Evaluation of results of thymectomy in myasthenia gravis

The results of thymectomy carried out in 150 cases of myasthenia gravis are discussed. In a group of 123 cases followed for 1 to 5 years after the operation, full remission was observed in 24.4% of cases, significant improvement in 36.6%, slight improvement in 24.4% and no improvement in 8.1%, while deterioration occurred in 1.6% of patients. No correlation was found between the result of the operation and the age and sex of patients, but better results were achieved in those treated surgically rather soon after the onset of symptoms. This correlation was particularly evident in the group with full remissions. The results obtained in the cases without thymic tumors were better than in the cases with tumors. No correlation was noted between the results of the operation and the histological characteristics of the thymus in the group with thymic hyperplasia and in the group with thymic atrophy. The surgically treated group (150 cases), compared with the conservatively treated group (75 cases), showed the superiority of the surgical method (lower rate of death and deterioration, higher rate of improvement and remission). In discussing the indications for surgical treatment the authors emphasize that advances in anaesthesiology in recent years have reduced the risk of operation. It is suggested that the indications for surgical treatment should be expanded and operations should be performed as early as possible after the onset of clinical manifestations without regard to the age and sex of the patient. Operation should not be considered in cases belonging to group 1, 2a (sometimes 2b) only, with duration of the disease over 8-10 years and with little or no progression of the process, if the presence of a thymic tumor has been excluded.