Endovascular Thrombectomy after 24 Hours for Patients with Acute Ischemic Stroke Due to Large Vessel Occlusion: A Systematic Review and Meta-Analysis of Outcomes

Abstract

Objective

To evaluate the role of endovascular thrombectomy in patients presenting with acute ischemic stroke (AIS) due to large vessel occlusion in the very late window (>24 hours).

Methods

A systematic review was conducted according to PRISMA guidelines using PubMed, CINAHL, Scopus, and Google Scholar databases till 2024. Quality assessment was performed using the Newcastle-Ottawa Scale (NOS). Outcomes were analyzed with a single-arm meta-analysis (Sidik-Jonkman model) and a double-arm meta-analysis (Mantel-Haenszel model) to compare EVT within and after 24 hours, reporting pooled risk ratios. Analysis was performed using STATA version 18.0 and Review Manager version 5.4.1, with p<0.05 considered significant.

Results

This review included 35 studies with 15,086 patients. The frequency of symptomatic intracerebral hemorrhage (sICH) in patients treated with EVT after 24 hours was 4.74% (CI: 3.20%-6.58%), with a risk ratio (RR) of 0.85 (CI: 0.44-1.64) compared to EVT patients treated within 24 hours. The pooled percentage for functional independence (90 day mRS 0-2) was 35.73% (CI- 27.26%, 44.64%) with an overall pooled risk ratio of 0.85 (CI: 0.34, 2.09). The frequency of the 90-day mortality rate was 22.30% (CI: 16.12%, 29.09%), with an overall pooled risk ratio of 1.80(CI: 0.73, 1.61). The overall frequency of intracerebral hemorrhage (ICH) was 12.23% (CI: 5.47-20.86) following EVT after 24 hours.

Conclusion

Patients treated with EVT after 24 hours have comparable safety and effectiveness to those treated within 24 hours. The outcomes suggest that EVT after 24 hours is a viable treatment option, offering similar benefits to earlier intervention.