Video-assisted thoracic surgery thymectomy for nonthymomatous myasthenia gravis

STUDY OBJECTIVES: Minimal-access thymectomy has become increasingly popular as surgical treatment for patients with nonthymomatous myasthenia gravis (NTMG) because of its comparable efficacy, safety, and lesser degree of tissue trauma compared with conventional open surgery. We reviewed and analyzed our data on video-assisted thoracic surgery (VATS) thymectomy and present the clinical outcomes according to the Myasthenia Gravis Foundation of America classification. DESIGN: A retrospective review of VATS thymectomy for NTMG in a university hospital over a 12-year period. Data were collected from the medical records and supplemented with telephone surveys. The impact of surgery and other variables potentially affecting complete stable remission (CSR) were calculated using Kaplan-Meier survival curves; comparisons between survival curves was performed using the log-rank test. RESULTS: A total of 38 consecutive patients underwent VATS thymectomy for NTMG. Median postoperative stay was 3 days. Pathologic examination revealed thymic hyperplasia in 61.1% of cases, normal thymus in 22.2%, and thymic atrophy in 16.6%. There was no perioperative mortality; complications occurred in four patients. After a median follow-up of 69 months, 91.6% of patients experienced improvement, with crude CSR achieved in 22.2%. Kaplan-Meier survival curve demonstrated a 75% CSR rate at 10-year follow-up. On univariate analysis, only disease duration < or = 12 months (p = 0.03) was associated with a statistically significant improvement in CSR. CONCLUSIONS: VATS thymectomy for NTMG results in symptomatic improvement in the vast majority of patients, with a high rate of CSR. The procedure is associated with low morbidity and no perioperative mortality. Future studies on thymectomy for myasthenia gravis should be reported in a standardized manner to allow accurate comparisons between results in the absence of randomized prospective trials.