Thymectomy in myasthenia gravis. Results of 662 cases operated upon in 15 years

The results of thymectomy in the treatment of myasthenia gravis (MG) arereviewed in the light of a personal series of 662 MG patients, operatedupon during the last 15 years. In 500 MG patients without thymoma, thefollowing results have been achieved: remission 37.9%, improvement 49.4%, unchanged or worse 7.4%, dead 5.2%. There is no sex prevalence and theremission rate is higher in patients under 40 years of age (P<0.01), with mild disease (P<0.05), with a MG duration of lessthan 1 year (P<0.05) and with a follow-up length of between 5 and10 years (P<0.01). No correlations are found between outcome andthymic histology. The results of 162 MG patients with thymomaare:remission rate 15.7%, improvement 60.3%, unchanged or worse 3.7% and dead20.1%. The remission rate is higher with mild symptoms (P<0.05)and when the tumour is encapsulated (P<0.02). The postoperativemortality is 0.8% (none in the last 5 years) for non-thymomatous MG and4.9% for thymomatous MG (2 of 8 patients died of pancytopaenia and 1 ofpulmonary embolism).