Bailout stent deployment during coil embolization of intracranial aneurysms

Abstract

Background and purpose: Self-expandable stents are an effective tool for coil embolization of wide-neck intracranial aneurysms. The purpose of this study was to assess the feasibility and results of bailout stent positioning during rescue situations after deployment of > or =1 coil.

Materials and methods: Among 318 aneurysms treated by coil embolization in 267 patients, 16 patients who were treated by bailout stent deployment were retrospectively reviewed. Bailout procedures were performed to relieve potential parent artery compromise caused by the protruded coil loops or to prevent migration of the unstable coil basket. The size/location of the aneurysm, technical feasibility, successful stabilization rate, and procedure-related complications were evaluated.

Results: The locations of the aneurysms were the internal carotid artery (n = 12) and basilar artery (n = 4). The mean aneurysm size was 8.3 mm (range, 3.5-19.4 mm) with hemorrhagic presentation in 3 patients. Relief/prevention of parent artery compromise was achieved by molding the encroached loops back into the sac (n = 11), scaffolding the aneurysmal neck in cases with an unstable coil basket (n = 4), and sidetacking the migrated loop to the parent vessel wall (n = 1). The procedure was technically successful in 87.5% (n = 14). Satisfactory molding or stabilization of the coil was seen in 75% (n = 12). Unsatisfactory molding of the protruded small coil loop was noted in 2 cases of small aneurysms. Acute in-stent thrombosis was successfully managed by thrombolysis (n = 1).

Conclusions: Bailout self-expandable stent deployment may be a feasible and effective method for relief/prevention of parent artery compromise or coil migration caused by prolapsed or unstable coil loops during embolization of aneurysms.

Fig 1.

A 68-year-old woman presented with SAH from a right IC-PcomA aneurysm. A double-microcatheter technique was used for coiling of the wide-neck aneurysm. A, Native oblique anteroposterior and lateral views. After detachment of the third coil, encroachment of the coil mesh into the parent artery is noted. B, Due to concerns of parent vessel compromise, a 4 × 15 mm Neuroform stent was deployed at the site of the protruded coil mesh, achieving successful molding of the protruded coil mesh and restitution of the parent artery lumen. Residual protruding coil loop is seen on the lateral view, which is probably tacked to the sidewall by the stent. C, Subtracted views. Good parent vessel patency is maintained without signs of thrombus formation.

Fig 2.

A 66-year-old woman presented with an unruptured right superior hypophyseal aneurysm. A, Native anteroposterior/lateral views. During the deployment of the third coil by using balloon remodeling, protrusion and migration of a loop of the previously detached coil was noted (arrows). Pulsatile movement of the migrated distal coil loop was seen. B, A 4 × 20 mm Neuroform stent is deployed, which successfully sidetacks and stabilizes the migrated loop along the lateral wall of the parent vessel (arrows).