovine pericardial patch using 5-0 Prolene suture, and mitral valve re-replacement. The postoperative course was good, without any complication. This case report demonstrates that patch closure using a bovine patch and re-replacement of the mitral valve was feasible for the rare mitral valve annulus complication.