Thymectomy for myasthenia gravis.

Between 1951 and 1971 thymectomy was performed on 41 patients with myasthenia gravis. They were selected from a total group of 95 myasthenic patients receiving anticholinesterase therapy. The criteria for selecting patients for thymectomy and the assessment of their progress after operation are described. All the patients have been examined by us at intervals and the results of this follow-up are presented. The survey has shown that substantial improvement after thymectomy occurred in 21 patients (group A), seven of whom had complete remissions without medication for periods of up to 12 years after operation. Considerable benefit from the operation was also observed in seven patients (group B); although their response was less spectacular, in that their daily requirement of anticholinesterase drugs was not changed, their functional activities were significantly enhanced. The most favourable results were seen in female patients aged 15 to 40 years, six of whom had one or more successful pregnancies. Thymectomy did not improve the general condition or progress of six patients (group C). There were three deaths within 16 days of operation, and two patients died within one year. Eight patients survived for periods of 3 to 16 years; six of these died from causes other than directly from myasthenia, and two died at home without established cause.