Limited adoption of thymectomy for nonthymomatous myasthenia gravis

Thymectomy had been an accepted treatment for myasthenia gravis (MG) for decades. Despite this, practice patterns of thymectomy for MG vary even though there is growing evidence of its safety and efficacy. This retrospective database study aimed to assess the safety of thymectomy for patients with nonthymomatous MG and to determine how surgical management of nonthymomatous MG changed following the 2016 publication of results from a phase 3, multicenter, randomized trial (MGTX trial) demonstrating thymectomy plus prednisone was superior to medical management alone.

We retrospectively reviewed all thymectomy cases 2005-2023 in the National Surgical Quality Improvement Program (NSQIP) database. We compiled postoperative complications and mortality into broad and narrow composite outcomes to display adverse events associated with thymectomy in MG patients. We then used National Institutes of Health (NIH) Joinpoint models to indicate changes in annual rates of thymectomy (in general) and minimally invasive thymectomy (specifically) for MG between 2005-2023 pre- and post- publication of the MGTX trial.

The queried NSQIP database had a total of 352 nonthymomatous thymectomies performed on MG patients between 2005-2023. The odds of experiencing a broad composite outcome following thymectomy was 7.1% (N=25) and the odds of experiencing a narrow outcome was 3.1% (N=11). The data also showed that there were no 30-day mortalities. Annual percentage change (APC) of thymectomy and minimally invasive thymectomy for MG gradually increased until 2019 and 2020 (2.52% and 4.01% APC, respectively), before decreasing through 2023 (-10.79% APC, P=0.02, and -17.51% APC, P=0.27, respectively).

Following the 2016 MGTX trial, thymectomy continues to be a safe procedure among MG patients. Despite this, the current study reveals limited adoption of thymectomy into practice as reflected by the predicted annual rate of thymectomy in MG patients.