The BEST study is an academically initiated, single-center, prospective, randomized controlled clinical trial investigating the potential advantages and disadvantages of using a guide catheter with or without a balloon in the interventional treatment of acute ischemic stroke.

The study population consists of adult patients with acute ischemic stroke of the anterior circulation for whom interventional recanalization therapy via catheter is indicated following interdisciplinary consultation between the Department of Neurology and Neuroradiology at Heidelberg University Hospital.

In addition to routine clinical treatment measures and data collection, patients will be interviewed by telephone after 90 days to assess their quality of life and level of independence using standardized scoring systems.

All medical devices used or investigated in this study bear the CE mark (Conformité Européenne ) and will be used within their intended purpose. Study participants will not be subjected to any additional invasive or burdensome procedures beyond normal usage.

Are balloon guide catheters in endovascular stroke therapy of the anterior circulation superior? (BEST) Background Meta-analyses on the use of balloon-guided catheters (BGK) suggest a better technical and clinical outcome after endovascular stroke therapy (EST). However, no randomised controlled trials exist to support these results, yet.

Study objective To investigate whether usage of BGK for EST of anterior circulation ischemic stroke due to large vessel occlusion results in improved degree of recanalization of the target vessel and the associated vascular territory.

Study population N = 110 patients (55 per group, 1:1 randomisation) with acute ischemic stroke due to large vessel occlusion of the anterior circulation and intention to treatment with EST.

Inclusion criteria

1. Patients with acute ischemic stroke due to large vessel occlusion of the anterior circulation (internal carotid artery-T, M1 (segment of the middle cerebral artery) or proximal M2 (M2 segment of the middle cerebral artery) occlusion) proven by either computed tomography (CT) or magentic resonance imaging (MRI)
2. Estimated time between stroke onset / last seen well and study procedure of < 24 hours
3. No relevant pre-stroke functional disability (pre-morbid modified Rankin Sacle (mRS) of 0 - 3)
4. Neurological deficit with a National Instutute of Health Stroke Scale (NIHSS) of ≥ 4 and ≤ 25
5. Age ≥ 18
6. Alberta Stroke Program Early CT Score (ASPECTS) ≥ 6 on baseline non-contrast CT < 4,5h after onset or CT perfusion / MRI > 4,5h after onset

Exclusion criteria

1. Pre-existing stenosis in the target vessel requiring stent therapy
2. Tandem occlusions of both cervical and intracranial vessels
3. Prior intracranial hemorrhage or signs of intracranial hemorrhage during procedure
4. Notably increased risk of intracranial hemorrhage
5. Excessive vascular tortuosity that will likely result in unstable access or inability to access the target vessel
6. Dissection of the extra- or intracranial cerebral arteries
7. Pregnant or breast-feeding women
8. Known severe illness with life expectancy less than 6 months
9. Participating in another clinical trial during the follow-up period that could confound the treatment or outcomes of this investigation

Intervention EST is performed with usage of either i) a BGK (Stryker MERCI 9F, Stryker Flowgate2 8F) or ii) a standard guide catheter without balloon (Cordis Vista Brite Tip 8F) Study design Mono-centric, prospective, parallel-group, randomized controlled trial with blinded endpoint evaluation (PROBE design) Clinical Site Location Heidelberg University Hospital, Germany Endpoints Primary endpoint: Proportion of patients with successful technical recanalisation (expanded treatment in cerebral infarction (eTICI) score 2c/3) Secondary endpoint (selected): Clinical outcome after 90 days using the modified Rankin Scale (mRS); severity of stroke symptoms after 24h measured by National Institute of Health Stroke Scale (NIHSS); Infarct Growth between baseline and first follow-up MRI measured by volume of lesion on diffusion-weighted imaging; volume and number of peripheral emboli on follow-up MRI measured on diffusion-weighted imaging; safety endpoints.

Participant duration 3 months Estimated Study duration 2-3 years

Inclusion Criteria:

• Patients with an acute ischemic stroke

• Location of the primary occlusion in the anterior cerebral circulation

• Pre-therapeutic modified Rankin Scale (mRS) score of ≤ 3.

• Written informed consent from

  1. the patient or
  2. their legal representative/guardian or
  3. patient enrollment by an independent physician and the principal investigator

Exclusion Criteria:

• Patients with contraindications to interventional therapy
• Patients with acute intracranial hemorrhage
• Pregnancy/Breastfeeding
• Pre-therapeutic mRS > 3
• National Institute of Health Stroke Scale (NIHSS) ≤ 4
• Patients detained in an institution by court or government order
• Patients who require intubation for treatment

The IPD may not be shared since participants have not consented to secondary use or data sharing.