Introduction: Flexible micro-stents, such as the closed-cell Enterprise (EN) device, have facilitated adjunctive coiling of intracranial aneurysms. Little data is available on stent struts’ ability to maintain vessel-wall apposition once deployed in the tortuous cerebral vasculature and the prevalence of incomplete stent apposition (ISA).
Methods: Post-procedural 3.0-Tesla MRA (3T-MRA) was obtained in a cohort of 39 patients undergoing EN stent-assisted intracranial aneurysm coiling. 3T-MRA was analyzed for presence of ISA and supplemented by angiographic C-arm Flat-panel CT (FPCT; DynaCT). Parent vessel diameter, curvature radius, and stent-subtended arc angle were measured at the site of deployment and analyzed for prediction of ISA in the ICA.
Results: 3T-MRA uncovered a unique crescent flow pattern (Crescent Sign, CS) outside of the EN struts, which was confirmed by FPCT to indicate ISA resulting from Enterprise stent crimping. ISA was detected on 3T-MRA in 19/39 patients (49%). Univariate analysis revealed ISA in the ICA to correlate with large stent-subtended angle, small curvature radius, and large diameter, but not stent length or jailing vs. sequential technique. Multivariate analysis identified ISA to correlate with vessel curvature radius (OR 253, P=.009), stent-subtended angle (OR 225, P=.005), and parent vessel diameter (OR 8.49, P=.044).
Conclusions: In this study, incomplete stent apposition was detectable by 3T-MRA in a significant proportion of patients undergoing EN stent-assisted coiling of ICA aneurysms in a vessel geometry- and stent deployment location-dependent manner. This characteristic of EN stent-coiling at this potentially tortuous location should be taken into account when selecting an endovascular strategy.
Patient Care: The research will help identify risk factors associated with an increased risk of undesirable incomplete stent apposition during aneurysm stent-coiling procedures.
Learning Objectives: 1-Identify presence of incomplete stent apposition in cases of intracranial stent-coiling
2-Learn link between target vessel geometric features and likelihood of developing incomplete stent apposition