Impact of next-generation delivery assist catheters and crossing strategy on reperfusion success in aspiration thrombectomy

Abstract

BackgroundIn mechanical thrombectomy procedures, physicians are often forced to cross the clot to get more support in tortuous anatomy. Stentriever procedures always require traversing the clot. Novel delivery assist catheters with a tapered distal tip have been developed to aid aspiration catheter delivery. This study compares a novel delivery assist catheter to conventional support strategies in terms of reperfusion and distal embolization. The impact of remaining proximal versus entering the clot is also investigated, as is the impact of incorporating a Superbore 088 catheter.MethodsSoft, medium, and stiff ovine blood clots were used to form ICA/M1 occlusions in an in-vitro thrombectomy model. Two approaches were tested: navigating the aspiration catheter with and without crossing/entering the clot with support devices. Six setups were tested: Millipede⁸⁸ + Zipline⁸⁸, Millipede⁸⁸ + Millipede⁷⁰ + Zipline⁷⁰, Millipede⁷⁰ + Zipline⁷⁰, SOFIA Plus + 021 Microcatheter, SOFIA Plus + 3MAX, SOFIA Plus + 021 Microcatheter + Stentriever. Each setup was tested nine times totaling 72 tests. Revascularization endpoints were First-Pass-Effect (FPE), final complete revascularization, and distal embolization.ResultsAvoiding clot entry was associated with higher FPE rates, improved final revascularization, and fewer distal emboli. Using a 3MAX as a microcatheter and crossing the clot resulted in more distal emboli than a standard 021 microcatheter or stentriever procedure. Millipede⁸⁸ + Zipline⁸⁸ configuration achieved the highest FPE (67%) when the clot was not crossed (vs. 56% with clot entry). Both 070 aspiration catheters had the same FPE rate (33%) but using Millipede⁸⁸ for flow control with Millipede⁷⁰ improved the FPE rate (44%). Of the conventional techniques, SOFIA Plus + 021 Microcatheter + Stentriever was associated with the highest FPE rate (44%).ConclusionsRemaining proximal to the clot is advantageous. Next-generation delivery catheters, like Zipline, may enhance catheter delivery without increasing embolization risk. Using larger internal catheters, such as 3MAX, leads to higher rates of emboli when crossing the clot.

Keywords: Acute ischemic stroke; aspiration catheter; delivery catheter; mechanical thrombectomy; microcatheter.

Figure 1.

Schematic of techniques evaluated in the study. (a) Delivery catheter kept proximal of the clot face while delivering the aspiration catheter (b). (c) Delivery catheter entering the clot to facilitate delivery of the aspiration catheter/stentriever (d).

Figure 2.

(a) Revascularization success (mTICI 2c/3) and (b) distal embolization rates for the various thrombectomy setups evaluated. The weighting applied to the distal emboli was as follows; ((5 × 1000 µm) + (2.5 × 500 µm) + (1 × 200 µm)).