title: Thymectomy in myasthenia gravis: response, complications, and associated conditions.
abstract: BACKGROUND
  Thymectomy is considered the most effective treatment for achieving sustained improvement as well as remission in patients with myasthenia gravis (MG), and most neurologists favor the use of this procedure. The main focus of many current studies is to determine response-predicting factors.
  
  
  METHODS
  Clinical records of 152 patients with an established diagnosis of MG who underwent thymectomy at our institution were reviewed. The purpose was to evaluate outcome of surgical management for MG and prognostic factors that influence that outcome.
  
  
  RESULTS
  The majority of patients were women (119 of 152); mean age was 32.10 +/- 14.42 years, while time elapsed from diagnosis to surgery was 20.67 +/- 19.7 months. Transsternal thymectomy was performed on 113 patients and transcervical on 39. Forty percent of patients achieved remission and 28% showed improvement; with this, a good response to thymectomy was seen in 68% of patients (n = 103). The most important variables associated with remission were <60 years of age, <2 years of preoperative symptoms, and use of pyridostigmine at low doses. Factors related with poor response were >60 years of age, preoperative Osserman stage other than II, use of high doses of pyridostigmine, use of corticosteroids, and presence of thymic atrophy or thymoma in histopathologic analyses. There was no mortality, although 20 patients (13%) presented complications.
  
  
  CONCLUSIONS
  Mexican patients with MG undergoing thymectomies show improvement and remission rates similar to those reported by other studies. Age, length of symptoms, thymic pathology, and medications appear to be predictors of response to thymectomy for MG.
authors.affiliation: Departamento de Medicina Interna, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, INCMNSZ, Mexico City, Mexico.
authors.forename: José María
authors.initials: JM
authors.lastname: Remes-Troche
authors.forename: José Francisco
authors.initials: JF
authors.lastname: Téllez-Zenteno
authors.forename: Bruno
authors.initials: B
authors.lastname: Estañol
authors.forename: Juan
authors.initials: J
authors.lastname: Garduño-Espinoza
authors.forename: Guillermo
authors.initials: G
authors.lastname: García-Ramos
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D008800:Mexico; D008875:Middle Aged; D009157:Myasthenia Gravis / Q000401:mortality* / Q000601:surgery*; D012074:Remission Induction; D012737:Sex Factors; D013934:Thymectomy; D013950:Thymus Gland / Q000473:pathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome