A Potential Predictor of Proximal Flow-Diverter Stent Jailed Artery Stenosis: Distal to Proximal Artery Diameter Ratio.

Background: Flow-diverting stents (FDS) are widely used in the treatment of intracranial aneurysms. During treatment, many side branches-especially small ones-are inevitably covered, leading to narrowing and impaired blood flow. However, the factors contributing to stenosis have not been thoroughly studied.

Methods: A retrospective cross-sectional study was conducted. Digital subtraction angiography (DSA) images and clinical data were collected. Two neuroradiologists independently assessed arterial geometry characteristics. Participants were divided into a narrow group and unchanged group based on preoperative and follow-up data, and the characteristics of the two groups were compared. A simplified model was established to evaluate changes in wall shear stress (WSS) before and after FDS implantation.

Results: The distal small branch diameter in the unchanged group was significantly smaller than that in the narrow group. The ratio of distal to proximal diameters of the ophthalmic artery (DPOA) in the narrow group was concentrated between 0.9 and 1.1. WSS in the proximal ophthalmic artery region (POAR) increased with larger distal ophthalmic artery diameters, both pre- and post-operatively. The difference between preoperative and postoperative WSS also increased with higher DPOA. Conclusions: After FDS implantation, the WSS of most jailed ophthalmic arteries in POAR decreased. However, in cases with proximal stenosis, the DPOA of these jailed ophthalmic arteries was primarily concentrated between 0.9 and 1.1. This pattern may occur because WSS decreased from high level to low level.