Minimally invasive cardiac surgery in a patient with osteopetrosis and symptomatic mitral regurgitation.

Osteopetrosis is a rare hereditary bone development disorder caused by osteoclast dysfunction, which increases bone density. Although few studies have investigated cardiovascular disease in osteopetrosis, sternotomy outcomes in this condition are unclear. We report the case of a patient with osteopetrosis and severe mitral regurgitation. A 63-year-old woman with exertional dyspnea had regurgitant systolic murmur audible at the apex. Transthoracic echocardiography showed severe mitral regurgitation due to posterior leaflet prolapse on the anterolateral side. Radiological findings revealed increased bone density (consistent with osteopetrosis). Considering risks in median sternotomy, we performed minimally invasive cardiac surgery through right minithoracotomy for mitral regurgitation. Preoperative imaging showed sclerotic rib changes; nevertheless, sufficient surgical views obtained involved the intercostal space. No residual mitral regurgitation was observed, and the postoperative course was good. To the best of our knowledge, this is the first case report on minimally invasive cardiac surgery for mitral regurgitation with osteopetrosis.