Perioperative medical management and outcome following thymectomy for myasthenia gravis

To describe the evolution of the perioperative management of myasthenia gravis (MG) patients undergoing thymectomy and to question the need for systematic postoperative ventilation.

We collected data retrospectively from 36 consecutive MG patients who underwent thymectomy over a 21-yr period, via transthoracic, -cervical or -sternal incisions (n=5, n=7, n=24, respectively). From 1980 to 1993, a balanced anesthetic technique (n=24) included various inhalational agents with opiates and myorelaxants (in eight cases); 22 patients were admitted to the intensive care unit (ICU). Since 1994, i.v. propofol was combined with epidural bupivacaine and sufentanil (n=12); all patients were admitted to the postanesthesia care unit. Short-term postoperative ventilation (median time four hours, range from three to 48 hr) was required in eight patients who had longer hospital stay (median stay=12 days, range (8-28) vs five days (4-15) for patients with early extubation, P <0.05) but similar clinical improvement six months after thymectomy. Postoperative ventilatory support was required more frequently when a balanced anesthetic technique was used (odds ratio=4.2 (1.1-9.7), P=0.03) and particularly when myorelaxants were given (odds ratio=13.9 (2.1-89.8), P=0.009). Leventhal's scoring system had low sensitivity (22.2%) and positive predictive values (25%).

Our data show that the severity of MG failed to predict the need for postoperative ventilation. A combined anesthetic technique was a safe and cost-effective alternative to balanced anesthesia as it provided optimal operating conditions and resulted in fewer admissions in ICU and shorter hospital stays.