Outcomes of thoracoscopic thymectomy in patients with juvenile myasthenia gravis

Introduction: Myasthenia gravis (MG) is an autoimmune disorder of the postsynaptic neuromuscular junction resulting in fatigability of voluntary muscles. There has been increasing evidence supporting thymectomy for MG in adults, and evidence for the role of surgery in pediatric age groups is increasing. The purpose of this study is to describe the outcomes of our patients with juvenile MG undergoing thoracoscopic thymectomy.

Material and methods: All patients with juvenile MG who underwent thoracoscopic thymectomy at Phoenix Children's Hospital between 1999 and 2014 were included. Patients were diagnosed by their treating neurologist. An Osserman and Genkins criterion was used to classify the severity of the disease and DeFilippi classification was used to assess remission.

Results: Twelve patients underwent thoracoscopic thymectomy for juvenile MG during the time frame studied. Nine (75%) patients had an Osserman stage of IIB, with only two patients with ocular disease. There were no conversions to an open procedure. Seven (59%) patients had normal thymic histology, 4 (33%) had evidence of follicular hyperplasia and one (8%) had involutional changes. The median length of hospital stay was 2days (range 1-5days). There was no 30-day postoperative morbidity, reoperations or mortality. The median length of follow-up was 31months (range, 4-91months) and at the time of their last follow-up; all 12 (100%) patients had a DeFilippi Classification of 3 or better.

Conclusion: Surgery for MG in children is indicated for antibody-receptor-positive patients with moderate to severe disease. Thoracoscopic thymectomy is a safe and acceptable treatment for juvenile MG with good disease control. The low morbidity and shorter hospital duration make it an excellent option for consideration.