[Concomitant Operations for Thoracic Aortic Aneurysm and Myasthenia Gravis;Report of a Case].

A 77-year-old man, who had been under medical treatment for myasthenia gravis without thymoma, was diagnosed with aortic arch aneurysm. He underwent total aortic arch replacement and total resection of the thymus through median sternotomy. His symptoms relating to myasthenia gravis dramatically disappeared after the surgery. The serum anti-acetyl chorine receptor antibody decreased from 2.7 to 0.7 nmol/l (N<0.2) with the reduction of oral predonisolone from 12.5 to 5 mg/day at 4 years after the surgery. The concomitant operations significantly improved his quality of life.