O-065 Technical and clinical outcomes in medium vessel occlusion (MeVO) thrombectomy by frontline technique – a multicenter study

Abstract

<h3>Background</h3> Endovascular thrombectomy (EVT) is the standard of care for proximal large vessel occlusion (LVO) stroke. Due to the high effect size of EVT, neurointerventionalists have expanded the indications of EVT to include more distal occlusions. Data on technical and clinical outcome in Medium vessel occlusions (MeVOs) comparing frontline technqiues remain limited. We evaluated technical and clinical outcomes after EVT in MeVO while comparing different frontline thrombectomy techniques. <h3>Methods</h3> We report an international multicenter retrospective study of patients, 18 years or older, undergoing EVT for ischemic stroke at 32 centers between 01/2015 and 12/2021. Patients were divided into proximal occlusions(ICA/M1/Veretebrobasilar) or isolated medium vessel occlusions (M2, A1, P1) and categorized by the thrombectomy technique. Primary outcome was a good functional outcome (mRS 0–2) at 90 days and compared between different techniques. Secondary outcomes included successful recanalization, procedure time, thrombectomy attempts, post-procedural hemorrhage and mortality. Multivariate logistic regressions were used to evaluate the impact of technical variables including procedure time, attempts, and frontline technique on clinical outcomes. Propensity score matching was used to compare outcome in patients with MeVO treated with aspiration versus stent retriever as frontline approach. <h3>Results</h3> We included 7,477 patients including 5977 proximal occlusions and 1287 medium vessel occlusions. MeVO did not independently predict good functional outcome at 90 days compared to proximal when baseline covariates were accounted for (p=0.55). In MeVO, successful recanalization was an independent predictor of good outcome at 90 days (aOR=3.2,p&lt;0.05) irrespective of frontline technique. Younger age, use of bridging therapy, lower ASPECT scores and lower admission NIHSS were also predictors of good outcome. Procedure time less than 1 hr or thrombectomy attempts less than 4 were independent predictors of 90-day good outcomes in the MeVO cohort irrespective of technique (aOR = 2.2 and 2.8 respectively, p &lt; 0.05). Use of frontline stent-retriever was an independent predictor of symptomatic hemorrhage compared to aspiration (aOR = 2.6, p&lt;0.01) without impacting odds of good outcome at 90 days (aOR =0.95, p&gt; 0.1). In a propensity matched cohort of aspiration versus stent-retriever patients with MeVO thrombectomy, there were no differences in 90-day mRS scores. The rates of hemorrhage were higher with stent-retriever use (9% vs. 4%, p&lt;0.01), procedure time was longer with stent retriever use (51 min vs. 33 min, p&lt;0.01) while the number of attempts was higher with aspiration (2.5 vs. 2, p &lt;0.01). Rates of hemorrhage and good outcome showed an exponential relationship to procedural metrics, and were more dependent on procedure time in the aspiration group compared to the number of attempts in the stent-retriever group. <h3>Conclusions</h3> Clinical outcomes following EVT for MeVO are comparable to those in LVOs with similar baseline covariates with no differences between the different frontline techniques. The golden hour or 3-pass rules in LVO thrombectomy still apply to MeVO thrombectomy. Different frontline techniques may exhibit different futility metrics; SR thrombectomy was more influenced by more attempts whereas aspiration outcomes were more dependent on procedure time. <h3>Disclosures</h3> <b>A. Alawieh:</b> None. <b>R. Chalhoub:</b> None. <b>S. Al-Kasab:</b> None. <b>P. Jabbour:</b> None. <b>M. Psychogios:</b> None. <b>R. Starke:</b> None. <b>A. Arthur:</b> None. <b>K. Fargen:</b> None. <b>R. DeLeacy:</b> None. <b>P. Kan:</b> None. <b>T. Dumont:</b> None. <b>A. Rai:</b> None. <b>R. Crosa:</b> None. <b>S. Tjoumakaris:</b> None. <b>I. Maier:</b> None. <b>N. Goyal:</b> None. <b>S. Wolfe:</b> None. <b>C. Cawley:</b> None. <b>J. Osbun:</b> None. <b>B. Howard:</b> None. <b>L. Dimisko:</b> 1; C; T32NR012715. <b>H. Saad:</b> None. <b>C. Ogilvy:</b> None. <b>W. Cawley:</b> None. <b>J. Mascitelli:</b> None. <b>I. Fragata:</b> None. <b>M. Levitt:</b> None. <b>A. Shaban:</b> None. <b>J. Kim:</b> None. <b>S. Yoshimura:</b> None. <b>A. Polifka:</b> None. <b>R. Williamson:</b> None. <b>B. Gory:</b> None. <b>M. Mokin:</b> None. <b>M. Moss:</b> None. <b>M. Park:</b> None. <b>A. Spiotta:</b> 1; C; Penumbra, Pulsar Vascular, MicroVention, and Stryker. 2; C; Penumbra, MicroVention, and PulsarVascular;. <b>J. Grossberg:</b> None.