Computer simulation of flow dynamics in paraclinoidal aneurysms.

SUMMARY: Endovascular treatment, which is very useful method especially for paraclinoidal aneurysms, has the limitations of coil compaction and recanalization, which are difficult to predict. We tried to understand flow dynamic features, one of the important factors of such problems, using computer flow dynamics (CFD) simulations. CFD simulations were made in paraclinoidal aneurysm model of different size and protruded directions. Flow patterns, flow velocities and pressure are analyzed. Although the pressure on the aneurismal orifice is highest in the aneurysm protruding vertically - upward, the flow velocity is highest in the superior-medial protruding one. Significant difference is not observed in either flow patterns, flow velocities or pressures on the aneurismal orifices between the sizes of aneurismal sac. Among paraclinoidal aneurysms, an aneurysm protruding to superior-medially receives the most severe haemodynamic stresses at the orifice and the aneurysm size does not cause significant differences in the aspect of flow dynamics. It should be considered in the treatment of such aneurysms.