Application of dual Willis covered stents in the management of large fusiform carotid aneurysms in a canine model

Abstract

This study evaluates the efficacy of dual Willis covered stents for the treatment of large fusiform carotid aneurysms in a canine model. Carotid fusiform aneurysms >10 mm long were surgically created in 10 dogs and were then repaired using either single or dual covered stents. Clinical results were assessed by scheduled angiography and histological features by light and electron microscopy. Angiography immediately post-op and 6 months after surgery revealed aneurysm isolation rates of 60 and 20% for the single stent technique and 60 and 100% for the dual stent technique, respectively. The rate of complete obliteration of the aneurysm sac differed significantly between treatments (P = 0.048). The dual stent technique also resulted in greater endothelialization. For large carotid fusiform aneurysms in a canine model, endovascular repair using dual Willis covered stents is technically feasible and more effectively obliterates the aneurysm sac than the use of a single stent.

A single-center experience in the endovascular treatment of carotid siphon aneurysms using the Willis covered stent: a retrospective analysis

“…In addition, no or few embolization materials are deployed into the aneurysm sac, so the procedure causes no mass effects and does not impact aneurysm shrinkage after complete exclusion 10. Despite these advantages, the performance of the Willis covered stent requires further investigation for aneurysms of the cavernous, clinoid, and superclinoid segments.…”

Willis Covered Stent for Treating Intracranial Pseudoaneurysms of the Internal Carotid Artery: A Multi-Institutional Study

“…21,22 Compared with a flow diverting stent, the WCS seems safer and more efficient in treating pseudoaneurysms, and has several advantages: (1) WCSs allow instant exclusion of the aneurysm sac from the circulation; (2) WCSs have no procedural manipulations in the aneurysm sac, reducing the (3) the absence of coil embolization in the aneurysm sac results in no mass effects. 23 In this study, the WCS had good efficacy in occluding ICA pseudoaneurysms.…”

Endovascular isolation of intracranial blood blister-like aneurysms with Willis covered stent

“…Our results demonstrate that the WCS could be safe and efficient for the treatment of BBAs. The advantages of the WCS are as follows:16 18 (1) WCS placement is technically simple and the procedure is swift, safe, and less invasive; (2) none of the procedural manipulations occurred in the aneurysm lumen that could reduce the risk of procedural-related rupture; (3) the WCS can lead to an immediate exclusion of the aneurysm from circulation; (4) no embolization materials are deployed into the aneurysm sac so the procedure neither causes mass effects nor does it affect aneurysm shrinkage after complete exclusion. Despite these advantages, several points require further discussion.…”

“…The potential causes of endoleak after WCS deployment include incomplete occlusion of the aneurysm orifice, the inhomogeneous lumen of the blood vessel, aneurysms located at an acutely angled vessel segment, a tear in the graft, and retrograde flow from a collateral vessel 16 19…”

“…It has been improved from previously available stent models to enhance the flexibility and to facilitate its passing through the tortuous intracranial vasculature, especially the carotid siphon segment of the ICA. It has been reported that the WCS can safely and efficiently exclude recurrent intracranial aneurysms after coiling,14 distal ICA aneurysms,15 large fusiform carotid aneurysms,16 and large or giant intracranial aneurysms 17. Despite these encouraging studies, the safety and feasibility of endovascular treatment of BBAs with the WCS are unknown.…”