Three-dimensional pulsatile flow simulation before and after endovascular coil embolization of a terminal cerebral aneurysm

The effect of different percentages of coil mesh in a cerebral aneurysm on the pulsatile flow and pressure in the parent vessel and aneurysm lumen was evaluated. Geometric data on a basilar tip aneurysm and vertebrobasilar ar teries after subarachnoid hemorrhage was obtained by computer tomographic a ngiography. Intraarterial pressure was measured at four vertebrobasilar poi nts before and after treatment with detachable coils. Pulsatile flow was do cumented by transcranial ultrasonography, A three-dimensional computer simu lation was created using a commercial fluid dynamics solver for four aneury sm conditions: (1) before intervention; (2) with a 20% filling showing a co mplete cessation of the inflow through the aneurysm neck; (3) with a 12% fi lling showing an incomplete deceleration of inflow through the aneurysm nec k, with a remaining flow around the embedded platinum coils and (4) with a 12% filling and simulation of clotted aneurysm dome, which did not inhibit persisting flow phenomena. The relative pressure amplitudes neither increas ed nor decreased under the different simulated aneurysm filling conditions. Inserted platinum coils can immediately and decisively relieve the influx of pulsating blood and allow for initial clotting. To reach this effect, a volume density of 20% platinum coil mesh in the aneurysm neck is needed.