Protected stent retriever thrombectomy prevents iatrogenic emboli in new vascular territories

Abstract

Introduction Diagnostic tools to show emboli reliably and protection techniques against embolization when employing stent retrievers are necessary to improve endovascular stroke therapy. The aim of the present study was to investigate iatrogenic emboli using susceptibility-weighted imaging (SWI) in an open series of patients who had been treated with stent retriever thrombectomy using emboli protection techniques. Methods Patients with anterior circulation stroke examined with MRI before and after stent retriever thrombectomy were assessed for iatrogenic embolic events. Thrombectomy was performed in flow arrest and under aspiration using a balloonmounted guiding catheter, a distal access catheter, or both. Results In 13 of 57 patients (22.8 %) post-interventional SWI sequences detected 16 microemboli. Three of them were associated with small ischemic lesions on diffusion-weighted imaging (DWI). None of the microemboli were located in a new vascular territory, none showed clinical signs, and all 13 patients have been rated as Thrombolysis in Cerebral Infarction (TICI) 2b (n=3) or 3 (n=10). Retrospective reevaluation of the digital subtraction angiography (DSA) detected discrete flow stagnation nearby the iatrogenic microemboli in four patients with a positive persistent collateral sign in one. Conclusion Our study demonstrates two things: First, SWI seems to be more sensitive to detect emboli than DWI and DSA and, second, proximal or distal protected stent retriever thrombectomy seems to prevent iatrogenic embolization into new vascular territories during retraction of the thrombus, but not downstream during mobilization of the thrombus. Both techniques should be investigated and refined further.

Predictors of the Aspiration Component Success of a Direct Aspiration First Pass Technique (ADAPT) for the Endovascular Treatment of Stroke Reperfusion Strategy in Anterior Circulation Acute Stroke

“…25 Nonetheless, controversies about the relevance of the technique have arisen as in case of aspiration component failure, it might induce a potential delay in reperfusion which could have been avoided using the SR technique and also because this technique does not use a proximal flow arrest with Balloon guide catheter known to prevent embolus in new territory. 26,27 Although no comparative studies have been conducted with ADAPT versus the validated SR technique, some evidences suggest noninferiority 9 or superiority of the ADAPT technique to achieve better reperfusion rates. 7 In this perspective, more insights are needed to identify which patients may benefit from this technique.…”

Time to redefine success? TICI 3 versus TICI 2b recanalization in middle cerebral artery occlusion treated with thrombectomy

“…Endovascular treatment strategies that consequently strive to achieve TICI 3 may be warranted and cost-effective, and their risk:benefit ratios should be evaluated in pertinent studies. The majority of observable distal branch occlusions after MTE—which make the difference between TICI 2b and TICI 3—arise owing to distal embolization during the endovascular procedure 21 24. The rate of TICI 3 recanalizations can therefore be viewed as a suitable and—as shown here—clinically relevant safety measure for studies evaluating MTE devices and techniques.…”

Novel Distal Emboli Protection Technology: The EmboTrap

“…Reported clinical rates range from 0 to 12.5% embolization to new territory (Table 1). Assessment of distal embolization with angiography can be difficult, and a recent study using susceptibility-weighted imaging indicated that rates may be in the range of 23% [28]. Susceptibility-weighted imaging seems to be more sensitive to detect emboli than digital subtraction angiography.…”