Complications and efficacy of transsternal thymectomy in myasthenia gravis

Between January 1977 and September 1985, 75 patients in our department underwent elective surgery for myasthenia gravis through a median sternotomy. The main prerequisite was optimal stabilization by medical treatment with the best possible vital capacity. The Osseman types were as follows: type I (22), type IIa (19), type IIb (26), type III (7), and type IV (1). All patients, except for 3 who were mechanically ventilated for a few hours after surgery, were immediately extubated at the end of the operation. The most frequent histologic finding was thymic hyperplasia (36%); 21.3% of the patients had thymomas. No surgery-related deaths occurred. Wound healing was impaired in 6.7% of the patients, including one patient with complete sternal instability, while 5.3% developed pneumonia. The most serious complications were myasthenic (9.3%) and cholinergic (2.7%) crises. Paresis of the phrenic (2.7%) and recurrent laryngeal (1.3%) nerves occurred only in the thymoma patients, who also had a higher frequency of all other complications. The effect on the myasthenic symptoms 3 months after surgery was as follows: 7.5% of the patients were in complete remission, 61.2% had improved, 9% had deteriorated. In a logistic regression model, the parameters age, sex, duration of disease, Osserman type, histology, pre-operative antibody titer to acetylcholine receptors, and post-operative change in titer were examined with respect to their influence on the effect of surgery. Only thymic histology had an appreciable influence (p = 0.057). The effect of these parameters on the success of surgery as well as the type and frequency of complications in relation to perioperative procedure are discussed in detail.