title: Navigation of Stents across Communicating Arteries for Aneurysm Embolization.
abstract: BACKGROUND
  Endovascular coiling of aneurysms crossing the Circle of Willis has been described in small case series. The technical challenges in manipulating a stent across the Circle of Willis lie in negotiating difficult angles and small arteries. We present our experience with treating aneurysms by stent assistance in which the Circle of Willis was crossed to facilitate optimal stent deployment.
  
  
  METHODS
  We retrospectively reviewed the cases in our institution from January 2009 to June 2012 in which the Circle of Willis was traversed to facilitate optimal stent deployment. We measured the diameter of the communicating arteries traversed, caliber of the target arteries in which the stent was deployed and the most acute angle negotiated ("critical angle"). We compare our results with other published series in the literature.
  
  
  RESULTS
  Eight patients fulfilled the criteria: 5 males (45-66 years). There were three anterior and five posterior circulation aneurysms. Four of the aneurysms were ruptured. The PCOM was traversed in five cases, the ACOM in three cases. The mean diameter of the communicating artery was 1.17 mm. The mean diameter of target arteries was 1.27 mm. The "critical angle" was 72-147 degrees. In all patients, there was satisfactory obliteration of the aneurysm. There were two cases of minor SAH post procedure.
  
  
  CONCLUSIONS
  Utilizing the Circle of Willis for optimal stent placement in aneurysm remodeling is technically feasible but challenging. This technique can be performed successfully in patients with acute SAH. The procedural risk must be balanced against potential complications such as SAH.
authors.forename: Muhammad Ejaz
authors.initials: ME
authors.lastname: Ahmed
authors.forename: Cheemun
authors.initials: C
authors.lastname: Lum
authors.forename: Howard
authors.initials: H
authors.lastname: Lesiuk
authors.forename: Daniela
authors.initials: D
authors.lastname: Iancu
authors.forename: Marlise
authors.initials: M
authors.lastname: dos Santos
mesh_terms: D000368:Aged; D017542:Aneurysm, Ruptured / Q000628:therapy*; D002533:Cerebral Angiography; D002941:Circle of Willis / Q000000981:diagnostic imaging / Q000601:surgery*; D004621:Embolization, Therapeutic / Q000379:methods*; D057510:Endovascular Procedures / Q000379:methods*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015607:Stents; D013345:Subarachnoid Hemorrhage / Q000209:etiology / Q000628:therapy*; D014057:Tomography, X-Ray Computed