Carotid artery stenosis occurs when fatty or calcified deposits narrow the carotid arteries, the primary vessels supplying oxygen-rich blood to the brain. This condition reduces blood flow, increases the risk of stroke, and can alter the blood-brain barrier (BBB), which is a protective cellular barrier that controls the exchange of substances between the brain and bloodstream. The resulting oxygen deprivation and vascular dysfunction contribute to cognitive decline and neurological complications. Now, a new clinical study has shown that surgical intervention can restore both cerebral blood flow and BBB integrity in affected patients.

Researchers from the China National Clinical Research Center for Neurological Diseases (NCRC-ND, Beijing, China) conducted a clinical study investigating how carotid endarterectomy (CEA), which is a surgical procedure that clears arterial blockages, affects the BBB in patients with bilateral carotid artery stenosis. The study, published in the Chinese Neurosurgical Journal, included 17 patients with severe stenosis of 70% or greater in both carotid arteries. Participants underwent brain imaging through computed tomography perfusion (CTP) scans one week before and several months after surgery to measure cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP), and BBB permeability (PS).

Before surgery, the operative side showed decreased CBF and prolonged MTT and TTP compared to the nonoperative side, indicating sluggish blood flow and delayed perfusion. CBV and PS values were similar on both sides, suggesting increased BBB permeability but no structural recovery. After surgery, however, the operative side demonstrated marked improvements—CBF increased while CBV, MTT, TTP, and PS all decreased, reflecting restored blood dynamics and normalized BBB function. The nonoperative side remained unchanged due to persistent severe blockage.

These findings confirm that CEA can reverse cerebral hemodynamic impairments and repair BBB dysfunction in treated arteries. By improving both blood flow and barrier integrity, the procedure may prevent stroke recurrence and mitigate cognitive decline associated with vascular insufficiency. The authors highlight that these effects may also support long-term neurological recovery, making the surgery valuable beyond its traditional role in stroke prevention.

The study’s results underscore the importance of early surgical management in patients with high-grade carotid stenosis. Improved understanding of BBB restoration after surgery could guide future interventions and imaging-based monitoring of recovery. Further multicenter studies are expected to explore the duration and magnitude of BBB normalization across larger populations and varying stenosis severities.

“Given the role of BBB in cognitive functions, it is important to examine if CEA can stabilize the BBB and potentially improve long-term cognitive recovery in patients with carotid artery stenosis,” said Dr. Yan Zhang, lead author.

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