[Predictive analysis for myasthenic crisis after transsternal thymectomy in patients with myasthenia gravis]

The risk factors for postoperative myasthenic crisis (MC) in patients with myasthenia gravis (MG) receiving preoperative corticosteroids were unknown.

Sixty-three consecutive patients who had undergone a transsternal thymectomy for MG were retrospectively analyzed. Of these, 59 patients (93.7%) received preoperative corticosteroids (prednisolone 1-2 mg x kg(-1)) every-other day. In this study, our definition of postoperative-MC was the need for prolonged postoperative mechanical ventilation for more than 48 hours. Six patients (9.5%) met this criterion. The patient background, and preoperative as well as intraoperative management were evaluated to identify risk factors for postoperative-MC.

Student's t-test revealed that the lengths of the operation and anesthesia were significantly longer in the postoperative-MC group compared with the control group (P < 0.05). Fisher's exact test revealed that the existence of preoperative bulbar symptoms and incomplete resection of the thymus gland were also more common in the postoperative-MC group (P < 0.05). A logistic regression analysis revealed that the existence of preoperative bulbar symptoms was the only significant risk factor for postoperative-MC.

Based on this study, we concluded that the existence of preoperative bulbar symptoms seems to be a predictor for the development of postoperative-MC in patients with MG undergoing a transsternal thymectomy.