Proximal embolic protection versus distal filter protection versus combined protection in carotid artery stenting: A systematic review and meta-analysis

OBJECTIVE

Proximal embolic protection devices (P-EPD) and distal filters (DF) are used to prevent distal cerebral embolizations during carotid artery stenting (CAS). We compared their comparative effectiveness in regards to prevention of intraprocedural and periprocedural adverse events, including ischemic lesions (ipsilateral and contralateral), stroke, transient ischemic attacks (TIA) and death. We also compared the combination of the two neuroprotection strategies vs. a single strategy in regards to ischemic lesions and stroke.

MATERIALS & METHODS

This study was performed according to the PRISMA and MOOSE guidelines and eligible studies were identified through search of PubMed, Scopus and Cochrane Central. A meta-analysis was conducted with the use of a random effects model. The I-square statistic was used to assess for heterogeneity.

RESULTS

Twenty-nine studies involving 16,307 patients were included. There was a significant reduction in ischemic lesions with the use of P-EPD among observational studies (RR: 0.66 [0.45-0.97]). There were no statistically significant differences for the other outcomes between the two treatment groups.

CONCLUSIONS

There is a number of studies reporting outcomes on the comparison between P-EPD and DF for CAS. P-EDP can reduce distal embolization phenomena resulting into ischemic lesions when compared to DF based on the results from real-world studies. P-EPD was not superior however, in regards to periprocedural stroke, TIA and death. Further studies are anticipated to provide a clear answer to this debate.

Valsartan prevents neointimal hyperplasia after carotid artery stenting by suppressing endothelial cell injuries

OBJECTIVES

Restenosis or neointimal hyperplasia remains an important complication after carotid artery stenting (CAS) for carotid artery stenosis. The purpose of this study was to examine if an anti-hypertensive drug, angiotensin receptor blocker (ARB), prevents post-CAS neointimal hyperplasia during the first 1-year period after CAS, and to clarify the possible mechanisms.

METHODS

Hypertension had been treated with a calcium channel blocker (CCB) and/or an ARB, valsartan, by the preference of the neurosurgeon in charge in our department. At admission to perform CAS, patients were assigned to normotensive, valsartan (hypertensive patients treated with valsartan with/without any kind of CCBs), and non-valsartan (hypertensive patients treated with any kind of CCBs without ARBs) groups. Post-CAS neointimal hyperplasia was evaluated by carotid duplex ultrasound imaging in terms of intima-media thickening (IMT), which was performed at pre-CAS and at 90, 180, 270, and 360 days post-CAS. Biomarkers of oxidative stress (8-hydroxy-2'-deoxyguanosine), inflammation (C-reactive protein, tenascin-C) and endothelial cell injury (von Willebrand factor [vWF] antigen) were measured at pre-CAS and at 1, 7, and 180 days post-CAS.

RESULTS

The non-valsartan group (n  =  8) had a higher incidence of maximum in-stent IMT ≧ 1.1 mm compared with the normotensive group (n  =  6). Valsartan (n  =  9) significantly suppressed plasma vWF levels at 7 days post-CAS and decreased the incidence of maximum in-stent IMT ≧ 1.1 mm compared with the non-valsartan group, although clinical parameters were similar between the two groups. Other biomarkers were not significantly different among the three groups.

CONCLUSIONS

These findings suggest that valsartan may prevent post-CAS neointimal hyperplasia possibly by suppressing endothelial cell injury.