Short-term safety outcomes of carotid artery stenting with double-layer stents: a systematic review

Carotid artery stenting (CAS) with double-layer stents (DLS) has been increasingly adopted for carotid revascularization, particularly in patients considered high risk for surgery. However, evidence regarding their early clinical outcomes remains limited and heterogeneous. This systematic review aims to assess the 30-day safety outcomes of CAS using DLS, focusing on stroke, mortality, myocardial infarction (MI), and device-related complications. A systematic search was conducted across PubMed/MEDLINE, Embase, IEEE Xplore, Scopus, and Cochrane Library for studies published between January 2020 and August 2025. Eligible studies included randomized controlled trials (RCTs), prospective and retrospective cohort studies, and registry analyses reporting 30-day safety outcomes after CAS with DLS. Two reviewers independently screened records, extracted data, and assessed risk of bias using the Newcastle-Ottawa Scale (NOS) for observational studies and the Cochrane Risk of Bias 2 (RoB 2) tool for randomized trials. Ten studies comprising 6067 patients were included. The 30-day stroke rate ranged from 0 to 3.4%, though these rates should be interpreted cautiously given the lack of head-to-head comparisons and potential influence of patient selection. Mortality rates were consistently low, and the composite stroke/death endpoint ranged from 0 to 5.3%. MI rates were infrequently reported but remained low. Device-related complications were rare, with access site issues and in-stent thrombosis being the most reported. Comparative data between double-layer and single-layer stents were limited, and heterogeneity in outcome reporting precluded meta-analysis. Accordingly, all conclusions are based on narrative synthesis of the available data. Risk of bias assessment indicated low risk in 8 of 10 studies using the selected tools; however, the overall certainty remains limited by the observational nature of most included studies. CAS with DLS was associated with low reported rates of stroke, death, and complications in the included studies. The effect of the micromesh design on embolic protection remains uncertain due to limited comparative evidence. Further randomized trials and standardized outcome reporting are needed to validate these findings and guide clinical practice.