The effect of first pass effect in mechanical thrombectomy for acute terminal internal carotid artery occlusion.

Introduction: This study aimed to elucidate the impact of the first-pass effect (PFE) on patients with acute terminal internal carotid artery occlusion.

Methods: We conducted a retrospective analysis of patients with acute terminal internal carotid artery occlusion who underwent endovascular treatment. PFE was defined as achieving complete revascularization with a single use of the thrombectomy device, without the requirement for salvage therapy during the procedure. The primary functional outcome was measured using the 90-day modified Rankin Scale (mRS). mRS score of 0-3 was defined as a favorable outcome. A comprehensive assessment was performed on baseline patient characteristics, procedural parameters, and clinical outcomes. Multivariate analysis was employed to determine the association between PFE and 90-day functional outcomes.

Results: A total of 150 patients were included, of which 36 (24%) achieved PFE. Compared to the non-PFE group, the PFE group exhibited lower rates of general anesthesia, higher rates of intravenous thrombolysis and aspiration thrombectomy, and a shorter puncture-to-recanalization time. When contrasted with the unfavorable outcome group, the favorable outcome group presented with lower NIHSS scores, shorter puncture-to-recanalization durations, a reduced prevalence of atrial fibrillation, and a higher proportion of PFE. Multivariate analysis revealed that PFE was significantly associated with favorable functional outcomes (mRS 0-3, 49.12% vs. 72.22%; adjusted odds ratio [aOR], 3.78; 95% confidence interval [CI], 1.21-11.81; P = 0.022), yet showed no significant association with secondary or safety outcomes.

Conclusion: This study demonstrates that among patients with acute terminal internal carotid artery occlusion who underwent endovascular treatment, 24% achieved FPE, which was associated with improved 90-days functional outcome.