Thymectomy for myasthenia gravis in children: a comparison of open and thoracoscopic approaches.

PURPOSE: Thymectomy is an accepted component of treatment for myasthenia gravis (MG), but optimal timing and surgical approach have not been determined. Though small series have reported the feasibility of thoracoscopic resection, some studies have suggested that minimally invasive methods are suboptimal compared to open sternotomy owing to incomplete clearance of thymic tissue. Here we report the largest series of thymectomies for pediatric myasthenia gravis in the literature to date.

METHODS: A retrospective review of patients undergoing thymectomy for MG between 1990 and 2013 in a tertiary referral hospital was performed. Twelve patients who underwent thoracoscopic thymectomy were compared to 16 patients who underwent open thymectomy via median sternotomy. Postoperative outcomes were determined by electronic chart review in consultation with the treating pediatric neurologist. Disease severities were graded according to a modified Myasthenia Gravis Foundation of America (MGFA) Quantitative MG (QMG) score.

RESULTS: Overall, thoracoscopic resections tended to be performed on patients with earlier and less severe disease than open surgeries. Inpatient length of stay was significantly shorter after thoracoscopic surgery (mean 1.8 vs 8.0 days, p=0.045). The preoperative and postoperative MGFA QMG scores were equivalent between the two groups. Both groups experienced a decrease in disease severity (p<0.001) after median follow-up time of 23 months in the thoracoscopic group and 44 months in the open group.

CONCLUSIONS: Minimally invasive thymectomy for MG in children has increased in popularity as surgeons and neurologists compare the risks and benefits of surgery against other therapies. This analysis suggests that thoracoscopic thymectomy is not inferior to median sternotomy in terms of disease control in this small series, and that the morbidity of the thoracoscopic approach appears sufficiently low to be considered for early stage disease. Low perioperative morbidity and shortened hospital course make thoracoscopic thymectomy an attractive option in centers with sufficient medical and surgical experience.