Outcomes after major surgery in patients with myasthenia gravis: A nationwide matched cohort study

OBJECTIVE To validate the comprehensive features of adverse outcomes after surgery for patients with myasthenia gravis. METHODS Using reimbursement claims from Taiwan's National Health Insurance Research Database, we analyzed 2290 patients who received major surgery between 2004 and 2010 and were diagnosed with myasthenia gravis preoperatively. Surgical patients without myasthenia gravis (n = 22,900) were randomly selected by matching procedure with propensity score for comparison. The adjusted odds ratios and 95% confidence intervals of postoperative adverse events associated with preoperative myasthenia gravis were calculated under the multiple logistic regressions. RESULTS Compared with surgical patients without myasthenia gravis, surgical patients with myasthenia gravis had higher risks of postoperative pneumonia (OR = 2.09; 95% CI: 1.65-2.65), septicemia (OR = 1.31; 95% CI: 1.05-1.64), postoperative bleeding (OR = 1.71; 95% CI: 1.07-2.72), and overall complications (OR = 1.70; 95% CI: 1.44-2.00). The ORs of postoperative adverse events for patients with myasthenia gravis who had symptomatic therapy, chronic immunotherapy, and short-term immunotherapy were 1.76 (95% CI 1.50-2.08), 1.70 (95% CI 1.36-2.11), and 4.36 (95% CI 2.11-9.04), respectively. CONCLUSIONS Patients with myasthenia gravis had increased risks of postoperative adverse events, particularly those experiencing emergency care, hospitalization, and thymectomy for care of myasthenia gravis. Our findings suggest the urgency of revising protocols for perioperative care for these populations.