Aneurysm of a right-sided descending thoracic aorta with a left-sided aortic arch and aberrant right subclavian artery.

We describe a rare case of an arteriosclerotic aneurysm in the right-sided descending thoracic aorta with a left-sided aortic arch and concomitant aberrant right subclavian artery. A 76-year-old woman, who was found to have an aneurysm of the right-sided descending thoracic aorta, was referred to our hospital for surgical treatment. Contrast computed tomography scan revealed a left-sided aortic arch with an aberrant right subclavian artery, a descending thoracic aorta passing downward behind the esophagus, and an aneurysm of the right-sided and distal (level between the 8th and 10th vertebral bodies) descending thoracic aorta. With a right posterolateral thoracotomy, the patient underwent descending thoracic aorta replacement using an 18-mm woven Dacron prosthesis. The patient had an uneventful postoperative course and was discharged 24 days after surgery. Histological microscopic examination of the resected aneurysmal wall revealed an arteriosclerotic aneurysm. The postoperative computed tomography scan 18 days after surgery revealed no anastomotic aneurysm or abnormal fluid collection.