# Dynamic trajectory of cerebral autoregulation recovery after carotid artery stenting in severe carotid stenosis

## TL;DR

This study shows that carotid artery stenting rapidly improves brain blood flow regulation in patients with severe artery blockage.

## Contribution

The study reveals a fast and complete recovery of cerebral autoregulation after stenting, with no difference between symptomatic and asymptomatic patients.

## Key findings

- Bilateral cerebral autoregulation is impaired in severe carotid stenosis patients.
- Carotid artery stenting restores autoregulation within 3 days, with the affected side recovering faster.
- Symptomatic and asymptomatic patients show similar recovery trajectories after stenting.

## Abstract

To investigate the temporal changes and recovery patterns of dynamic cerebral autoregulation (dCA) after carotid artery stenting (CAS) in patients with severe internal carotid artery stenosis.

In this prospective study, 44 patients undergoing CAS (19 symptomatic and 25 asymptomatic) and 44 age-matched healthy controls were enrolled. Patients in the CAS group underwent dCA assessments at four time points: pre-CAS (baseline, within 24 h prior to surgery), postoperative day 1 (POD 1), postoperative day 3 (POD 3), and 1 month postoperatively (POM 1). dCA was quantified using transfer function analysis (TFA), including phase difference (PD) and gain, to evaluate dCA.

Pre-CAS, patients had bilateral dCA impairment, worse on the affected (stenotic) side (PD: affected side: 30.56 ± 19.87° vs. unaffected side: 43.29 ± 23.29°, p < 0.001; both lower than healthy controls at 52.96 ± 14.82°, affected side: p < 0.001, unaffected side: p = 0.019). After CAS, dCA recovered rapidly. The affected side’s PD improved to the unaffected (non-stenotic) level by day 1 (POD 1 PD: affected side: 36.94 ± 20.59°, unaffected side: 41.69 ± 23.29°, p > 0.05), and both sides reached the level of healthy controls by day 3 (POD 3 PD: affected side: 47.71 ± 23.64°, unaffected side: 51.07 ± 24.43°, p > 0.05). The recovery trajectory was consistent between symptomatic and asymptomatic subgroups and aligned with the overall patient cohort.

Unilateral severe carotid stenosis impairs bilateral dCA, while CAS significantly restores cerebral autoregulation. Recovery is faster on the affected side, reaching the unaffected level within 1 day, and both hemispheres reach healthy control levels by day 3. Early CAS intervention can timely improve dCA regardless of symptom status.