Morphological Stability of Intracranial Aneurysms and the Contour Neurovascular System: A Longitudinal Analysis

The Contour Neurovascular System (CNS) is a novel intrasaccular flow disruptor for the endovascular treatment of wide-necked aneurysms. While more longitudinal studies are needed to fully assess its efficacy, initial study results over the past few years have been promising. However, no studies have yet assessed the CNS's robustness to deformation over time, and few have assessed its effect on the morphology of intracranial aneurysms.

Thirteen IAs were retrospectively analyzed using co-registered 3D meshes from serial imaging (2-5 scans per patient, up to 26 months of follow-up). Morphological parameters of the ostium and CNS were compared across defined time points. Intra-patient variance was also assessed through scans taken on the same day, and morphology was correlated with treatment outcome.

Significant postprocedural changes were observed in the ostium's ellipticity index (EI; $\Delta$ = -0.07 ±0.06, p = 0.01, d = -1.18) and neck circularity index (NCI; $\Delta$ = +0.04 ±0.04, p = 0.04, d = 0.90). No statistically significant long-term changes were detected for either the ostium or CNS. Most variations were within intra-patient variance, and many measured deformations were below imaging resolution (0.16-0.47 mm). No correlation was found between recurrence and morphology.

Only immediate postprocedural shape changes of the ostium were significant. No measurable long-term deformation of the CNS or ostium was observed. The CNS appears morphologically stable, though larger, high-resolution studies are needed to confirm these findings.