Cortical venous opacification score predicts outcomes after thrombectomy in large vessel occlusion stroke: a systematic review and meta-analysis.

Purpose: This study aimed to assess whether the Cortical Vein Opacification Score (COVES), a visual scoring system based on single-phase Computed Tomography Angiography (CTA), is associated with clinical and radiological outcomes in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO) after endovascular treatment (EVT).

Methods and materials: A systematic review and meta-analysis were conducted according to PRISMA guidelines. PubMed, EMBASE, and Cochrane Library were searched from inception to early June 2025, identifying 572 articles, of which 6 were included. Post-hoc analyses of randomized controlled trials (RCTs) and observational studies, with patients stratified by venous outflow (VO) status, were included. Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity was assessed using I² statistic. Sensitivity analyses were performed in outcomes that presented high heterogeneity.

Results: The six studies included 2,709 patients. VO + was associated with higher excellent (RR 1.34; p < 0.001) and successful reperfusion (RR 1.05; p = 0.001). Functional independence at 90 days (modified Rankin Scale [mRS] 0-2) was higher in the VO + group (RR 2.67; p = 0.002). VO + was associated with lower rates of symptomatic intracranial hemorrhage (sICH), parenchymal hematoma (PH), and mortality at 90 days.

Conclusion: VO + is associated with better reperfusion and functional independence, as well as reduced hemorrhagic complications and mortality. These findings support the potential prognostic value of VO in AIS-LVO patients undergoing EVT. Heterogeneity and limited number of studies warrant cautious interpretation. Standardized imaging protocols and prospective validation are needed.