Impact of Carotid Stent Design on Embolic Filter Debris Load During Carotid Artery Stenting

BACKGROUND: The carotid stent design may influence the risk of embolization during carotid artery stenting. The aim of the study was to assess this risk by comparing the quantity of embolized material captured by filters during carotid artery stenting, using different stent designs. METHODS: We conducted a single-center retrospective study of patients undergoing carotid artery stenting for asymptomatic carotid stenosis >70% (2010-2022) in a tertiary academic hospital (Padua University Hospital, Italy). Carotid stents were classified according to their design as open-cell (OCS), closed-cell (CCS), or micromesh stents (MMS). A distal filter protection was used in all patients, and the amount of captured embolized particles was semiautomatically analyzed using a dedicated software (Image-Pro Plus, Media Cybernetics). Primary end point was embolic filter debris (EFD) load, defined as the ratio of the filter area covered by particulate material to the total filter area. Secondary end points were 30 days major stroke and death. RESULTS: Four-hundred-eighty-one carotid artery stentings were included; 171 (35%) using an OCS, 68 (14%) a CCS, and 242 (50%) a MMS. Thirty-days mortality was 0.2% (n=1) and major stroke rate was 0.2% (P=0.987). Filters of patients receiving MMS were more likely to be free from embolized material (OCS, 30%; CCS, 13%; MMS, 41%; P<0.001) and had a lower EFD load (OCS, 9.1 +/- 14.5%; CCS, 7.9 +/- 14.0%; MMS, 5.0 +/- 9.1%; P<0.001) compared with other stent designs. After stratification by plaque characteristics, MMS had a lower EFD load in cases of hypoechogenic plaque (OCS, 13.4 +/- 9.9%; CCS, 10.9 +/- 8.7%; MMS, 6.5 +/- 13.1%; P<0.001), plaque length>15 mm (OC, 10.2 +/- 15.3; CC, 8.6 +/- 12.4; MM, 8.2 +/- 13.6; P<0.001), and preoperative ipsilateral asymptomatic ischemic cerebral lesion (OCS, 12.9 +/- 16.8%; CCS, 8.7 +/- 19.5%; MMS, 5.4 +/- 9.7%; P<0.001). After multivariate linear regression, use of MMS was associated with lower EFD load (P=0.038). CONCLUSIONS: The use of MMS seems to be associated with a lower embolization rate and EFD load, especially in hypoechogenic and long plaques and in patients with a preoperative evidence of asymptomatic ischemic cerebral lesion.