AbstractID: 8434 Title: Imaging Stent-Induced Flow Modification In Cerebro-Vascular
Aneurysms With X-Ray Micro-Angiography
High-resolution images unavailable with standard x-ray imaging systems have been obtained with
a new micro-DQJLRJUDSKLFGHWHFWRUUHFRUGLQJZLWK PSL[HOVDWIUDPHVVWRVKRZGHWDLOHG
flow in aneurysms. With this new detector, we have demonstrated increasing disruption of
common vortex aneurysmal flow and reduced flow into an aneurysm model when less porous
stents are placed over the aneurysm orifice. For the untreated aneurysm model, a vortex stream
emanating from a thin distal orifice section is seen. For a single stent in place the vortex flow is
modified so that a jet-like stream emanating from the space between segments of the stent is
visualized. When three stents are deployed, one over the other, vortex-like flow returns, but
originating over the whole region of the orifice. When 100-PHVKVWHHOFORWKPDWHULDO PZLUH
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replaced by a convective seepage-like flow. The contrast media appears to go from the orifice to
the aneurysm body in spatially uniform pulses. Although interpretation of these flow images must
take into consideration the difference in the physical density and viscosity of contrast media and
the carrier fluid, the study justifies further development of an asymmetric stent designed with a
low-porosity patch-like region to cover the aneurysm orifice for minimally invasive treatment of
cerebrovascular aneurysms. The accurate angular positioning of such an asymmetric stent is
made possible by high-resolution image guidance using the new micro-angiographic detector.
[Support: NIH 1R01NS38745]