Surgical Treatment of Myasthenia Gravis

중증 근무력증의 외과적 치료

Myasthenia gravis is a functional neuromuscular disorder with characteristic voluntary muscle weakness. The role of thymus in pathogenesis of this disorder has become apparent that thymectomy in treatment has gained acceptance. Between January 1976 and June 1987, twenty patients underwent thymectomy for myasthenia gravis at the Department of Thoracic and Cardiovascular Surgery, College of Medicine, Korea University. A clinical study that is focused on the factors affecting the operative results was analyzed and the following results were obtained. Among the 20 patients, male to female ratio was 8:12 and the age of onset was ranged from 3 years to 67 years. The chief complaints in order of frequency were as follows; ocular symptoms such as ptosis and diplopia[7 cases], general weakness[4 cases], swallowing difficulty[3 cases], dyspnea[3 cases], dysphasia[1 case], headache[1 case] and dizziness[1 case]. The severity of disease was classified by modified Osserman`s method that Group IIa was 8 cases, Group IIb; 7 cases, Group IIc; 3 cases and Group I; 2 cases. In histopathology of thymus, the most frequent finding was hyperplasia[11 cases] followed by thymoma[4 cases], normal tissue[3 cases] and malignant` thymoma[2 cases]. There were two cases of postoperative complications; one case was wound infection and the other was mediastinitis. One case of malignant thymoma died due to respiratory failure with pulmonary metastasis. There was 16 cases[80%] of improvement after thymectomy as follows; complete remission was 4 cases[20%], marked improvement was 9 cases[45%] and subjective improvement only was 3 cases[15%]. The effect of severity and duration of disease on operative result has statistically significant. The effect of thymus histopathology on operative result was not statistically significant. But there were comparable results between thymoma cases and non-thymoma cases.