Wall shear stress distribution of small aneurysms prone to rupture: a case-control study.

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage after intracranial aneurysm rupture remains a serious condition. We performed a case-control study to evaluate the use of computed hemodynamics to detect cerebral aneurysms prone to rupture.

METHODS

Four patients with incidental aneurysms that ultimately ruptured (cases) were studied after initially being included in a prospective database including their 3-dimensional imaging before rupture. Ruptures were located in different arterial segments: M1 segment of the middle cerebral artery; basilar tip; posterior inferior cerebellar artery; and anterior communicating artery. For each case, 5 controls matched by location and size were randomly selected. An empirical cumulative distribution function of aneurysm wall shear stress percentiles was evaluated for every case and used to define a critical prone-to-rupture range. Univariate logistic regression analysis was then used to assess the individual risk of rupture.

RESULTS

A cumulative wall shear stress distribution characterizing a hemodynamic prone-to-rupture range for small-sized aneurysms was identified and fitted independent of the location. Sensitivity and specificity of the preliminary tests were 90% and 93%, respectively.

CONCLUSIONS

The wall shear stress cumulative probability function may be a potential predictor of small-sized aneurysm rupture.