Effectiveness of very low profile thrombectomy device in primary distal medium vessel occlusion, as rescue therapy after incomplete proximal recanalization or following iatrogenic thromboembolic events

Abstract

Background: Recent progress with smaller retrievers has expanded the ability to reach distal brain arteries. We herein report recanalization, bleeding complications and short-term clinical outcomes with the smallest currently known low profile thrombectomy device in patients with primary or secondary distal medium vessel occlusion (DMVO).

Methods: We performed a retrospective analysis of 115 patients receiving mechanical thrombectomy (MT) in DMVO using the extended Thrombolysis in Cerebral Infarction (eTICI), European Cooperative Acute Stroke Study (ECASS) II classification, The National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores at admission and discharge to evaluate outcomes. Patients were stratified into three groups: (1) primary isolated distal occlusion (n=34), (2) secondary distal occlusion after MT of a proximal vessel occlusion (n=71), or (3) during endovascular treatment of aneurysms or arteriovenous malformations (AVMs) (n=10).

Results: Successful distal recanalization, defined as an eTICI score of 2b67, 2c and 3, was achieved in 74.7% (86/115) of patients. More specifically, it was 70.5% (24/34), 73.2% (52/71), and 100% (10/10) of primary DMVO, secondary DMVO after proximal MT, and rescue MT during aneurysm or AVM embolization, respectively. Symptomatic intraparenchymal bleeding occurred in 6.9% (eight patients). In-hospital mortality occurred in 18.1% (19/105) of patients with stroke. The most common cause of death was large infarct, old age, and therapy limitation.

Conclusion: Direct or rescue MT of DMVO using a very low profile thrombectomy device is associated with a high rate of successful recanalization and a reasonable rate of symptomatic hemorrhagic complication, despite a risk of 18.1% hospital mortality in elderly patients. Further trials are needed to confirm our results and assess long-term clinical outcomes.

Keywords: stent; stroke; thrombectomy; thrombolysis.

Figure 1

Small vessel occlusion reperfusion by Tigertriever 13 device. (A) Primary distal small vessel occlusion in the M3 branch of the middle cerebral artery. (B) Navigation of Headway duo microcatheter over Traxes wire beyond the thrombosis, and selective injection of contrast agent distal to the occluded vessel. (C) Picture depicts the expanded stent retriever Tigertriever 13, advanced through the Headway27 microcatheter into the target branch artery. (D) Reperfusion of the occluded branch after the procedure.

Figure 2

Column A (left) and B (right) displaying CBCT immediately after thrombectomy and regular CT scan after 24 hours, respectively. Upper row: minimal contrast agent extravasation in the left sylvian fissure initially with complete resolution on follow-up. Middle row: moderate contrast agent extravasation in the right sylvian fissure with marked but incomplete resorption at 24 hours (rated as asymptomatic intracranial bleeding). Lower row: important contrast agent extravasation in the left sylvian fissure with an associated temporal parenchymal hemorrhage and intraventricular extension on the control CT the following day (rated as symptomatic intraparenchymal hemorrhage). CBCT=flat panel cone-beam CT.