Minimally invasive vs. trans-sternal thymectomy for non-thymomatous myasthenia gravis: a multi-institutional longitudinal study examining neurologic outcomes.

BACKGROUND

Trans-sternal thymectomy has been shown to be an effective treatment for select patients with non-thymomatous myasthenia gravis (MG). The purpose of this study was to evaluate whether similar neuromuscular benefits are achieved when utilizing minimally invasive surgical approaches to thymectomy, as compared to a trans-sternal approach, in patients with non-thymomatous MG.

METHODS

Pooled data for all patients undergoing thymectomy from 2012 to 2020 for non-thymomatous MG from four institutions were retrospectively reviewed. Patients were stratified by surgical approach, minimally invasive [robotic or video-assisted thoracoscopic (VATS) vs. trans-sternal]. Clinical neurologic follow-up was ascertained from the medical record by a neurologist at 3-month intervals, for 2 years postoperatively.

RESULTS

A total of 54 patients were included with 54% (n=29) undergoing minimally invasive thymectomy (MIT) and 46% (n=25) undergoing a trans-sternal approach. There were no differences in baseline disease severity measured by proportion requiring intravenous immunoglobulin (IVIG), quantitative myasthenia scores, or daily prednisone dose. Similarly, there were no significant differences in major comorbidities. There was one conversion to a sternotomy for innominate vein bleeding. Perioperative complications were uncommon and largely similar between groups. Patients undergoing minimally invasive surgery had decreased length of hospital stay (2.5 vs. 5 days, P<0.01). There were no differences observed in prednisone dose or quantitative myasthenia scores during the 2-year follow-up period.

CONCLUSIONS

Our study confirms the results of the landmark MGTX (Randomized Trial of Thymectomy in Myasthenia Gravis) trial in a real-world multicenter experience. Similar outcomes were achieved regardless of surgical approach. These data support thymectomy for MG either by a minimally invasive or trans-sternal approach. This is the first study to compare disease-specific, rather than perioperative, outcomes of thymectomy via sternotomy vs. minimally invasive approach.