A Surgical Case of Severe Aortic Valve Calcification Complicated by X-linked Hypophosphatemic Osteomalacia

Abstract

A 34-year-old woman had received a diagnosis of X-linked hypophosphatemic osteomalacia when she was born. As an adult she complained of general fatigue, palpitations dyspnea exertional and leg edema. Transthoracic echocardiography showed aortic stenosis and regurgitation with severe aortic valve calcification. Chest computed tomography revealed her ascending aorta to be circumferentially calcified. Surgery was performed through a median sternotomy via cardiopulmonary bypass, with perfusion from the right subclavian artery and the right femoral artery and drainage from the superior and the inferior venae cavae. A left ventricular venting cannula was inserted from the right superior pulmonary vein. When her bladder temperature had dropped to 28°C by central cooling, we stopped the perfusion from the right femoral artery and performed aortotomy. We examined the lumen and clamped the aorta at the usual site, while flushing with blood by femoral perfusion. Aortic valve calcification was observed to extend from the sinus of valsalva to the outflow tract of the left ventricle on the non-coronary cusp side. He was necessary to repair the aortic annulus due to a defect resulting from careful removal of the calcified valve. We then performed aortic valve replacement using a 19-mm Carpentier-Edwards perimount Magna. Her postoperative course was uneventful without any sign of neurological complications, and she was discharged 13 days after surgery. On pathological examination, localized ossification with calcification was observed in her aortic valve which seemed to be characteristic of X-linked hypophosphatemic osteomalacia.