Comparison of complete remission rates after 5 year follow-up of three different techniques of thymectomy for myasthenia gravis☆

Abstract

OBJECTIVE: This study aims to analyse the effectiveness of treatment of myasthenia gravis with three different techniques of thymectomy. METHODS: Results of complete remission rates after 5-year follow-up of 60 patients who underwent basic transsternal thymectomies (group A) from 1 January 1996 to 31 December 1997, 75 patients who underwent extended transsternal thymectomies (group B) from 1 January 1998 to 30 June 2000 and 291 patients who underwent transcervical-subxiphoid-videothoracoscopic 'maximal' thymectomy (group C) from 1 September 2000 to 31 January 2009 were compared. RESULTS: There were no differences between groups according to patient's characteristics and postoperative complications' rate. Ectopic foci of the thymic tissue were discovered in the fat of the neck and the mediastinum in 53.9% of patients from the group B and in 65.9% patients from the group C. After 1, 2, 3, 4 and 5 years of follow-up, complete remission rates were 8.3%, 11.7%, 15.0%, 16.7% and 20.0%, respectively, in group A; 26.7%, 38.7%, 42.7%, 46.7% and 50.7%, respectively, in group B; and 31.5%, 39%, 45.8%, 46.3% and 53.1%, respectively, in group C. The differences between group A and the groups B and C after 1, 2, 3, 4 and 5 years were statistically significant. There were no significant differences between groups B and C. CONCLUSIONS: (1) The results of complete remission rates after 5-year follow-up were statistically better in patients with myasthenia gravis (MG), who were operated on with extended transsternal thymectomy and transcervical-subxiphoid-videothoracoscopic 'maximal' thymectomy than the patients who underwent basic transsternal thymectomy. (2) The difference can be explained by the removal of ectopic foci of the thymic tissue from the neck and the mediastinum in these patients.