Routine versus selective plasma exchange before thymectomy in myasthenia gravis

Background: Prethymectomy plasma exchange may improve the outcome of surgery; however, the technique is associated with an increased risk of complications. Therefore, the objective of this study was to compare selective versus routine plasma exchange before thymectomy in patients with myasthenia gravis. Method: We conducted a prospective multi-center cohort study to compare two protocols for plasma exchange before thymectomy. We compared the routine plasma exchange in all patients undergoing thymectomy for myasthenia gravis (group I; n= 30) versus selective exchange (Group II; n= 30). Endpoints were the duration of postoperative mechanical ventilation, plasma exchange, and operative complications. Results: There was no difference in age between both groups (30± 10.1 vs. 29± 9.2 years in Group I and II, respectively; p= 0.69). There were 17 females in Group I (56.67%) vs. 16 in group II (53.33%) (p= 0.8). Comorbidities are comparable between groups. All patients preoperative pyridostigmine, and 27 patients (90%) in Group I and 26 patients (87%) in Group II received glucocorticoids. There was no difference in pulmonary function tests between groups. Plasma exchange related complications were not different between groups. Immediate extubation was achieved in 29 patients (97%) in Group II, and after 6 hours in one patient (3.33%). In Group I, 28 patients (93%) extubated immediately, and two patients were ventilated for 7-12 hours. The mean ICU stay was 1.5 days in Group I and 1.4 days in group II (p= 0.615). The mean hospital stay was 8.5 days in Group I and 9.2 days in group II (p= 0.118). There was no significant difference in pathology between groups (p= 0.137). Conclusion: Selective plasma exchange is feasible before thymectomy for myasthenia gravis. Selective plasma exchange may decrease exchange related complications without affecting the operative outcomes.