Clinical Outcomes of Thymectomy in Myasthenia Gravis Patients with a History of Crisis.

Abstract

The use of thymectomy in myasthenia gravis (MG) patients with a history of myasthenic crisis (MC) has not been well established. Here, we determined the efficacy of thymectomy by assessing the long-term clinical outcomes and reviewed thymectomy reports on MC patients. Subjects included 31 patients who suffered at least one crisis before surgery, with a cumulative total 73 episodes of MC in Southern China between May 2000 and December 2010. Long-term follow-up was performed and clinical outcomes were evaluated. We used complete stable remission (CSR), termed an asymptomatic status without medication for at least 12months; general complete remission (GCR), termed an asymptomatic status with or without some form of therapy excluding cholinesterase inhibitors, to assess patient outcomes. All patients underwent thymectomy with an overall complication rate of 16.1% and a perioperative mortality rate of 3.2%. Long-term follow-up occurred between 12.6 and 177months, at which point 18 (58.1%) patients experienced improved status, including one patient who achieved CSR; 13 (41.9%) patients achieved GCR; 6 (19.4%) showed unchanged status and one worse (3.2%) status. The remaining 6 patients died, with 3 due to MG-related causes. Using a multivariate Cox regression analysis of GCR by characteristics, patients with better response to medical treatments before thymectomy were positively associated with GCR rates (p=0.028). Extended transsternal thymectomy is a feasible and effective therapy for MG patients with crisis history, especially for those patients who have shown positive signs of remission after exhausting conventional medical treatments.