右胸腔を占拠し呼吸困難を呈した巨大上行大動脈瘤

Surgical Repair of a Giant Ascending Aortic Aneurysm Occupying the Right Thoracic Cavity and Presenting With Dyspnea

胸部大動脈瘤の多くは無症候性であるが，周辺組織への圧迫症状で診断されることもある．われわれは右胸腔を占拠して呼吸困難を呈した巨大上行大動脈瘤の手術を経験したので報告する．

We report a surgical case of giant ascending aortic aneurysm presenting with dyspnea due to compression of the right thoracic cavity. A 58-year-old man was referred after computed tomography （CT） revealed a large intrathoracic lesion. Contrast-enhanced CT demonstrated a 14.8×18.5 cm dissecting aneurysm of the ascending aorta and arch with severe aortic regurgitation, superior vena cava obstruction, occlusion of the right pulmonary artery and vein, and extensive right lung atelectasis. Because both safe median sternotomy and conventional venous drainage were difficult, cardiopulmonary bypass was established through the femoral vessels before sternotomy, with additional adjustments for venous drainage and left ventricular venting. Bentall procedure and partial arch replacement were successfully performed. Postoperative recovery was prolonged, likely because of the long-standing compressive effects of the aneurysm. CT at 1 year still showed superior vena cava and right pulmonary venous obstruction, with persistent right lung collapse.