Since 2015, multiple randomized controlled trials (MR CLEAN, SWIFT PRIME, REVASCAT, HERMES) have confirmed the superiority and efficiency of endovascular thrombectomy (EVT) for large vessel occlusion (LVO) regarding the anterior circulation . Accordingly, EVT within a 6-hour time window has been included in several national and international guidelines as a standard of care . The time window is extended up to 24h for patients who meet the entry criteria of the DAWN and DEFUSE 3 trial results [3,4]. The widespread adoption of EVT for LVO concerning the anterior circulation in selected patients into routine clinical practice has started. Current studies deal with the selection criteria and scientific standards for borderline cases. Further, the evidence level for EVT regarding the posterior circulation ischemic stroke still remains unclear.
In my lecture, I will cover the proven and the latest trials as well as recent advances concerning treatment of acute ischemic stroke with an emphasis on prehospital care, imaging, patient selection, and treatment modalities, which may influence patient outcome.
Stroke is still a major contributor to death and disability worldwide. Within the prehospital care, having an optimal logistics workflow is a key point in order to establish modern stroke treatment. The topics I will address are prehospital stroke severity screening, clinical decision-making regarding mothership and drip-and-ship approach, mobile stroke units, and how to implement new technologies. Acute stroke management contains early recognition by well-trained emergency medical services personnel, taking into account that the optimal triage and treatment model is highly dependent on regional network capabilities.
Recent advancements in neuroimaging have established a tissue-based approach over purely relying on time. To identify the presence of a mismatch (mismatch ratio >= 1.8) between the core infarction (≤70ml) and the salvageable penumbra CT perfusion, DW-MRI or MRI perfusion imaging is recommended in stroke within 6-24 hours and has also been validated in several prospective studies.
A direct transfer to the angiography suite and using a flat panel CT has shown to reduce the door-to-puncture time . Interdisciplinary communication and parallel workflows are key points of stroke treatment, in order to safe time.
In several trials and guidelines, patients with LVO and NIHSS score ≥ 6 are considered for EVT. ASPECTS, the collateral status and Penumbral Imaging are tools used to assess infarct volume and predict outcome. The American Heart Association/American Stroke Association’s guidelines indicate ASPECTS ≥6 as a class I indication for EVT treatment for the patient within 6 hours of stroke onset.
Current trials explore EVT in large infarct volume, low stroke severity and medium vessel occlusion (MVO).
The RESCUE-Japan LIMIT, SELECT2, and ANGEL-ASPECT trials which enrolled patients with large core anterior circulation ischemic strokes (ASPECTS ≤5) within 24 hours of last seen well confirm the superiority of EVT regarding clinical outcome in selected patients. Results from additional large core trials including LASTE, TESLA, and TENSION are pending.
However, 24% to 40% of acute ischemic strokes are caused by medium and distal occlusions. EVT has been established as an option, but further studies are warranted.
EVT represents one of the most powerful treatments in medicine: the number needed to treat to prevent disability in one patient with stroke is 2.3. Timely restoration of cerebral blood flow using reperfusion therapy is one of the most effective manoeuvre for salvaging ischemic brain tissue with better functional independence compared with medical management alone. Stent retriever based thrombectomy, aspiration and combined techniques are effective methods to achieve good clinical outcomes. Several studies have shown the benefit of balloon guide catheters (BGCs) in EVT, certain modifications are made based on the type of intervention performed.
Anaesthetic modalities during EVT have not yet been finally clarified. Prior observational studies have suggested that patients undergoing EVT without conscious sedation have a higher probability of good clinical outcomes than patients treated with general anaesthesia (GA). The randomized trials GOLIATH, SIESTA, and ANSTROKE, comparing general anaesthesia to conscious sedation during EVT, support GA as a viable anaesthetic approach during EVT. Prospective studies will hopefully provide further insight and help improve overall acute ischemic stroke management.