田邉 淳

This study investigated the hemodynamic effects of anastomosis site selection in superficial temporal artery to middle cerebral artery bypass surgery using computational fluid dynamics based on three-dimensional cerebral vascular models. By noninvasively reproducing blood flow changes that are difficult to evaluate in clinical settings, we visualized and quantified the effects of different bypass locations under both normal and stenotic conditions. To our knowledge, this is the first study to noninvasively evaluate the validity of anastomosis site selection in superficial temporal artery to middle cerebral artery bypass surgery using computational fluid dynamics simulation. The results demonstrated that factors, such as the distance from the anastomosis site to the target territory, flow direction, recipient vessel diameter, and pressure gradient, significantly influenced cerebral perfusion. In particular, bypass configurations that ensured antegrade flow, minimized the distance to the target region, and involved a larger recipient vessel diameter showed greater improvement in blood flow. These findings offer practical guidance for preoperative planning and are expected to contribute to the safer and more effective selection of bypass sites.

BACKGROUND: This study evaluated the safety and efficacy of a treatment strategy for Posterior communicating artery (PCOM) aneurysms using first-line Woven EndoBridge (WEB), supplemented by Flow diverter (FD) in selected cases. METHODS: This retrospective study included patients who underwent endovascular treatment for PCOM aneurysms between January 2021 and March 2025. Aneurysms were categorized as fetal or non-fetal. A first-line WEB strategy was adopted when morphology was suitable. Radiological and clinical outcomes were assessed. RESULTS: Forty-six PCOM aneurysms met the criteria: 14 fetal-type and 32 non-fetal-type. All previously untreated fetal-type aneurysms were treated with WEB (n = 9). In the non-fetal group, the initial treatments included WEB (n = 14), FD (n = 10), and coiling (n = 4). All recurrent fetal-type aneurysms were retreated with FD (n = 5), whereas non-fetal recurrences were managed with FD (n = 3) or coiling (n = 1), depending on prior treatment. At a median follow-up of 21 months, complete occlusion was achieved in 66.7% of fetal-type and 59.4% of non-fetal-type aneurysms (P = 0.739), and adequate occlusion was achieved in 75.0% and 90.6%, respectively (P = 0.321). Retreatment was required in two cases (4.3%): one in the fetal group (7.1%) and one in the non-fetal group (3.1%) (p = 0.512). No modified Rankin Scale worsening or major complications occurred. No significant differences in treatment efficacy were observed among modalities selected under the WEB first-line strategy. CONCLUSION: A first-line WEB strategy is safe and effective for PCOM aneurysms, including fetal-type variants, with outcomes for fetal-type aneurysms comparable to non-fetal-type aneurysms.