title: Morphology of Ruptured and Unruptured Intracranial Aneurysms.
abstract: BACKGROUND
  In addition to size and location, the morphology of intracranial aneurysms has been proposed to predict rupture. This study was undertaken to compare morphologic features between ruptured and unruptured aneurysms and identify those associated with greater risk of rupture.
  
  
  METHODS
  Between 2010 and 2014, 301 patients with subarachnoid hemorrhage and 204 with unruptured aneurysms were admitted to our hospital. Two investigators reviewed 3-dimensional angiograms of all aneurysms. Risk factors for rupture were identified. Morphology was classified into single-sac aneurysms with smooth margin, single-sac aneurysms with irregular margin, aneurysms with a daughter sac, and multilobulated aneurysms. The value of morphology in predicting rupture was tested with the use of logistic regression.
  
  
  RESULTS
  A total of 420 aneurysms met the inclusion criteria. Multilobulated aneurysm was the most frequent finding among ruptured aneurysms, followed by single sac with irregular margin, aneurysm with daughter sac, and single sac with smooth margin (44.9%, 25.9%, 18%, and 11.2%, respectively). Among unruptured aneurysms, single sac with smooth margin was the most frequent finding, followed by single sac with irregular margin, multilobulated aneurysm, and aneurysm with daughter sac (38.1%, 29.8%, 20.9%, and 11.2%, respectively). Morphology was an independent predictor of rupture (receiver operating characteristic-area under the curve 0.693, P < 0.001). Risk of rupture increased by factor of 3 (5, 95% confidence interval [CI] 1.6-5.3) from single sac with regular margin to irregular margin, by factor of 5.5 (5, 95% CI 2.8-11.0) to daughter sac, and by factor of 7.3 (5, 95% CI 4.1-13.1) to multilobulated aneurysm.
  
  
  CONCLUSIONS
  Morphology might have an independent predictive value of aneurysm rupture. Risk of rupture might increase according to extent of morphologic change. Prospective studies will be necessary to evaluate the influence of aneurysm morphology on natural history.
authors.affiliation: Department of Neurosurgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany. Electronic address: tabboud@uke.de.
authors.forename: Tammam
authors.initials: T
authors.lastname: Abboud
authors.affiliation: Department of Internal Medicine, Klinikum Itzehoe, Itzehoe, Germany.
authors.forename: Jihad
authors.initials: J
authors.lastname: Rustom
authors.affiliation: Department of Neuroradiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Maxim
authors.initials: M
authors.lastname: Bester
authors.affiliation: Department of Neurosurgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Czorlich
authors.affiliation: Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Eik
authors.initials: E
authors.lastname: Vittorazzi
authors.affiliation: Department of Medical Biometry and Epidemiology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Hans O
authors.initials: HO
authors.lastname: Pinnschmidt
authors.affiliation: Department of Neurosurgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Manfred
authors.initials: M
authors.lastname: Westphal
authors.affiliation: Department of Neurosurgery, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Regelsberger
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000150:complications / Q000000981:diagnostic imaging*; D019540:Area Under Curve; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging*; D002533:Cerebral Angiography; D000072226:Computed Tomography Angiography; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D002532:Intracranial Aneurysm / Q000150:complications / Q000000981:diagnostic imaging*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging* / Q000209:etiology; D055815:Young Adult
keywords: Aneurysm rupture; Intracranial aneurysm; Morphology; Subarachnoid hemorrhage