Relation between hemodynamic force, displacement, and the recurrence of coils after coil embolization for cerebral aneurysms: A pilot study

Abstract

Objective: The objective of this study is to test the hypothesis that hemodynamic stress causes displacement or deformation of coils, resulting in cerebral aneurysm recanalization after treatment. Methods: Twenty-two patients with internal carotid artery cerebral aneurysms treated with coil embolization were included in this study. All patients were imaged with three-dimensional (3D) rotational angiography before and after treatment. The displacement and deformation of the coils were evaluated using a 3D workstation. Hemodynamic parameters were calculated using aneurysm images before treatment. Results: Four aneurysms (18%) showed recanalization one year after treatment. These four recurrence aneurysms had larger displacement after treatment (P = 0.049). Furthermore, they tended to have greater coil deformation. Among several hemodynamic parameters, inflow velocity at the aneurysmal neck before treatment was related to coil displacement (P = 0.0008), which resulted in the recurrence of the aneurysm after treatment (P = 0.049). The inflow velocity was linked to aneurysm recurrence after treatment (P = 0.0002). Furthermore, aneurysm recurrence with a slightly elevated pressure loss coefficient was associated with a greater volume ratio (P = 0.03). Conclusions: High flow velocity at the aneurysmal neck might cause displacement and/or deformation of the coils, resulting in aneurysm recanalization after treatment.