Early Outcomes of Simple versus Extended VATS Thymectomy in Non-Thymomatous Myasthenia Gravis; a Comparative Study

Background: Myasthenia gravis (MG) disease affects the neuromuscular junction and leads to muscle weakness and fatigue. Thymectomy may be useful in patients with MG and the operation can be done through many different techniques, however dispute exists as to which approach and extent of excision yields the best results. Methods: This is a prospective multi-center randomized controlled study involving 40 patients who underwent Thoracoscopic Thymectomy for management of non-thymomatous Myasthenia Gravis during the period from April 2019 to August 2020 in three tertiary hospitals. The patients were classified into two groups; group A included 20 patients that did simple VATS thymectomy and group B included 20 patients that did extended VATS thymectomy. Preoperative, operative and postoperative data were collected and analyzed to compare early results of the two techniques including AChR-Ab titre and examination of excised mediastinal fat for ectopic thymic tissue. Results: The results showed no Intra-operative complications or conversions to an open approach in either group. The operative time was slightly longer in the extended thymectomy group but without statistical significance. The Improvement in post-op MGFA class was more pronounced in the extended group than in the simple group and is statistically significant (P=0.02). The extended thymectomy group showed more improvement in pyridostigmine and prednisone dosage compared to the simple group. The enhanced improvement in pyridostigmine dose in the extended group was statistically significant. The drop in post-op AchR-Ab titre was more in the extended group than that in the simple group, but the difference between the groups did not reach statistical significance. The extended thymectomy group showed statistically significant (p < 0.001) better correlation between clinical improvement and AchR-Ab levels. Patients in the extended thymectomy group stayed slightly less in hospital and had less Post-op pain but it was not of statistical significance. Conclusion: Extended right-sided thoracoscopic thymectomy is a safe and efficient procedure which combines the benefits of extensive resection including better MGFA class with a minimally invasive approach with its benefits of less pain and improved cosmesis without added risk of complications.