The CLEAR-ROAD study: evaluation of a new dual layer micromesh stent system for the carotid artery

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.

Dual-layered micromesh stent technology for embolic prevention in carotid revascularization: technical experience and clinical outcomes from a high-volume interventional radiology center

BACKGROUND

Carotid artery stenting (CAS) has become a cornerstone of carotid revascularization for stroke prevention. Despite the advantages of CAS, large-scale randomized trials involving prior (single-layer) first generation stents (FGS) demonstrated a higher risk of periprocedural cerebrovascular events compared to surgery. Dual-layer mesh-covered stents (DLSs) showed promising results in terms of 30-day embolic events in initial studies; larger-scale evidence is accumulating. This study aims to evaluate 30-day clinical efficacy of DLS against a closed-cell stent, based on large-volume data.

METHODS

The study center is part of the Italian National Outcomes Evaluation Program (PNE). CAS procedures performed between November 2017 and September 2023 were eneterd into a prospectively collected database. Our The primary endpoint was survival free of death, stroke, and myocardial infarction (MI) at 30 days. In addition, technical success and periprocedural major adverse clinical event rate (with a focus on stroke) were also evaluated.

RESULTS

Over a total of 1101 CAS procedures (745 males; mean age 79±7.8 years), 48.6% were symptomatic. Majority (80.2%) were treated with DLSs. Technical success was achieved in 98.9%. The FGSs group showed a significantly higher peri-procedural stroke rate when compared with CGuard and Roadsaver DLS: 4.59% vs. 1.18% vs. 2.63% (P=0.008); minor stroke rates were 4.13% vs. 0.83% and 0% P=0.01). The cumulative stroke, MI and death - free survival at 30 days was 97.46%. A statistically significant higher cumulative 30-day death/stroke/MI rate occurred in FGSs-treated patients compared to the CGuard and Roadsaver DLS-treated (6.42% vs. 1.42% and 2.63%, P=0.001).

CONCLUSIONS

The use of DLS in patients undergoing CAS in our large-volume center showed a high technical success rate and minimal cerebral embolic complications by 30 days. High volumes and an experienced interventional team may contribute to these favorable outcomes.

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.

Subacute In-Stent Occlusion 2 Weeks after CASPER Rx Stenting: A Case Report

Objective

CASPER Rx stent (Terumo, Tokyo, Japan) is one of the dual-layer micromesh stents for carotid artery stenosis. Although it is expected to be safe and efficacious even for vulnerable plaque, we report a case of in-stent occlusion 2 weeks after stenting with CASPER Rx stent.

Case Presentation

The patient was a 78-year-old man with a symptomatic, severely stenosed lesion of the cervical internal carotid artery (ICA). He had an unstable plaque and underwent carotid artery stenting with the CASPER Rx stent. There were no problems with the procedure or the patient's subsequent course, and he was discharged home 1 week after the procedure. However, on postoperative day 14, the patient had a transit ischemic attack and imaging showed acute occlusion due to thrombus in the stent and in the distal part of the ICA. Mechanical thrombectomy was performed and good recanalization was achieved, but postoperative cerebral infarction was observed and the patient was transferred to other hospital with modified Rankin Scale 2.

Conclusion

We experienced a case of in-stent occlusion 2 weeks after stenting with the CASPER Rx stent.

PERFORMANCE 1 study: Novel carotid stent system with integrated post-dilation balloon and embolic protection device

OBJECTIVES

The PERFORMANCE I study was designed to evaluate the safety and feasibility of the Neuroguard IEP® System, a novel carotid stent system with an integrated embolic filter and post-dilatation balloon, to treat clinically significant carotid artery stenosis.

BACKGROUND

The risk of major adverse events during carotid artery stenting is comparable to carotid endarterectomy, however, the risk of minor stroke remains higher with stenting.

METHODS

In total, 67 patients undergoing carotid artery stenting were enrolled at nine centers in Europe. Follow-up assessments included neurological exams, duplex ultrasound, 12-lead electrocardiogram, and cardiac enzyme analysis. The primary endpoint was the 30-day composite rate of stroke, death, and myocardial infarctions versus a prespecified performance goal. Secondary endpoints included procedure success, device success, and target lesion revascularization.

RESULTS

The study population was predominantly male (74.6%) with a mean age of 69.3 ± 8.9 years and 67% of subjects met at least one criterion placing them at an elevated risk for adverse events following carotid endarterectomy. All patients were treated successfully with the study device. There were no deaths or strokes within 30 days of the index procedure. One subject (1.5%) experienced a non-ST elevation myocardial infarction at day 17. The primary endpoint was met with a 30-day major adverse events rate of 1.5% (1/67). Through 12-month follow-up, there were no strokes, neurological deaths, target lesion revascularizations, or instances of in-stent-restenosis.

CONCLUSIONS

Results from this study demonstrate the Neuroguard IEP system is safe and feasible with a stroke/death rate of 0% at 30 days. A large pivotal study is currently underway.

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.

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

PURPOSE

The aim of this study was to report intermediate-term results of duplex ultrasound follow-up of carotid artery stenting performed with the dual-layer stent as compared to concurrent patients treated with other commercially available single-layer carotid stents.

MATERIALS AND METHODS

A single centre, retrospective, nonrandomized study including 162 non-consecutive patients with 199 implanted carotid stents treated over a 7-year period was conducted. Patients with at least one ultrasound examination after treatment were included. Procedural and follow-up data for patients treated with the dual-layer stent implantation (83 stents) vs first-generation carotid stents implantations (116 stents) were compared.

RESULTS

The median follow-up time was 24.0 months (IQR 10-32 months) for dual-layer stents and 27.5 months (IQR 10.3-59 months) for single-layer stents. The rate of severe restenosis was significantly higher in the dual-layer stent group than in the single-layer group (13.3% [11/83] vs 3.4% [4/116], p = 0.01). Seven reinterventions were performed in 5 patients with dual-layer stents. The rate of reintervention was significantly higher compared to no reinterventions in single-layer stents (6% [5/83] vs 0% [0/116], p = 0.012). Patients with restenosis had significantly higher presence of dyslipidaemia (100% [12/12] vs 63.3% [95/150], p = 0.009).

CONCLUSIONS

In this real-world cohort of patients undergoing carotid artery stenting, the patients treated with low-profile dual-layer micromesh stent showed higher rates of restenosis and reinterventions compared to first-generation single-layer stents.

Efficacy of Post-Dilatation during Carotid Artery Stenting for Unstable Plaque Using a Double-Layer Stent Evaluated by OFDI

Objective

This study aimed to use optical frequency domain imaging (OFDI) to evaluate the efficacy of post-dilatation (PD) after stent placement for unstable plaques during carotid artery stenting (CAS) using a double-layer stent.

Methods

Twelve unstable carotid plaque lesions diagnosed by MRI were evaluated using OFDI during CAS. The pre-procedural minimum lumen diameter was 1.6 ± 0.7 mm. Each lesion was pre-dilated with balloon catheters (diameter, 5.3 ± 0.5 mm), and a double-layer stent was deployed. PD was performed with balloon catheters of the same size as those used for pre-dilatation. Cross-sectional OFDI images within the stented segment were evaluated at 1-mm intervals for a 20-mm segment, including the most stenotic lesion. Slice rates for the presence of in-stent plaque protrusion (PP) and plaque between the double-layer lumen were calculated.

Results

No procedural complications occurred with the use of an embolic protection device. Compared to after stent placement, slice rates for any PP (44 ± 19% to 62 ± 22%, P <0.05) and plaque between the double-layer lumen (79 ± 16% to 91 ± 34%, P <0.05) were significantly increased after PD; slice rates for >500 μm PP (7.5 ± 14% to 0%, P <0.05) were significantly decreased. Visible debris were captured in 50% of lesions.

Conclusion

PD after double-layer carotid stent placement decreases in-stent large PP. Double-layer construction contributed to the prevention of large PP, as the PP may have been crushed into debris by PD.

Endovascular treatment of extracranial carotid artery stenosis using a dual-layer micromesh stents: a systematic review

Introduction: We aimed to review the safety and effectiveness of dual-layer micromesh stents for the endovascular treatment of carotid artery stenosis.Methods: Electronic bibliographic databases were searched using the words 'micromesh carotid stent'. The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement standards.Results: The search of the Literature retrieved 84 results. After assessment of full texts, 13 papers were included in the study. The analyzed studies included 797 patients, 32.1% of them were symptomatic. The reported technical success rate was 100% in all cases. During early follow-up, complications occurred overall in 16/797 patients (2%: 12 strokes, 3 deaths, and one transient ischemic attack). The study with the longest follow-up reported a survival rate of 82% at 4 years and a stroke-free survival rate of 84% at 4 years.Conclusion: With the limit of low data quality, the use of dual-layer stents was reported to be as safe and effective at 30 days for the endovascular treatment of extracranial carotid artery stenosis. The reported technical success was 100% in all cases. Further data coming from randomized controlled trials and larger cohort studies with longer follow-up are nevertheless needed for a better evaluation.

Contemporary Results of Carotid Artery Stenting Using Low-Profile Dual-Metal Layer Nitinol Micromesh Stents in Relation to Single-Layer Carotid Stents

PURPOSE

To evaluate patients characteristics, procedural details, perioperative outcomes, and midterm results of carotid artery stenting (CAS) performed with the Roadsaver/Casper stent (Terumo Corp, Tokyo, Japan) as compared to concurrent patients treated with other commercially available carotid stents.

MATERIALS AND METHODS

This is a single-center, retrospective, nonrandomized study including 200 consecutive patients who underwent a total of 205 elective CAS procedures due to severe internal carotid artery stenosis between April 2015 and December 2018. Procedural data and outcomes for patients treated with the Roadsaver/Casper stent implantation (100 procedures, in 97 patients) vs first-generation carotid stents implantations (90 procedures, in 88 patients) were compared. Fifteen patients were treated with CGuard carotid stent (InspireMD, Tel Aviv, Israel), and outcomes were reported separately. Primary endpoints were the occurrence of major adverse cerebrovascular events (MACE), including death, ipsilateral stroke, and transitory ischemic attack (TIA). Secondary endpoints were the rate of intrastent stenosis, the need for reintervention, and the occurrence of adverse cardiovascular events, including myocardial infarction, arrhythmias, and need for inotropic support.

RESULTS

No difference in demographics and preoperative risk factors were observed between patients treated with and without the Roadsaver/Casper stent. The mean procedure time was shorter in the Roadsaver/Casper group (40.7±16.9 vs 49.4±27.3 minutes; p=0.008), while radial percutaneous access was more frequent (24% vs 5%; p<0.001). The rate of stroke/TIA/death at 30 days was 3% in the Roadsaver group vs 1% in the first-generation stent group (p=0.623). The primary patencyrate was 100% and 93.4% at 1- and 3-year of follow-up in the Roadsaver/Casper groupand 99% and 94.3% in the other stent group, respectively (p=0.95).

CONCLUSIONS

In this real-world cohort of patients undergoing CAS, the Roadsaver/Casper stent was used to treat more symptomatic and vulnerable carotid plaques as compared to other carotid stents. Nevertheless, patients treated with this low-profile dual-layer micromesh stent showed low events rates at both 30 days and follow-up, similar to that observed for other stents.

Thirty-Day Results of the Novel CGuard-Covered Stent in Patients Undergoing Carotid Artery Stenting

OBJECTIVE

The aim of this study was to provide early-term evaluation, safety, and efficacy of the novel CGuard (Inspire MD, Tel Aviv, Israel) micromesh self-expanding stent with embolic protection system (EPS) during carotid artery stenting (CAS) procedure.

MATERIALS AND METHODS

All patients who underwent CAS with CGuard carotid stent system from January 2018 to September 2020 in a tertiary center were prospectively evaluated. Primary endpoints included technical success and perioperative neurological events (0-48 hours). Secondary endpoint was the rate of neurologic, cardiac events, and death (major adverse event or MAE) at 30 days. Patency of CGuard, peak systolic velocity (PSV), and end diastolic velocity (EDV) were evaluated at 30 days with duplex ultrasound.

RESULTS

A total of 103 patients underwent CAS procedure. Forty patients were symptomatic, and 63 patients were asymptomatic with stenosis greater than 70%. Technical success was 100%. Local anesthesia was applied in 94 patients (93%). Embolic protection devices were used in 6 patients (5.8%). Access site complications were 1.9%. Mean internal carotid artery stenosis diameter reduced from 79.47% to 14.68%. Two patients had transient ischemic attack (1.9%) and 1 patient experienced a cerebral hyperperfusion syndrome (CHS) perioperatively. External carotid artery (ECA) occlusion occurred in 1.9%. Four patients experienced jaw claudication (3.8%) postoperatively. Mean time of operation was 41 minutes. Mean duration of hospitalization was 3.1 days. The 30-day rate of MAE was 0%. CGuard patency was 100%, mean internal carotid PSV was reduced from 251.57 to 77.29 cm/s, and mean internal carotid EDV was reduced from 154.62 to 24.63 cm/s at 30 days.

CONCLUSION

Our study shows that CGuard stent with EPS is an effective and safe device for treatment of carotid artery stenosis with acceptable low perioperative neurologic events, even with low embolic protection device usage. Larger multicenter and randomized studies are necessary to confirm its long-term efficacy.

Effectiveness and safety of dual-layer stents in carotid artery disease: a systematic review

INTRODUCTION

Carotid artery stenting (CAS) has emerged as a minimally invasive alternative to carotid endarterectomy (CEA) in atherosclerotic carotid artery disease, even though the risk for procedural stroke after CAS remains significantly higher. Recently, in order to reduce embolic cerebral events after CAS, a new generation of dual-layer stents (DLS) has been developed. This review aimed to perform a detailed analysis of the available evidence on safety and efficacy of DLS in both symptomatic and asymptomatic atherosclerotic carotid artery stenosis.

EVIDENCE ACQUISITION

A systematic review was conducted according to the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The primary endpoint was the 30-day rate of myocardial infarction (MI), stroke and death. Secondary outcomes included rate and timing of stent occlusion/restenosis.

EVIDENCE SYNTHESIS

A total of 20 articles with 1193 patients were included. Thirty-day MI ranged from 0-5%, 30-day stroke ranged from 0-10.5% and 30-day mortality ranged from 0-10%. Stent occlusion rate ranged from 0-52.4%, the majority of which occurred intraprocedurally (N.=50; 61.7%), in emergency treated patients. The incidence of new ipsilateral cerebral ischemic lesions after CAS with DLS was reported in five studies, ranging from 5.5-37%.

CONCLUSIONS

Despite the theoretic advantage of reducing the risk for procedural embolic events when compared to conventional stents, high quality evidence is scarce. Also, safety issues regarding DLS in the emergency setting have been raised, particularly for thrombotic complications. Additional data from well-designed Randomized Controlled Trials are needed to assert the true value of DLS.

Carotid artery stenting with Roadsaver stent. Early and four-year results from a single-center registry

INTRODUCTION

Prevention of peri- and postprocedural complications is still a challenge in carotid artery stenting (CAS).

AIM

To assess immediate and long-term safety and effectiveness of CAS using the Roadsaver double-nitinol-layer-micromesh stent.

MATERIAL AND METHODS

Since 2014, 298 CAS procedures in 287 non-consecutive patients (203 men, mean age 70.5 ±8.6 years, 100% symptomatic/high risk lesions) have been performed using the Roadsaver stent and proximal (40%) or distal (60%) neuroprotection system. Clinical and neurological examinations as well as duplex ultrasound were completed before CAS, before discharge, at 1, 6 and 12 months, then annually.

RESULTS

All CAS procedures were successful. Carotid stenosis was reduced from 84.9 ±9.9% to 11.0 ±9.4% (p < 000.1). In hospital, 1 ipsilateral periprocedural major (0.3%) and 3 minor (1.34%) ischemic strokes occurred, 2 (0.7%) patients died due to a cerebral hemorrhage on day 9 and 21. Three (1.0%) additional ipsilateral minor strokes within 30 consecutive days occurred. Thus, 30-day complications were observed in 9 (3.0%) patients. Two minor strokes were associated with in-stent thrombosis (0.7%). The 4-year follow-up showed 82% overall survival (95% CI: 69-91%) with no significant difference between asymptomatic (77%) and symptomatic patients (97%; p = 0.076). The stroke-free survival was 89% (95% CI: 77-95%), 84% asymptomatic vs. 98% symptomatic (p = 0.187). Seven (2.3%) patients developed > 50% in-stent restenosis.

CONCLUSIONS

Carotid artery stenting using the Roadsaver stent for symptomatic patients and high risk lesions showed to be safe and effective, with a low complication rate and acceptable in-stent restenosis risk in 4-year follow-up.

Clinical trial of carotid artery stenting using dual-layer CASPER stent for carotid endarterectomy in patients at high and normal risk in the Japanese population

BACKGROUND

The dual-layer nitinol CASPER stent was designed to prevent plaque prolapse into its strut and periprocedural stroke.

OBJECTIVE

To conduct a clinical trial for government approval of the device in patients at either high or normal risk for carotid endarterectomy (CEA).

METHODS

Eligible patients had ≥50% symptomatic stenosis or ≥80% asymptomatic stenosis according to the North American Symptomatic Carotid Endarterectomy Trial methods (peak systolic velocity 130 and 230 cm/s on ultrasonography, respectively). The primary endpoint was the lack of major adverse events (MAEs), defined as death, stroke, and myocardial infarction within 30 days, and ipsilateral stroke within 1 year. The performance goal was set at 90.5%. MAE rates were also compared between the CEA high- and normal-risk groups.

RESULTS

140 carotid artery stenting procedures, including 40% of patients at high risk and 60% at normal risk for CEA, were performed in 13 institutes. MAEs occurred in two cases (one intraprocedural and one postprocedural stroke), and the MAE rate was 1.4%. The non-MAE rate was 98.6% according to Kaplan-Meier analysis, which was superior to the previously set performance goal. The deployment success, target lesion revascularization (TLR), in-stent restenosis, and cerebrovascular event rates were 99.3%, 2.4%, 8.5%, and 7.2%, respectively. The MAE rate in patients with normal CEA risk was 1.2%, which was similar to the high-risk CEA group, with no significant difference due to the small number of MAEs.

CONCLUSIONS

The MAE rate following use of the CASPER stent was low (1.4%). The MAE, deployment success, TLR, in-stenosis, and cerebrovascular event rates were similar to those of previous reports.

A Patient with Carotid Mobile Plaques Treated by Carotid Artery Stenting Using a Double-layer Micromesh Stent

Objective

We report a case of carotid mobile plaques treated by carotid artery stenting (CAS) using a double-layer micromesh stent (CASPER stent).

Case Presentation

An 86-year-old male presented with lightheadedness. Carotid artery ultrasound revealed mobile plaques in the right internal carotid artery (ICA). Head and neck MRI demonstrated concomitant left ICA occlusion. We first started medical treatment, but it could not reduce the plaque size. Then, we performed CAS using a CASPER stent in addition to medical treatment. The procedure was finished without complications, and there was no plaque protrusion. The postoperative course was uneventful during 3 years of follow-up.

Conclusion

A mobile plaque of the carotid artery may be treated less-invasively with a micromesh stent.

Carotid Artery Stenting Using a Double-layer Micromesh Stent

Carotid artery stenting (CAS) has recently emerged as a potential alternative to carotid endarterectomy (CEA) in Japan. However, one of its disadvantages is the higher incidence of ischemic complications than CEA, such as distal embolism during or after the procedure. Plaque protrusion (PP) through the stent strut after deployment of the stent has been suggested as one of the major causes of distal embolism, especially in patients with unstable plaques. The need for increased plaque coverage to reduce the risk of PP through the stent struts has led to the development of a double-layer micromesh stent (micromesh stent) system. This stent system has already been used clinically in European countries with good short- to medium-term follow-up results. Also clinical trials evaluating micromesh stents have been completed in Japan. Hence, usefulness of the micromesh stent for CAS is expected. According to the results of several clinical studies, CAS with the double-layer micromesh stent has the potential to minimize distal embolism during or after the procedure even in patients with unstable plaques. However, it may not be suitable for emergency CAS at this point. Also, since results of only short- to medium-term follow-up have been reported, longer-term follow-up will be required in the near future.

Comparison of different carotid stent designs in endovascular therapy of severe carotid artery stenosis

Background:

One of the major periprocedural risks of carotid artery stenting is embolism caused either by plaque debris or by local thrombus forming. Double-layer micromesh stent design has shown to lower the chance of debris embolism but might have a slightly higher risk of local thrombus forming. Thus, we compared two different stent designs regarding safety and outcome profile in elective patients with high-grade carotid artery stenosis using a self-expanding, double-layer micromesh carotid stent system (DLCS) or a self-expanding hybrid carotid stent system (HCS).

Methods:

A single-center, open-label, retrospective cohort study of 67 consecutive, elective patients with high-grade symptomatic and asymptomatic carotid stenosis was executed at a comprehensive stroke center. Outcome measures were reocclusion rate, periprocedural symptomatic ischemic events, as well as other periprocedural complications, and recurrent stroke and mortality at 30 days’ follow-up.

Results:

Thirty-two patients (24% women, median age 75 years (interquartile range (IQR) 71–80) were treated with DLCS, and 35 patients (29% women, median age 71 years (IQR 63–76) years) with HCS. In both groups, pretreatment carotid stenosis degree was similar (median NASCET of 80%). Successful deployment was achieved in all cases without technical failure, and both groups did not differ in reocclusion rates, recurrent stroke, and mortality within 30 days.

Conclusions:

DCLS and HCS revealed to have similar safety and outcome profile in elective patients with high-grade symptomatic as well as asymptomatic carotid artery stenosis.

Carotid Artery Stenting Using a Closed-Cell Stent-in-Stent Technique for Unstable Plaque

Purpose: To examine whether carotid artery stenting (CAS) of stenoses with unstable plaque using a closed-cell stent-in-stent technique prevents plaque protrusion. Materials and Methods: Between December 2014 and August 2018, 35 consecutive patients (mean age 75.8 years; 29 men) with carotid artery stenosis (20 symptomatic) and unstable plaque diagnosed by magnetic resonance imaging were prospectively analyzed. Mean diameter stenosis was 83.5%. All CAS procedures were performed with stent-in-stent placement of Carotid Wallstents using an embolic protection device and conservative postdilation. The technical success rate, incidence of plaque protrusion, ischemic stroke rate within 30 days, and new ipsilateral ischemic lesions on diffusion-weighted imaging (DWI) within 48 hours after CAS were prospectively assessed. Follow-up outcomes included the incidences of ipsilateral stroke and restenosis. Results: The technical success rate was 100%. No plaque protrusion or stroke occurred in any patient. New ischemic lesions were observed on DWI in 10 (29%) patients. During the mean 11.6-month follow-up, no ipsilateral strokes occurred. Two (6%) patients developed asymptomatic restenosis recorded as 53% lumen narrowing and occlusion, respectively. Conclusion: CAS using a closed-cell stent-in-stent technique for unstable plaque may be useful for preventing plaque protrusion and ischemic complications.

Thirty-day results from prospective multi-specialty evaluation of carotid artery stenting using the CGuard MicroNet-covered Embolic Prevention System in real-world multicentre clinical practice: the IRON-Guard study

AIMS

The aim of the present study was to evaluate periprocedural and 30-day outcomes in a prospective series of patients treated with the CGuard Embolic Prevention System (EPS).

METHODS AND RESULTS

From April 2015 to June 2016, a physician-initiated prospective multicentre study was performed in 200 consecutive patients admitted for protected carotid artery stenting (CAS) and treated using the CGuard EPS in twelve vascular centres. Outcome measures were: technical success, periprocedural (0-24 hours) and post-procedural (24 hours-30 days) major and minor strokes, death, acute myocardial infarction (AMI), transient ischaemic attack (TIA), and external carotid occlusion. In three centres, consecutive diffusion-weighted magnetic resonance cerebral imaging (DW-MRI) was performed ≤72 hours prior to and within 72 hours after the intervention. A distal embolic protection device was employed in 182 patients (91%). Technical success was 100%. No death, AMI or major stroke occurred periprocedurally. There were two TIAs and five periprocedural minor strokes (2.5%), including one thrombosis solved by surgery. In the remaining patients (199/200; 99.5%) one-month follow-up duplex ultrasound revealed optimal technical results. Post-procedural clinical follow-up was uneventful. No external carotid artery occlusion occurred. New post-procedural DW-MRI lesions were detected in 12 patients out of 61 (19.6%), including bilateral in five (8.2%) and isolated ipsilateral in six (9.8%), whereas one patient (1.6%) had contralateral only lesions.

CONCLUSIONS

Multicentre multi-specialty use of the CGuard EPS in routine clinical practice was associated with no major periprocedural neurologic complications and a total elimination of post-procedural neurologic complications by 30 days.

Reduction of cerebral DWI lesion burden after carotid artery stenting using the CASPER stent system

INTRODUCTION

Despite various measures to protect against distal embolization during carotid artery stenting (CAS), periprocedural ischemic lesions are still encountered.

OBJECTIVE

To evaluate the periprocedural cerebral diffusion weighted imaging (DWI) lesion burden after CASPER stent placement.

METHODS

Patients who underwent CAS using the CASPER stent system were reviewed. Degrees of carotid stenosis and plaque configuration were determined. All patients were pretreated with dual antiplatelet agents and cerebral pre- and postprocedural MRI was obtained. All CAS procedures were performed by a single operator.

RESULTS

A total of 110 patients with severe carotid artery stenosis (median degree of stenosis 80%, median length of stenosis 10 mm) were treated with CAS. Hypoechogenic or heterogeneous, mostly hypoechogenic, plaques were documented in 48.6% (52/107) of patients. Carotid ulceration was present in 15.9% (17/107). Postprocedurally, 7.3% (8/110) of patients were found to have ischemic DWI lesions. They were asymptomatic in all patients. Follow-up at 90 days was available in 88.2% (97/110) of patients with excellent functional outcome (modified Rankin Scale score 0-1) in 95.9% (93/97).

CONCLUSION

Carotid artery stenting using the new CASPER stent in combination with a distal embolic protection device is safe and results in a lower rate of periprocedural DWI lesion burden compared with reported results for historic controls.

Early carotid artery stenting after onset neurologic symptoms

Multicenter clinical trials level 1 evidence favors the application of carotid endarterectomy in symptomatic patients, especially the in the elderly cohort. Carotid artery stenting has been proposed as a possible early alternative in selected patients after onset of ipsilateral neurologic symptoms. It is well known that treatment of acute stroke is time-dependent in patients with acute ischemic stroke caused by high-grade stenosis of the internal carotid artery, but intensive medical treatment in conjunction with intervention to improve stroke severity and clinical outcomes has not been established. Two major clinical concerns exist: (1) the risk of hemorrhagic infarction after cerebral revascularization in the acute stage and (2) application of carotid stenting in the acute embolic stage, which may be associated with continued embolic risk after carotid artery stenting compared to carotid endarterectomy, which removes the symptomatic plaque. This review summarizes the indications and results of early carotid artery stenting after onset of neurologic symptoms, considering the new carotid stents and cerebral protection systems available for clinical use and enhanced stenting techniques.

The Casper Stent System for carotid artery stenosis

Purpose

To report the results of a retrospective analysis of prospectively collected data evaluating the safety and efficacy of a double layer stent engineered for carotid artery occlusive disease.

Methods

Between January 2014 and February 2017, 138 patients (25.4% women; median age 71 years) underwent Casper stent implantation for carotid artery stenosis. Eligibility criteria included stenosis >70% of vessel diameter (or >50% diameter with ulceration) in symptomatic patients or asymptomatic patients with >80% stenosis at the carotid bifurcation or in the proximal internal carotid artery. For all procedures, a distal embolic protection device was used. The primary endpoint was the rate of 90 day major adverse neurological events, defined as minor stroke, major stroke, or death by independent neurological assessment.

Results

Stent deployment was completed successfully in all cases without documented technical failure. There were no adverse neurological events or mortalities within 90 days. One thromboembolic occlusion of a small distal branch of the anterior cerebral artery occurred during the procedure and resolved with systemic recombinant tissue plasminogen activator administration. New ischemic lesions, all clinically silent, were seen in 6.5% of patients on post-procedure cerebral MRI.

Conclusion

The Casper carotid stent demonstrated safety and efficacy in the treatment of carotid stenosis, with no technical failures and no adverse neurological events seen throughout the 90 day follow-up period. Its double layer structure seems to combine adequate plaque scaffolding with high vessel adaptability.

Carotid Artery Stenting: Investigation of Plaque Protrusion Incidence and Prognosis

OBJECTIVES

This study sought to clarify the incidence and prognosis of PP in carotid artery stenting (CAS).

BACKGROUND

Projections thought to be plaque may be observed inside the stent on angiography or intravascular ultrasound (IVUS) during CAS. Known as plaque protrusion (PP), the incidence and prognosis of this complication are unclear.

METHODS

A total of 354 consecutive carotid atherosclerotic stenoses in 328 patients (285 men, 43 women; age range 51 to 97 years [mean age 73.6 years]; 158 symptomatic cases; stenosis rate, 50% to 99% [mean 81.0%]) who underwent CAS under IVUS between October 2007 and March 2016 were retrospectively analyzed. PP was defined as plaque seen inside the stent lumen on both digital subtraction angiography and IVUS. The incidence and prognosis (rate of stroke within 30 post-operative days) of PP and the rate of ischemic lesions on the treated side on diffusion-weighted imaging performed within 48 post-operative hours within the PP group were investigated.

RESULTS

PP was observed in 9 cases (2.6%). Ischemic stroke occurred in 6 of 9 PP cases (66.7%; 1 major, 5 minor). Ischemic lesions were observed on diffusion-weighted imaging in 8 of 9 cases (88.9%). PP was strongly associated with perioperative ischemic stroke. A significant increase in PP susceptibility was observed with open-cell stent use and unstable plaque.

CONCLUSIONS

The incidence of PP in CAS was 2.6%, with a high risk of ischemic complications if PP was observed. The present findings indicate the necessity of appropriate device selection to avoid PP.

Device selection for carotid stenting: reviewing the evidence

INTRODUCTION

Carotid artery stenting (CAS) has recently changed the status in the treatment of the extracranial carotid atheromasic disease. In recent years, evolution in both stents and protection devices as well as in carotid stenting techniques, has resulted in an important reduction in the rate of stroke in patients undergoing CAS procedures. Areas covered: The purpose of this article is reviewing the literature and summarizing the current evidence of the new available materials to underline the importance of the correct choice of the devices during the procedure. Expert commentary: Certainly a key issue in order to limit the periprocedural events to the lowest possible, is to select the appropriate device for the appropriate patient anatomy and clinical syndrome, the so called 'tailored approach'.

One swallow does not a summer make but many swallows do: accumulating clinical evidence for nearly-eliminated peri-procedural and 30-day complications with mesh-covered stents transforms the carotid revascularisation field

Atherosclerotic carotid artery stenosis (CS) continues to be a common cause of acute ischaemic stroke. Optimised medical therapy (OMT), the first-line treatment modality in CS, may reduce or delay - but it does not abolish - CS-related strokes. As per current AHA/ASA and ESC/ESVS/ESO guidelines, carotid artery stenting (CAS) is a less-invasive alternative to carotid endarterectomy (CEA) for CS revascularisation in primary and secondary stroke prevention. Ten-year follow-up from the CREST trial in patients with symptomatic and asymptomatic CS confirmed equipoise of CAS and CEA in the primary endpoint. Nevertheless CAS - using a widely open-cell, first-generation stent and first-generation (distal/filter) neuroprotection - has been criticised for its relative excess of (mostly minor) strokes by 30 days, a significant proportion of which were post-procedural. Atherosclerotic plaque protrusion through conventional carotid stent struts, confirmed on intravascular imaging, has been implicated as a leading mechanism of the relative excess of strokes with CAS vs. CEA, including delayed strokes with CAS. Different designs of mesh-covered carotid stents have been developed to prevent plaque prolapse. Several multi-centre/multi-specialty clinical studies with CGurad MicroNet-Covered Embolic Prevention Stent System (EPS) and RoadSaver/Casper were recently published and included routine DW-MRI cerebral imaging peri-procedurally and at 30 days (CGuard EPS). Data from more than 550 patients in mesh-covered carotid stent clinical studies to-date show an overall 30-day complication rate of ~1% with near-elimination of post-procedural events. While more (and long-term) evidence is still anticipated, these results - taken together with optimised intra-procedural neuroprotection in CAS (increased use of proximal systems including trans-carotid dynamic flow reversal) and the positive 12-month mesh-covered stent data reports in 2017 - are transforming the carotid revascularisation field today. Establishing effective algorithms to identify the asymptomatic subjects at stroke risk despite OMT, and large-scale studies with mesh-covered stents including long-term clinical and duplex ultrasound outcomes, are the next major goals.

Mesh-covered (Roadsaver) stent as a new treatment modality for symptomatic or high-risk carotid stenosis

Introduction

Prevention of periprocedural stroke has a crucial role in carotid artery stenting (CAS) procedures.

Aim

To assess retrospectively 30-day safety and effectiveness of 41 procedures of internal and common carotid artery stenting using the Roadsaver double nitinol layer micromesh stent in 40 non-consecutive patients with symptomatic or high-risk carotid artery stenosis.

Material and methods

The patients were men (n = 31) and women (n = 9); mean age was 67.8 ±7.9 years. Femoral access was used in 39 cases, whereas radial access was used in 2. Proximal (n = 27) or distal (n = 14) embolic neuroprotection was used.

Results

The Roadsaver stents (nominal diameter 7, 8 or 9 mm, length 25 or 30 mm) were implanted successfully in all cases. One minor stroke occurred after common carotid artery intubation with a guiding catheter (before stent deployment) and one transient postprocedural ischemic attack (TIA) of the ipsilateral cerebral hemisphere was observed. Internal/common carotid artery stenosis severity was evaluated by duplex Doppler. Maximal peak systolic velocity (PSV) before CAS was in the range: 2.0–7.0 m/s, mean: 3.9 ±1.0 m/s, at 24–48 h after stenting mean PSV was 1.1 ±0.4 m/s (p < 0.05), and at 30 days 1.1 ±0.3 m/s (p < 0.05). Maximal end-diastolic velocity (EDV) was 0.85–3.5 m/s, mean 1.4 ±0.5 m/s, at 24–48 h after stenting mean EDV was 0.3 ±0.1 m/s (p < 0.05), and at 30 days 0.4 ±0.1 m/s (p < 0.05). No restenosis or thrombosis was observed. Angiographic stenosis decreased from 82.9 ±9.1% (range: 61–97%) to 19.3 ±7.3% (range: 0–34%) (p < 0.05).

Conclusions

The CAS using the Roadsaver stent seems to be safe and effective. Further studies involving larger patient populations and longer follow-up are needed.

The Casper carotid artery stent: a unique all metal micromesh stent designed to prevent embolic release

Background

Stroke due to the release of embolic debris during the placement of a stent to correct carotid artery stenosis is a constant procedural and peri-procedural threat. The new all metal Casper stent has been created with two layers of nitinol, the inner layer of which has pores diminutive enough to prevent embolic release.

Objective

To evaluate the safety, effectiveness, and utility of the double layer nitinol Casper carotid artery stent in the treatment of patients with severe carotid artery stenosis.

Methods

19 patients with severe internal carotid artery stenosis, 14 symptomatic and 5 asymptomatic, were treated with the Casper stent. After stent placement, angiographic and cone beam CT images were recorded in all patients.

Results

The unique low profile delivery system allowed for easy stent placement, re-sheathing, and repositioning of the stent. The large cell external layer produced excellent apposition to the artery wall. The inner layer prevented prolapse of atherosclerotic debris through the device. Plaque coverage was achieved; residual stenosis ranged from 0% to 20%. Long term angiographic follow-up in 5 patients showed wall apposition of the device covering the lesion and no restenosis. There were no procedure related complications. Two patients experienced a delayed ischemic stroke, likely related to inconsistent medical management.

Conclusions

The Casper has been an excellent stent for the treatment of internal carotid artery stenosis and its internal micromesh layer has been effective in preventing plaque prolapse. It provides the flexibility of large cell stents and the inner layer provides maximum protection against plaque prolapse.

Use of Micropatterned Thin Film Nitinol in Carotid Stents to Augment Embolic Protection

Stenting is an alternative to endarterectomy for the treatment of carotid artery stenosis. However, stenting is associated with a higher risk of procedural stroke secondary to distal thromboembolism. Hybrid stents with a micromesh layer have been proposed to address this complication. We developed a micropatterned thin film nitinol (M-TFN) covered stent designed to prevent thromboembolism during carotid intervention. This innovation may obviate the need or work synergistically with embolic protection devices. The proposed double layered stent is low-profile, thromboresistant, and covered with a M-TFN that can be fabricated with fenestrations of varying geometries and sizes. The M-TFN was created in multiple geometries, dimensions, and porosities by sputter deposition. The efficiency of various M-TFN to capture embolic particles was evaluated in different atherosclerotic carotid stenotic conditions through in vitro tests. The covered stent prevented emboli dislodgement in the range of 70%–96% during 30 min duration tests. In vitro vascular cell growth study results showed that endothelial cell elongation, alignment and growth behaviour silhouettes significantly enhance, specifically on the diamond-shape M-TFN, with the dimensions of 145 µm × 20 µm and a porosity of 32%. Future studies will require in vivo testing. Our results demonstrate that M-TFN has a promising potential for carotid artery stenting.

Carotid artery stenting with a new-generation double-mesh stent in three high-volume Italian centres: clinical results of a multidisciplinary approach

AIMS

Carotid artery stenting (CAS) is still associated with higher periprocedural cerebrovascular events (CEs) compared to vascular surgery. The Roadsaver carotid artery stent is a double layer micromesh stent which reduces plaque prolapse and embolisation by improving plaque coverage. Its clinical impact on neurological outcome was unknown. The aim of this study was therefore to report the clinical results of a large real-world population from three different centres receiving a Roadsaver stent to treat carotid artery disease.

METHODS AND RESULTS

One hundred and fifty (150) patients (age 74±8 yrs, 75% male, symptomatic 29%) treated with CAS using the Roadsaver carotid stent in three high-volume Italian centres were included in the study. Intraprocedural optical coherence tomography (OCT) evaluation was performed in 26 patients, with an off-line analysis by a dedicated core laboratory. All patients underwent duplex ultrasound and neurological evaluation at 24 hours and at 30 days. CAS was technically successful in all cases (stent diameter: 8.6±0.8 mm, stent length: 25.0±4.5 mm). No in-hospital or 30-day CEs were observed. OCT evaluation detected a low rate of plaque prolapse (two patients, 7.7%). Duplex ultrasound showed stent and external carotid artery patency in all cases both before discharge and at 30-day follow-up.

CONCLUSIONS

The Roadsaver stent is a safe and promising technology for CAS, with a low percentage of plaque prolapse and good short-term clinical outcome. Larger studies with longer follow-up are necessary to confirm this favourable clinical outcome.