Carotid artery stenting (CAS) has previously been shown to spur the release of bioactive agents that produce oxidative stress. Now, new research is showing that chemical indicators of such stress found in the arterial blood correlate with poor cognitive outcomes and more ischemic lesions after the procedure.
The findings, published online recently in the Journal of NeuroInterventional Surgery, stem from a laboratory analysis of arterial blood collected from patients undergoing CAS in Japan.
Investigators led by Norihito Shimamura, MD, PhD (Hirosaki University Graduate School of Medicine, Hirosaki, Japan), explain that after stenting some carotid plaque, with its multiple proinflammatory and proatherosclerotic bioactive agents, is left behind within the artery. In addition, “balloon angioplasty of carotid plaque causes the release of intra-plaque bioactive agents into the blood,” they write.
In an email to Neurovascular Exchange, Shimamura said that the “incidence and importance of atherosclerotic disease has been increasing,” noting that he and his colleagues sought to find “an easy way to identify risk factors for periprocedural complications.”
The authors collected arterial blood four times during 22 consecutive CAS procedures that were performed between May 2014 and April 2016:
- After the sheath insertion without use of edaravone, a known antioxidant
- Before angioplasty with use of edaravone in the carotid artery
- After poststenting angioplasty from an occluded carotid artery
- Before sheath removal
They then used photometry to measure derivatives of reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP). The d-ROM values were reduced significantly after edaravone infusion (P < 0.05).
Changes in d-ROM During Carotid Artery Stenting
|
|
d-ROM (Carratelli Units) |
|
At Sheath Insertion |
355 ± 58.8 |
|
After Edavarone |
315 ± 57.2 |
|
After Poststenting Angioplasty |
328 ± 56.8 |
|
Just Before Sheath Removal |
315 ± 53.0 |
BAP did not change significantly during stenting, but BAP at sheath insertion correlated negatively with aging (P < 0.05). In addition, d-ROMs at sheath insertion correlated negatively with scores on the revised Hasegawa Dementia Scale (HDS-R) and positively with the poststenting DWI high spots (1.00 ± 1.07, P < 0.05). Other biochemical parameters did not correlate with the d-ROM values or BAP.
“Compression of carotid plaque oozes chemical substances that harm the human body,” concluded Shimamura. “Oxidative stress can be [a] risk factor for perioperative complications. Also, oxidative stress that is strongly related to atherosclerosis correlates with cognitive function.”
In the paper, the authors note: “High oxidative stress means a high sclerotic state. A preoperative value for oxidative stress can alert surgeons to possible postoperative ischemic complications.”
To NVX, Shimamura speculated that reducing oxidative stress and increasing antioxidant potential may improve the clinical outcomes of carotid artery stenting, particularly cognitive function.
The study is limited by its small sample size and the fact that it was only conducted in Japan, he acknowledged. In addition, questions remain regarding the “details of the chemical substances that influence oxidative stress,” Shimamura said.
Source:
Shimamura N, Naraoka M, Matsuda N, et al. Intra-arterial oxidative stress correlates negatively with cognitive function and positively with postoperative ischemic lesions in carotid artery stenosis stenting. J NeuroInterv Surg. 2017;Epub ahead of print.
Disclosures:
Shimamura reports no relevant conflicts of interest.
