Long-Term Outcomes after Thymectomy for Myasthenia Gravis
Chawalit Wongbuddha MD1, Rachata Mala MD1, Chalach Mitrprachapranee MD1, Thiti Chanmeka MD1, Chanaya Karunasumetra MD1, Sompop Prathanee MD1
Affiliation : 1 Division of Cardiovascular and Thoracic Surgery, Department of Surgery, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand
Objective : To investigate the long-term clinical outcomes, including complete remission rate, and the prognostic factors after
thymectomy in patients with myasthenia gravis.
Materials and Methods: A total of 183 patients with generalised myasthenia gravis who underwent thymectomy from
January 1993 to December 2013 were retrospectively reviewed. Of these, 113 patients had complete follow-up for more
than 10 years that could be enrolled for long term complete stable remission rate analysis. 42 cases (23%) were male patients
and 141 cases (77%) were female patients. Preoperative and postoperative patient evaluations were based on MGFA
classification, including complete stable remission, minimal manifestation, improved, unchanged and worsening. Complete
remission was defined as the patient being asymptomatic with normal strength without medication at a 10-year follow-up.
Results : Trans-sternal thymectomy was performed in 94% of patients. Histological analysis revealed 62% of patients had
thymic hyperplasia and 14% of patients had thymoma. According to MGFA postoperative statuses, complete stable
remission was presented in 47.5%, minimal manifestation in 12%, improved in 31%, unchanged in 5.5%, and worsening in
1.6%. The complete stable remission rate at a 10-year follow-up was 51%. There were no significant prognosis factors for
complete stable remission.
Conclusion : Trans-sternal thymectomy is an effective modality of treatment which is associated with highly complete
stable long term remission rates for patients with generalized myasthenia gravis.
Keywords : Generalized myasthenia gravis, Thymectomy, Complete stable remission rate
