title: Comparison of the Efficacy and Safety of Endovascular Coiling Versus Microsurgical Clipping for Unruptured Middle Cerebral Artery Aneurysms: A Systematic Review and Meta-Analysis.
abstract: OBJECTIVE
  Middle cerebral artery aneurysms (MCAAs) are regularly treated by both microsurgical clipping and endovascular coiling. We performed a systematic meta-analysis to compare the safety and efficacy of these 2 methods.
  
  
  METHODS
  Literature was reviewed for all studies reporting angiographic occlusion and/or functional outcomes in adults with unruptured MCAA treated by endovascular coiling or microsurgical clipping. All studies in English that reported results for adults (≥18 years) with unruptured MCAAs, from 1990 to 2011 were considered for inclusion.
  
  
  RESULTS
  Twenty-six studies involving 2295 aneurysms treated with clipping or coiling for unruptured MCAAs were included for analysis. There were 1530 aneurysms that were treated with clipping and 765 aneurysms treated with coiling. Pooled analysis revealed failure of aneurysmal occlusion in 3.0% (95% confidence interval [CI] 1.2%-7.4%) of clipped cases. Pooled analysis of 15 studies (606 aneurysms) involving coiling and occlusion revealed lack of occlusion rates of 47.7% (95% CI 43.6%-51.8%) with the fixed-effects model and 48.2% (95% CI 39.0%-57.4%) with the random-effects model. Thirteen studies examined neurological outcomes after clipping and were pooled for analysis. Both fixed-effect and random-effect models revealed unfavorable outcomes in 2.1% (95% CI 1.3%-3.3%) of patients. There were 17 studies evaluating potential unfavorable neurological outcomes after coiling that were pooled for analysis. Fixed-effect and random-effect models revealed unfavorable outcomes in 6.5% (95% CI 4.5%-9.3%) and 4.9% (95% CI 3.0%-8.1%) of patients, respectively.
  
  
  CONCLUSIONS
  Based on this systematic review and meta-analysis of unruptured MCAAs, after careful consideration of patient, aneurysmal, and treatment center factors, we recommend surgical clipping for unruptured MCAA.
authors.affiliation: Cushing Neurosurgery Outcomes Center, Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA. Electronic address: trsmith@partners.org.
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Smith
authors.affiliation: Cushing Neurosurgery Outcomes Center, Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: David J
authors.initials: DJ
authors.lastname: Cote
authors.affiliation: Cushing Neurosurgery Outcomes Center, Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Hormuzdiyar H
authors.initials: HH
authors.lastname: Dasenbrock
authors.affiliation: Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Youssef J
authors.initials: YJ
authors.lastname: Hamade
authors.affiliation: Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Samer G
authors.initials: SG
authors.lastname: Zammar
authors.affiliation: Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Najib E
authors.initials: NE
authors.lastname: El Tecle
authors.affiliation: Department of Neurological Surgery, UT Southwestern Medical Center, Dallas, Texas, USA.
authors.forename: H Hunt
authors.initials: HH
authors.lastname: Batjer
authors.affiliation: Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
authors.forename: Bernard R
authors.initials: BR
authors.lastname: Bendok
mesh_terms: D004621:Embolization, Therapeutic / Q000379:methods; D057510:Endovascular Procedures / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D008866:Microsurgery / Q000009:adverse effects / Q000379:methods*; D020768:Middle Cerebral Artery / Q000601:surgery*; D061214:Patient Safety; D013525:Surgical Instruments; D016896:Treatment Outcome
keywords: Aneurysm; Clipping; Coiling; Endovascular; MCA aneurysm; Meta-analysis