title: Perioperative variables contributing to the rupture of intracranial aneurysm: an update.
abstract: BACKGROUND
  Perioperative aneurysm rupture (PAR) is one of the most dreaded complications of intracranial aneurysms, and approximately 80% of nontraumatic SAHs are related to such PAR aneurysms. The literature is currently scant and even controversial regarding the issues of various contributory factors on different phases of perioperative period. Thus this paper highlights the current understanding of various risk factors, variables, and outcomes in relation to PAR and try to summarize the current knowledge.
  
  
  METHODS
  We have performed a PubMed search (1 January 1991-31 December 2012) using search terms including "cerebral aneurysm," "intracranial aneurysm," and "intraoperative/perioperative rupture."
  
  
  RESULTS
  Various risk factors are summarized in relation to different phases of perioperative period and their relationship with outcome is also highlighted. There exist many well-known preoperative variables which are responsible for the highest percentage of PAR. The role of other variables in the intraoperative/postoperative period is not well known; however, these factors may have important contributory roles in aneurysm rupture. Preoperative variables mainly include natural course (age, gender, and familial history) as well as the pathophysiological factors (size, type, location, comorbidities, and procedure). Previously ruptured aneurysm is associated with rupture in all the phases of perioperative period. On the other hand intraoperative/postoperative variables usually depend upon anesthesia and surgery related factors. Intraoperative rupture during predissection phase is associated with poor outcome while intraoperative rupture at any step during embolization procedure imposes poor outcome.
  
  
  CONCLUSIONS
  We have tried to create such an initial categorization but know that we cannot scale according to its clinical importance. Thorough understanding of various risk factors and other variables associated with PAR will assist in better clinical management as well as patient care in this group and will give insight into the development and prevention of such a catastrophic complication in these patients.
authors: Department of Anesthesiology, Health Sciences Center, University of Manitoba, 2nd Floor Harry Medovy House, 671 William Avenue, Winnipeg, MB, Canada R3E 0Z2.
authors: Tumul
authors: T
authors: Chowdhury
authors: Ronald B
authors: RB
authors: Cappellani
authors: Nora
authors: N
authors: Sandu
authors: Bernhard
authors: B
authors: Schaller
authors: Jayesh
authors: J
authors: Daya
mesh_terms: D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications* / Q000453:epidemiology* / Q000503:physiopathology* / Q000601:surgery; D020300:Intracranial Hemorrhages / Q000453:epidemiology* / Q000209:etiology* / Q000473:pathology*; D059035:Perioperative Period / Q000706:statistics & numerical data*; D039781:PubMed; D012307:Risk Factors