title: Cerebral aneurysm wall thickness analysis using intraoperative microscopy: effect of size and gender on thin translucent regions.
abstract: OBJECTIVE
  Wall thickness is a poorly documented characteristic of cerebral aneurysms which may provide insight into adaptive aneurysmal growth, aneurysm rupture risk and response to endovascular treatment. The distribution of aneurysm wall thickness, as observed by intraoperative video microscopy, is described.
  
  
  METHODS
  54 unruptured saccular cerebral aneurysms were selected based on the availability of intraoperative video obtained from patients undergoing microsurgical clipping. Aneurysms were assessed for the distribution of wall thickness based on color translucence and quantitation of pixel values at superthin translucent, intermediate and thick regions of the dome. The data were analyzed with respect to aneurysm morphology, location and associated demographic factors.
  
  
  RESULTS
  The mean proportions of tissue characteristic among all domes analyzed were found to be 27% superthin, 65% intermediate, and 8% thick. Smaller aneurysms having a maximal dimension Dmax <7 mm had a higher proportion of superthin tissue (p=0.003) and lower thick tissue (p=0.001) content. Female gender was associated with a significantly higher proportion of superthin tissue at the aneurysm dome (p=0.038), with no statistical dependence seen with patient age, smoking status or anatomical location.
  
  
  CONCLUSIONS
  The dome of unruptured aneurysms is a highly heterogeneous region with areas of variable thickness that appear to be intimately related to the process of aneurysm development. This inconstant property affects wall tensile stress, may play a role in aneurysm pathogenesis and focal rupture, and should be incorporated into future analyses of aneurysm rupture risk and mechanics.
authors.affiliation: Cerebrovascular and Endovascular Division, Department of Neurosurgery, Tufts Medical Center, Boston, Massachusetts 02111, USA.
authors.forename: Laith M
authors.initials: LM
authors.lastname: Kadasi
authors.forename: Walter C
authors.initials: WC
authors.lastname: Dent
authors.forename: Adel M
authors.initials: AM
authors.lastname: Malek
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000601:surgery*; D008297:Male; D018715:Microscopy, Video / Q000379:methods; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D012737:Sex Factors; D016896:Treatment Outcome