Arterial Collapse during Thrombectomy for Stroke: Clinical Evidence and Experimental Findings in Human Brains and In Vivo Models

Clinical evidence of arterial collapse. A, Left ICA angiography in an anterior-posterior projection demonstrates a giant fusiform aneurysm in the left MCA. B, Left ICA angiogram after deployment of multiple telescoping flow diverters with acute occlusion of the aneurysm. C, Unsubtracted angiography of the left ICA obtained 5 days postprocedure shows in-stent thrombosis (arrow). D, Direct aspiration with a 068 catheter navigated distal to flow diverters (arrow). E, Severe collapse of the distal flow diverters on vacuum and device pull back (arrow). F and G, Partial collapse of the distal telescoping flow diverters with a suction catheter connected to vacuum at the proximal cavernous ICA.

Aortoiliac rabbit model. A, Overview of the rabbit model with transcarotid aortic access. A 7F sheath (blue line) was advanced to the upper third of aorta, and a 5F aspiration catheter (green line) was coaxially advanced to the abdomen. B, 3D rotational angiography of a rabbit aorta. C, A stent retriever was delivered through a microcatheter and unsheathed to expand distal to a 5F aspiration catheter. D, On activation of vacuum, the radiopaque markers of the stent came in close proximity, suggesting arterial collapse (arrowheads). The most distal fluoromarker did not collapse. E, Intravascular OCT imaging of the aorta depicted the arterial wall (with boundaries indicated by arrowheads) close to the probe, which becomes blurry on the opposite side of the circumference due to the scattering effect of blood. F, Vacuum applied to the catheter resulted in arterial collapse visualized by the whole circumference of the arterial wall (with boundaries indicated by arrowheads) in contact with the OCT probe.

Different modes of arterial collapse in the brain model. A, Indentation at the aspiration catheter tip (asterisk) in the BA. B, Focal collapse at the aspiration catheter tip (asterisk) in the MCA. C, Full/extended collapse of the BA spanning the catheter tip (asterisk). D, OCT shows a full collapse of the BA.