Clinical outcome of juvenile myasthenia gravis after extended transsternal thymectomy in a chinese cohort

Abstract

Background: The role of surgical treatment for juvenile myasthenia gravis (MG) remains unclear. Here, we performed a retrospective study to evaluate the predictors of clinical outcome of juvenile MG treated with extended transsternal thymectomy.

Methods: A total of 141 consecutive juvenile MG patients underwent extended transsternal thymectomy at an academic hospital over a 20-year period were reviewed. Thymectomy was performed in patients resistant to pyridostigmine therapy, with generalized symptoms or ocular MG with partial response to pyridostigmine for more than 2 years. Variables potentially affecting responses to extended transsternal thymectomy were evaluated using Kaplan-Meier analysis and Cox regression modeling. Complete stable remission (CSR) is defined as asymptomatic without medication for more than 12 months.

Results: There were 96 patients with ocular MG and 45 generalized MG, the median age at disease onset was 6 years and that at operation was 12 years. Among 135 patients with complete postoperative follow-up, 34 (25.2%) achieved CSR, 28 (20.7%) experienced pharmacologic remission, 61 (45.2%) improved, 5 (3.7%) remained stable, and 7 (5.2%) deteriorated. The results indicated the disease-onset age greater than 6 years and age at operation greater than 12 years were both positively associated with CSR responses. Postoperative steroid treatments in ocular MG and preoperative disease duration in generalized MG (>12 months) were negatively associated with CSR responses.

Conclusions: Extended transsternal thymectomy for Chinese juvenile MG patients has an efficacy comparable with reports from other ethnicities. Juvenile patients with disease-onset age greater than 6 years, age at operation greater than 12 years, and shorter disease duration of generalized MG are associated with favorable clinical outcomes.