Analysis of slipstream flow in two ruptured intracranial cerebral aneurysms

Replicas of ruptured posterior communicating and basilar artery aneurysms w ere created from cadaveric specimens and then were placed in a circuit of p ulsating non-Newtonian fluid. Individual fluid slipstreams were opacified w ith isobaric dyes, and images were recorded on film. The slipstreams entere d the distal aneurysm neck with impact against the distal lateral wall of t he aneurysm. They then swirled slowly in a reverse vortical pattern within the aneurysm sac, Fluid exited the aneurysm at the proximal neck. The flow pattern clearly shows the impact zone of entering slipstreams (the point of aneurysm rupture) and provides information pertaining to aneurysm growth a nd formation.