Myasthenia gravis: effect of thymectomy in 425 patients. A 15-year experience.

We report 425 myasthenic patients who underwent thymectomy during the last 15 years. The authors analyse the results of thymectomy in separate groups, including thymomas (12.7%), childhood myasthenia (9.4%) and combined cases (12.4%). They evaluate the results according to the Disability Status Scale based on a points system. Three series were evaluated: patients operated upon between 1972-1977, 1977-1982 and 1982-1987. Although the results in all three series were good, there has been steady improvement over the years. Childhood myasthenia gravis gave the best results but thymectomy was beneficial in the combined (immunological) group, in long-lasting myasthenia and in thymomas. Factors influencing the results of thymectomy were patients' age, time interval between onset of disease and thymectomy, resistence to therapy and thymic tumour. Thymic activity as reflected in germinal centres can also influence the results: the more active the thymus, the better the results.