Thymectomy in myasthenia gravis. Results of 662 cases operated upon in 15 years.

Abstract

The results of thymectomy in the treatment of myasthenia gravis (MG) are reviewed in the light of a personal series of 662 MG patients, operated upon during the last 15 years. In 500 MG patients without thymoma, the following results have been achieved: remission 37.9%, improvement 49.4%, unchanged or worse 7.4%, dead 5.2%. There is no sex prevalence and the remission rate is higher in patients under 40 years of age (P less than 0.01), with mild disease (P less than 0.05), with a MG duration of less than 1 year (P less than 0.05) and with a follow-up length of between 5 and 10 years (P less than 0.01). No correlations are found between outcome and thymic histology. The results of 162 MG patients with thymoma are: remission rate 15.7%, improvement 60.3%, unchanged or worse 3.7% and dead 20.1%. The remission rate is higher with mild symptoms (P less than 0.05) and when the tumour is encapsulated (P less than 0.02). The postoperative mortality is 0.8% (none in the last 5 years) for non-thymomatous MG and 4.9% for thymomatous MG (2 of 8 patients died of pancytopaenia and 1 of pulmonary embolism).