title: Endovascular Treatment of Unruptured Paraclinoid Aneurysms: Single-Center Experience with 400 Cases and Literature Review.
abstract: OBJECTIVE
  Paraclinoid aneurysms have been increasingly treated endovascularly. The natural history of these aneurysms has gradually been elucidated. The purpose of this study was to assess the safety and efficacy of endovascular treatment for these aneurysms.
  
  
  METHODS
  We performed a retrospective review of 377 patients with 400 paraclinoid aneurysms treated between January 2006 and December 2012. Their clinical records, endovascular reports, and radiologic and clinical outcomes were analyzed. Because aneurysms ≥7 mm are at higher risk of rupture, we classified aneurysms as small (<7 mm) or large (≥7 mm).
  
  
  RESULTS
  Overall, 115 of the 400 aneurysms (28.8%) were large (≥7 mm). Thromboembolic complications were found significantly more often with large aneurysms than with small ones (7.4% vs 1.0%, P = .001). Hemorrhagic complications were found only with small aneurysms (0.7%). The 6-month morbidity rates were similar for small (1.0%) and large (0.8%) aneurysms. Immediate angiographic outcomes were similar (P = .37), whereas recurrences and retreatment occurred more frequently with large aneurysms (P = .001 and P = .007, respectively). Multivariate analysis showed that aneurysm size was the only independent predictor for recurrence (P = .005). Most recurrences (81%) were detected by scheduled angiography at 6 months.
  
  
  CONCLUSIONS
  Aneurysm size influenced the type of complication (thromboembolic or hemorrhagic) and the recurrence rate. Given the approximately 1% annual rupture rate for aneurysms ≥7 mm, analysis of our data supports the rationale of using prophylactic endovascular treatment for unruptured paraclinoid aneurysms ≥7 mm.
authors.affiliation: From the Department of Neurosurgery (K.S., H.I., H.A., N.S.), Kobe City Medical Center General Hospital, Kobe, Japan k.shimizu.830923@gmail.com.
authors.forename: K
authors.identifier: http://orcid.org/0000-0003-4952-0608
authors.initials: K
authors.lastname: Shimizu
authors.affiliation: From the Department of Neurosurgery (K.S., H.I., H.A., N.S.), Kobe City Medical Center General Hospital, Kobe, Japan.
authors.forename: H
authors.identifier: http://orcid.org/0000-0001-8923-7861
authors.initials: H
authors.lastname: Imamura
authors.affiliation: Department of Neurosurgery (Y.M.), Kyoto University Graduate School of Medicine, Kyoto, Japan.
authors.forename: Y
authors.identifier: http://orcid.org/0000-0002-6346-3999
authors.initials: Y
authors.lastname: Mineharu
authors.affiliation: From the Department of Neurosurgery (K.S., H.I., H.A., N.S.), Kobe City Medical Center General Hospital, Kobe, Japan.
authors.forename: H
authors.identifier: http://orcid.org/0000-0002-8144-6906
authors.initials: H
authors.lastname: Adachi
authors.affiliation: Division of Neuroendovascular Therapy (C.S., N.S.), Institute of Biomedical Research and Innovation, Kobe, Japan.
authors.forename: C
authors.identifier: http://orcid.org/0000-0002-4957-9450
authors.initials: C
authors.lastname: Sakai
authors.affiliation: From the Department of Neurosurgery (K.S., H.I., H.A., N.S.), Kobe City Medical Center General Hospital, Kobe, Japan Division of Neuroendovascular Therapy (C.S., N.S.), Institute of Biomedical Research and Innovation, Kobe, Japan.
authors.forename: N
authors.identifier: http://orcid.org/0000-0002-3289-1210
authors.initials: N
authors.lastname: Sakai
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D002533:Cerebral Angiography; D002543:Cerebral Hemorrhage / Q000453:epidemiology / Q000209:etiology / Q000628:therapy; D057510:Endovascular Procedures / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000628:therapy; D012008:Recurrence; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D015607:Stents; D013923:Thromboembolism / Q000209:etiology / Q000628:therapy; D016896:Treatment Outcome