Therapeutic internal carotid or vertebral artery occlusion using the WEB device

Abstract

The WEB device was used to occlude the internal carotid artery or vertebral artery as treatment for large aneurysms. The WEB could be placed accurately at the desired position inside the vessel. Two WEBs were sufficient to occlude the parent artery.

In the endovascular treatment of large and giant intracranial aneurysms, therapeutic occlusion of the internal carotid artery (ICA) or the vertebral artery is an important modality.^1,2 Tolerance to ICA occlusion can be evaluated reliably with the angiographic test. ICA occlusion during testing can be done by temporary inflation of a non-detachable balloon mounted on a micro-catheter. Several device manufacturers offer these non-detachable micro-balloons. Permanent occlusion of the ICA is mostly performed by placing detachable micro-balloons mounted on a specially designed micro-catheter (for example Goldvalve balloons, Balt, Montmorency, France). However, from about a year ago, these detachable micro-balloons are no longer available on the market.

Some operators do not use detachable balloons but detachable coils to occlude the ICA with trapping of the aneurysm.² This technique is more difficult to perform than balloon occlusion and many coils are often needed in a long segment before total ICA occlusion is accomplished.

We have recently used the WEB device^3,4 (Sequent Medical, Aliso Viejo, CA, USA) for ICA and vertebral artery occlusion in five patients with good results (Table 1). The WEB can be placed and detached exactly in the desired location in the vessel. The following cases may be illustrative.

Table 1.

Patient and aneurysm characteristics of five patients with therapeutic large vessel occlusion using the WEB.

Patient no. gender, age (years)	Treatment date	Clinical presentation	Aneurysm location	Parent vessel occlusion	WEB devices	Follow-up
1. M, 49	18 May 2015	Brain stem compression	Fusiform vertebrobasilar	Right vertebral	SLS 5 mm SLS 7 mm	3 months unchanged
2. V, 70	1 June 2015	Brain stem compression	Fusiform basilar	Right vertebral	SLS 7 mm SLS 6 mm	3 months unchanged
3. M, 18	6 October 2015	Abducens palsy	ICA petrosal segment	ICA	SL 9 × 6 mm (2×) SL 9 × 7 mm SL 8 × 6 mm	2 months cured
4. M, 72	15 October 2015	Ophthalmoparesis	ICA cavernous segment	ICA	SL 9 × 7 mm SL 9 × 6 mm	NA
5. V, 74	17 December 2015	Ophthalmoplegia	ICA cavernous segment	ICA	SLS 9 mm 2×	NA

ICA: internal carotid artery.

Case 1, patient 3

A 19-year-old man presented with headaches and left-sided abducens paresis for a duration of one week. Magnetic resonance imaging (MRI) showed a large area with flow void in the skull base on the left side consistent with an ICA aneurysm. The patient was referred to our institution and angiography demonstrated a large, irregular shaped fusiform aneurysm in the petrosal segment of the left ICA (Figure 1(a) and (d)). After multidisciplinary consultation, it was decided to perform a test occlusion of the left ICA. Angiography of the right ICA during balloon occlusion of the left ICA showed excellent overflow to the left hemisphere with synchronous opacification of the cortical veins (Figure 1(b) and (c)). Subsequently, the left ICA was occluded by trapping the aneurysm. Two WEBs were placed after each other distal to the aneurysm in the C5 segment (Figure 1(e)) and another two WEBs were placed after each other proximal in the cervical ICA (Figure 1(f), arrows). Clinical and MRI follow-up 4 weeks later was uneventful, with normal vision and eye movements.

Figure 1.

An 18-year-old man with abducens palsy caused by a giant carotid petrosal aneurysm.

Case 2, patient 4

A 72-year-old man presented with progressive double vision. On examination, partial right third nerve palsy caused ophthalmoparesis. MRI revealed a giant, partially thrombosed aneurysm in the right cavernous sinus. The patient consented to a test occlusion of the right ICA followed by permanent occlusion when possible. Angiography of the right ICA confirmed the giant cavernous sinus aneurysm (Figure 2(a)). During balloon test occlusion there was ample overflow via both anterior and posterior communicating arteries (Figure 2(b) and (c)) with synchronous filling of the cortical veins. Next, the right ICA was permanently occluded with two WEBs (Figure 2(d), arrows) resulting in total occlusion of the ICA (Figure 2(e), arrow). MRI the next day confirmed thrombosis of the aneurysm (Figure 2(f)).

Figure 2.

A 72-year-old man with oculomotor palsy from a giant, partially thrombosed carotid cavernous aneurysm.

In our preliminary experience, large vessel occlusion using the WEB proved reliable and technically easy to perform. We used oversized WEBs of about two times the vessel diameter: 9 mm WEBs in 4–5 mm ICAs and 5–7 mm WEBs in 3–4 mm V4 segments of vertebral arteries. We used maximum available WEB heights to ensure a long segment occlusion of the vessels. Oversized WEBs are tightly secured in the vessel without risk of distal displacement by the flow. WEBs of these sizes can be delivered through a 0.027 inch lumen micro catheter (VIA, Sequent Medical). Although we used four WEBs in the illustrated case 1, two WEBs were sufficient for immediate artery occlusion as illustrated in case 2. After placement of the two WEBs, flow was stopped in the occluded vessel within a few minutes.

In our experience, large vessel occlusion with the WEB is technically much easier than coil occlusion. The WEB can be placed exactly in the desired location. With coils, oversized coil loops are prone to extend distally and many coils are often needed before the vessel is finally occluded. With trapping of the aneurysm, distal ICA occlusion over a short segment with coils is technically difficult or impossible. During the process of coil placement, thrombus may develop and dual anticoagulation may be necessary. With WEB occlusion, we only used 5000 U heparin during the procedure and no anticoagulation in the postoperative period. Although the price of the WEB is relatively high, only two WEBs are needed as opposed to many (five to 10) coils. In our opinion, the technical advantages of the WEB outweigh the possible higher costs compared to coils.

A single WEB could possibly also be used in combination with coils to occlude proximally the artery or trap the aneurysm. After placement of a WEB at the desired distal location in the vessel, coils could be used for further proximal occlusion. With proximal occlusion without aneurysm trapping, the WEB will prevent the coil loops extending distally in the vessel.

In conclusion, the WEB is a valuable alternative to the no longer available detachable balloons in the occlusion of large vessels as treatment for large and giant aneurysms.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.