title: One versus double burr holes for treating chronic subdural hematoma meta-analysis.
abstract: OBJECTIVE
  There is controversy among neurosurgeons regarding whether double burr hole craniostomy (DBHC) is better than single burr hole craniostomy (SBHC) in the treatment of chronic subdural hematoma (CSH), in terms of having a lower revision rate. In order to compare the revision rates after SBHC versus DBHC, we performed a meta-analysis of the available studies in the literature.
  
  
  METHODS
  Multiple electronic health databases were searched to identify all the studies published between 1966 and December 2010 that compared SBHC and DBHC. Data were processed in Review Manager 5.0.18. Effect sizes were expressed in pooled odds ratio (OR) estimates, and due to heterogeneity between studies we used random effect of the inverse variance weighted method to perform the meta-analysis.
  
  
  RESULTS
  Five observational retrospective cohort studies were identified: four published studies and one unpublished, describing the outcomes of 355 DBHC and 358 SBHC to evacuate 713 CSH in 631 patients. Meta-analysis showed that there was no significant difference in the revision rates between double burr hole craniostomy and single burr hole craniostomy when performed to evacuate CSH. Pooled odds ratio for all the studies was 0.62 (95% confidence interval 0.26 - 1.46).
  
  
  CONCLUSIONS
  The results of this meta-analysis suggest that SBHC is as good as DBHC in evacuating chronic subdural hematoma and is not associated with a higher revision rate compared to DBHC.
authors.affiliation: Division of Neurosurgery, Dalhousie University, QE II Health Sciences Centre, Halifax, Nova Scotia, Canada. sirajeeddin@hotmail.com
authors.forename: Sirajeddin
authors.initials: S
authors.lastname: Belkhair
authors.forename: Gwynedd
authors.initials: G
authors.lastname: Pickett
mesh_terms: D016009:Chi-Square Distribution; D016208:Databases, Factual / Q000706:statistics & numerical data; D005260:Female; D020200:Hematoma, Subdural, Chronic / Q000601:surgery*; D006801:Humans; D008297:Male; D019370:Observation; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D016896:Treatment Outcome; D014207:Trephining / Q000379:methods*