Thymectomy in thymomatous generalized myasthenia gravis: An analysis of the prognosis and risk factors.

BACKGROUND AND PURPOSE: This study investigated the postthymectomy outcomes and factors affecting the prognosis of thymomatous generalized myasthenia gravis (TGMG).

METHODS

Clinical records of 86 patients with TGMG who underwent thymectomy at our institution between 2012 and 2020 were retrospectively reviewed. Predictors of complete stable remission (CSR) and exacerbation were analyzed using multivariate regression analysis.

RESULTS

A total of 16 patients achieved CSR, four achieved pharmacological remission, six exhibited deterioration, and eight died of myasthenia gravis (MG; mean follow-up = 75.1 months). Male sex (p = 0.049) and disease duration < 11.5 weeks before surgery (p = 0.003) were significant positive predictors of CSR. Onset age < 52.8 years and symptoms of ocular and limb muscle weakness had a higher CSR rate than onset age > 52.8 years (p = 0.056) and symptoms of bulbar muscles (p = 0.071). Female patients had a significant higher risk of exacerbation (p = 0.042).

CONCLUSIONS

Male sex and disease duration < 11.5 weeks were independent predictors of CSR in TGMG postthymectomy. Onset age < 52.8 years and ocular and limb muscle weakness at onset were associated with a higher probability of achieving CSR than onset age > 52.8 years and bulbar muscle weakness. Female sex was an independent predictor of MG symptom exacerbation in TGMG postthymectomy.