IntraCranial Atherosclerosis Related Large-vessel Occlusion Treated With Urgent Stenting (ICARUS)

The goal of this international, multi-center, randomized clinical trial is to compare two treatment options, early intracranial stenting and continued stent-retriever or aspiration based endovascular treatment, for stroke patients with a large vessel occlusion, who experienced failure of recanalisation after initial treatment due to intracranial atherosclerosis.

This clinical tiral focuses on comparing treatment options for patients with an acute ischemic stroke, which is a significant cause of death and disability worldwide. Currently, endovascular treatment (EVT) is the gold standard for the removal of large blood clots in the brain arteries (large vessel occlusion, LVO), but sometimes it fails to reopen blocked blood vessels, especially when caused by an underlying intracranial atherosclerosis (ICAD). When restoring blood flow fails, patients' outcomes are much worse, with more than 70% experiencing severe disability or death.

One potential solution for these cases is intracranial stenting, where a stent is permanently implanted in the affected blood vessel to restore blood flow to the brain. This approach has shown promise in other conditions like myocardial infarction. However, there is an ongoing debate whether the benefits are offset by possibly higher bleeding risk, and current guidelines don't provide clear recommendations on the use of intracranial stenting.

Therefore, this study aims to compare the clinical efficacy and safety of early intracranial stenting versus continued conventional EVT (stent-retriever or aspiration based) in LVO stroke patients who haven't responded to conventional EVT due to ICAD.

The results of this clinical trial will offer high quality clinical evidence to determine whether intracranial stenting provides benefits over conventional EVT for LVO stroke patients experiencing recanalisation failure due to ICAD.

Eligibility Criteria:
Inclusion Criteria:

* A relevant clinical deficit defined as a National Institute of Health Stoke Scale (NIHSS) Score of ≥ 6 points for anterior circulation stroke and a NIHSS Score of ≥ 10 for posterior circulation stroke
* Patients presenting within 24 hours of last seen well to the treating hospital
* Occlusion of the Internal Carotid Artery, the M1 segment, the proximal/dominant M2 segment of the Middle Cerebral Artery, the Basilar Artery or the V4 segment of the Vertebral Artery
* Absence of recanalization (thrombolysis in myocardial infarction score of 0 or 1) after up to three endovascular treatment passes
* High probability of underlying intracranial atherosclerotic disease based on the assessment of the treating physician
* Age ≥ 18 years
* Occluded artery amendable to stenting by judgement of the treating physician
* Absence of a large infarct core defined as (posterior circulation) Alberta Stroke Program Early CT Score of 6 or above
* Informed Consent as documented by signature or fulfilling the criteria for emergency consent procedures

Exclusion Criteria:

* Acute intracranial haemorrhage
* Pre-stroke modified Rankin Scale score of 2 or above
* Known, severe comorbidities, which will likely prevent improvement or follow-up (cancer, alcohol/drug abuse or dementia)
* Known clotting disease or suspicion of underlying disease which might lead to a hyper coagulant state
* In-hospital Stroke
* Known contraindications for anti-platelet therapy
* Known (serious) sensitivity to radiographic contrast agents, nickel, titanium metals or their alloys
* Foreseeable difficulties in follow-up due to geographic reasons (e.g., patients living abroad)
* Evidence of an ongoing pregnancy prior to randomization
* Radiological confirmed evidence of mass effect or intracranial tumour (except small meningioma)
* Radiological confirmed evidence of cerebral vasculitis
* Evidence of vessel recanalization prior to randomisation
* Participation in another interventional trial which could confound the primary endpoint