Ten-year Results of Thoracoscopic Unilateral Extended Thymectomy Performed in Nonthymomatous Myasthenia Gravis

Objective: The aim of this study was to analyze the 10-year results of thoracoscopic unilateral extended thymectomy (TUET) performed in nontumoral myasthenia gravis according to the Myasthenia Gravis Foundation of America recommendations.

Background Data: Thoracoscopic unilateral extended thymectomy has the benefits of a minimally invasive approach. Previous data have shown promising midterm results but long-term results were lacking.

Methods: Two hundred forty patients with nontumoral myasthenia gravis who underwent surgery between 1999 and 2009 were eligible for the study. The mean follow-up was of 67 months (range: 12-125), 134 patients completed follow-up assessments more than 60 months after TUET.

Results: There were 39 males (16.3%) and 201 females (83.7%), with an age range from 8 to 60 years. The mean preoperative disease duration was 21.5 months. All patients underwent preoperative steroid therapy. Anticholinesterase drugs were required for 123 patients (51.3%), and immunosuppressive drugs were required for 87 (36.3%) patients. The pathologic findings were as follows: normal thymus in 13 patients (5.5%), involuted thymus in 65 patients (27%), and hyperplastic thymus in 162 patients (67.5%). The average weight of the thymus was 110 ± 45 g. Ectopic thymic tissue was found in 147 patients (61.3%). There was no mortality, and morbidity consisted of 12 patients (5%). Complete stable remission was achieved in 61% of the patients, and the cumulative probability of achieving complete stable remission was 0.88 at 10 years.

Conclusions: With zero mortality, low morbidity, and comparable long-term results to open surgery, TUET can be regarded as the best treatment option for patients undergoing surgery for myasthenia gravis.