Purpose: To clarify the factors that influence improvement and remission after thymectomy for patients with nonthymomatous myasthenia gravis (MG).
Methods: We retrospectively reviewed 204 patients with nonthymomatous MG who underwent thymectomy and anterior mediastinal dissection through a partial median sternotomy, between 1980 and 2001, and examined whether age, sex, preoperative classification, and duration of symptoms influenced their prognosis.
Results: There was no perioperative or hospital mortality. The mean follow-up period was 7.2 +/- 1.2 years, with early and late postoperative remission rates of 44.6% and 73%, respectively. Seven patients died; two from pneumonia and five from causes unrelated to MG. Preoperative treatment and classification, duration of symptoms, age, and sex did not seem to have a significant influence on remission, but the response to thymectomy was greater in patients with thymic hyperplasia. Remission and improvement rates were significantly better at the end of the first year, with the same status found at the last follow-up.
Conclusion: Thymectomy is an effective and highly curative method of treatment for patients. with MG. It provides excellent symptomatic improvement, which is enhanced over the long term.