Desired Qualities of Endovascular Tools and Barriers to Treating Medium Vessel Occlusion MeVO : Insights from the MeVO-FRONTIERS International Survey

[Neurothrombectomy 2022-Extension of indications and technical innovations]

For advanced territorial ischemia numerous retrospective and prospective studies have shown a positive effect of mechanical thrombectomy (MT) compared to best medicinal treatment alone. For patients with minor stroke (NIHSS < 6) there is currently a lack of evidence for MT. Appropriate study protocols must differentiate between patients with large vessel occlusion with disproportionately mild symptoms and more distal vascular occlusion and therefore correspondingly fewer clinical symptoms. The role of intravenous lysis treatment before MT as bridging lysis also currently retains its general recommendation, as large studies could not show a uniform noninferiority of MT alone. In addition, the use of intra-arterial lysis after successful MT offers a promising approach, which still needs to be evaluated. Novel aspiration catheters and stent-retrievers as well as competing thrombectomy techniques can be compared by the first pass effect, the successful recanalization with only one attempt at thrombectomy. Contact aspiration and stent-retriever thrombectomy under aspiration are equivalent and established thrombectomy procedures. For the latter, several detailed maneuver tactics are described for improvement of thrombectomy success. Also, in retrospective studies the combination with a balloon-guided catheter promises a further improvement of recanalization results. In the case of failure of supra-aortic vessel probing with inguinal access, radial access and direct carotid puncture are alternative access routes. Recent studies on ICA stenting with tandem occlusions showed a benefit of stents without an increased risk for symptomatic intracranial hemorrhage. The retrograde approach, to first treat the intracranial vessel occlusion and then the carotid stenosis, seems to be advantageous.