Reoperation after mitral valve repair in viewpoints of kidney injury as well as hemolytic anemia.

A 70-year-old woman developed anemia and kidney injury 10 months after mitral valve (MV) repair. Serological findings and Doppler echocardiography suggested hemolytic anemia due to mitral regurgitation jet collision with an annuloplasty ring (MRCR). Since kidney injury persisted even without exacerbation of anemia over 10 months, we performed an MV replacement. The anemia improved rapidly after the surgery; however, the renal function remained chronic kidney disease (CKD) after reoperation. Kidney injury was thought to be due to iron deposition and decreased renal perfusion that caused tubular injury. A comprehensive literature review shows that hemolysis due to MRCR in the early postoperative phase (within 3 postoperative months) can be often ameliorated with endothelialization without the need for reoperation; however, hemolysis in the late postoperative phase can persist even for a long period without reoperation. Chronic hemolysis can lead to kidney injury and progress to CKD even without clinical evidence of exacerbation of anemia. Therefore, in cases of late postoperative phase hemolysis, reoperation should be considered for better management of kidney injury and hemolytic anemia.