The outcome of thymectomy in nonthymomatous myasthenia gravis.

From October 1979 to December 1984, 77 patients with nonthymomatous myasthenia gravis underwent thymectomy and 74 patients were available for careful follow-up study in this review. Among these 74 patients, 18 were male and 56, female. Their ages ranged from 13 to 68 years with an average age of 30.2 years. Men tend to be affected at a later age than women (an average age of 38.0 versus 26.1 years). Duration of the disease was from one to 30 years, with an average of 4.2 years. A sternal-splitting incision was performed for all patients. Thymectomy was made by removal of all anterior mediastinal fat between the pleuropericardial reflection and phrenic nerve bilaterally. Seventy of the 74 patients benefited from thymectomy. Of these, 34 patients had remission and 36 patients had substantial improvement; three patients did not improve after thymectomy but did not increase in severity of symptoms or medication requirement. There was no postoperative death. Myasthenic crisis developed in four patients and five patients had pulmonary complications. These nine patients were among the 21 patients who did not receive either plasmapheresis preoperatively or a high dose of steroids perioperatively. Early thymectomy is recommended for patients with nonthymomatous myasthenia gravis. We also recommend that patients undergoing thymectomy should be treated either with plasmapheresis preoperatively or with high doses of steroid perioperatively.