Etiological Approach to Understanding Recanalization Failure in Intracranial Large Vessel Occlusion and Thrombectomy: Close to Embolism but Distant From Atherosclerosis.

So Young Park,Jeong-Ho Hong,Yong-Won Kim,Raul G. Nogueira,Jin Soo Lee,Yang-Ha Hwang,Yong-Sun Kim,Seong-Joon Lee,Dong-Hun Kang,Jin Wook Choi,Joonsang Yoo,Chang-Hyun Kim,Sung-Il Sohn,Ji Man Hong

doi:10.3389/fneur.2020.598216

Abstract

Introduction: In patients with intracranial large vessel occlusion (LVO) who undergo endovascular treatment (EVT), recanalization failure may be related to intracranial atherosclerotic stenosis (ICAS). We evaluated whether the risk factors of recanalization failure could possibly be a marker of ICAS among various types of LVO.Methods: From a multicenter registry, patients with middle cerebral artery M1 segment occlusions who underwent thrombectomy within 24 h were included. Based on the on-procedure and post-procedure angiographic findings, patients were classified into embolic, ICAS-related, tandem occlusion, and recanalization failure groups. Recanalization failure was defined if the occluded vessel could not be recanalized by stent retrieval, contact aspiration, or local lytics treatment. Risk factors, imaging markers, and EVT methods were compared between groups.Results: Among 326 patients, 214 were classified as embolism, 76 as ICAS, 16 as tandem, and 20 as recanalization failure. The group with recanalization failure showed higher scores on the National Institutes of Health Stroke Scale (NIHSS) (median, 16.0 vs. 14.5 vs. 14.0 vs. 17.0, p = 0.097), frequent atrial fibrillation (59.3 vs. 18.4 vs. 0 vs. 40.0% p < 0.001), and elevation in erythrocyte sedimentation rate (ESR) (14.5 ± 15.7 vs. 15.0 ± 14.1 vs. 21.2 ± 19.5 vs. 36.0 ± 32.9, p < 0.001) among the groups. The rate of computed tomography angiography-based truncal-type occlusion in recanalization failure group was not as high as that in the ICAS group (8.1 vs. 37.5 vs. 0 vs. 16.7%, p < 0.001). Balloon guide catheters (BGC) were less frequently utilized in the recanalization failure group as compared to their use in the other groups (72.0 vs. 72.4 vs. 62.5 vs. 30.0%, p = 0.001). In the multivariable analysis, initial higher NIHSS [odds ratio (OR), 1.11 95% confidence interval (CI), 1.01–1.22 p = 0.027], higher ESR (OR, 1.03 CI, 1.01–1.05 p = 0.006), and non-use of BGCs (OR, 3.41 CI, 1.14–10.17 p = 0.028) were associated with recanalization failure. In M1 occlusions, the predominant mechanism of recanalization failure was presumed to be embolic in 80% and due to ICAS in 20%.Conclusion: The analysis of recanalization failures does not suggest an underlying predominant ICAS mechanism. Sufficient utilization of thrombectomy devices and procedures may improve the rates of recanalization.

Highlights

In patients with intracranial large vessel occlusion (LVO) who undergo endovascular treatment (EVT), recanalization failure may be related to intracranial atherosclerotic stenosis (ICAS)
Initial higher National Institutes of Health Stroke Scale (NIHSS) [odds ratio (OR), 1.11 95% confidence interval (CI), 1.01–1.22 p = 0.027], higher erythrocyte sedimentation rate (ESR) (OR, 1.03 CI, 1.01–1.05 p = 0.006), and non-use of Balloon guide catheters (BGC) (OR, 3.41 CI, 1.14–10.17 p = 0.028) were associated with recanalization failure
Patients were retrospectively identified from the Acute Stroke due to Intracranial Atherosclerotic Occlusion and Abbreviations: Alberta Stroke Program Early CT Score (ASPECTS), alberta stroke program early CT score; BGC, balloon guide catheters; BSO, branching-site occlusion; CT, computed tomography; ESR, erythrocyte sedimentation rate; EVT, endovascular treatment; HAS, hyperdense artery sign; ICAS, intracranial atherosclerotic stenosis; LVO, large vessel occlusion; MCA, middle cerebral artery; NIHSS, National Institutes of Health Stroke Scale; TTO, truncal-type occlusion

Summary

Introduction

In patients with intracranial large vessel occlusion (LVO) who undergo endovascular treatment (EVT), recanalization failure may be related to intracranial atherosclerotic stenosis (ICAS). We evaluated whether the risk factors of recanalization failure could possibly be a marker of ICAS among various types of LVO. Possible causes of recanalization failure include tandem occlusion, clot characteristics and its burden, or different occlusion pathomechanisms (atherosclerotic occlusions) apart from anatomical challenges that limit the initiation of mechanical thrombectomy itself [2,3,4]. It was reported that truncal-type occlusion (TTO), which is a marker of ICAS, was associated with stent retriever failure [5]. Despite recent studies regarding clots, it is difficult to evaluate which clot characteristics would result in recanalization failure because sufficient clot burden could not be retrieved. A hyperdense artery sign (HAS) on computed tomography (CT) may indirectly show some characteristic differences among clots in LVO

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