A new covered stent designed for intracranial vasculature: application in the management of pseudoaneurysms of the cranial internal carotid artery

Abstract

Background and purpose: The management of intracranial pseudoaneurysms is controversial. The purpose of this study was to provide a preliminary evaluation of the clinical efficacy of a Willis covered stent specially designed for the intracranial vasculature in the management of a pseudoaneurysm of the cranial internal carotid artery (CICA).

Materials and methods: Eight patients with pseudoaneurysms of the CICA were treated with use of the Willis covered stent. The flexibility of the entire stent system was gauged from the resistance met when reaching the target lesion and was categorized as no resistance, no apparent resistance, or resistance that could be overcome. The apposition of the Willis stent after deployment was scored as excellent with no endoleak, good with a small endoleak, or bad with an apparent endoleak. Follow-up angiography was performed 3 to 12 months after placement of the stent, and angiographic assessments were categorized as endoleak, stenosis of the covered segment of vessel, or occlusion of parent arteries. Follow-up clinical evaluations were also performed, and outcomes were graded as full recovery, improvement, unchanged, and aggravation.

Results: Endovascular treatment was technically successful in all aneurysms without procedural-related complications, and all of the stents were easily navigated to the targeted lesions in the CICA. Complete resolution of the pseudoaneurysm was observed in 6 patients immediately after the procedure, and a minimal endoleak into the aneurysm persisted in 2 patients. No morbidity or mortality and no technical adverse event occurred. A follow-up angiogram confirmed complete reconstruction of the internal carotid artery, with no recurrent aneurysmal filling and no occurrence of stenosis in the area of the stent. By the final follow-up visit, 4 patients had fully recovered, 3 had improved, and 1 patient's condition was unchanged.

Conclusion: On the basis of our preliminary experience, the Willis covered stent specially designed for the intracranial vasculature can manage a CICA pseudoaneurysm safely and effectively, but longer follow-up and expanded clinical trials are needed.

Fig 1.

The Willis covered stent. A, The covered stent is attached to the balloon catheter, with the arrows demonstrating the 2 ends of the covered stent. The diameter of the entire system is 3.8F (1.27 mm) when it is not expanded. B, The covered stent is expanded completely against the wall of the model glass tube similar to the siphon segment of the internal carotid artery (arrows).

Fig 2.

Case 8, a 11-year-old boy with a pseudoaneurysm secondary to a traumatic internal carotid artery. A,B, Anteroposterior and lateral cerebral angiograms show a narrow-necked pseudoaneurysm on the right C7 segment (arrow), with the stenosis of the parent artery. C, A plain film after stent placement clearly shows the position of the covered stent (arrow). D,E, Anteroposterior and lateral cerebral angiograms show complete resolution of the aneurysm immediately after stent placement, with obliteration of the stenosis of the parent artery.

Fig 3.

Case 6, a 23-year-old man with a pseudoaneurysm secondary to post-balloon embolization of a CCF. A, Lateral cerebral angiogram reveals a wide-necked pseudoaneurysm (black arrow) on the left C4 segment, with stenosis at the proximal part of the parent artery (empty arrow). B, Plain film after stent placement clearly shows the covered stent bridging the pseudoaneurysm and the stenosis (arrows). C, Lateral cerebral angiogram shows complete resolution of the aneurysm immediately after the stent placement. D, Cerebral angiography 3 months after the procedure shows total obliteration of the aneurysm with patency of the parent artery.

Fig 4.

Case 5, a 35-year-old man with massive epistaxis. A, Lateral cerebral angiogram shows a giant pseudoaneurysm on the left C5 segment (arrow). B, The Willis covered stent can be clearly seen in the plain film (arrows) after stent placement. C, Cerebral angiogram immediately after stent placement demonstrates a minimal endoleak into the pseudoaneurysm (arrow) in the orifice of the ophthalmic artery (arrow). D, Follow-up cerebral angiogram 2 months after the procedure demonstrates that retention of contrast medium at the orifice of the ophthalmic artery is increased (arrow), which suggests the existence of a residual cavity. E, Follow-up cerebral angiogram 6 months after the procedure demonstrates obvious shrinkage of the residual cavity (arrow) with patency of the parent artery.