1-Month Results From a Prospective Experience on CAS Using CGuard Stent System

Carotid Artery Stenting With Double-Layer Stent: A Systematic Review and Meta-Analysis

BACKGROUND

Carotid artery stenting (CAS) in the treatment of significant stenosis is a cause of stroke due to both plaque prolapse and cerebral embolization. New types of stents with a double-layer structure have been designed to minimize plaque prolapse and embolization; these double-layer stents (DLSs) should be able to reduce the stroke risk; however, definite data on their performance are scarce in the literature.

METHODS

A systematic search was performed through PubMed, Scopus, and Cochrane Library, according to PRISMA guidelines; all studies on CAS with DLS (Roadsaver/Casper or CGuard) up to January 1, 2022, with a cohort of at least 20 patients were considered eligible. The present meta-analysis was approved and registered on PROSPERO register (CRD42022297512). Patients with tandem lesions or complete carotid occlusion were excluded from the study. The 30-day stroke rate after CAS was analyzed evaluating the preoperative symptomatic status and DLS occlusion. The estimated pooled rate of events was calculated by random effect model and moderators were evaluated.

RESULTS

A total of 14 studies were included in the meta-analysis for a total of 1955 patients. The estimated overall (95% confidence interval [CI]) stroke rate was 1.4% (0.9%-2.2%, I2 = 0%), which was not influenced by the type of DLS used: CGuard 0.8% (0.4%-1.8%, I2 = 0%) versus Roadsaver/Casper 1.5% (0.7%-3.2%, I2 = 0%), p=0.30. The 30-day estimated stroke rate was 1.5% (0.8%-2.9%, I2 = 0%) in asymptomatic and 1.9% (1.0%-3.6%, I2 = 0%) in symptomatic patients, with no influence by moderators. The 30-day DLS occlusion rate was 0.8% (0.4%-1.8%, I2 = 0%). The publication bias assessment identified asymmetry in the asymptomatic populations.

CONCLUSION

The overall 30-day stroke rate in CAS with DLS is low (1.4%), with similar results in symptomatic and asymptomatic patients. Acute occlusion of DLS is rare (0.8%). Further studies are necessary to reduce the publication bias for asymptomatic patients.

CLINICAL IMPACT

CAS with DLS is associated to a low rate of 30-day stroke in both symptomatic (1.9%) and asymptomatic (1.5%) patients. The type of DLS (CGuard or Roadsaver/Casper) did not affect the 30-day stroke rate.

Carotid artery stenting with flow inversion cerebral protection and MicroNet-covered stent

BACKGROUND

The study aims to evaluate the association of proximal flow-inversion cerebral protection and MicroNet-covered CGuard stents in reducing early and late embolic events in carotid artery stenting procedures.

METHODS

From 2018 to 2023, we performed 204 procedures in 180 patients with flow inversion cerebral protection and CGuard stents at the Vascular Surgery Unit of Sant'Eugenio Hospital in Rome. Cerebral protection was achieved with a Flow-Gate2 catheter connected to a peripheral vein. The tip balloon is inflated in the CCA to obtain an effective endoclamping, the pressure difference between the carotid bifurcation and the venous compartment ensures a constant back flow with wash-out in the venous compartment. Inclusion criteria were: life expectancy of >12 months, target lesions indicating treatment according to ESVS Guidelines, increased surgical risk due to comorbidities or anatomic issues. ECD follow-up was performed immediately postoperatively, at 30 days, 6 and 12 months, and subsequently annually.

RESULTS

The treatment protocol was successfully implemented in 99% of cases. No major strokes occurred, while one minor stroke (0.5%) occurred within 8 hours of the procedure, regressing in the following months. One perioperative death (0.5%) due to cerebral hemorrhage occurred three hours after the procedure. All patients remained asymptomatic, with no short or medium-term neurological score deterioration. One hemodynamically significant restenosis (0.5%) was detected at the 6-month follow-up. All patients completed the 6 months follow-up, though 6 (3%) were lost at the 12-month appointment.

CONCLUSIONS

Our prospective monocentric study has demonstrated the effectiveness and safety of the FlowGate2 flow inversion cerebral protection system in association with MicroNet covered CGuard stent.

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).

Vascular surgery study of the CGuard MicroNet-covered stent in patients with indication to carotid revascularization: POLGUARD

BACKGROUND

In a recent randomized study, MicroNet-covered stent (CGuard) significantly reduced procedural and post-procedural cerebral embolism in relation to a single-layer CREST study carotid stent, but real-life clinical practice data are limited. The aim is to prospectively assess clinical outcomes of CGuard as a routine revascularization tool for patients with indication to carotid revascularization.

METHODS

From April 2019 to November 2021, 204 elective patients (age 71.0±7.1years, 69.6% males, 21.7% symptomatic) were enrolled.

RESULTS

Mean basal peak-systolic velocity was 251.41±91.85 cm/s with angiographic diameter stenosis 89.7±8.46%. About 34.4% lesions were severely calcified, 6.8% were angulated, and 4.4% showed significant access tortuosity. Access was femoral, with 100% protection device (filter) use. Two hundred and three lesions in 203 patients were treated (1 cross-over to surgery for lack of effective access, no cross-over to other devices); in most cases (66.9%) the stent was placed directly. For pre-dilated lesions, mean balloon diameter was 3.36±0.34mm. Mean nominal stent diameter was 7.64±0.5 mm; length was 37.19±4.5 mm. All stents were post-dilated (balloon diameter 5.2±0.25 mm). Residual stenosis was <30% in all (3.77±6.91%). By discharge, there were 2 minor strokes (0.9%) and one transient ischemic attack. By 30-days, one other minor stroke occurred in relation to de-novo atrial fibrillation. With no deaths or myocardial infarctions, 30-day total death/stroke/myocardial infarction rate was 1.48%. No in-stent thrombosis or patency loss occurred by 30-days. In-stent peak-systolic velocity was 55.49±22.73 cm/s.

CONCLUSIONS

Thirty-day results from POLGUARD study indicate safety and a low complication rate of the MicroNet-covered carotid stent use in every-day vascular surgery practice of carotid revascularization. Long-term observation is underway.

12-Month Outcomes of Carotid Artery Stenting With CGuard MicroNET-Covered Stent: A Single-Center Study in 113 Patients

Dual layer mesh stents constitute a novel treatment option for patients who undergo carotid artery stenting (CAS). The aim of this prospective study is to report 12 month outcomes of patients who underwent CAS with CGuard (Inspire MD, Tel Aviv, Israel) microNET self-expanding stent with embolic protection system in a tertiary center from October 2018 to March 2022. Primary endpoints included in-stent restenosis >70% verified by ultrasound (DUS), ipsilateral transient ischemic attack (TIA), and stroke at 12 months. Secondary endpoints included cardiovascular-related mortality (stroke, myocardial infarction, heart failure) and all-cause mortality during follow-up. One hundred thirteen patients were included in the study (male 72.5%), symptomatic 47.8%. Median follow-up was 25 months (2-48). By 12 months, there was one in-stent occlusion that manifested as stroke (1/113, 0.8%) but no other forms of in-stent restenosis. Two patients experienced contralateral TIA (1.7%). CVRM was 3.5% (4 MI) and all-cause mortality was 6% at follow-up. This prospective study shows that CAS with CGuard MicroNET-covered stent is safe with minimal neurological adverse events at 12 months follow-up. Larger, and longer-term studies are necessary to define CGuard long-term safety and protection against carotid-related stroke.

Carotid artery interventions - endarterectomy versus stenting

Current management of patients with carotid artery stenosis is based on well-established guidelines, including surgical procedures - carotid endarterectomy (CEA) and endovascular carotid artery stenting (CAS) - and optimal medical treatment alone. Outcomes in the postprocedural period after CAS and CEA are similar, suggesting strong clinical durability for both treatments. Recent advances, which include the emergence of novel endovascular treatment tools and techniques, combined with more recent randomised trial data shed new light on optimal patient selection and treatment in contemporary practice. Improved, modern technologies including enhanced embolic protection devices and dual-layered micromesh stents yield better outcomes and should result in further improvements in CAS. In centres of excellence, nowadays, the majority of patients with severe carotid artery stenosis can be successfully treated with either CEA or CAS.

Carotid endarterectomy or stenting or best medical treatment alone for moderate-to-severe asymptomatic carotid artery stenosis: 5-year results of a multicentre, randomised controlled trial

BACKGROUND

The optimal treatment for patients with asymptomatic carotid artery stenosis is under debate. Since best medical treatment (BMT) has improved over time, the benefit of carotid endarterectomy (CEA) or carotid artery stenting (CAS) is unclear. Randomised data comparing the effect of CEA and CAS versus BMT alone are absent. We aimed to directly compare CEA plus BMT with CAS plus BMT and both with BMT only.

METHODS

SPACE-2 was a multicentre, randomised, controlled trial at 36 study centres in Austria, Germany, and Switzerland. We enrolled participants aged 50-85 years with asymptomatic carotid artery stenosis at the distal common carotid artery or the extracranial internal carotid artery of at least 70%, according to European Carotid Surgery Trial criteria. Initially designed as a three-arm trial including one group for BMT alone (with a randomised allocation ratio of 2·9:2·9:1), the SPACE-2 study design was amended (due to slow recruitment) to become two substudies with two arms each comparing CEA plus BMT with BMT alone (SPACE-2a) and CAS plus BMT with BMT alone (SPACE-2b); in each case in a 1:1 randomisation. Participants and clinicians were not masked to allocation. The primary efficacy endpoint was the cumulative incidence of any stroke or death from any cause within 30 days or any ipsilateral ischaemic stroke within 5 years. The primary safety endpoint was any stroke or death from any cause within 30 days after CEA or CAS. The primary analysis was by intention-to treat, which included all randomly assigned patients in SPACE-2, SPACE-2a, and SPACE-2b, analysed using meta-analysis of individual patient data. We did two-step hierarchical testing to first show superiority of CEA and CAS to BMT alone then to assess non-inferiority of CAS to CEA. Originally, we planned to recruit 3640 patients; however, the study had to be stopped prematurely due to insufficient recruitment. This report presents the primary analysis at 5-year follow-up. This trial is registered with ISRCTN, number ISRCTN78592017.

FINDINGS

513 patients across SPACE-2, SPACE-2a, and SPACE-2b were recruited and surveyed between July 9, 2009, and Dec 12, 2019, of whom 203 (40%) were allocated to CEA plus BMT, 197 (38%) to CAS plus BMT, and 113 (22%) to BMT alone. Median follow-up was 59·9 months (IQR 46·6-60·0). The cumulative incidence of any stroke or death from any cause within 30 days or any ipsilateral ischaemic stroke within 5 years (primary efficacy endpoint) was 2·5% (95% CI 1·0-5·8) with CEA plus BMT, 4·4% (2·2-8·6) with CAS plus BMT, and 3·1% (1·0-9·4) with BMT alone. Cox proportional-hazard testing showed no difference in risk for the primary efficacy endpoint for CEA plus BMT versus BMT alone (hazard ratio [HR] 0·93, 95% CI 0·22-3·91; p=0·93) or for CAS plus BMT versus BMT alone (1·55, 0·41-5·85; p=0·52). Superiority of CEA or CAS to BMT was not shown, therefore non-inferiority testing was not done. In both the CEA group and the CAS group, five strokes and no deaths occurred in the 30-day period after the procedure. During the 5-year follow-up period, three ipsilateral strokes occurred in both the CAS plus BMT and BMT alone group, with none in the CEA plus BMT group.

INTERPRETATION

CEA plus BMT or CAS plus BMT were not found to be superior to BMT alone regarding risk of any stroke or death within 30 days or ipsilateral stroke during the 5-year observation period. Because of the small sample size, results should be interpreted with caution.

FUNDING

German Federal Ministry of Education and Research (BMBF) and German Research Foundation (DFG).

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.

Diabetes Mellitus and Clinical Outcomes in Carotid Artery Revascularization Using Second-Generation, MicroNet-Covered Stents: Analysis from the PARADIGM Study

INTRODUCTION

Carotid artery stenting (CAS) using conventional (single-layer) stents is associated with worse clinical outcomes in diabetes mellitus (DM) vs. non-DM patients: an effect driven largely by lesion-related adverse events. CAS outcomes with MicroNet-covered stents (MCS) in diabetic patients have not been evaluated.

AIM

To compare short- and long-term clinical outcomes and restenosis rate in DM vs. non-DM patients with carotid stenosis treated using MCS.

MATERIALS AND METHODS

In a prospective study in all-comer symptomatic and increased-stroke-risk asymptomatic carotid stenosis, 101 consecutive patients (age 51-86 years, 41% diabetics) underwent 106 MCS-CAS. Clinical outcomes and duplex ultrasound velocities were assessed periprocedurally and at 30 days/12 months.

RESULTS

Baseline characteristics of DM vs. non-DM patients were similar except for a higher prevalence of recent cerebral symptoms in DM. Type 1 and type 1+2 plaques were more prevalent in DM patients (26.7% vs. 9.8%, p = 0.02; 62.2% vs. 37.7%, p = 0.01). Proximal embolic protection was more prevalent in DM (60% vs. 36%; p = 0.015). 30-day clinical complications were limited to a single periprocedural minor stroke in DM (2.4% vs. 0%, p = 0.22). 12-month in-stent velocities and clinical outcomes were not different (death rate 4.8% vs. 3.3%; p = 0.69; no new strokes). Restenosis rate was not different (0% vs. 1.7%, p = 0.22).

CONCLUSIONS

MCS may offset the adverse impact of DM on periprocedural, 30-day, and 12-month clinical complications of CAS and minimize the risk of in-stent restenosis. In this increased-stroke-risk cohort, adverse event rate was low both in DM and non-DM. Further larger-scale clinical datasets including extended follow-ups are warranted.

Randomized Controlled Trial of Conventional Versus MicroNet-Covered Stent in Carotid Artery Revascularization

OBJECTIVES

The aim of this study was to compare procedure-related ipsilateral cerebral embolism with a conventional (Acculink, Abbott Vascular) versus a MicroNet-covered (CGuard, InspireMD) stent in carotid artery stenting (CAS).

BACKGROUND

The MicroNet-covered stent may reduce periprocedural cerebral embolism in CAS, but level 1 evidence is lacking.

METHODS

A total of 100 consecutive patients were randomized 1:1 to filter-protected CAS using the Acculink or the CGuard device. The study was powered for its primary endpoint of at least 50% reduction in ipsilateral diffusion-weighted magnetic resonance imaging lesion average volume 48 hours postprocedure (blinded external core laboratory analysis).

RESULTS

The baseline characteristics of the study groups were similar. Eighty-two (total volume = 18,212 mm³) diffusion-weighted magnetic resonance imaging postprocedural cerebral lesions occurred in 26 Acculink-treated patients and 45 lesions (total volume = 3,930 mm³; 78.4% reduction) in 25 CGuard-treated patients. New cerebral lesion average volume was 171 mm³ vs 73 mm³ (P = 0.017) per affected patient and 222 mm³ vs 84 mm³ (P = 0.038) per lesion (Acculink vs CGuard). In lesion-affected patients, the average sum of lesion volumes was 701 mm³ vs 157 mm³ (P = 0.007). The Acculink significantly increased the risk for multiple (≥5) cerebral lesions (relative risk: 7.8; 95% CI: 1.3-14.9; P = 0.021). At 30 days, new permanent (fluid-attenuated inversion recovery) lesion prevalence was 3:1 (P < 0.001), with total permanent lesion volume 7,474 mm³ vs 574 mm³ (92.3% reduction with the CGuard). There were 6 vs 0 new ipsilateral lesions (P = 0.030) and 2 versus 0 strokes.

CONCLUSIONS

The MicroNet-covered stent significantly reduced periprocedural and abolished postprocedural cerebral embolism in relation to a conventional carotid stent. This is consistent with the MicroNet-covered stent's sustained embolism prevention, translating into cerebral protection not only during but also after CAS. The present findings may influence decision making in carotid revascularization. (The SIBERIA Trial [Acculink™ Versus CGuard™]; NCT03488199).

1-Year Results From a Prospective Experience on CAS Using the CGuard Stent System: The IRONGUARD 2 Study

OBJECTIVES

The aim of this study was to evaluate the 1-year safety and efficacy of a dual-layered stent (DLS) for carotid artery stenting (CAS) in a multicenter registry.

BACKGROUND

DLS have been proved to be safe and efficient during short-term follow-up. Recent data have raised the concern that the benefit of CAS performed with using a DLS may be hampered by a higher restenosis rate at 1 year.

METHODS

From January 2017 to June 2019, a physician-initiated, prospective, multispecialty registry enrolled 733 consecutive patients undergoing CAS using the CGuard embolic prevention system at 20 centers. The primary endpoint was the occurrence of death and stroke at 1 year. Secondary endpoints were 1-year rates of transient ischemic attack, acute myocardial infarction, internal carotid artery (ICA) restenosis, in-stent thrombosis, and external carotid artery occlusion.

RESULTS

At 1 year, follow-up was available in 726 patients (99.04%). Beyond 30 days postprocedure, 1 minor stroke (0.13%), four transient ischemic attacks (0.55%), 2 fatal acute myocardial infarctions (0.27%), and 6 noncardiac deaths (1.10%) occurred. On duplex ultrasound examination, ICA restenosis was found in 6 patients (0.82%): 2 total occlusions and 4 in-stent restenoses. No predictors of target ICA restenosis and/or occlusion could be detected, and dual-antiplatelet therapy duration (90 days vs 30 days) was not found to be related to major adverse cardiovascular event or restenosis occurrence.

CONCLUSIONS

This real-world registry suggests that DLS use in clinical practice is safe and associated with minimal occurrence of adverse neurologic events up to 12-month follow-up.