Thymectomy promotes maintained complete stable remission in myasthenia gravis.

AIMS: This study aimed to evaluate the impact of thymectomy on the long-term prognosis of myasthenia gravis (MG) patients, using maintainable complete stable remission (mCSR) as the primary outcome.

METHODS

We performed a retrospective analysis of prospectively collected data from the MG database at West China Hospital. mCSR was defined as the cessation of all MG-related treatments with symptom-free status for at least 1 year until the last follow-up. Kaplan-Meier curves and multivariable Cox proportional hazards model were used to assess thymectomy's effect on mCSR.

RESULTS

A total of 421 MG patients were included, with a median disease duration of approximately 10 years. A higher proportion of thymectomy patients achieved mCSR compared to the conservative treatment group (20/164 [12.2%] vs. 11/257 [4.3%], p = 0.002). Subgroup analysis showed thymectomy significantly predicted mCSR in early-onset MG (HR = 4.61, 95% CI: 1.83-11.63, p = 0.001), females (HR = 2.68, 95% CI: 1.11-6.48, p = 0.028), and ocular MG patients (HR = 3.03, 95% CI: 1.27-7.19, p = 0.012). After adjusting for age, sex, and baseline classification (ocular or generalized), thymectomy remained an independent predictor of mCSR in both the overall cohort (HR = 3.40, 95% CI: 1.61-7.19, p = 0.001) and non-thymomatous MG subgroup (HR = 5.56, 95% CI: 2.35-13.2, p < 0.001). In ocular MG, thymectomy was also associated with a higher mCSR rate (16.7% vs. 5.7%, p = 0.008).

DISCUSSION: Thymectomy is beneficial for MG patients in achieving mCSR, including ocular and non-thymomatous subgroups.