Dual- vs single-layer stents for endovascular treatment of symptomatic and asymptomatic internal carotid artery stenosis

Backgrounds: Plaque protrusion is a common event among carotid artery stenting (CAS) patients and increases ischemic complication risk. Dual-layer stents (DLS) with micromesh technology may offer greater plaque protection compared to single-layer stents (SLS), but few data are available. The aim of the study is to compare clinical outcomes at 12 months for asymptomatic and symptomatic patients treated for primary CAS with DLS or SLS in a high-volume center. Methods: A retrospective analysis of consecutive symptomatic and asymptomatic patients treated with primary CAS for internal carotid artery (ICA) stenosis, with either DLS or SLS between 2015 and 2019, was performed. Primary endpoints included rates of ipsilateral transient ischemic attacks (TIA)/stroke and death within 1-year from CAS. Secondary endpoints included patency rates and survival according to stent type. Results: Of the 301 patients who met inclusion criteria (74.8 % male; 73.6 mean age ± 8.7 years), most patients were asymptomatic (77.4 %). Among all patients DLS was most frequently deployed (66 %); also, among asymptomatic (62 %) and symptomatic patients (81 %), p < 0.01. Symptomatic patients had less comorbidities and severe disease than asymptomatic patients. Six peri-operative strokes were recorded and, within 1 year, 2 additional strokes were registered among symptomatic patients treated with SLS. No post-operative strokes were encountered in the DLS group (p = 0.04) among symptomatic patients. Higher rates of TIA were observed among asymptomatic patients treated with DLS compared to SLS while rates of TIA were reduced among symptomatic patients treated with DLS. There were no differences in patency rates for DLS and SLS in symptomatic and asymptomatic patients. Primary patency was similar among DLS stent types but differed among SLS stent types (p = 0.01). At a mean follow-up of 27 months ±17.6, survival was comparable between DLS and SLS groups (p = 0.98). Conclusion: CAS with DLS seems to reduce the risk of post-procedural stroke for symptomatic patients compared to SLS whilst the choice of stent did not influence ipsilateral TIA, survival or patency rates. These data require confirmation from larger, randomized, prospective studies.