Factors predicting surgical outcome of thymectomy in myasthenia gravis: A 16-year experience

AIM: To assess the surgical outcome of myasthenia gravis (MG) following thymectomy and to determine the outcome predictors to such therapeutic approach. MATERIALS AND METHODS: This study is a retrospective review of 80 consecutive thymectomies performed for MG over a 16-year period. RESULTS: There were 41 females and 39 males (mean age, 34.32 years) with mean disease duration of 17.45 months prior to surgery. Stagewise distribution of the patients revealed 2.5% in stage I, 48.7% in stage IIA, 33.8% in stage IIB, 8.7% in stage III, and 6.3% in stage IV. The surgical approach was either trans-sternal (n=67) or video-assisted thoracoscopic route (n=13). Follow-up was obtained in 91.2% (n=73) of patients with mean duration of 67.7 months. At their last follow-up, 26.0% were in complete remission, 35.6% were asymptomatic on decreased medications, and 17.8% had clinical improvement on decreased medications. Overall, 79.4% of patients benefited from surgery, 8.2% had unchanged disease status, and 12.3% worsened clinically. Factors influencing favorable outcome include sex, disease stage, gland weight, and preoperative medication with anti-cholinesterase (P<0.05). There was one death in the perioperative period due to septicemia. Two patients died at fourth and seventh month following thymectomy. CONCLUSION: Thymectomy for MG is safe and effective. Certain influencing factors may shape treatment decisions and target higher risk patients.