Thymectomy: its role in the management of myasthenia gravis

The management and clinical course of patients with myasthenia gravis admitted to a neurological intensive therapy unit (ITU) for thymectomy over a 66 month period were reviewed. There were 53 patients, 20 male and 33 female, mean age 35.2 years (18-74) and median ITU stay of 5 days (2-30). Indications for thymectomy were thymic enlargement on computed tomography (34%), persistence of generalized symptoms (38%), a combination of both (20%), steroid side effects or dependency (4%) and progressive bulbar symptoms (4%). Following thymectomy, thymic histology revealed thymic follicular hyperplasia (26/53; 49%), atrophy (11/53; 21%), thymoma (12/53; 23%) and normal thymus (4/53; 8%). Post-operatively 23% required prolonged intubation (> 48 hrs); two patients required a tracheostomy 10 and 13 days post-operatively. Plasma exchange was required for two patients (3.8%) due to persistent severe myasthenic weakness. Three patients (6%) developed a post-operative chest infection and one pseudomembranous colitis. There were no post-operative mortalities during the study period. After 2 years, 35% of patients were in remission and 46% had ocular or mild generalized symptoms only. Thymectomy for myasthenia gravis is followed by sustained clinical improvement in the majority of patients. The appropriate post-operative management of these patients is best undertaken setting in a specialized neuro-intensive care setting. (C) 1998 Rapid Science Ltd.