Impact of device pass count and reperfusion levels in anterior circulation stroke: differential effects based on large-scale data from clinical practice.

Background: The relationship between angiographic success, number of device passes and functional outcome is a topic of clinical interest in endovascular thrombectomy (EVT) for acute ischemic stroke (AIS). This study systematically assessed differential effects of reperfusion levels and device pass counts based on large-scale, multicenter registry data.

Methods: Patients enrolled in the prospective, multicenter German Stroke Registry between 06/2015-12/2023 were screened. Inclusion criteria were anterior circulation AIS, pre-stroke mRS of 0-1, ≥ 1 passes and availability of clinical data. The primary outcome was functional independence at 90 days. Outcomes were evaluated across different degrees of reperfusion and number of passes employing Inverse Probability Regression Adjustment to control for confounding factors.

Results: 6,398 patients fulfilled the inclusion criteria. Single-pass mTICI 3 reperfusion was associated with the highest estimated rate of functional independence (54.3% [95% CI: 52.1-56.4]; p < 0.01) and the lowest mortality (19.6% [95% CI: 18.3-20.9]; p < 0.01) at 90 days. Up to three passes, mTICI 2b reperfusion achieved with n + 1 passes was associated with significantly better outcomes compared to mTICI 0-2a achieved with n passes. No significant difference in 90-day functional independence was observed between n pass mTICI 2b and n + 1 pass mTICI 3.

Conclusions: The highest rate of functional independence at 90 days was observed for single-pass mTICI 3 reperfusion. Up to three passes, achieving mTICI 2b with one additional pass was associated with improved outcomes compared to lower reperfusion grades. Improvement from mTICI 2b to 3 did not significantly increase outcomes.