title: Relationship between Angiographic Results and Morphology in Sidewall Intracranial Aneurysms after Stent-Assisted Coil Embolization.
abstract: BACKGROUND
  Stent-assisted coil embolization (SACE) is used to address wide-necked or complex aneurysms. However, as they may recanalize after SACE, predictors of recanalization are needed. We investigated the relationship between follow-up angiographic results and the morphology of sidewall (SW) aneurysms in patients treated by SACE.
  
  
  METHODS
  Between September 2010 and September 2014, we performed 80 SACE procedures for SW intracranial aneurysms. Angiographic findings, obtained immediately after the procedure, 3-6 months thereafter, and when aneurysmal recanalization was suspected on MR angiogram scan, were recorded. Morphologically, the SW aneurysms were classified as "outside" (OS) and "partially inside" (PI) based on the curve of the axes of the proximal or distal parent artery with respect to the aneurysmal neck. Follow-up angiographic studies on OS- and PI SW aneurysms were compared.
  
  
  RESULTS
  On the initial angiograms, we classified 42 aneurysms as OS and 38 as PI. Immediately after SACE, there was no significant difference in the angiographic findings on OS and PI aneurysms. However, on follow-up angiograms, there was a significant difference in the rate of spontaneous improvement (4 of 42 [OS] versus 21 of 38 [PI], P = .001). We performed additional coil embolization to treat 3 recanalized OS aneurysms.
  
  
  CONCLUSIONS
  SW aneurysms classified morphologically as PI tended to occlude progressively even after incomplete occlusion by SACE. In contrast, aneurysms classified as OS must be observed carefully after SACE.
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, Fukuoka, Japan. Electronic address: k.nii@cis.fukuoka-u.ac.jp.
authors.forename: Kouhei
authors.initials: K
authors.lastname: Nii
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Aikawa
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Tsutsumi
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Ayumu
authors.initials: A
authors.lastname: Eto
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Iko
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Kimiya
authors.initials: K
authors.lastname: Sakamoto
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Ritsuro
authors.initials: R
authors.lastname: Inoue
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Mitsutake
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Hayatsura
authors.initials: H
authors.lastname: Hanada
authors.affiliation: Department of Neurosurgery, Fukuoka University Chikushi Hospital, Fukuoka, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Kazekawa
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004621:Embolization, Therapeutic / Q000009:adverse effects*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000209:etiology* / Q000628:therapy; D018810:Magnetic Resonance Angiography / Q000379:methods*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*
keywords: Angiographic results; intracranial aneurysm; morphology; sidewall; stent-assisted coil embolization