Abstract
BACKGROUND AND PURPOSE: FDs are new intracranial stents designed to occlude aneurysms while preserving flow to jailed arterial branches. We tested this fundamental principle in a new aneurysm model.
MATERIALS AND METHODS: Canine lateral wall aneurysms, featuring a branch located immediately opposite the aneurysm, were created in 16 animals to study the effects on aneurysm or branch occlusion using single HP stents (n = 4), 2 overlapping HP stents (n = 4), or an FD (n = 8). Two other animals, in which an efferent arterial branch was anastomosed to the aneurysm fundus, were also treated with FDs. Angiographic results after deployment, at 2 weeks, and at 3 months were scored using an ordinal scale. The metal porosity of the FSS and the amount of FSS neointima formation was determined by postmortem photography.
RESULTS: FDs led to better angiographic occlusion scores compared with HP stents (P = .026). FDs were significantly more likely to occlude the aneurysm than the branch (P = .01). When the branch was switched to originate from the aneurysm fundus, the FDs became ineffective (0/2). Neointimal closure of the aneurysm ostium was significantly better with FDs than with single or double HP stents (P = .039). Angiographic occlusion correlated with metallic porosity and neointimal tissue coverage (Spearman ρ = −0.81; P = .001).
CONCLUSIONS: In this study, flow diverters occluded lateral wall aneurysms more readily than branches. Metal device porosity strongly influenced the occlusion rate.
Abbreviations
- ASA
- aspirin
- CCA
- common carotid artery
- CFD
- computational fluid dynamics
- FD
- flow diverters
- FSS
- free segment of stent
- HP
- high-porosity
- © 2012 American Society of Neuroradiology