Common carotid artery endovascular clamping for neuroprotection during carotid stenting: Flow‐gate system as an innovative treatment approach

Abstract

Objectives: We here report our clinical experience in CAS management through common carotid artery endovascular clamping with FlowGate2 system. Methods: Forty-five patients were enrolled with de novo asymptomatic internal carotid artery stenosis ≥70%. Cerebral protection during the stenting procedure was achieved using a unique endovascular clamping technique developed in our Institution which includes: (a) the occlusion of the common carotid artery only, through inflatable balloons integrated in the FlowGate2 Balloon Guide Catheter system; (b) flow inversion connecting catheter to 16 G blood cannula previously placed in arm vein; (c) after the placement of the stent, the flow inversion is maintained for 30 s to allow debris washout. The related primary end-point was the rate of Diffusion-weighted imaging magnetic resonance (DWI) micro-embolic scattering of infarction. The patient's clinical and the neurological status were assessed prior, during and after intervention, at discharge. Results: Transient clamping intolerance was observed in two patients (2/45; 4%). One minor stroke (1/45; 2%) occurred 8 hr the procedure with DWI ipsilateral microembolic lesions. No major strokes or deaths were observed at 3 months follow-up. DWI demonstrated ipsilateral micro-embolic scattering of infarction, in one asymptomatic patient. In all patients, no worst changes in NIHSS scale assessment were recorded at 1, 3, and 6 months. Conclusions: Our data confirmed the efficacy of FlowGate2 in terms of neuroprotection during CAS. To our knowledge, these are the first published data on this innovative approach developed in our institution. A large controlled trial is ongoing to confirm preliminary evidences. 1 | INTRODUCTION Carotid artery stenosis is responsible for 20-30% of ischemic strokes. This is due to plaque rupture, arterial dissection, thrombus embolization and occlusive thrombosis. 1-3 Randomized trials showed that the carotid endarterectomy (CEA) reduces stroke risk in these patients. 4-7 Carotid artery stenting (CAS) has emerged as an alternative to CEA due to its minor invasivity. Neverthless, the efficacy and safety of both techniques appear to be not equal, due to patient's selection, operator experience and device evolution dependent. 8,9 Novel equipment technologies and advanced stents as double layer mesh technology, flow reversal with alternative types of proximal/distal emboli protecting devices (EPD), have been reported to improve CAS outcomes. However, embolic events can complicate up to 90% of CAS.

Carotid Artery Stenting Using the Walrus Balloon Guide Catheter With Flow Reversal for Proximal Embolic Protection: Technical Description and Single-Center Case Series

“…Darganzanli et al 8 reported a 1% periprocedural stroke rate using the Concentric BGC (Stryker Neurovascular) with intermittent pump aspiration. 7,8 A preference for the Walrus BGC at our institution came from experience with its versatility, navigability, and stability. We did not experience difficulties even in challenging bovine and type III arches.…”

“…Flow reversal can be performed with BGCs alone by allowing back bleeding or by active aspiration, as seen in this study, or by constructing a closed system through cannulation of a vein. 7,8 In all these, the flow is reversed by a difference in pressure. These techniques are not novel because they have been explored by pioneers developing protection systems for CAS.…”

“…4 Literature reporting the use of other modern BGCs for flow reversal during CAS is scarce. Gabrielli et al 7 reported a 2% periprocedural stroke rate in their experience using the FlowGate2 BGC (Stryker Neurovascular, Fremont C) in combination with cephalic vein cannulation to obtain flow reversal. Darganzanli et al 8 reported a 1% periprocedural stroke rate using the Concentric BGC (Stryker Neurovascular) with intermittent pump aspiration.…”

“…4 The use of modern transfemoral balloon guide catheters (BGC) for flow reversal is scarcely described in the literature but represents a promising and efficient technique for cerebral protection. 7,8 The Walrus (Q'Apel Medical Inc.) is the most recent 8-French (F) BGC available and has been described to have improved navigability and stability in comparison with earlier BGCs, while also being compatible with most catheter systems currently available. 9,10 In this case series, we report our center's experience with the use of the Walrus BGC to obtain flow reversal during CAS, aiming to evaluate its effectiveness and safety, and provide a detailed description and illustration of this technique.…”

A propensity score-matched comparative study of balloon guide catheters versus conventional guide catheters for concurrent mechanical thrombectomy with carotid stenting in tandem strokes: comparison of first pass effect, symptomatic intracranial hemorrhage, and 90-day functional outcomes

“…In the majority of our cases (90%), we opted to cross the occluded carotid artery and deploy a stent for recanalization. The use of BGCs has been described for CAS, and the usefulness of this catheter resides in its key ability to allow flow arrest to occur while the area of proximal occlusion is traversed and the stent is deployed, which prevents showering of emboli from the area of stenosis and plaque into the distal cerebral vasculature 22 23. Treatment of tandem occlusions is riskier due to the blind navigation across the occluded carotid artery, unlike in cases of carotid stenosis 24.…”