Analysis of thymoma excision in patients with myasthenia gravis

Objective. To study the clinical characteristics of myasthenia gravis (MG) with thymoma and the effect of tracheostomy at the early stage after operation. Methods. Thymoma excision and selective tracheostomy were performed on 46 patients with MG from March 1983 to December 1994. Results. There were 15 patients with benign thymomas and 31 patients with malignant thymomas. MG crises were seen in 52.2% of patients postoperatively, most in type II and III. The mortality of in-patients after operation was 10.9%. Thirty-nine patients with thymoma were followed up for 6 months to 12 years after being discharged from hospital. The MG symptoms were relieved in 33.3%, improved in 20.5% and unchanged in 2.6% of patients. 38.5% of patients died of the disease. Conclusion. The characteristics of MG with thymoma are: more severe condition of the patient, rapid advance, and more MG crises before and after operation. The perioperative mortality from MG with thymoma is higher and its prognosis is unfavourable. It is very important to treat severe cases of MG with thymoma by tracheostomy with thymoma excision at the early stage after the operation. This is an effective method to prevent and treat MG crises as well as to lower the perioperative mortality.