Thymectomy after Plasmapheresis in Myasthenia Gravis: Results of Long Term Follow up


1 Department of Surgery, Shohada-E-Tajrish Medical Center,

2 Department of Surgery, Shohada-E-Tajrish Medical Center

3 Department of Epidemiology, Shaheed Beheshti University of Medical Sciences and Health Services, TEHRAN- IRAN


Background: Myasthenia gravis is the most common disorder of neuromuscular junction and several treatment modalities have been described for its management. Thymectomy has been employed as a treatment modality for several years. Plasmapheresis has also been supposed as an adjunct to thymectomy in several articles. In this study, we describe long-term results of thymectomy after plasmapheresis in myasthenic patients operated on in Shohada-e-Tajrish medical center from March 1996 to March 2001. Materials and Methods: Information related to patients was obtained from medical records. All 46 patients underwent plasmapheresis before thymectomy and were transferred to ICU (intensive care unit) postoperatively. The surgical approach in all patients was median sternotomy and complete removal of thymus gland. Long term results of surgery were obtained via calling the patients. By this manner 31 of 46 patients were followed up. Results: Forty-six patients including 36 women (78.3%) and 10 men (21.7%) with the mean age of 25.6±11.8 years were operated on in this period of time. The mean duration of symptoms was 15.7 months before the surgery. No postoperative mortality was seen. Five patients (10.9%) developed postoperative myasthenic crisis which was minimal in 4 of them. The mean duration of ICU stay was 18.9 hours. Thirtyone of 46 patients were followed up with a mean duration of 7. 7 years. Twelve patients (38.7%) had complete remission without using any drug. Twelve patients (38.7%) had significant improvement via decreasing the drug dosage necessary to control their symptoms. Two patients (6.4%) had no change in their disease status after the operation and in 1 patient (3.2%) with thymic pathology of invasive thymoma, the disease worsened. Four patients (12.9%) had disease recurrence after a period of complete remission. Result of operation was more satisfactory in patients younger than 30 years (p <0.05%). Thymic hyperplasia foresees more favorable outcome compared to other thymic pathologies. The mean duration of time necessary to reach final results was 19.6 months. Conclusion: As a result of this study, thymectomy seems to be a successful treatment modality in myasthenic patients and should be performed as soon as possible during the disease course. Besides, plasmapheresis has a significant role in decreasing the complications and improving the results of thymectomy in myasthenic patients and long term follow up is necessary for accurate evaluation of final results of operation. (Tanaffos 2007; 6(1): 23-28)