Response to thymectomy and analysis of influencing factors in the treatment of children with myasthenia gravis

Objective To evaluate the efficacy of thymectomy and relevant influencing factors in the treatment of children with myasthenia gravis through a long-term follow-up.Methods The clinical records of 59 patients undergoing expanded thymectomy for the treatment of myasthenia gravis ( MG ) between January 2003 and August 2009 were reviewed retrospectively.Their postoperative outcomes were categorized into complete stable remission (CSR),pharmacological remission (PR),improvement,no change and deterioration ( including mortality).Results During a median follow-up period of 35 months,none of them died or deteriorated clinically among 53 patients with a postoperative follow-up.The overall remission rate was 69.8％ and the effective rate 90.6％.No symptomatic relapse occurred among 16 patients in CSR.None of the ocular patients progressed to generalized MG while 16 thymectomized generalized MG developed from ocular MG.Both univariate and logistic regression analyses revealed that the preoperative duration of illness influenced the surgical curative effect( P ＜ 0.05 ).Survival analysis indicated that the rates of overall remission were 56％ or 88％ at 24 months and 42％ or 75％ at 48 months among ocular MG and generalized MG respectively.According to Log-rank analysis,no difference in remission existed between two types of MG.Conclusion Thymectomy is an effective and safe treatment in selected MG children,especially in those with a shorter illness duration. Key words: Myasthenia gravis;  Child;  Thymectomy