Author: Zdravka Poljakovic

The last Session on day 2 held in Hall Montreal was all about neurointervention dealing with challenges and pitfalls in this exceptional stroke treatment field. Moderators were professors Wim Van Zwam (Maastricht, Netherlands) and Pooja Khatri (Cincinnati, United States), who managed to point out the most important conclusions from all lectures in an interesting and scientific discussion, keeping the whole session together and in perfect timing. 

First lecture, “The benefit of a complete over a successful reperfusion decreases with time”, given by Stefanos Finitsis from Thessaloniki, Greece, on behalf of ETIS Registry Investigators, posed a question about the benefit of thrombectomy over (extended) time. In order to answer the question, the authors analysed data from 4.444 patients from ETIS registry, a prospective, observational, multicentric study of acute ischemic stroke patients treated with endovascular treatment in 21 centers in France. Patients with anterior occlusions with known symptoms onset were analysed. The trial showed that the prognostic value of a complete over successful reperfusion progressively declined with time, with a clear-cut value of 5.7 hours.

The session continued with the talk given by Anne Berberich from Ludwigshafen, Germany, who discussed the Comparison of anesthetic strategies for endovascular therapy of isolated posterior cerebral occlusion: a PLATO study. In her talk, she showed the results from an analysis of 376 patients with isolated posterior cerebral occlusion, nearly half of them being under general anesthaesia (183). The groups were comparable except of GA group had a more severe stroke. The results did not show any difference in primary outcome, namely functional outcome in both groups, however showed higher rates of complete reperfusion in the first pass in the GA group. In conclusion, she emphasized that non-GA protocols were feasible and safe in patients with EVT for isolated PCA occlusion stroke, GA led to higher rates of successful reperfusion compared to non-GA, and that there were no differences in short and long-term functional outcomes between the anesthetic strategies. For sure, this finding supports further investigation.

Safety and efficacy of endovascular treatment for large-core ischaemic stroke: a systematic review and meta-analysis was presented by Georgios Tsivgoulis, from Athens, Greece where he, in his meta-analysis of six RCT’s comparing endovascular treatment with medical therapies with nearly 1900 patients, and very low risk of bias, clearly showed the benefit of EVT. Endovascular treatment is beneficial in all investigated points showing statistical significance in all but mortality where it showed benefit but did not reach statistical significance. The results also showed higher hemorrhagic transformation in spite of functional benefit in the endovascular group.

The next talk was a posthoc analysis of the ANGEL-ASPECT trial analysing clinical severity and endovascular therapy outcomes in patients with large infarcts, which was nicely presented in a talk by Qiyuan Lu, from Beijing, China. The aim of this trial was to investigate the efficacy and safety of EVT in patients with anterior-circulation large vessel occlusion and large infarcts, stratified by clinical severity of stroke by NIHSS score, based on ANGEL-ASPECT trial. In her conclusions, she emphasized that in this group of patients, EVT was again associated with better functional outcomes than medical therapy in the group of moderate stroke, but not in the group of severe stroke. Surprisingly, there was not even a trend towards better outcomes when treated with EVT  in severe stroke, which implies caution in selection for EVT but even more a pooled analysis of large infarct trials to verify this finding.

Coming into the other half of the Session, we heard the results of the analysis of the society of Vascular and interventional neurology registry about rescue therapy for failed mechanical thrombectomy, presented by Santiago Ortega-Gutierrez form Iowa City, USA. He began his talk by a short introduction where he reminded the audience about unsuccessful reperfusion in at least 20% of patients but also about lowel level of evidence about rescue therapy which raises questions about the optimal rescue therapy approach. So the aim of the presented study was actually to investigate whether rescue therapy yields superior functional outcomes compared to medical therapy in patients with acute ishemic stroke due to large vessel occlusion after failed mechanical thrombectomy. The study had its limitations, in the first place due to the fact that the SVIN registry contains non-randomized data. However, the results of the study showed that rescue therapy correlates with enhanced functional outcome and decreased haemorrhagic complications and mortality compared to medical therapy. The results of the study are published in Annals of Neurology. 

The next speaker, Thanh N.Nguyen from Boston, USA presented the results from “Noncontrast computed tomography selected thrombectomy versus medical management for late-window anterior large vessel occlusion” study inspired by the important fact that the availability of advanced imaging is not particularly high when comparing low to high-income countries. A crucial question in the study was whether the functional outcome in patients with large vessel occlusion presenting at a 6 to 24-hour window and selected with CT is better compared with medically treated patients, which actually confirmed the value of a noncontrast computed tomography, which was nicely pointed out in a sentence from prof Raul Nogueira who said: “CT in the late window is like a red wine – it gets better with time”…

Relation between first-line thrombectomy technique and outcomes in late-window stroke patients; an MRCLEAN late trial sub-study,  was presented by Robrecht Knapen, from Maastricht, Netherlands. The results of this sub-study showed that stent retriever thrombectomy, direct aspiration, or the combined technique as first-line techniques showed no significant difference in clinical outcome in late-window stroke patients. However, direct aspiration was accompanied by higher rates of symptomatic intracerebral haematomas and higher switch rates to other techniques compared to other groups.

The final lecture, “Effect of thrombolysis type on the efficacy of aspiration vs stent-retriever first-line thrombectomy: results from the ACT trial” was presented by Fouzi Baia from Tours in France. The aim of this group of investigators was to study the influence of i.v. tenecteplase versus alteplase on the efficacy of first-line thrombectomy strategy. The study is a secondary analysis of AcT trial and included 435 patients from which 51% received Tenecteplase, and reached an interesting result showing that IV Tenecteplase before EVT may enhance the efficacy of the first-line aspiration, but it may have no effect on stent-retrievers!

In conclusion, the audience has learned the results of several clinically important studies, which should for sure inspire further investigations but might as well influence some clinical decisions.