Cerebral hyperperfusion following carotid endarterectomy

Area of Science:

• Neurology
• Vascular Surgery
• Cerebrovascular Physiology

Background:

• Carotid endarterectomy is a common procedure to prevent stroke.
• Cerebral blood flow (CBF) dynamics after carotid endarterectomy are not fully understood.
• Autoregulation of cerebral blood flow is crucial for brain health.

Purpose of the Study:

• To investigate serial changes in CBF after carotid endarterectomy.
• To correlate CBF changes with the internal carotid artery (ICA) to common carotid artery (CCA) pressure ratio.
• To identify patient subgroups at higher risk for cerebrovascular complications post-surgery.

Main Methods:

• Serial CBF measurements in 56 patients before and after carotid endarterectomy.
• Calculation of the ICA/CCA mean pressure ratio.
• Comparison of CBF changes between patients with low (<0.7) and high (≥0.7) ICA/CCA pressure ratios.

Main Results:

• CBF significantly increased within 24 hours post-surgery (ipsilateral: 37%, contralateral: 33%).
• Patients with an ICA/CCA ratio <0.7 showed a more pronounced and sustained CBF increase (ipsilateral Day 1: 61%) compared to those with a ratio ≥0.7 (ipsilateral Day 1: 24%).
• Low-ratio patients exhibited improved hemispheric asymmetry and hyperemia, suggesting impaired autoregulation.

Conclusions:

• Carotid endarterectomy leads to transient hyperemia, particularly in patients with low ICA/CCA pressure ratios.
• Impaired autoregulation may underlie the pronounced hyperemia in the low-ratio group.
• Postoperative hypertension should be carefully managed in these patients to prevent cerebral edema or hemorrhage.