A335 ‘Larger is not always better’ – comparing cyclical and static aspiration in a neurovascular flow model

<h3>Introduction</h3> Endovascular treatment with 0.088’ catheters and cyclical aspiration (CyA) may improve procedural outcomes in ischemic stroke patients. <h3>Aim of Study</h3> To evaluate the safety and efficacy of different aspiration patterns and catheter sizes in a neurovascular model with physiological flow. <h3>Method</h3> The middle cerebral artery (MCA-M1; proximal diameter = 3.5 mm, distal = 2.2 mm) was embolized using 40 friable (Length = 8.28 ± 0.16 mm) and 40 stiff clot analogs (Length = 5.29 ± 0.12 mm). CyA and static aspiration (StA) were tested with 0.071’ and 0.088’ catheters across four arms: CyA 71, CyA 88, StA 71, and StA 88. Endpoints included First Pass Recanalization rate (FPR%), distal embolization, and vessel collapse. <h3>Results</h3> Overall FPR was 65% (52/80), with CyA outperforming StA (FPR: 80% vs. 50%, p=0.005). FPR was lower with friable clots (55% vs. 75%, p=0.061). CyA 71 achieved higher FPR (85%) compared to StA 71 and StA 88 (both 50%, p=0.054). For stiff clots, CyA 71 (100%) and CyA 88 (80%) were superior to StA 88 (30%) (p=0.019 and p=0.037, respectively). Vessel collapse reduced FPR (69% vs. 41%; p=0.066). The 0.071’ catheter did not cause collapse. With 0.088’ catheters, collapse was less frequent with CyA (CyA 88: 10% vs. StA 88: 70%, p=0.044). No differences were found in distal embolization rates. <h3>Conclusion</h3> Large bore catheters enhance recanalization unless vessel collapse occurs. Cyclical aspiration reduces vessel collapse and improves clot retrieval efficacy without increasing distal embolization. <h3>Conflict of Interest</h3> No