Impact of aspiration catheter size on clinical outcomes in aspiration thrombectomy

Direct aspiration thrombectomy is a well-established method for mechanical thrombectomy in acute ischemic stroke. Yet, the influence of aspiration catheter internal diameter (ID) on aspiration thrombectomy efficacy is incompletely understood.

A systematic literature review and meta-regression analysis was completed to evaluate the impact of primary aspiration thrombectomy outcomes based on the ID of the aspiration catheter. Primary outcome measures were: final recanalization of modified Thrombolysis In Cerebral Ischemia (mTICI) 2b-3 with aspiration only and with rescue modalities, first pass effect (FPE), need for rescue modalities, intracranial hemorrhagic complication rates, and functional outcomes of 90-day modified Rankin Scale (mRS) of 0-2.

30 studies were identified with 3228 patients. Meta-regression analysis revealed a significant association between increasing aspiration catheter ID and FPE (p=0.032), between ID and final recanalization with aspiration only (p=0.05), and between ID size and recanalization including cases with rescue modalities (p=0.002). Further, subgroup analysis indicated that catheters with an ID ≥0.064 inch had a lower rate of need for rescue than smaller catheters (p=0.013). Additionally, catheters with an ID ≥0.068 inch had a higher rate of intracranial bleeding complications (p=0.025). Lastly, no significant association was found in functional outcomes overall.

Larger aspiration catheters are associated with a higher rate of FPE, final recanalization with only an aspiration catheter, and in cases with rescue modalities, though with a higher rate of hemorrhagic complications. These findings confirm that aspiration catheter size functions as a variable in aspiration thrombectomy, which should be considered in future study and trial design.