Recanalization, Regrowth, and Delayed Rupture of a Previously Coiled Unruptured Anterior Communicating Artery Aneurysm: A Longitudinal Hemodynamic Analysis

BACKGROUND: Delayed rupture of a previously coiled unruptured aneurysm is extremely rare, and no hemodynamic analysis of such aneurysms has been reported during the postprocedural course. CASE DESCRIPTION: We present a case of an initially successfully embolized, unruptured anterior communicating artery aneurysm that subsequently underwent recanalization, regrowth, and delayed rupture 35 months after embolization. We used computational fluid dynamics to determine the hemodynamics at different stages during longitudinal follow-up and to evaluate wall shear stress (WSS) and flow velocity at peak systole. We found that high-flow impingement was associated with recanalization, that regrowth as bleb formation was induced by high WSS and flow velocity, and that low WSS was a risk factor for aneurysm rupture. CONCLUSIONS: Heterogeneous hemodynamic characteristics were involved in the outcomes of intracranial aneurysm after endovascular treatment. High-flow impingement and WSS were associated with recanalization and regrowth, whereas low WSS was associated with aneurysm rupture.