Is aspect ratio a reliable predictor of intracranial aneurysm rupture?
OBJECTIVE
This study was undertaken to assess the reliability of the aspect ratio (AR) (i.e., aneurysm depth to aneurysm neck) in predicting aneurysm rupture. It has been shown that the AR is a key factor in predicting intraaneurysmal blood flow and aneurysm rupture.


METHODS
Seventy-five patients with subarachnoid hemorrhage and multiple aneurysms were studied. The sizes of the aneurysms and their ARs were determined by examining the angiographic films. By comparing the difference between ruptured and unruptured aneurysms in the same individual, each patient in effect served as his or her own control. Each ruptured aneurysm was confirmed during surgery.


RESULTS
There were 75 ruptured and 107 unruptured aneurysms. The mean AR was 2.70 for ruptured aneurysms, compared with 1.8 for unruptured aneurysms. This difference between the ARs was statistically significant (P < 0.001). The difference in aneurysm sizes in the two groups also was significant (P < 0.001).


CONCLUSIONS
AR on its own is as reliable a variable as the size of the aneurysm for predicting aneurysm rupture.
Nader-Sepahi
Ali
A
Victor Horsley Department of Neurosurgery, The National Hospital for Neurology and Neurosurgery, Queen Square, London, England.
Casimiro
Miguel
M
Sen
Jon
J
Kitchen
Neil D
ND
D000293:Adolescent; D000328:Adult; D000368:Aged; D017542:Aneurysm, Ruptured / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D001783:Blood Flow Velocity; D016022:Case-Control Studies; D002536:Cerebral Arteries / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011859:Radiography; D015203:Reproducibility of Results