Why Is a Large-Bore Catheter Necessary in Large Vessel Occlusion from a Biomechanical Perspective?

Aspiration thrombectomy is a widely adopted treatment for acute ischemic stroke due to large vessel occlusion. Among several technical factors, the diameter of the aspiration catheter plays a critical role in determining thrombus fixation, aspiration efficiency, and overall procedural success. This study aimed to investigate the biomechanical effects of a larger catheter diameter on thrombus behavior and vessel wall response during aspiration thrombectomy.

Finite element analysis was employed to simulate aspiration using three clinically relevant aspiration catheters with different diameters. Thrombi of two lengths and two compositions, varying in red blood cell content, were modeled to reflect clinical variability. Mechanical outcomes, including thrombus deformation, internal stress distribution, and vessel wall loading, were analyzed under standardized aspiration pressure conditions.

0.080- and 0.084-inch large-bore catheters produced greater thrombus deformation and internal stress than the 0.072-inch catheter, particularly in softer thrombi with higher red blood cell content. In both 3 and 5 mm thrombi with red blood cells, deformation increased by approximately 12.3% with the 0.084-inch catheter compared to the 0.072-inch catheter. These changes indicate improved clot engagement and aspiration efficiency, while vessel stress remained within physiological limits. This mechanical advantage is partly due to greater luminal occupancy, with the 0.084-inch catheter occupying 65.6% of the vessel lumen, about 14% more than the 0.072-inch catheter.

Large-bore aspiration catheters can enhance thrombus fixation and aspiration performance without compromising vascular integrity. These findings support the broader clinical use of larger-bore catheters in patients with large artery occlusion, particularly in cases requiring strong clot engagement and efficient recanalization.