Robotic thymectomy for thymoma in patients with myasthenia gravis: neurological and oncological outcomes

The goal of this study was to analyse the outcomes in 53 patients with thymoma, 34 of whom had myasthenia gravis (MG), who were treated with robotic surgery. The oncological outcomes of the whole series of patients were analysed. Furthermore, because consistent data are not yet available in the literature, the main focus was the analysis of the neurological results of the patients affected by MG and thymoma.

The clinical outcomes of 53 patients with a diagnosis of thymoma who underwent robotic thymectomy between January 2014 and December 2019 in our institution were collected and evaluated; 34 of these patients had a concomitant diagnosis of MG. The neurological status of the patients was determined from a clinical evaluation according to the Osserman classification and on pre- and post-surgery Myasthenia Gravis Composite scores, whereas neurological clinical outcomes were assessed using the Myasthenia Gravis Foundation of America Post-Intervention Score. Reduction of steroid therapy was also considered. The recurrence rate, adjuvant radiotherapy and overall survival of the patients with a thymoma were evaluated.

Neurological outcomes: improvement of the clinical conditions was obtained in 26 patients (76.5%) following the operation: complete stable remission was observed in 5 patients (14.7%), pharmacological remission in 10 (29.4%) and minimal manifestation in 11 (32.3%). Four patients (11.8%) exhibited no substantial change from the pretreatment clinical manifestations or reduction in MG medication and 4 (11.8%) patients experienced worsening of clinical conditions. In 21 patients (61.7%) a reduction of the dosage of steroid therapy was obtained. Oncological outcomes: at an average follow-up of 36 months, the overall survival was 96%, 4 patients (7.5%) had pleural relapses and 12 patients (22.6%) underwent postoperative radiotherapy, according to their stage. In accordance with Masaoka staging, 34% were in stage I, 56.6% in stage II and 9.4% in stage III.

Our results suggest that robotic surgical treatment of patients with thymoma and concomitant MG is effective in improving the neurological outcomes. Moreover, the oncological results obtained in this series confirm the efficacy of robotic surgery for the treatment of thymic malignancies, with results in line with those of open surgery. However, due to the indolent growth of thymomas, further observations with longer follow-up are necessary.