title: Predictive Factors for the Occurrence of Visual and Ischemic Complications After Open Surgery for Paraclinoid Aneurysms of the Internal Carotid Artery.
abstract: To investigate the predictive factors for visual and ischemic complications after open surgery for paraclinoid aneurysms of the internal carotid artery (ICA).
  
  
  
  Thirty-eight consecutive patients with unruptured paraclinoid aneurysms of ICA operated on between 2009 and 2013 were included in this study. The male:female ratio was 6:32 and the ages ranged from 33 to 81 (mean: 60 ± 2). Twenty cases were asymptomatic and 18 had ophthalmological symptoms. The sizes of the aneurysms ranged from 2 to 35 mm (mean: 10.6 ± 9 mm). Twenty-three patients were treated by clipping and 15 by trapping with bypass (high-flow bypass in 11, and low-flow in 4). Twenty-four patients underwent removal of the anterior clinoid process. Among them, 8 underwent en bloc anterior clinoidectomy with a high-speed drill, and 16 had piecemeal excision with a microrongeur or ultrasonic bone curette. Intraoperative monitoring was performed using motor-evoked potentials (MEP) and visual-evoked potentials (VEP) in 27 and 15 cases, respectively.
  
  
  
  Complete obliteration of the aneurysm was achieved in 37 cases (97.4 %). The patency rate of bypass was 100 %. Postoperative worsening of visual acuity, including one case of blindness, was observed in six cases (11 %). Worsening of visual field defects occurred in 14 cases (38 %), but 10 of them were transient. Transient oculomotor nerve palsy occurred in six cases (15 %). Postoperative stroke was detected by diffusion-weighted imaging (DWI) in five cases (13 %), four of which were symptomatic. Statistical analysis showed that piecemeal anterior clinoidectomy was significantly safer than en bloc removal in preserving visual function. Trapping with high-flow bypass had a significantly greater risk of postoperative stroke than direct clipping.
  
  
  
  Intraoperative VEP monitoring might be useful for preventing postoperative worsening of visual function. Two-stage treatment with bypass and endovascular trapping might be safer than single-stage trapping alone.
authors.affiliation: Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan. kikuta@u-fukui.ac.jp.
authors.forename: Ken-Ichiro
authors.initials: K
authors.lastname: Kikuta
authors.affiliation: Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
authors.forename: Ryuhei
authors.initials: R
authors.lastname: Kitai
authors.affiliation: Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Kodera
authors.affiliation: Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
authors.forename: Hidetaka
authors.initials: H
authors.lastname: Arishima
authors.affiliation: Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Isozaki
authors.affiliation: Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
authors.forename: Norichika
authors.initials: N
authors.lastname: Hashimoto
authors.affiliation: Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Neishi
authors.affiliation: Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Higashino
authors.affiliation: Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Yamada
authors.affiliation: Division of Neurosurgery, Department of Sensory and Locomotor Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Matsuokashimoaizuki, Eiheiji-cho, Yoshida-gun, Fukui, 910-1193, Japan.
authors.forename: Munenori
authors.initials: M
authors.lastname: Yomo
authors.affiliation: Section of Operating Theater, University of Fukui Hospital, Fukui, Japan.
authors.forename: Kousuke
authors.initials: K
authors.lastname: Awara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002545:Brain Ischemia / Q000000981:diagnostic imaging / Q000453:epidemiology*; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000601:surgery*; D002533:Cerebral Angiography; D038524:Diffusion Magnetic Resonance Imaging; D005074:Evoked Potentials, Visual; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D064795:Intraoperative Neurophysiological Monitoring; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures; D015840:Oculomotor Nerve Diseases / Q000453:epidemiology*; D011183:Postoperative Complications / Q000453:epidemiology*; D012307:Risk Factors; D013100:Sphenoid Bone / Q000601:surgery; D020521:Stroke / Q000000981:diagnostic imaging / Q000453:epidemiology*; D014786:Vision Disorders / Q000453:epidemiology*
keywords: Anterior clinoidectomy; Bypass; Paraclinoid aneurysm; Visual function