Outcomes of juvenile myasthenia gravis: a comparison of robotic thymectomy with medication treatment.

BACKGROUND The study aims to compare the clinical outcomes of patients with juvenile myasthenia gravis (JMG) who underwent robotic thymectomy with that of those who only received medication therapy. METHODS We retrospectively reviewed patients who visited our institution for the diagnosis or treatment of MG with an age at onset younger than 18 years. Patients who underwent thymectomy comprised the surgical group and those who received only medication therapy comprised the nonsurgical group. The clinical outcomes were assessed according to the Myasthenia Gravis Foundation of America Post Intervention Status. RESULTS Forty-seven patients (35 female: 12 male) were included as the surgical group and 20 patients (15 female: 5 male) comprised the nonsurgical group. Significant differences were observed between the surgical and nonsurgical groups in antibody against acetylcholinesterase receptor (91.5% versus 65%, p=0.012), disease duration (16 [7-25] months versus 96 [42-480] months, p<0.001) and corticosteroids requirement (53.2% versus 15%, p=0.004) at baseline. Kaplan-Meier analysis showed a higher cumulative probability of complete stable remission (CSR) in the surgical group (p=0.002), compared with that in the nonsurgical group. Moreover, thymectomy (HR 3.842, 95%CI: 1.116-13.230, p=0.033) and age at onset (HR 0.89, 95%CI: 0.80-0.99, p=0.037) were still associated with the achievement of CSR in the multivariable analysis. Furthermore, a significant steroid-sparing effect was only observed in the surgical group, but not in the nonsurgical group. CONCLUSIONS Robotic thymectomy seems to be more effective than medication therapy on JMG in terms of inducing remission and reducing the use of corticosteroids.