Repeated mitral valve replacement in a patient with extensive annular calcification

A 47-year-old lady had undergone mitral valve replacement (Starr-Edwards 6320; Edwards Lifesciences, Irvine, CA, USA) with concomitant aortic valve replacement (Bjork-Shiley; Pfizer, New York City, NY, USA) for rheumatic disease at our hospital 27 years before. On this occasion the patient developed dyspnea with New York Heart Association (NYHA) functional class II and was admitted for surgery. The chest X ray showed marked left atrial dilatation with the cardiothoracic ratio being 73% (Figure 1). The echocardiography showed that the mitral valve area measured by the pressure half time method was 1.4 cm² and that the transvalvular gradient through the aortic prosthesis was 78 mmHg. The radiography demonstrated severe mitral annular calcification extending on to the left ventricle (Figure 2). Both the mitral and aortic valve prostheses were considered to have dysfunction, therefore, replacement of the both valves was scheduled. At operation, through redo median sternotomy and right side left atriotomy, the mitral prosthesis was examined. It was evident that the calcification of the left ventricle leading to the papillary muscles was obstructing the disc motion (Figure 3). The mitral prosthesis, which had no structural defect, was removed (Figure 4) and then the aortic valve prosthesis was examined both through the aortotomy and through the left ventricle with the help of an endoscope. The aortic valve prosthesis did not have any disorder and it was left untouched. The posterior mitral annular calcification looking like a base rock was thoroughly debrided and a 27 mm mechanical valve (St Jude Medical, St Paul, MN, USA) was implanted in a paraannular position. Postoperatively transesophageal echocardiography (TEE) showed paravalvular leak and the patient developed hemolytic anemia with elevated serum lactate dehydrogenase, bilirubin and aspartate transaminase levels. Therefore, it was decided to redo the operation and a prosthesis with a heavier sewing cuff (MIRA; Edwards Lifesciences) was used this time. This reoperation was performed three days after the previous operation. A crack was found in the posterior part of the mitral annulus, and, after more aggressive debridement, a 25 mm MIRA valve was implanted in a paraannular position. Postoperatively TEE initially showed no paravalvular leak. However, a head CT demonstrated a small cerebral hemorrhage. Five days after the second operation, TEE revealed recurrent paravalvular leak which gradually worsened, and again hemolysis developed. Fourteen days after the second operation, when it was ascertained that the cerebral hemorrhage was improving, a reoperation was performed for the third time. A crack was observed at the same point in the posterior annulus and an ultrasonic aspirating device was used for further decalcification. It was concluded that the left ventricular pressure was elevated because of the pressure gradient produced by the aortic valve prosthesis. Hence a 27 mm tissue valve (Carpentier-Edwards Perimount; Edwards Lifesciences) was selected despite her age with the expectation that the risk of hemolysis would be reduced. Two equine pericardial patches were used, one on the posterior aspect of the mitral annulus for better fitting of the prosthesis (Figure 5), and the other fashioned as a collar around the prosthesis (Figure 6) to reduce paravalvular leak (Figure 7). Postoperatively TEE showed no paravalvular leak and the patient was discharged home 96 days following the procedure. At 7 years postoperatively, she has been doing well in NYHA functional class I without any evidence of paravalvular leak or structural valve deterioration.