[Thymectomy in myasthenia gravis]

Abstract

Objective: To analyze outcome after thymectomy in patients with myasthenia gravis (MG).

Material and methods: Thirty-five patients with MG underwent surgery in our service between June 1987 and June 1998. Ten had associated thymomas. Preoperative Osserman classification showed 2 at level I, 20 at level IIA, 11 at level IIB and 2 at level III. Extended thymectomy through a medial sternotomy was performed in all.

Results: Postoperative complications developed in three patients (1 medullary aplasia, 1 postoperative reintubation, 1 myasthenic crisis). Mean follow-up was 89 months, with 22.8% achieving complete remission and 97.1% reporting improvements. The results were similar in the 10 patients with thymomas (20% full remission and 90% showing improvement). By DeFilippi classification, 22.8% were in class 1, 22.8% in class 2, 51.4% in class 3 and 2.8% in class 4. By Osserman classification, 9 were in the same category before and after surgery, 12 had improved one level, 10 had improved 2 levels, 3 had improved 3 levels and 1 patient had improved 4 levels.

Conclusion: Thymectomy is an appropriate therapeutic procedure in the multidisciplinary treatment of patients with MG and it is the approach of choice for patients with associated thymomas. The intra- and post-operative complication rate is low and the rate of clinical improvement is high.