Comparison of Restenosis Risk in Single-Layer versus Dual-Layer Carotid Stents: A Duplex Ultrasound Evaluation

Stroke risk management in carotid atherosclerotic disease: a clinical consensus statement of the ESC Council on Stroke and the ESC Working Group on Aorta and Peripheral Vascular Diseases

Carotid atherosclerotic disease continues to be an important cause of stroke, often disabling or fatal. Such strokes could be largely prevented through optimal medical therapy and carotid revascularization. Advancements in discovery research and imaging along with evidence from recent pharmacology and interventional clinical trials and registries and the progress in acute stroke management have markedly expanded the knowledge base for clinical decisions in carotid stenosis. Nevertheless, there is variability in carotid-related stroke prevention and management strategies across medical specialities. Optimal patient care can be achieved by (i) establishing a unified knowledge foundation and (ii) fostering multi-specialty collaborative guidelines. The emergent Neuro-Vascular Team concept, mirroring the multi-disciplinary Heart Team, embraces diverse specializations, tailors personalized, stratified medicine approaches to individual patient needs, and integrates innovative imaging and risk-assessment biomarkers. Proposed approach integrates collaboration of multiple specialists central to carotid artery stenosis management such as neurology, stroke medicine, cardiology, angiology, ophthalmology, vascular surgery, endovascular interventions, neuroradiology, and neurosurgery. Moreover, patient education regarding current treatment options, their risks and advantages, is pivotal, promoting patient's active role in clinical care decisions. This enables optimization of interventions ranging from lifestyle modification, carotid revascularization by stenting or endarterectomy, as well as pharmacological management including statins, novel lipid-lowering and antithrombotic strategies, and targeting inflammation and vascular dysfunction. This consensus document provides a harmonized multi-specialty approach to multi-morbidity prevention in carotid stenosis patients, based on comprehensive knowledge review, pinpointing research gaps in an evidence-based medicine approach. It aims to be a foundational tool for inter-disciplinary collaboration and prioritized patient-centric decision-making.

The Dual-layer CGuard Stent Is Safe and Effective in Emergent Carotid Artery Stenting and in Tandem Occlusions: a Multi-centric Study

BACKGROUND

Dual-layer stents have fallen into disrepute after several studies reported high rates of in-stent occlusions in acute stroke treatments. The CGuard stent is a new-generation hybrid dual-layer stent that has been designed to provide less thrombogenicity and to prevent peri- and postinterventional emboli. The aim of the study is to evaluate the safety and efficacy of the CGuard stent for the acute treatment of occlusion or high-grade stenosis of the extracranial internal carotid artery (ICA) in patients with acute ischemic stroke (AIS) with and without concomitant intracranial large vessel occlusion (LVO).

METHODS

All patients who underwent emergent carotid artery stenting (CAS) with the CGuard stent were identified and analyzed from the stroke registries from four tertiary German stroke centers. Clinical, procedural, and imaging data were evaluated. Stent patency within 72 h, intracranial hemorrhage, and modified Rankin score (mRS) at discharge were the safety and efficacy end points.

RESULTS

Overall, ninety-six patients were included (mean age 70.2 ± 11.8, 66 males (68.8%), median NIHSS score at admission 11 (7-17), IV lysis: n = 44 (45.8%)). Stent placement was successful in all patients. Eighty-three (86.4%) patients had tandem occlusions. In-stent occlusion occurred in 5 patients (5.2%) and 3 patients developed early in-stent stenosis (3.1%). Median mRS at discharge was 2 (1-4).

CONCLUSION

In this multicenter study, the use of the dual-layer CGuard stent for emergent CAS, particularly in tandem occlusions, was safe and resulted in low rates of in-stent occlusions.

Carotid single- and dual-layer stents reduce the wall adhesion of platelets by influencing flow and cellular transport

An ongoing thrombosis on a ruptured atherosclerotic plaque in the carotid may cause stroke. The primary treatment for patients with tandem lesion is stenting. Dual-layer stents have been introduced as an alternative to single-layer stents for elective and emergent carotid artery stenting. While the dual-layer structure shows promise in reducing plaque prolapse through the stent struts and with it the occurrence of post-procedural embolism, there are early signs that this newer generation of stents is more thrombogenic. We investigate a single- and a dual-layer stent design to assess their influence on a set of thrombosis-related flow factors in a novel setup of combined experiments and simulations. The in vitro results reveal that both stents reduce thrombus formation by approximately 50% when human anticoagulated whole blood was perfused through macrofluidic flow chambers coated with either collagen or human atherosclerotic plaque homogenates. Simulations predict that the primary cause is reduced platelet presence in the vicinity of the wall, due to the influence of stents on flow and cellular transport. Both stents significantly alter the near-wall flow conditions, modifying shear rate, shear gradient, cell-free zones, and platelet availability. Additionally, the dual-layer stent has further increased local shear rates on the inner struts. It also displays increased stagnation zones and reduced recirculation between the outer-layer struts. Finally, the dual-layer stent shows further reduced adhesion over an atherosclerotic plaque coating. The novel approach presented here can be used to improve the design optimization process of cardiovascular stents in the future by allowing an in-depth study of the emerging flow characteristics and agonist transport.

Stenting with dual-layer CGuard stent in acute sub-occlusive carotid artery stenosis and in tandem occlusions: a monocentric study

PURPOSE

Double-layer design carotid stents have been cast in a negative light since several investigations reported high rates of in-stent occlusions, at least in the acute setting of tandem occlusions. CGuard is a new generation double-layered stent that was designed to prevent periinterventional embolic events. The aim of this study was to analyze the safety and efficacy of the CGuard in emergent CAS and for the acute treatment of tandem occlusions in comparison with the single-layer Carotid Wallstent (CWS) system.

METHODS

All patients who underwent CAS with CGuard or CWS after intracranial mechanical thrombectomy (MT) between 11/2018 and 12/2022 were identified from our local thrombectomy registry. Clinical, interventional and neuroimaging data were analyzed. Patency of the stent was assessed within 72 h. Intracranial hemorrhage and modified Rankin score (mRS) at discharge were the main endpoints.

RESULTS

In total, 86 stent procedures in 86 patients were included (CWS: 44, CGuard: 42). CGuard had a lower, but not statistically significant rate (p = 0.431) of in-stent occlusions (n = 2, 4.8%) when compared to the CWS (n = 4, 9.1%). Significant in-stent stenosis was found in one case in each group. There was no statistically significant difference in functional outcome at discharge between the two groups with a median mRS for CGuard of 2 (IQR:1-5) vs. CWS 3 (IQR:2-4).

CONCLUSION

In our series, the rate of in-stent occlusions after emergent CAS was lower with the dual-layer CGuard when compared to the monolayer CWS. Further data are needed to evaluate the potential benefit of the design in more detail.

Clinical results of 30 consecutive patients of carotid artery stenosis treated with CASPER stent placement: 1-year follow-up and in-stent findings on intravascular ultrasound examination immediately and 6 months after treatment

BACKGROUND

The CASPER stent is expected to reduce periprocedural ischemic complications, but there is concern about restenosis in the early period. One-year follow-up results of CASPER stenting and findings on intravascular ultrasound (IVUS) immediately and 6 months after treatment are evaluated.

METHODS

Thirty consecutive patients were treated with CASPER stents for carotid artery stenosis. IVUS was performed immediately after stenting, and MRI and carotid ultrasonography were performed the next day, at 1 week, at 2 weeks, and then every 3 months. One-year follow-up results were evaluated. Twenty-five patients underwent follow-up angiography and IVUS after 6 months and their findings were investigated.

RESULTS

All patients were treated without complications during the intraoperative and periprocedural periods. After 6 months, all 25 patients with follow-up angiography and IVUS showed various degrees of intimal formation on IVUS and 8 of them had ≥50% stenosis on angiography. Three of the 30 patients required retreatment within 6 months because of severe restenosis. In these patients, the inner layer of the stent was deformed toward the inside due to intimal hyperplasia on follow-up IVUS, and there was dissociation between the inner and outer layers. All but the 3 of 30 patients with 1-year follow-up did not lead to symptomatic cerebrovascular events or retreatment.

CONCLUSIONS

The CASPER stent appears to be effective for preventing periprocedural ischemic complications. IVUS showed various degrees of intimal formation within 6 months after treatment, and it is possible that the CASPER stent is structurally prone to intimal formation or hyperplasia.

Carotid artery revascularization using second generation stents versus surgery: a meta-analysis of clinical outcomes

INTRODUCTION

Meta-analyses and emerging randomized data indicate that second-generation ('mesh') carotid stents (SGS) may improve outcomes versus conventional (single-layer) stents but clinically-relevant differences in individual SGS-type performance have been identified. No comparisons exist for SGS versus carotid endarterectomy (CEA).

EVIDENCE ACQUISITION

Thirty-day death (D), stroke (S), myocardial infarction (M), and 12-month ipsilateral stroke and restenosis in SGS studies were meta-analyzed (random effect model) against CEA outcomes. Eligible studies were identified through PubMed/EMBASE/COCHRANE. Forest plots were formed for absolute adverse evet risk in individual studies and for relative outcomes with each SGS deign versus contemporary CEA outcomes as reference. Meta-regression was performed to identify potential modifiers of treatment modality effect.

EVIDENCE SYNTHESIS

Data were extracted from 103,642 patients in 25 studies (14 SGS-treated, 41% symptomatic; nine randomized controlled trial (RCT)-CEA-treated, 37% symptomatic; and two Vascular Quality Initiative (VQI)-CEA-treated, 23% symptomatic). Casper/Roadsaver and CGuard significantly reduced DSM versus RCT-CEA (-2.70% and -2.95%, P<0.001 for both) and versus VQI-CEA (-1.11% and -1.36%, P<0.001 for both). Gore stent 30-day DSM was similar to RCT-CEA (P=0.581) but increased against VQI-CEA (+2.38%, P=0.033). At 12 months, Casper/Roadsaver ipsilateral stroke rate was lower than RCT-CEA (-0.75%, P=0.026) and similar to VQI-CEA (P=0.584). Restenosis with Casper/Roadsaver was +4.18% vs. RCT-CEA and +4.83% vs. VQI-CEA (P=0.005, P<0.001). CGuard 12-month ipsilateral stroke rate was similar to VQI-CEA (P=0.850) and reduced versus RCT-CEA (-0.63%, P=0.030); restenosis was reduced respectively by -0.26% and -0.63% (P=0.033, P<0.001). Twelve-month Gore stent outcomes were overall inferior to surgery.

CONCLUSIONS

Meta-analytic integration of available clinical data indicates: 1) reduction in stroke but increased restenosis rate with Casper/Roadsaver, and 2) reduction in both stroke and restenosis with CGuard MicroNET-covered stent against contemporary CEA outcomes at 30 days and 12 months used as a reference. This may inform clinical practice in anticipation of large-scale randomized trials powered for low clinical event rates (PROSPERO-CRD42022339789).

Comparison of the Outcome and Efficacy of Single-Layer versus Dual-Layer Mesh Stent among Carotid Stenosis Patients Attending a Tertiary Care Setting—A Prospective Observational Study

Introduction The effect of stent design whether single-layer or double-layer on long-term durability of carotid artery stenting (CAS) is unknown. The aim of this article was to compare the clinical outcome and efficacy of single-layer versus dual-layer mesh stent for CAS among carotid stenosis patients.

Methods A prospective observational study was conducted among 41 consecutive patients, who underwent CAS procedures between November 2019 and November 2021. Procedural data and outcomes for patients treated with the single-layer stent (n = 19patients) and double-layer stent (n = 22) were compared. Procedural efficacy and complications were considered as primary outcome variable. SPSS version 22 was used for statistical analysis.

Results Mean age of study population in dual-layer stents group was 63.86 ± 11.08 years and it was 61.47 ± 8.26 years in single-layer stent group. There was no statistically significant difference between two groups with age, stenosis, side of stenosis, prestenting angioplasty, and poststenting angioplasty (p-value >0.05). Out of 22 participants with dual-layer stent, only one (4.5%) participant experienced five episodes of transient ischemic attack in last 1 month. Both clinical and associated complaints were more in dual-layer group compared with single layer. One (5.26%) participant in single-layer group had reclusion/restenosis at 30 days. Majority in single-(57.8%) and double-layer (63.64%) stents group showed modified Rankin Scale score of 0.

Conclusion Restenosis after CAS occurred less frequently in patients treated with double-layer mesh when compared with single-layer stent. However, both stents were equally effective at preventing peri procedural complications.

Intraprocedural Plaque Protrusion during Carotid Artery Stenting with a CASPER Stent: A Case Report

Objective

Plaque protrusion (PP) during carotid artery stenting (CAS) is considered to be associated with periprocedural ischemic stroke. A new double-layer micromesh stent, the CASPER stent (CS), was approved for use in Japan in 2020. The expectation is that this micromesh stent system will reduce the risk of PP, but we report a case of PP during CAS despite the use of a CS.

Case Presentation

An 87-year-old man presented with left hemiparesis. MRI showed right brain infarction and angiography showed right internal carotid artery stenosis with thrombus. Follow-up angiography after medical treatment showed that thrombus disappeared. We therefore performed CAS for right internal carotid artery stenosis with unstable plaque. CAS was performed under local anesthesia with Mo.Ma Ultra and FilterWire EZ protection using a CS placed to sufficiently cover the stenotic region. Conservative post-dilatation was then performed. Intravascular ultrasonography (IVUS) after post-dilatation showed the presence of PP. A second CS was then added using the stent-in-stent technique. No postoperative neurological abnormalities were found and the patient was discharged without postoperative complications. No stroke or restenosis has been observed as of 16 months after CAS.

Conclusion

PP can occur even when CAS is performed using the CS for carotid artery stenosis with unstable plaque. The importance of checking for PP using IVUS is suggested.

Clinical Outcomes of Second- versus First-Generation Carotid Stents: A Systematic Review and Meta-Analysis

Background: Single-cohort studies suggest that second-generation stents (SGS; “mesh stents”) may improve carotid artery stenting (CAS) outcomes by limiting peri- and postprocedural cerebral embolism. SGS differ in the stent frame construction, mesh material, and design, as well as in mesh-to-frame position (inside/outside). Objectives: To compare clinical outcomes of SGS in relation to first-generation stents (FGSs; single-layer) in CAS. Methods: We performed a systematic review and meta-analysis of clinical studies with FGSs and SGS (PRISMA methodology, 3302 records). Endpoints were 30-day death, stroke, myocardial infarction (DSM), and 12-month ipsilateral stroke (IS) and restenosis (ISR). A random-effect model was applied. Results: Data of 68,422 patients from 112 eligible studies (68.2% men, 44.9% symptomatic) were meta-analyzed. Thirty-day DSM was 1.30% vs. 4.11% (p < 0.01, data for SGS vs. FGS). Among SGS, both Casper/Roadsaver and CGuard reduced 30-day DSM (by 2.78 and 3.03 absolute percent, p = 0.02 and p < 0.001), whereas the Gore stent was neutral. SGSs significantly improved outcomes compared with closed-cell FGS (30-day stroke 0.6% vs. 2.32%, p = 0.014; DSM 1.3% vs. 3.15%, p < 0.01). At 12 months, in relation to FGS, Casper/Roadsaver reduced IS (−3.25%, p < 0.05) but increased ISR (+3.19%, p = 0.04), CGuard showed a reduction in both IS and ISR (−3.13%, −3.63%; p = 0.01, p < 0.01), whereas the Gore stent was neutral. Conclusions: Pooled SGS use was associated with improved short- and long-term clinical results of CAS. Individual SGS types, however, differed significantly in their outcomes, indicating a lack of a “mesh stent” class effect. Findings from this meta-analysis may provide clinically relevant information in anticipation of large-scale randomized trials.