title: Effect of repeated transsphenoidal surgery in recurrent or residual pituitary adenomas: A systematic review and meta-analysis.
abstract: BACKGROUND
  Recurrent or residual pituitary adenomas previously treated by transsphenoidal surgery are not uncommon. There are no strongly established guidelines to perform treatment of such cases. The objective of this study is to elucidate the effect of transsphenoidal reoperation in residual or recurrent pituitary adenomas.
  
  
  METHODS
  We made a systematic review of the literature to elucidate this effect through electronic search in MEDLINE/PubMed and Cochrane Central database. PRISMA statement was used as a basis for this systematic review and analysis of the risk of bias was made according to the Grading of Recommendations, Assessment, Development and Evaluation recommendations.
  
  
  RESULTS
  In this review, fifteen studies were finally pooled analyzed. Although remission rates (RRs) and follow-up periods varied widely, from 149 patients with growth hormone-secreting tumors the mean RR was 44.5%, from 273 patients with adrenocorticotropic hormone-secreting tumors the mean RR was 55.5% and among 173 patients with nonsecreting tumors, RR was 76.1%. There was significant higher RR in nonsecreting tumors. Mean follow-up was 32.1 months. No difference was found between microscopic and endoscopic techniques.
  
  
  CONCLUSIONS
  A second transsphenoidal surgery is accompanied by a chance of remission in approximately half of cases with secreting tumors. In nonsecreting ones, success is higher.
authors.affiliation: Department of Neurosurgery, Hospital do Servidor Público Estadual, São Paulo, Brazil.
authors.forename: Lindolfo Carlos
authors.initials: LC
authors.lastname: Heringer
authors.affiliation: Department of Neurosurgery, Hospital do Servidor Público Estadual, São Paulo, Brazil.
authors.forename: Matheus Fernandes
authors.initials: MF
authors.lastname: de Oliveira
authors.affiliation: Department of Neurosurgery, Hospital do Servidor Público Estadual, São Paulo, Brazil.
authors.forename: José Marcus
authors.initials: JM
authors.lastname: Rotta
authors.affiliation: Department of Neurosurgery, Hospital do Servidor Público Estadual, São Paulo, Brazil.
authors.forename: Ricardo Vieira
authors.initials: RV
authors.lastname: Botelho
keywords: Endoscopy; microsurgery; pituitary adenoma; transsphenoidal; treatment