The effect of vascular reconstruction device-assisted coiling on packing density, effective neck coverage, and angiographic outcome: An in vitro study

OBJECTIVE: The objective of this study was to assess the variations in packing density, effective neck coverage, and angiographic outcome between aneurysm coiling alone and with the support of the Enterprise Vascular Reconstruction Device (VRD; Cordis Neurovascular, Inc., Miami Lakes, FL). Although the use of VRD-assisted coiling is growing due to the availability of better devices, little is known about the impact of the VRDs on the aforesaid variables. METHODS: Ten groups of two silicone aneurysm models each were embolized with detachable coils, one with VRD support and one without. Coil embolization ceased once the microcatheter backed out of the aneurysm or there was a risk that further packing would lead to coil herniation. Angiograms were assessed using the Raymond classification scale. Gross macroscopic images of the aneurysm neck were taken to quantify the coil neck coverage, defined as the surface area fraction of coils at the neck divided by the total neck area. Packing density was calculated. RESULTS: Packing density significantly increased with VRD assistance (absolute increase, 10.5%; relative increase, 31%; P < 0.0001, paired t test). Effective neck coverage significantly increased by 9% with VRD deployment (P < 0.05, t test). Angiographically, aneurysms coiled without VRD support were more likely to have a dome remnant (P < 0.05, Fisher's exact test) and coil prolapse into the parent vessel. CONCLUSION: VRD deployment improves coil neck coverage and increases packing density. These results support the hypothesis that VRD deployment to reinforce coil embolization of cerebral aneurysms may lead to more durable aneurysm obliteration.