Thymectomy for myasthenia gravis: a 27-year experience.
OBJECTIVE
Thymectomy is considered an effective therapeutic option for patients with myasthenia gravis (MG). We reviewed our 27-year experience with surgical treatment of MG with respect to long-term results and factors affecting outcome.


METHODS
Between 1970 and 1997, we performed 232 thymectomies for MG. Fifteen patients were lost to follow-up; the remaining 217 form the object of our study. Sixty-two patients (28.4%) had thymoma. Myasthenia was graded according to a modified Osserman classification: 51 patients (23.5%) were in class I, 81(37.3%) in class IIA, 52 (24%) in class IIB, 26 (12%) in class III and seven (3.2%) in class IV. Mean duration of symptoms before the operation was 12+/-10 months. Fifty-eight thymectomies for thymoma were performed through a median sternotomy and four through a clamshell incision. Forty-six thymectomies for non-thymomatous MG were performed through a standard cervicotomy, 101 procedures through a partial upper sternal-splitting incision and eight through a complete median sternotomy.


RESULTS
Operative mortality was 0.92% (two patients). After a mean follow-up of 119 months, 71% of all patients improved their clinical status (25% without medications and asymptomatic; 46% with a reduction of medications and/or clinically improved); 39 (18%) have a stable disease with no clinical modifications; 12 (5%) presented a deterioration of their clinical status with worse symptoms, required more medications, or both. Thirteen patients (6%) died because of MG (mean survival 34.3+/-3.6 months). The presence of a thymoma negatively influenced the prognosis. Younger patients showed a more favorable outcome as well as patients with a shorter duration of symptoms before the operation; patients with lower classes of myasthenia showed a higher rate of remission.


CONCLUSIONS
Thymectomy is effective in the management of patients with MG at all stages with low morbidity. Patients with thymoma present a less favorable outcome.
Venuta
F
F
Department of Thoracic Surgery, University of Rome La Sapienza, Italy. fevenuta@tin.it
Rendina
E A
EA
De Giacomo
T
T
Della Rocca
G
G
Antonini
G
G
Ciccone
A M
AM
Ricci
C
C
Coloni
G F
GF
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D015996:Survival Rate; D013934:Thymectomy / Q000379:methods*; D016896:Treatment Outcome