Comparison of Vacuum Pressures and Forces Generated by Different Catheters and Pumps for Aspiration Thrombectomy in Acute Ischemic Stroke

Abstract

Background: Direct aspiration thrombectomy is an increasingly utilized technique in endovascular stroke treatment that relies on vacuum and suction force to remove the clot. This report assesses the pressures and forces generated by different catheters and pumps. Methods: Vacuum pressures were measured using a vacuum gauge for several catheters (Stryker Catalyst6, Penumbra Ace 064, Medtronic Arc 061, and Penumbra 041) and pumps (Penumbra pump, 60-mL syringe, and the ASPIRE device). Suction forces were calculated based on pressure and catheter tip size (force = area × pressure). Vacuum pressures and forces were also assessed with a coaxial microcatheter (Rebar 18; inner diameter = 0.021 inches), mimicking a combined aspiration and stent retriever approach. Results: All catheters transmitted similar vacuum pressures, but suction force was proportionate to catheter tip area. Pump vacuum pressures were also similar, although the Penumbra pump (mean -25.63 inches Hg [inHg]) was slightly weaker than the syringe and the ASPIRE device (-27.04 and -27.58 inHg, respectively; p < 0.001, two-way ANOVA). A coaxial microcatheter lowered the mean vacuum pressure by only 1.2 inHg (p = 0.005), though it would theoretically create a very significant reduction in suction force if partially blocking the aspiration catheter tip area. Conclusions: All catheters transmit similar vacuum pressure, but the suction force on the clot is stronger with larger catheter tips. Coaxial microcatheters will have a minimal impact on suction force as long as they are proximal to the aspiration catheter tip. Currently available thrombectomy suction devices, including the Penumbra pump, the ASPIRE handheld pump, and the 60-mL syringe, all develop similar vacuum pressures.