title: Factors Determining Surgical Approaches to Basilar Bifurcation Aneurysms and Its Surgical Outcomes.
abstract: BACKGROUND
  The basilar bifurcation aneurysm (BBA) is still considered to be one of the most challenging aneurysms for micro- and endovascular surgery. Classic surgical approaches, such as subtemporal, lateral supraorbital (LSO), and modified presigmoid, are still reliable and effective.
  
  
  OBJECTIVE
  To analyze the clinical and radiological factors that affect the selection of these classic surgical approaches and their outcomes.
  
  
  METHODS
  A retrospective analysis was conducted on the clinical and radiological data from computed tomographic angiography of BBA that have been clipped in the Department of Neurosurgery of Helsinki University Central Hospital between 2004 and 2014. Statistical analyses were performed using parametric and nonparametric tests where values were considered significant below P = .05.
  
  
  RESULTS
  One hundred four patients with BBA underwent surgical clipping in our department between 2004 and 2014. Eight patients were excluded from the study because of incomplete preoperative radiological evaluations, leaving 96 patients for further analysis. Multiple aneurysm clipping, mean basilar bifurcation angle, and aneurysm neck distance from posterior clinoid process were shown to be factors that determine the surgical approach. Unfavorable outcome is strongly associated with poor Hunt-Hess grade on admission, distance from aneurysm neck (the posterior clinoid process), thrombosis, and dome size.
  
  
  CONCLUSIONS
  Microsurgery for BBA clipping can be performed safely with simple surgical approaches: subtemporal and LSO. There are several factors determining the approach selected. Poor patient outcome in BBA was highly associated with poor preoperative clinical grade and large size of aneurysm dome.
authors.affiliation: Department of Neurosurgery, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Mardjono
authors.initials: M
authors.lastname: Tjahjadi
authors.forename: Juri
authors.initials: J
authors.lastname: Kivelev
authors.forename: Joseph C
authors.initials: JC
authors.lastname: Serrone
authors.forename: Hidetsugu
authors.initials: H
authors.lastname: Maekawa
authors.forename: Oleg
authors.initials: O
authors.lastname: Kerro
authors.forename: Behnam Rezai
authors.initials: BR
authors.lastname: Jahromi
authors.forename: Hanna
authors.initials: H
authors.lastname: Lehto
authors.forename: Mika
authors.initials: M
authors.lastname: Niemelä
authors.forename: Juha A
authors.initials: JA
authors.lastname: Hernesniemi
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000601:surgery*; D008297:Male; D008866:Microsurgery / Q000379:methods*; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D011859:Radiography; D012189:Retrospective Studies; D013525:Surgical Instruments; D016896:Treatment Outcome