Cerebral hemodynamic benefits after carotid artery stenting in patients with near occlusion
Fumiaki Oka1, Hideyuki Ishihara, Shoichi Kato
1Department of Neurosurgery, Yamaguchi University School of Medicine, Yamaguchi, Japan.
Insights
Carotid artery stenting (CAS) improved cerebral hemodynamics in patients with near occlusion (NO). This procedure normalized cerebral blood flow and reactivity, suggesting CAS is an effective treatment for NO from a hemodynamic standpoint.
Area of Science:
- Neurology
- Vascular Surgery
- Radiology
Background:
- Management of internal carotid artery near occlusion (NO) remains controversial.
- Cerebral hemodynamic compromise in NO patients is not fully understood.
- The benefit of carotid revascularization on preventing ischemic stroke in NO is debated.
Purpose of the Study:
- To evaluate cerebral hemodynamics in patients with NO before and after carotid artery stenting (CAS).
- To assess the effectiveness of CAS in improving cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) in NO patients.
Main Methods:
- Carotid artery stenting (CAS) was performed on 15 patients with NO.
- Resting CBF and CVR were measured using SPECT before and 3-6 months after CAS.
- CBF and CVR data were compared with 78 patients with severe stenosis and healthy controls.
Main Results:
- Patients with NO showed significantly lower resting CBF and CVR compared to controls.
- After CAS, resting CBF and CVR in NO patients significantly improved.
- Post-CAS hemodynamics in NO patients normalized, showing no significant difference from controls.
Conclusions:
- Patients with NO exhibit significant hemodynamic compromise.
- Carotid artery stenting (CAS) effectively improves cerebral hemodynamics in NO patients long-term.
- CAS is a hemodynamically effective treatment for near occlusion of the internal carotid artery.
Objective:
The natural history and management of patients with near occlusion (NO) of the internal carotid artery are controversial. In particular, it is unclear whether cerebral hemodynamics are compromised in these patients and whether improvement by carotid revascularization leads to the prevention of ischemic stroke. In this study, we measured cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) using single-photon emission computed tomography before and after carotid artery stenting (CAS) for NO to examine the effectiveness of CAS from the perspective of cerebral hemodynamics.
Methods:
CAS was performed in 15 patients with NO and in 78 with severe stenosis (≥70%) but without NO at our institution. Resting CBF and CVR to acetazolamide were measured using N-isopropyl-p-[I-123] iodoamphetamine single-photon emission computed tomography before and at 3 to 6 months after CAS. We also measured CBF using the same method for healthy individuals and compared the results among the three groups.
Results:
CAS was successfully performed in all patients. Before CAS, the mean resting CBF was 26.68 ± 4.23 mL/100 g/min, and the mean CVR was -0.8% ± 15.1% in the patients with NO, both of which were significantly lower than in patients with severe stenosis without NO and in healthy individuals. After CAS, the mean resting CBF and mean CVR in patients with NO increased significantly to 30.07 ± 5.67 mL/100 g/min and 37.0% ± 21.4%, respectively, and there were no significant differences among the three groups.
Conclusions:
Before CAS, patients with NO were more hemodynamically compromised than those with severe stenosis without NO. After CAS, significant cerebral hemodynamic improvement and normalization occurred long-term. Thus, from a hemodynamic perspective, CAS was effective in patients with NO.
