THYMECTOMY IN SEVERE (MGFA CLASS IV-V) GENERALIZED MYASTHENIA GRAVIS: IS THE GAME REALLY WORTH THE CANDLE?

OBJECTIVES: Total thymectomy in addition to medical treatment is an accepted standard therapy for myasthenia gravis. Patients with severe generalized myasthenia gravis present life-threatening events, poor prognosis and higher risk of postoperative myasthenic crisis. Aim of our study is to investigate neurological and surgical results in patients with MGFA class IV and V MG following thymectomy.

METHODS: Data on 76 myasthenia gravis patients with preoperative MGFA class IV and V who underwent thymectomy were retrospectively collected. Primary end-points included short-term surgical outcomes and long-term neurological results including the achievement of complete stable remission and any improvement as defined by MGFA postintervention status criteria.

RESULTS: There were 27(35.5%) males and 49(64.5%) females; 53(69.7%) were classified as MGFA class IV and 23(30.3%) as class V. Thymectomy was performed through sternotomy in 25(32.9%) patients, by VATS in 5(6.6%) and RATS in 46(60.5%). Median operative time was 120(IQR 95; 148) min. In-hospital mortality was observed in 1(1.3%) patient, postoperative complications in 14 (18.4%). Median postoperative hospital stay was 4(IQR 3; 6) days. Pathological examination revealed 31(40.8%) thymic hyperplasia/other benign and 45(59.2%) thymomas. Cumulative complete stable remission and improvement probabilities were 20.6% and 83.7% at 5-year, and 66.9% and 97.6% at 10-year, respectively. A significant improvement rate was found in patients with age at time of thymectomy of ≤ 50 years(p = 0.0236), MGFA class V(p = 0.0154), and AchR-antibodies positivity(p = 0.0152).

CONCLUSIONS: Thymectomy in patients with severe myasthenia gravis yields good perioperative outcomes and satisfactory long-term neurological improvement, especially for patients younger than 50 years, with MGFA class V and anti-AChR+ myasthenia gravis.