title: Factors for Achieving Safe and Complete Treatment for Unruptured Saccular Aneurysm Smaller Than 10 mm by Simple Clipping or Simple Coil Embolization.
abstract: OBJECTIVE
  Reducing complications from unruptured aneurysms (UAs) treatment is important. We clarify the criteria for achieving safe and complete treatment for UAs ≤10 mm by clipping or coil embolization.
  
  
  METHODS
  This study included 59 newly treated UAs in the past 2 years. We prospectively decided on criteria to recommend active treatment. UAs ≤10 mm and in ≤75 year-olds, located at in the internal carotid artery at the paraclinoid portion and the posterior circulation aneurysms except for a vertebral artery-inferior posterior cerebellar artery aneurysm were mainly treated by coil embolization, and those in the internal carotid artery except at the paraclinoid portion, in the anterior or middle cerebral artery, and in the vertebral artery-inferior posterior cerebellar artery were treated preferably by clipping. UAs with a height/neck ratio or a dome/neck ratio ≤1.4 were treated preferentially by clipping. Specific preoperative imaging and careful manipulation were adopted for clipping.
  
  
  RESULTS
  Fifty-seven (96.6%) achieved modified Rankin scale (mRS) 0-1, 2 (3.4%) mRS 2-5, and 0 had mRS 6. Fifty-three UAs (89.8%) achieved complete occlusion (CO) and 7 (10.1%) had neck remnants (NR). Forty-one UAs (100%) within the criteria achieved mRS 0-1, 40 (98%) achieved CO, and 1 (2%) NR. The odds ratio of NR for those outside the criteria was 18.5 (95% confidence interval, 1.83-186.6) (P < 0.05). CO treated within the criteria was 39 and NR was 1. CO treated outside the criteria was 14 and NR was 5 (P < 0.05). The mRS 0-1 with age ≤75 years was 55 and the mRS 2-6 was 0. The mRS 0-1 with age ≥76 years was 2 and the mRS 2-6 was 2 (P < 0.01).
  
  
  CONCLUSIONS
  The treatment for UAs within the criteria, with the most recent points of concern, can lead to safe and complete results.
authors.affiliation: Department of Neurosurgery, Kyoto Second Red Cross Hospital, Kyoto, Japan. Electronic address: htenjin@nn.iij4u.or.jp.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tenjin
authors.affiliation: Department of Neurosurgery, Kyoto Second Red Cross Hospital, Kyoto, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yamamoto
authors.affiliation: Department of Neurosurgery, Kyoto Second Red Cross Hospital, Kyoto, Japan.
authors.forename: Yudai
authors.initials: Y
authors.lastname: Goto
authors.affiliation: Department of Neurosurgery, Kyoto Second Red Cross Hospital, Kyoto, Japan.
authors.forename: Seisuke
authors.initials: S
authors.lastname: Tanigawa
authors.affiliation: Department of Neurosurgery, Kyoto Second Red Cross Hospital, Kyoto, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Takeuchi
authors.affiliation: Department of Neurosurgery, Kyoto Second Red Cross Hospital, Kyoto, Japan.
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Nakahara
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D021721:Balloon Occlusion / Q000379:methods; D000072226:Computed Tomography Angiography / Q000379:methods; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D016896:Treatment Outcome
keywords: Clipping; Coil embolization; Treatment selection; Unruptured aneurysm