title: Morphological Risk Factors for Rupture of Small (<7 mm) Posterior Communicating Artery Aneurysms.
abstract: BACKGROUND
  The management of small, unruptured intracranial aneurysms is still controversial. Given the distinctive natural history of aneurysm at different locations, location-specific analysis might be a reasonable approach. This study aimed to investigate morphological discriminators for rupture status by focusing on only posterior communicating artery (PcomA) aneurysms smaller than 7 mm.
  
  
  METHODS
  In 108 small PcomA aneurysms (68 ruptured, 40 unruptured), clinical and morphological characteristics were compared between the ruptured and unruptured groups. Multivariate logistic regression analysis was performed to determine the independent predictors for the rupture status of small PcomA aneurysms.
  
  
  RESULTS
  None of the clinical characteristics were significantly different between the ruptured and unruptured groups (P > 0.05). The ruptured group revealed a significantly larger size (P = 0.009), aspect ratio (P = 0.009), size ratio (P = 0.002), dome-to-neck ratio (P = 0.002), inflow angle (P < 0.001), and proportion of bleb formation (P = 0.039). Bottleneck factor (P = 0.154), diameter of PcomA (P = 0.302), and fetal-type PcomA (P = 0.832) showed no significance. With multivariate analyses, size ratio (P = 0.012) and inflow angle (P = 0.001) were shown to be independently associated with the rupture status of small PcomA aneurysms.
  
  
  CONCLUSIONS
  Morphological characteristics were closely related with the rupture status of small PcomA aneurysms. Size ratio and inflow angle were independent risk factors for rupture and might be useful in clinical risk stratification of small PcomA aneurysms.
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Lv
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Zhengzhe
authors.initials: Z
authors.lastname: Feng
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Chi
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Cao
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Yibin
authors.initials: Y
authors.lastname: Fang
authors.affiliation: Cerebrovascular Center, Department of Neurosurgery, Houston Methodist, Houston, Texas, USA.
authors.forename: Christof
authors.initials: C
authors.lastname: Karmonik
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China.
authors.forename: Jianmin
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Neurosurgery, Changhai Hospital, Second Military Medical University, Shanghai, China. Electronic address: ocinhqh@163.com.
authors.forename: Qinghai
authors.initials: Q
authors.lastname: Huang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000453:epidemiology / Q000473:pathology*; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000453:epidemiology / Q000473:pathology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D020769:Posterior Cerebral Artery / Q000473:pathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors
keywords: Intracranial aneurysm; Morphology; Posterior communicating artery; Rupture