Flow diverter (FD) implantation is increasingly performed for aneurysms that are difficult to treat with conventional endovascular therapy and direct surgery. Now, a new FD stent, the Flow-Redirection Endoluminal Device (FRED), enters into clinical practice and is expected to have higher therapeutic efficacy. To predict whether an aneurysm is completely occluded by FRED, we have developed a novel computational fluid dynamics (CFD) technique using dual-layer porous media modeling that simulates its characteristic stent strut. This technique may be useful to evaluate hemodynamic changes in an aneurysm after FRED implantation using the preoperative patient-specific aneurysm geometry. The authors describe the novel CFD technique with a dual-layer porous media and report the potential usefulness of the technique to predict the aneurysm-occlusion status after FRED implantation preoperatively using an illustrative case of an unruptured internal carotid artery anterior wall aneurysm.

Endovascular therapy is developing, but not all aneurysms are completely obliterated even by using the techniques such as stent-assisted coiling or a flow diverter. To predict the aneurysm-occlusion status after stent-assisted coiling, the authors applied computational fluid dynamics (CFD) using porous media modeling to propose a new technique with the double porous media settings, one of which is a porous media setting for a coiled aneurysm and another of which is that for an intracranial stent. CFD with double porous media settings using preoperative aneurysm geometry may be useful for simulating the hemodynamic changes in intracranial aneurysms after stent-assisted coiling.