The effects of stenting and endothelial denudation on aneurysm and branch occlusion in experimental aneurysm models.

Abstract

BACKGROUND: Stents are increasingly used in the endovascular treatment of intracranial aneurysms. We studied the effects of stenting and endothelial denudation on aneurysm and branch vessel occlusion. METHODS: Bilateral lingual bifurcation venous pouch aneurysms were created in eight dogs, surgically scraping the aneurysmal endothelial lining on one side. Both arteries were immediately stented using balloon-expandable stents. In four other dogs, a wide-neck carotid bifurcation aneurysm was created, with the vein pouch denuded or not (n=2 each), followed by immediate stenting. Results were compared using angiography and pathology at 10 days (n=2), 10 (n=8), and 20 weeks (n=2). Branch occlusion between initial and final angiograms was recorded. Pathological evaluation of aneurysms was studied, with attention to neointima formation at the aneurysm ostium and around branch vessel origins. RESULTS: All stented and denuded lingual aneurysms were obliterated compared with two of eight lingual aneurysms that were stented alone (P=.007). None of the carotid bifurcation aneurysms became obliterated (0/4), but denuded aneurysms showed partial thrombosis (2/2). Of 68 total stent-covered branches, 5 (7%) were occluded and 17 (27%) had altered angiographic flow. CONCLUSIONS: Stenting led to suboptimal results in the presence of an intact endothelial layer. Endothelial denudation can promote aneurysm occlusion when combined with stenting.