透析患者における僧帽弁位生体弁の早期構造的弁劣化

Early Structural Valve Deterioration of Bioprosthetic Mitral Valve in a Dialysis Patient

透析患者に対する人工弁の選択は，機械弁では抗凝固療法による出血性合併症，生体弁では早期石灰化による構造的弁劣化（structural valve deterioration：SVD）の問題があり，現在も議論のあるところである．生体弁による僧帽弁置換術（mitral valve replacement：MVR）後に早期SVDを呈し，再手術として機械弁によるMVRを行ったものの早期に脳出血をきたした症例を報告する．

Choice of prosthetic valve during valve replacement in dialysis patients is still controversial. There is a known risk of early structural valve deterioration of bioprosthesis in dialysis patients, whereas mechanical prosthesis is associated with a higher risk of bleeding and thrombotic events.

A 68-year-old dialysis-dependent woman, who had undergone bioprosthetic mitral valve replacement at the age of 66, was admitted to our hospital because of general malaise and hypotension during dialysis. Echocardiography revealed severe mitral stenosis and regurgitation due to restricted motion and dense calcification in prosthetic valve leaflets, which indicated early structural valve deterioration. Redo mitral valve replacement using a mechanical valve was performed, and the patient gradually recovered. However, she eventually died of intracranial hemorrhage three months after the surgery.