While carotid artery stenting (CAS) during mechanical thrombectomy appears to be safe, whether or not the approach is non-inferior to deferred management remains to be seen, as per late-breaking results from the CASES trial presented earlier today at the 2026 European Stroke Organisation Conference (ESOC; 6–8 May, Maastricht, Netherlands).
The CASES trial investigated the optimal management of acute ischaemic stroke patients with coexisting intracranial large vessel occlusion (LVO) and carotid artery stenosis ≥50% or occlusion, otherwise known as tandem lesions. Investigators compared immediate CAS versus deferred management with the aim of demonstrating the non-inferiority of immediate CAS performed during thrombectomy.
CASES is an open-label, multicentre, international randomised controlled trial (RCT) that recruited patients from 26 centres across the Netherlands and Belgium. Eligible patients had ischaemic stroke due to a tandem lesion and were suitable candidates for thrombectomy. Patients were randomised to CAS at the time of thrombectomy, or to deferred treatment, which included carotid endarterectomy (CEA), delayed CAS or best medical management.
The trial’s primary endpoint was the shift in modified Rankin scale (mRS) scores at 90 days, while safety outcomes included symptomatic intracranial haemorrhage (ICH) and mortality—both assessed within 90 days. Efficacy analyses were performed in the per-protocol set and full-analysis set of the study population, including crossovers, with adjustment for prognostic confounders. The safety analysis was conducted according to the as-treated principle, and the non-inferiority margin was set at 0.8.
Between 2023 and 2025, 633 patients were recruited to the CASES trial and deferred informed consent was ultimately obtained from 597. Of these, 297 were assigned to immediate CAS and 300 to deferred treatment. The mean age of included participants was 72 years and the median National Institutes of Health stroke scale (NIHSS) score at baseline was 14.
In the full analysis—presented at ESOC 2026 by leading investigator Maarten Uyttenboogaart (University Medical Center Groningen, Groningen, Netherlands)—the non-inferiority criterion was not met, as per an adjusted common odds ratio (acOR) of 1.06 (95% confidence interval [CI], 0.79–1.43). However, in the per-protocol set, immediate CAS was non-inferior to the deferred treatment strategy, with an acOR of 1.1 (95% CI, 0.81–1.5).
The rates of symptomatic ICH were 2.1% in the CAS group and 3.8% in the deferred treatment group (OR, 0.55; 95% CI, 0.29–1.4), while mortality rates were 21% in the CAS group versus 25% in the deferred treatment group (acOR, 0.79; 95% CI, 0.54–1.14).
The researchers conclude that the CASES trial provides new evidence that immediate CAS during a mechanical thrombectomy procedure is safe when compared with a deferred treatment strategy among patients with acute ischaemic stroke due to atherosclerotic tandem lesions.
