Acute Stroke of CArotid Artery Bifurcation Origin Treated With Use oF the MicronEt-covered CGUARD (SAFEGUARD-STROKE)

Acute Stroke of CArotid Artery Bifurcation Origin Treated With Use oF The MicronEt-covered CGUARD STent Under TRansient FlOw Reversal LinKed With Thrombus REtrieval: SAFEGUARD-STROKE Study

Prospective, single-center, clinical registry of patients with acute stroke of carotid artery bifurcation origin undergoing endovascular treatment using the Micronet-covered CGUARD Stent to seal the culprit lesion under proximal cerebral protection (by transient flow reversal using balloon catheter such as the MoMa or FlowGate) with thrombus retrieval achieved through active aspiration ± stentriever use.

A study involving clinical and cerebrovascular imaging data evaluation in consecutive patients with acute stroke of carotid artery bifurcation origin, presenting in the time-window and/or cerebral tissue window allowing guideline-indicated reperfusion by interventional management.

A registry of consecutive patients with the study condition. An open-label study, without randomization - a single arm, single-center study in John Paul II Hospital in Krakow, Poland.

Acute stroke of carotid artery bifurcation origin presents a major treatment challenge. With the large volume of affected brain tissue, this stroke type -if left untreated- has an extremely unfavorable prognosis. With a typical large thrombus load in the extracranial carotid artery, the efficacy of systemic intravenous thrombolysis - the mainstay of ischemic stroke treatment- is very poor (reported recanalization rates <5%). With a high risk of complications (including cerebral embolism) and poor clinical outcomes, patients with acute stroke of carotid artery bifurcation origin (≈20-30% large-vessel occlusion strokes) are underrepresented in stroke mechanical reperfusion trials that have typically not included such patients.

No contemporary clinical studies have been dedicated specifically to management acute stroke of carotid artery bifurcation origin. In contrast to cerebral artery occlusion, in which the treatment algorithm is well-established, in the stroke of carotid artery bifurcation origin neither the reperfusion window nor the optimal revascularization method are yet determined. This results in a low level of evidence regarding the choice of a particular treatment method - endovascular emergent mechanical revascularization or surgical. Carotid surgery in acute major stroke setting is particularly challenging. Also, the surgical treatment modality is unable to address the problem of acute embolus in the large intracerebral vessel(s) that co-exists in about one in every three patients with acute stroke of carotid bifurcation origin.

With regard to minimally-invasive endovascular treatment, one fundamental limitation of the carotid stents used so far to address the culprit lesion (single-layer, first-generation stents) has been their inability to adequately sequestrate (insulate) the atherothrombotic lesion, resulting in an increased risk of new cerebral embolism and enhancing the risk of stent acute occlusion. Circumstantial evidence suggests that the Micronet-covered stent (in particular in combination with 'proximal' cerebral protection and, whenever indicated and feasible, in combination with aspiration or stentriever thrombectomy) may increase both safety and efficacy of carotid revascularization in acute stroke of carotid bifurcation origin.

A novel dual-layered Micronet-covered stent system (CGuard) has been demonstrated to markedly reduce peri- (and eliminate post-) procedural cerebral embolism in elective carotid artery stenting (Level 1 evidence) but has not yet been systematically tested in the emergent setting. This prospective, single-center, clinical registry of patients with acute stroke of carotid artery bifurcation origin eligible for endovascular interventional management will evaluate the use of Micronet-covered Stent (CGuard) to seal the stroke culprit lesion and reconstruct the lumen of the artery supplying the brain. Proximal cerebral protection (by transient flow reversal using a balloon guide catheter such as the MoMa or FlowGate) is used whenever feasible. In addition, extra/intra-cranial thrombus retrieval will be performed as clinically indicated, using either the aspiration technique and/or a stentriever.

Eligibility for study treatment is based on the decision (recommendation) of a multidisciplinary NeuroVascular Team Committee, consisting of a cardioangiologist certified in stroke mechanical thrombectomy or an interventional (neuro)radiologist, stroke neurologist and anesthesiologist. Use of pharmacologic agents and intended devices is according to international guidelines and instructions for use.

The study involves evaluation of clinical and cerebrovascular imaging data (presentation, outcome) in consecutive patients with acute stroke of carotid artery bifurcation origin, presenting in the time-window and/or cerebral tissue window (salvageable cerebral tissue, small cerebral infarct core/large penumbra) allowing guideline-indicated reperfusion by interventional management. Cerebral and vascular non-invasive imaging will involve computed tomography and/or magnetic resonance imaging modalities as clinically indicated.

The study is a registry of consecutive patients with the study condition, treated using the device of interest. This is an open-label study, without randomization - a single arm, single-center study.

Inclusion Criteria:

• Consecutive patients with acute ischemic stroke with carotid artery bifurcation stenosis/occlusion as culprit lesion.
• Clinical picture of acute ischemic stroke, stroke-in-evolution, or crescendo TIAs.
• Patient eligible for endovascular stroke therapy according to AHA/ASA stroke management and accepted for emergent stroke intervention by the local NeuroVascular Team Committee according to local standard of practice.
• Signed informed consent form to participate in the study (obtained at the point of first feasibility; note that live-saving procedure track may be executed for performing intervention according to local regulations and routine practice in the center)
• Consent to (routinely performed in this group of patients) follow-up visits that may include imaging as per routine practice in the study center and as clinically indicated.

Exclusion Criteria:

• Known stroke cause other than the carotid bifurcation lesion
• Lack of effective endovascular route needed for intervention
• Any known contraindications to stroke endovascular management