Figure 1.
Angiograms and illustrations of straightening of vessels by stent placement in Case 1.
(A) An angiogram shows a sidewall aneurysm at the left vertebral artery. (B) Six months after stent-assisted coil embolization for the aneurysm, an angiogram shows complete occlusion of the aneurysm and straightening of the vessel. (C) Two 3D images of the vessel and the aneurysm at pre- (in red) and post-treatment (in blue) are fused. (D) The “inflow angle” and “outflow angle” are defined as angles between the neck plane of an aneurysm and an inflow line or an outflow line, respectively. The angles can be negative when the angles show opposite directions.
Figure 2.
Illustrations of hemodynamic analysis of reduction in flow velocity in an aneurysm of Case 1.
Contours of the cut plane are colored according to mean flow velocity. The white arrow in the pre-treatment image indicates the flow direction. Flow velocity was reduced by 20% after placement of stent struts on the initial geometry. Flow velocity was reduced by −11% (i.e., increased by 11%) after straightening of a vessel without stent struts. The combination of both stent struts and straightening resulted in a flow reduction of 15%. Straightening of the vessel changed the inflow angle from −24° to −15°.
Figure 3.
Reduction in flow velocity in 16 cases by either stent struts or straightening of vessels.
Figure 4.
Correlations among pre-operative inflow angle, changes in inflow angle, and flow reduction by vessel straightening.