Robotic thymectomy in patients with myasthenia gravis: neurological and surgical outcomes

OBJECTIVES Thymectomy is frequently used in the treatment of myasthenia gravis (MG). But indication, timing or surgical approach remain controversial. This study reports our experiences with robotic thymectomy and surgical and neurological outcomes in a large cohort of patients with MG. METHODS We retrospectively analysed the outcome of 125 patients with MG who underwent a robotic thymectomy using the da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA, USA) between 2004 and 2012. The Myasthenia Gravis Foundation of America (MGFA) Classification was used to determine preoperative and postintervention status. RESULTS Ninety-five women and 30 men underwent a robotic thymectomy. One hundred patients had a neurological follow-up of more than 12 months. Preoperative most severe MGFA classification was Stage I in 11 patients (8.8%), Stage IIA in 18 patients (14.4%), Stage IIB in 18 patients (14.4%), Stage IIIA in 7 patients (5.6%), Stage IIIB in 29 patients (23.2%), Stage IVA in 10 patients (8.0%), Stage IVB in 29 patients (23.2%) and Stage V in 3 patients (2.4%). Median surgical procedure time was 123 min (range 45–353 min). There were no major perioperative complications or deaths. The median postoperative hospital stay was 3 days (range 2–24 days). Histological analysis showed thymic remnant tissue in 41 patients (32.8%), follicular hyperplasia in 52 patients (41.6%), thymoma in 31 patients (24%), lipoma in 1 patient (0.8%) and a cyst in 1 patient (0.8%). Patients with thymic remnant tissue were significantly more preoperative steroid users compared with the follicular hyperplasia group (P = 0.02). With a median follow-up of 33 months (range 12–104 months), 77% of the patients showed neurological improvement. Three-year probability remission rate [complete stable remission (CSR) and pharmacological remission] is 28.2%. Patients who were not treated with prednisolone preoperatively showed a significant higher CSR than patients who did take prednisolone (P = 0.014). No significant difference was observed regarding timing of surgery (P = 0.37). CONCLUSIONS Robotic thymectomy in patients with MG is safe and feasible. A neurological benefit and decreased use of steroids can be obtained in the majority of patients. No significant difference in neurological outcome was observed as the result of timing of robot thymectomy after the onset of MG.