To evaluate whether the severity of the cervical lesion (occlusion vs. stenosis) in tandem lesions (TLs) affects angiographic and clinical outcomes following endovascular treatment (EVT).

Tandem lesions involve simultaneous intracranial large vessel occlusion and steno-occlusive disease of the ipsilateral cervical artery. Prior studies suggest that complete occlusion may result in lower recanalization rates and worse outcomes compared with stenosis. However, evidence remains inconclusive. This meta-analysis investigates the impact of cervical lesion severity on reperfusion success, functional recovery, and hemorrhagic complications in TLs undergoing EVT.

A comprehensive literature search was performed across PubMed, Embase, and Cochrane databases through June 2025. Studies comparing outcomes between TL patients with cervical occlusion versus stenosis after EVT were included. Outcomes of interest were successful recanalization (mTICI ≥2b), good functional outcome (modified Rankin Scale [mRS] 0–2 at 90 days), parenchymal hemorrhage, and 90-day mortality. Pooled risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model, with heterogeneity assessed by I² statistics.

Three studies (n=670; 328 occlusion, 342 stenosis) met inclusion criteria. No significant differences were observed in successful recanalization (RR 0.87; 95% CI 0.55–1.39; p=0.34), good functional outcome (RR 0.94; 95% CI 0.79–1.13; p=0.29), or 90-day mortality (RR 1.01; 95% CI 0.64–1.57; p=0.96). However, parenchymal hemorrhage was significantly lower in the occlusion group (RR 0.76; 95% CI 0.60–0.97; p=0.04).

In TLs treated with EVT, cervical occlusion was associated with similar angiographic and functional outcomes compared with stenosis, but with a lower risk of parenchymal hemorrhage. These findings suggest that cervical lesion severity may not significantly influence reperfusion or recovery but may affect hemorrhagic risk profiles.