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

Objective 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. Methods 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. Results 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. Conclusion 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.