title: Justification of unruptured intracranial aneurysm repair: a single-center experience.
abstract: OBJECTIVE
  Whether to treat UIAs is controversial. The aim of the study was to compare the clinical outcome of patients with UIAs who were either treated conservatively or preventively.
  
  
  METHODS
  Patients with UIAs referred to our institution were prospectively enrolled in the study. Data collected included baseline characteristics, aneurysmal features, and procedural and follow-up information. Preventive treatment was recommended if the aneurysm was larger than 5 mm and was considered safely treatable. Endovascular surgery was the first-line therapy if the aneurysmal shape was appropriate for coiling.
  
  
  RESULTS
  From January 2003 through April 2008, a total of 879 patients with 1110 UIAs were enrolled; 325 patients with 369 UIAs (mean size, 7.8 mm) were treated (treatment group), and 603 patients with 741 UIAs (mean size, 4.4 mm) were managed conservatively (observation group). Mean follow-up was 692.5 days (1405.5 person-years). In the observation group, 26 aneurysms (3.5%) had ruptured (1.8% per year; 1405.5 person-years), 10 patients died, and 7 were disabled (mRS, 3-6: 2.8%). Aneurysmal size was a significant risk factor for rupture (P = .001). The treatment group included aneurysms treated either with coiling (n=315), clipping (n=32), or a combined approach (n=9); 1 patient died, and 3 were disabled (mRS, 3-6: 1.2%). Therapeutic intervention was equal (UIAs of all sizes) or superior (UIAs > 5 mm; P = .025) to conservative management.
  
  
  CONCLUSIONS
  Treatment of UIAs was justified in aneurysms larger than 5 mm, and EVS can be safely applied to nearly 90% of UIAs.
authors.affiliation: Division of Endovascular Neurosurgery, Department of Neurosurgery, The Jikei University School of Medicine, Tokyo, Japan. t-ishibashi@jikei.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Ishibashi
authors.forename: Y
authors.initials: Y
authors.lastname: Murayama
authors.forename: T
authors.initials: T
authors.lastname: Saguchi
authors.forename: M
authors.initials: M
authors.lastname: Ebara
authors.forename: H
authors.initials: H
authors.lastname: Arakawa
authors.forename: K
authors.initials: K
authors.lastname: Irie
authors.forename: H
authors.initials: H
authors.lastname: Takao
authors.forename: T
authors.initials: T
authors.lastname: Abe
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging / Q000401:mortality* / Q000601:surgery*; D015897:Comorbidity; D057510:Endovascular Procedures / Q000401:mortality*; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000401:mortality* / Q000601:surgery*; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000401:mortality*; D011859:Radiography; D012307:Risk Factors; D017678:Sex Distribution; D015996:Survival Rate; D055815:Young Adult