title: Geometrical characteristics after Y-stenting of the basilar bifurcation.
abstract: OBJECTIVE
  We aimed to investigate the angular changes after Y-stenting of the basilar bifurcation aneurysms.
  
  
  METHODS
  A total of 19 patients (age range, 27-80 years; mean age, 52.5 years) underwent Y-stent coiling for basilar bifurcation aneurysm. Three vascular angles (α, β1, β2) were measured in the anteroposterior plane. β1 and β2 represented the angles between the basilar artery and the proximal P1 segments of the right and left posterior cerebral arteries, respectively. α represented the complementary angle between the β1 and β2 angles. Angles were measured before and after stent deployment. Diameters of the basilar artery and P2 segment of the posterior cerebral artery were measured at both sides. Correlation between vascular diameter and angular change of the basilar bifurcation was investigated.
  
  
  RESULTS
  Statistically significant α, β1, and β2 angle changes were found after stent deployment (P < 0.001). There was no statistically significant relationship between the diameter of the basilar artery and the α, β1, β2 angle changes (P > 0.05). There was no statistically significant relationship between the diameter of the posterior cerebral artery and the β angle change (P > 0.05). We found a statistically significant inverse correlation between pre-stent β angle and post-stent angle change (right side, P = 0.008; left side, P < 0.001).
  
  
  CONCLUSIONS
  Y-stenting narrows the effective neck and straightens the vascular bifurcation angle. Most of the angular remodeling occurs on the side that had a more acute angle before stent deployment.
authors.affiliation: Department of Radiology, GATA Haydarpaşa Training and Research Hospital, İstanbul, Turkey. mzsaglam@yahoo.com.
authors.forename: Muzaffer
authors.initials: M
authors.lastname: Sağlam
authors.forename: Osman
authors.initials: O
authors.lastname: Kızılkılıç
authors.forename: Vania
authors.initials: V
authors.lastname: Anagnostakou
authors.forename: Bülent
authors.initials: B
authors.lastname: Yıldız
authors.forename: Naci
authors.initials: N
authors.lastname: Koçer
authors.forename: Civan
authors.initials: C
authors.lastname: Işlak
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015607:Stents; D016896:Treatment Outcome; D014656:Vascular Surgical Procedures / Q000295:instrumentation* / Q000379:methods