Catheter Effects on Flow Dynamics and Safety in Thromboaspiration Procedures

Purpose Super large‐bore 8F catheters are increasingly employed in stroke thrombectomy due to perceived technical advantages, including reduction of cerebral blood flow. While volumetric flow rate (ml/min) has been studied extensively, flow velocity (cm/sec) remains underappreciated despite its potential implications for clot behavior during thromboaspiration. The CAT‐FLOW (Catheter‐Associated Thromboaspiration Flow) Study was designed to characterize the interrelationship between volumetric flow rate and flow velocity in an experimental model simulating MCA thromboaspiration. Methods Two experimental flow models were developed for bench testing: Setup 1 (without proximal bypass) and Setup 2 (with proximal bypass) (Figure 1). For each setup, the baseline volumetric flow rate was fixed at 120 ml/min. Relative changes in volumetric flow and tip velocity were measured under open‐flow conditions (reference) and during the introduction of four commercially available large and super large‐bore neurovascular catheters used for thromboaspiration. Each condition was repeated across five independent runs. Results In Setup #1, super large‐bore 088 catheters produced a 4.5‐6.1% reduction in volumetric flow rate but a striking 434.8‐572.8% increase in tip velocity. By comparison, the large bore 072 catheter caused a 3.2% reduction in volumetric flow and a 102.3% increase in velocity. In Setup #2, super large‐bore 088 catheters reduced volumetric flow by 55.2‐58.2% while increasing tip velocity by 150.6‐197.1% . The 072 catheter reduced volumetric flow by 18.5% and increased velocity by 70.3% (Table 1). Conclusions The CAT‐FLOW Study demonstrates that modest reductions in volumetric flow can paradoxically result in pronounced increases in catheter tip velocity, particularly with super large‐bore devices. Elevated tip velocity may contribute to unexpected clot fragmentation , which could influence procedural efficacy and safety. These findings highlight the importance of considering both volumetric flow and velocity when choosing catheters and planning thrombectomy. Further studies are warranted to validate these results and guide optimal device use. image image