Randomized clinical trial of open-cell vs closed-cell stents for carotid stenting and effects of stent design on cerebral embolization

Mid-Term Results of an Italian Multicentric Experience with the RoadsaverTM Dual-Layer Carotid Stent System

BACKGROUND

Carotid artery stenting (CAS) using first-generation single-layer stents is widely accepted as a good alternative to standard carotid endarterectomy (CEA) but it is associated with worse outcomes in terms of both plaque prolapse and cerebral embolization.

AIM

To evaluate the perioperative and midterm outcomes of CAS using the new-generation RoadsaverTM dual-layer micromesh-covered carotid stent.

METHODS

Herein, we present the results of an observational, retrospective, multicentric study on non-consecutive patients who underwent the CAS procedure between January 2017 and December 2022 at three Italian, high-volume vascular surgery centers. The inclusion criteria were the patients' eligibility for the CAS procedure in accordance with the current Italian guidelines, and the implantation of a Roadsaver stent. Both symptomatic and asymptomatic patients were included in the study. The patients requiring reintervention for carotid restenosis following CEA were also included. Perioperative data regarding procedural success was defined as the successful implantation of the device in the desired position, less than 30% residual stenosis, and the absence of intraoperative neurological complications. The primary outcome was any adverse cerebrovascular event such as stroke or transient ischemic attack (TIA) during the procedure and/or after discharge. The secondary outcomes were the need for further intervention, and all-cause death following procedure.

RESULTS

Three-hundred-fifty-three (353) patients were included in our study; the mean age was 74.3 years. A total of 5.9% of the patients were symptomatic on their operated side, while 7.3% had contralateral carotid occlusion. A cerebral embolic protection device (CPD) was employed in all patients. A total of 13.3% of the patients were operated on for restenosis after CEA Technical success was achieved in 96.9% of the cases with an intraoperative report of six TIAs (1.7%) and six ipsilateral strokes (1.7%). The mean hospital stay was 1.8 days. The thirty-day follow up showed one TIA and one more stroke. At the mean 35-month follow-up time, the primary outcome was present in six patients (1.7%), where four TIAs (1.1%) and two strokes (0.5%) were reported. Restenosis occurred in five patients (1.4%). Death for any cause was reported in 11 patients (3.1%).

CONCLUSIONS

As most recent, high-quality studies show, the CAS procedure with second-generation devices such as the Roadsaver stent is safe and effective in preventing carotid-related cerebrovascular events in both symptomatic and asymptomatic patients. The intraoperative and postoperative cerebrovascular complication rate in high volume centers is very low, ensuring confidence in its employment for the CAS procedure along with a CPD as a valid alternative to CEA.

Computational modeling of low-density lipoprotein accumulation at the carotid artery bifurcation after stenting

Restenosis typically occurs in regions of low and oscillating wall shear stress, which also favor the accumulation of atherogenic macromolecules such as low-density lipoprotein (LDL). This study aims to evaluate LDL transport and accumulation at the carotid artery bifurcation following carotid artery stenting (CAS) by means of computational simulation. The computational model consists of coupled blood flow and LDL transport, with the latter being modeled as a dilute substance dissolved in the blood and transported by the flow through a convection-diffusion transport equation. The endothelial layer was assumed to be permeable to LDL, and the hydraulic conductivity of LDL was shear-dependent. Anatomically realistic geometric models of the carotid bifurcation were built based on pre- and post-stent computed tomography (CT) scans. The influence of stent design was investigated by virtually deploying two different types of stents (open- and closed-cell stents) into the same carotid bifurcation model. Predicted LDL concentrations were compared between the post-stent carotid models and the relatively normal contralateral model reconstructed from patient-specific CT images. Our results show elevated LDL concentration in the distal section of the stent in all post-stent models, where LDL concentration is 20 times higher than that in the contralateral carotid. Compared with the open-cell stents, the closed-cell stents have larger areas exposed to high LDL concentration, suggesting an increased risk of stent restenosis. This computational approach is readily applicable to multiple patient studies and, once fully validated against follow-up data, it can help elucidate the role of stent strut design in the development of in-stent restenosis after CAS.

Safety Evaluation of Primary Carotid Stenting: Transcranial Doppler and MRI

BACKGROUND AND PURPOSE

Cerebral emboli are generated by every step of standard carotid angioplasty and stenting. Primary carotid stenting (PCS) is a technique in which the use of balloon angioplasty (BA) is minimized to decrease the embolic load. The primary aim of this study is to establish the number of emboli generated by each step of primary stenting and determine the relationship to new diffusion (DWI) lesions on subsequent magnetic resonance imaging (MRI).

METHODS

Eighty-five patients with severe, symptomatic carotid stenosis were prospectively recruited and underwent carotid stenting. Intraoperative transcranial Doppler was performed in 77 patients. The number and size of microemboli for each of seven procedural steps were recorded. Correlation was made with the number and location of new DWI lesions.

RESULTS

PCS was performed in 73 patients. BA was required in 12 patients. The mean number of microemboli was 114, and most microemboli were generated by stent deployment, followed by BA. Balloon techniques generated significantly more emboli than primary stenting (p = 0.017). There was a significant relationship between total microemboli and new DWI lesions (p = 0.009), and between new DWI lesions in multiple territories and the severity of pretreatment stenosis (p = 0.002).

CONCLUSIONS

During PCS, more emboli are generated by stent deployment than during any other stage of the procedure. When BA is necessary, more malignant emboli are generated but total emboli are unchanged and there is no difference in new diffusion lesions on MRI. PCS is safe and is not inferior to historical controls for the generation of new DWI lesions.

Evaluation of the association between silent ischemic lesions and stent design in carotid stenting applications

OBJECTIVE

Minor ischemic events and silent ischemic lesions are more common in carotid stenting than in endarterectomy. These silent ischemic lesions are also associated with stroke risk and cognitive impairment, so it is important to understand the factors that increase the risk and develop strategies to reduce the risk. We aimed to evaluate the association between carotid stent design and silent ischemic lesion development.

METHODS

The files of the patients who underwent carotid stenting between January 2020 and April 2022 were scanned. Patients with diffusion MR images taken within the postoperative 24 h were included in the study, while those undergoing acute stent placement were excluded. The patients were divided into two groups: those with open-cell stents and those with closed-cell stents.

RESULTS

A total of 65 patients, including 39 patients undergoing open-cell stenting and 26 patients undergoing closed-cell stenting, were included in the study. There was no significant difference in demographic data and vascular risk factors between the groups. New ischemic lesions were detected in 29 (74.4%) patients in the open-cell stent group and 10 (38.4%) patients in the closed-cell stent group and were significantly higher in the open-cell group. There was no significant difference between the two groups in terms of major and minor ischemic events and stent restenosis at the 3-month follow-up.

CONCLUSION

The rate of new ischemic lesion development was found to be significantly higher in carotid stent procedures performed with an open-cell Protégé stent than in those performed with a closed-cell Wallstent stent.

Patient Selection Criteria and Procedural Standardization for Carotid Artery Stenting-A Single Center Experience

The gold standard for the treatment of carotid artery stenosis is the carotid endarterectomy (CEA). According to current guidelines, carotid artery stenting (CAS) is an alternative. Randomized control trials (RCTs) show significantly higher rates of peri-interventional strokes after CAS compared to CEA. However, these trials were usually characterized by a great heterogeneity in the CAS procedure. In this retrospective analysis from 2012 to 2020, 202 symptomatic and asymptomatic patients were treated with CAS. Patients were carefully pre-selected according to anatomical and clinical criteria. In all cases, the same steps and material were used. All interventions were performed by five experienced vascular surgeons. Primary endpoints of this study were perioperative death and stroke. Asymptomatic carotid stenosis was present in 77% of the patients and symptomatic in 23%. The mean age was 66 years. The average degree of stenosis was 81%. The CAS technical success rate was 100%. Periprocedural complications occurred in 1.5% of cases, including one major stroke (0.5%) and two minor strokes (1%). The results of this study indicate that through a strict patient selection based on anatomical and clinical criteria, CAS can be performed with very low complication rates. Furthermore, standardization of the materials and the procedure itself is crucial.

The Height and Mobility of Protruding Plaque After Carotid Artery Stenting Are Associated with Postoperative Ischemic Lesions

BACKGROUND

Tissue protrusion (TP) is a possible cause of cerebral infarction after carotid artery stenting (CAS). Using optical frequency domain imaging (OFDI) and angioscopy, we investigated the relationship between the morphological features of TP and postoperative new ischemic lesions on magnetic resonance imaging (MRI)-diffusion weighted imaging (DWI) after CAS.

METHODS

Fifty patients who underwent CAS and subsequent poststenting intravascular evaluation using both OFDI and angioscopy were included. CAS was performed for proximal protection via the femoral artery approach, and intravascular evaluation with OFDI and angioscopy were performed after stent placement. We compared the background and poststenting intravascular findings between patients with and without postoperative new ischemic lesions on MRI-DWI.

RESULTS

TP was observed in 42 patients (84%), and postoperative new ischemic lesions on MRI-DWI were observed in 32 patients (64%). The frequency of TP did not differ between the 2 groups, but the height of TP was higher in the DWI-positive group (0.62 mm vs. 0.29 mm, P = 0.0028), and mobile TP was observed only in the DWI-positive group. The height of TP (P = 0.023) was an independent predictor of new periprocedural ischemic brain lesions after CAS, and its cut-off value for mobility was 0.55 mm on the receiver operating characteristic curve (area under the curve, 0.93).

CONCLUSIONS

The height of TP on OFDI and mobile-TP on angioscopy after CAS were associated with postoperative new ischemic lesions on MRI-DWI. The intravascular evaluation using OFDI and angioscopy could be helpful for a detailed evaluation of TP.

Carotid Artery Stenting for Patients With Carotid Stenosis and Contralateral Carotid Artery Occlusion: A 12-Year Experience

BACKGROUND

Carotid artery stenting (CAS) has emerged as a potential alternative for treating patients with extracranial cerebrovascular diseases. Contralateral carotid artery occlusion (CCO) occurs in approximately 2.3% to 25% of patients with carotid artery stenosis. However, the association of a CCO with long-term outcomes after CAS remains unclear. Here, we aimed to evaluate the perioperative and long-term recovery and safety of patients with CCO after receiving CAS.

METHODS

We retrospectively collected the data of patients with CCO treated with CAS between 2010 and 2021. The primary end point was a nonfatal major stroke. The secondary end points included cerebral hemorrhage, nonfatal myocardial infarction, restenosis, acute renal insufficiency, stent-related complications, and death. Long-term outcomes were analyzed by Kaplan-Meier survival analysis using the following variables: symptomatic carotid stenosis, age, stent type, collateral flow status, and postdilation.

RESULTS

Seventy one consecutive patients with CCO who underwent CAS were included in the study. Of these, 61 patients (86%) were followed up for 9-134 months, with an average of 63.3 ± 30.4 months. In the perioperative period, 2 patients (2.8%) experienced stroke and 1 patient (1.4%) died due to cerebral hemorrhage combined with cerebral hernia. During follow-up, 2 patients (3.3%) developed stroke at 4 and 6 months each after CAS and 6 patients (9.8%) died (2 patients died due to myocardial infarction and 4 patients died due to either severe liver failure, car accident, cervical fracture, or unknown cause). Kaplan-Meier survival analysis showed that symptomatic carotid stenosis, age, stent type, and postdilation were not associated with long-term stroke (P＜0.05). The inadequate collateral flow group showed a higher stroke rate than the control group (P = 0.009).

CONCLUSIONS

CAS is a safe and effective therapy for patients with CCO. Inadequate collateral flow is associated with a higher long-term rate of stroke. Our findings revealed that symptomatic carotid stenosis, age, stent type, and postdilation had no significant effect on outcome events after CAS.

Vascular remodeling in sheep implanted with endovascular neural interface

Objective.The aim of this work was to assess vascular remodeling after the placement of an endovascular neural interface (ENI) in the superior sagittal sinus (SSS) of sheep. We also assessed the efficacy of neural recording using an ENI.Approach.The study used histological analysis to assess the composition of the foreign body response. Micro-CT images were analyzed to assess the profiles of the foreign body response and create a model of a blood vessel. Computational fluid dynamic modeling was performed on a reconstructed blood vessel to evaluate the blood flow within the vessel. Recording of brain activity in sheep was used to evaluate efficacy of neural recordings.Main results.Histological analysis showed accumulated extracellular matrix material in and around the implanted ENI. The extracellular matrix contained numerous macrophages, foreign body giant cells, and new vascular channels lined by endothelium. Image analysis of CT slices demonstrated an uneven narrowing of the SSS lumen proportional to the stent material within the blood vessel. However, the foreign body response did not occlude blood flow. The ENI was able to record epileptiform spiking activity with distinct spike morphologies.Significance. This is the first study to show high-resolution tissue profiles, the histological response to an implanted ENI and blood flow dynamic modeling based on blood vessels implanted with an ENI. The results from this study can be used to guide surgical planning and future ENI designs; stent oversizing parameters to blood vessel diameter should be considered to minimize detrimental vascular remodeling.

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.

Double-lumen Carotid Plaque Associated with Severe Stenosis Treated with Staged Angioplasty: A Case Report

Double-lumen carotid plaque is a rare pathological condition, and only few reports about this condition have been recorded in the literature. However, no study has used endovascular therapy (EVT) for the treatment of double-lumen carotid plaque. Herein, we present a unique case of double-lumen carotid plaque associated with severe stenosis that was successfully treated with staged angioplasty (SAP). Moreover, a literature review of its pathology and other treatment options has been conducted. SAP is a two-stage carotid artery stenting (CAS) that can prevent hyperperfusion syndrome after revascularization. In this study, a 62-year-old man developed walking disturbance and left hemiparesis. Magnetic resonance imaging (MRI) revealed ischemic lesions in the watershed area of the right hemisphere and an irregular plaque in the right cervical internal carotid artery (ICA). Ultrasonography showed 84% stenosis in the area and a double lumen distal to the stenosis in the right ICA. Digital subtraction angiography (DSA) revealed a double-lumen plaque with 70% stenosis based on the North American Symptomatic Carotid Endarterectomy Trial criteria. SAP was performed after medication therapy and rehabilitation, and the surgery was uneventful. A double-lumen carotid plaque associated with severe stenosis is a rare condition with a high risk of emboli and stroke. In an unstable lesion, carotid endarterectomy is the first option. However, since the patient in this case was at high risk for general anesthesia, SAP was performed. Hence, if an appropriate device is used, EVT can be a safe treatment strategy for unstable and atypical plaques as in this case.

Non-protected carotid artery stenting for symptomatic carotid stenosis in low resource settings

Background

The use of a distal cerebral protection device during extracranial carotid artery stenting is still a matter of debate. The aim of this work was to evaluate the safety of performing carotid artery stenting procedure without the use of cerebral protection device in patients with symptomatic carotid stenosis. A retrospective study was performed during the period from September 2015 till March 2020 including 91 patients with symptomatic carotid artery stenosis. All patients were treated with a single stent type (Wall stent® - Boston scientific) without the use of cerebral protection device. Pre- and post-procedural clinical assessment with the national institute of health stroke scale (NIHSS). Post procedure brain diffusion-weighted magnetic resonance imaging (DW-MRI) if clinically indicated within 24 h was used to determine periprocedural cerebral embolization.

Results

A low complication rate was found as only one case (1%) showed mild deterioration in NIHSS and new acute cerebral emboli were detected with brain DW-MRI.

Conclusion

Carotid artery stenting can be performed safely without the use of cerebral protection device.

Treatment of carotid stenosis: surgery and stent in comparison

Carotid stenosis in the extracranial tract determines 10–15% of all ischaemic strokes. The aim of treatment, therefore, is to prevent major neurological events. Carotid endarterectomy surgery has proved effective in this regard, with various randomized studies that have demonstrated its validity in both symptomatic and asymptomatic patients. As an alternative, since the late 1990s, the endovascular treatment of carotid stenosis by stenting has gradually established itself. Numerous controlled clinical trials have compared surgery and carotid stenting in terms of perioperative outcomes (death, stroke, and myocardial infarction within 30 days of the procedure) and stroke prevention ipsilateral to the lesion treated during follow-up, evaluating both symptomatic and asymptomatic patients. From the systematic review of the data, it is legitimate to state that stenting may represent a safe alternative to conventional surgery in patients with symptomatic carotid stenosis under the age of 70, while endarterectomy is clearly safer and more effective than endovascular treatment for symptomatic older patients. On the other hand, as regards asymptomatic patients, the available evidence is limited and further data are needed to compare the two methods and to compare them with the best current medical therapy in order to draw conclusions.

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.

Comparison of open- and closed-cell stent design outcomes after carotid artery stenting in the Vascular Quality Initiative

BACKGROUND

The association between stent design and outcomes after carotid artery stenting (CAS) has remained controversial. The available data are conflicting regarding the superiority of any specific stent design. The present study investigated the association between cell design and outcomes after carotid artery stenting (CAS) in a real world setting.

METHODS

Patients who had undergone CAS with distal embolic protection in the Society for Vascular Surgery Vascular Quality Initiative (VQI) database from 2016 to 2018 were included in the present study. Patients undergoing CAS for trauma or dissection or more than two treated lesions were excluded. We also excluded lesions for which more than two carotid stents had been used and lesions confined to the common or external carotid artery. Univariable and multivariable logistic regression analyses were used to compare the outcomes after CAS between the open- and closed-cell stent designs.

RESULTS

Of the 2671 CAS procedures included in the present analysis, 1384 (51.8%) had used closed-cell stents and 1287 (48.2%) had used open-cell stents. On univariable analysis, no significant differences were noted between the closed- and open-cell stents in in-hospital mortality (1.8% vs 1.4%; P = .40), stroke (1.8% vs 2.4%; P = .28), and stroke/death (3.3% vs 3.5%; P = .81). After adjusting for potential confounders (ie, age, symptomatic status, previous major amputation, statin and antiplatelet use, American Society of Anesthesiologists class, elective procedures, approach, and post-stent dilatation), no difference was noted in in-hospital stroke/death between the two stent designs (odds ratio [OR], 1.08; 95% confidence interval [CI], 0.68-1.74; P = .74). However, the interaction between stent design (open vs closed) and lesion location (bifurcation vs internal carotid artery [ICA]) was statistically significant (P = .02). Closed-cell stents were associated with five times the odds of in-hospital stroke/death when used in carotid artery bifurcation (OR, 5.5; 95% CI, 1.3-22.2; P = .02). However, when the stent was limited to the ICA, no differences were noted (OR, 0.87; 95% CI, 0.51-1.45; P = .62). One-year follow-up data were available for 19% of patients. No differences in ipsilateral stroke or death at 1 year were noted between the open- and closed-cell stents, except when the lesion was located in the carotid bifurcation (hazard ratio, 6.7; 95% CI, 1.4-31.4; P = .02).

CONCLUSIONS

Closed-cell stents were associated with an increased odds of in-hospital stroke/death for carotid bifurcation lesions, which might be related to the relatively lower conformability of closed-cell stents in the tortuous and diameter-mismatched bifurcation anatomy vs the relatively linear uniform diameter of the ICA. Improved follow-up and in-depth analysis of lesion-specific characteristics that might influence the outcomes of these two designs are needed to validate these results.

Is it possible to prevent cerebral embolization by improving the design and technology of carotid stent implantation?

INTRODUCTION

The prevention of atherosclerotic plaque fragmentation during carotid artery stenting is a fundamental problem in decreasing the risk of disability of patients. The goal of this review is to clarify whether the stent design can have a decisive impact on the rate of intraoperative and postoperative complications.

AREAS COVERED

Different designs of the carotid stents are briefed and the advantages and disadvantages of different stent designs are discussed as well as the results of their clinical use. Various solutions are presented to reduce cerebral embolism during carotid artery stenting.

EXPERT OPINION

There is no conclusive evidence for the benefits of closed cell and hybrid stents. The stent design cannot completely resolve the problem of cerebral embolism. Most of the events of cerebral microembolism occur at the stages of stent delivery rather than protrusion of an atherosclerotic plaque in the long-term follow-up. Most likely, minimization of the risks for periprocedural and postprocedural strokes requires not only the new solutions in stent design as well as the corresponding delivery systems and brain embolic protection systems, but also the new strategies of preprocedural drug stabilization of the atherosclerotic plaque in the carotid artery. Abbreviations: CAS, carotid artery stenting; CE, carotid endarterectomy; DW-MRI, diffusion-weighted magnetic resonance imaging; ECA, external carotid artery; ICA, internal carotid artery; IVUS, intravascular ultrasound examination; OCT, optical coherence tomography.

Vascular Trauma in the Head and Neck and Endovascular Neurointerventional Management

Traumatic vascular injuries of the head and neck can pose life-threatening emergencies, and therefore, the detection and accurate characterization of these injuries by the radiologist is essential. Computed tomographic angiography (CTA) is commonly performed as part of the initial imaging work-up of patients who have sustained blunt or penetrating craniocervical injuries and are suspected to have or are at risk for vascular injuries. This pictorial essay reviews the CTA and conventional angiographic imaging appearance of various vascular injuries that can occur from trauma in the head and neck and also explores the neurointerventional management of these types of injuries.

Carotid artery stenting versus endarterectomy for treatment of carotid artery stenosis

BACKGROUND

Carotid artery stenting is an alternative to carotid endarterectomy for the treatment of atherosclerotic carotid artery stenosis. This review updates a previous version first published in 1997 and subsequently updated in 2004, 2007, and 2012.

OBJECTIVES

To assess the benefits and risks of stenting compared with endarterectomy in people with symptomatic or asymptomatic carotid stenosis.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched August 2018) and the following databases: CENTRAL, MEDLINE, Embase, and Science Citation Index to August 2018. We also searched ongoing trials registers (August 2018) and reference lists, and contacted researchers in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing stenting with endarterectomy for symptomatic or asymptomatic atherosclerotic carotid stenosis. In addition, we included RCTs comparing carotid artery stenting with medical therapy alone.

DATA COLLECTION AND ANALYSIS

One review author selected trials for inclusion, assessed trial quality and risk of bias, and extracted data. A second review author independently validated trial selection and a third review author independently validated data extraction. We calculated treatment effects as odds ratios (OR) and 95% confidence intervals (CI), with endarterectomy as the reference group. We quantified heterogeneity using the I² statistic and used GRADE to assess the overall certainty of evidence.

MAIN RESULTS

We included 22 trials involving 9753 participants. In participants with symptomatic carotid stenosis, compared with endarterectomy stenting was associated with a higher risk of periprocedural death or stroke (the primary safety outcome; OR 1.70, 95% CI 1.31 to 2.19; P < 0.0001, I² = 5%; 10 trials, 5396 participants; high-certainty evidence); and periprocedural death, stroke, or myocardial infarction (OR 1.43, 95% CI 1.14 to 1.80; P = 0.002, I² = 0%; 6 trials, 4861 participants; high-certainty evidence). The OR for the primary safety outcome was 1.11 (95% CI 0.74 to 1.64) in participants under 70 years old and 2.23 (95% CI 1.61 to 3.08) in participants 70 years old or more (interaction P = 0.007). There was a non-significant increase in periprocedural death or major or disabling stroke with stenting (OR 1.36, 95% CI 0.97 to 1.91; P = 0.08, I² = 0%; 7 trials, 4983 participants; high-certainty evidence). Compared with endarterectomy, stenting was associated with lower risks of myocardial infarction (OR 0.47, 95% CI 0.24 to 0.94; P = 0.03, I² = 0%), cranial nerve palsy (OR 0.09, 95% CI 0.06 to 0.16; P < 0.00001, I² = 0%), and access site haematoma (OR 0.32, 95% CI 0.15 to 0.68; P = 0.003, I² = 27%). The combination of periprocedural death or stroke or ipsilateral stroke during follow-up (the primary combined safety and efficacy outcome) favoured endarterectomy (OR 1.51, 95% CI 1.24 to 1.85; P < 0.0001, I² = 0%; 8 trials, 5080 participants; high-certainty evidence). The rate of ipsilateral stroke after the periprocedural period did not differ between treatments (OR 1.05, 95% CI 0.75 to 1.47; P = 0.77, I² = 0%). In participants with asymptomatic carotid stenosis, there was a non-significant increase in periprocedural death or stroke with stenting compared with endarterectomy (OR 1.72, 95% CI 1.00 to 2.97; P = 0.05, I² = 0%; 7 trials, 3378 participants; moderate-certainty evidence). The risk of periprocedural death or stroke or ipsilateral stroke during follow-up did not differ significantly between treatments (OR 1.27, 95% CI 0.87 to 1.84; P = 0.22, I² = 0%; 6 trials, 3315 participants; moderate-certainty evidence). Moderate or higher carotid artery restenosis (50% or greater) or occlusion during follow-up was more common after stenting (OR 2.00, 95% CI 1.12 to 3.60; P = 0.02, I² = 44%), but the difference in risk of severe restenosis was not significant (70% or greater; OR 1.26, 95% CI 0.79 to 2.00; P = 0.33, I² = 58%; low-certainty evidence).

AUTHORS' CONCLUSIONS

Stenting for symptomatic carotid stenosis is associated with a higher risk of periprocedural stroke or death than endarterectomy. This extra risk is mostly attributed to an increase in minor, non-disabling strokes occurring in people older than 70 years. Beyond the periprocedural period, carotid stenting is as effective in preventing recurrent stroke as endarterectomy. However, combining procedural safety and long-term efficacy in preventing recurrent stroke still favours endarterectomy. In people with asymptomatic carotid stenosis, there may be a small increase in the risk of periprocedural stroke or death with stenting compared with endarterectomy. However, CIs of treatment effects were wide and further data from randomised trials in people with asymptomatic stenosis are needed.

A meta-analysis of the effect of stent design on clinical and radiologic outcomes of carotid artery stenting

OBJECTIVE

Procedural characteristics, including stent design, may influence the outcome of carotid artery stenting (CAS). A thorough comparison of the effect of stent design on outcome of CAS is thus warranted to allow for optimal evidence-based clinical decision making. This study sought to evaluate the effect of stent design on clinical and radiologic outcomes of CAS.

METHODS

A systematic search was conducted in MEDLINE, Embase, and Cochrane databases in May 2018. Included were articles reporting on the occurrence of clinical short- and intermediate-term major adverse events (MAEs; any stroke or death) or radiologic adverse events (new ischemic lesions on postprocedural magnetic resonance diffusion-weighted imaging [MR-DWI], restenosis, or stent fracture) in different stent designs used to treat carotid artery stenosis. Random effects models were used to calculate combined overall effect sizes. Metaregression was performed to identify the effect of specific stents on MAE rates.

RESULTS

From 2654 unique identified articles, two randomized, controlled trials and 66 cohort studies were eligible for analysis (including 46,728 procedures). Short-term clinical MAE rates were similar for patients treated with open cell vs closed cell or hybrid stents. Use of an Acculink stent was associated with a higher risk of short-term MAE compared with a Wallstent (risk ratio [RR], 1.51; P = .03), as was true for use of Precise stent vs Xact stent (RR, 1.55; P < .001). Intermediate-term clinical MAE rates were similar for open vs closed cell stents. Use of open cell stents predisposed to a 25% higher chance (RR, 1.25; P = .03) of developing postprocedural new ischemic lesions on MR-DWI. No differences were observed in the incidence of restenosis, stent fracture, or intraprocedural hemodynamic depression with respect to different stent design.

CONCLUSIONS

Stent design is not associated with short- or intermediate-term clinical MAE rates in patients undergoing CAS. Furthermore, the division in open and closed cell stent design might conceal true differences in single stent efficacy. Nevertheless, open cell stenting resulted in a significantly higher number of subclinical postprocedural new ischemic lesions detected on MR-DWI compared with closed cell stenting. An individualized patient data meta-analysis, including future studies with prospective homogenous study design, is required to adequately correct for known risk factors and to provide definite conclusions with respect to carotid stent design for specific subgroups.

Carotid artery stenting: Current state of evidence and future directions

Both carotid endarterectomy (CEA) and carotid artery stenting (CAS) are common treatments for carotid artery stenosis. Several randomized controlled trials (RCTs) have compared CEA to CAS in the treatment of carotid artery stenosis. These studies have suggested that CAS is more strongly associated with periprocedural stroke; however, CEA is more strongly associated with myocardial infarction. Published long-term outcomes report that CAS and CEA are similar. A reduction in complications associated with CAS has also been demonstrated over time. The symptomatic status of the patient and history of previous CEA or cervical radiotherapy are significant factors when deciding between CEA or CAS. Numerous carotid artery stents are available, varying in material, shape and design but with minimal evidence comparing stent types. The role of cerebral protection devices is unclear. Dual antiplatelet therapy is typically prescribed to prevent in-stent thrombosis, and however, evidence comparing periprocedural and postprocedural antiplatelet therapy is scarce, resulting in inconsistent guidelines. Several RCTs are underway that will aim to clarify some of these uncertainties. In this review, we summarize the development of varying techniques of CAS and studies comparing CAS to CEA as treatment options for carotid artery stenosis.

Recent advances in the treatment of carotid artery disease

Transfemoral carotid stenting has struggled to become a suitable alternative to carotid endarterectomy for the treatment of carotid disease because of higher perioperative stroke risks, even with use of embolic protection devices. To reduce the perioperative stroke rates associated with carotid stenting, several advancements in stent design, embolic protection systems, and technical approaches have been developed. Transcarotid artery revascularization (TCAR) was also recently introduced as a novel carotid artery stenting option which circumvents several of the high embolic-risk maneuvers found in transfemoral carotid stenting and employs a flow reversal system that provides continuous embolic protection throughout the procedure. Early results from this technique have shown low stroke/death rates comparable to carotid endarterectomy while maintaining the minimally invasive benefits of carotid stenting. TCAR has a strong potential to become the preferred method of carotid stenting in the near future and may challenge carotid endarterectomy as the preferred carotid artery revascularization method.

Silent brain infarcts on diffusion-weighted imaging after carotid revascularisation: A surrogate outcome measure for procedural stroke? A systematic review and meta-analysis

Aim

To investigate whether lesions on diffusion-weighted imaging (DWI+) after carotid artery stenting (CAS) or endarterectomy (CEA) might provide a surrogate outcome measure for procedural stroke.

Materials and Methods

Systematic MedLine® database search with selection of all studies published up to the end of 2016 in which DWI scans were obtained before and within seven days after CAS or CEA. The correlation between the underlying log odds of stroke and of DWI+ across all treatment groups (i.e. CAS or CEA groups) from included studies was estimated using a bivariate random effects logistic regression model. Relative risks of DWI+ and stroke in studies comparing CAS vs. CEA were estimated using fixed-effect Mantel-Haenszel models.

Results

We included data of 4871 CAS and 2099 CEA procedures (85 studies). Across all treatment groups (CAS and CEA), the log odds for DWI+ was significantly associated with the log odds for clinically manifest stroke (correlation coefficient 0.61 (95% CI 0.27 to 0.87), p = 0.0012). Across all carotid artery stenting groups, the correlation coefficient was 0.19 (p = 0.074). There were too few CEA groups to reliably estimate a correlation coefficient in this subset alone. In 19 studies comparing CAS vs. CEA, the relative risks (95% confidence intervals) of DWI+ and stroke were 3.83 (3.17-4.63, p < 0.00001) and 2.38 (1.44-3.94, p = 0.0007), respectively.

Discussion

This systematic meta-analysis demonstrates a correlation between the occurrence of silent brain infarcts on diffusion-weighted imaging and the risk of clinically manifest stroke in carotid revascularisation procedures.

Conclusion

Our findings strengthen the evidence base for the use of DWI as a surrogate outcome measure for procedural stroke in carotid revascularisation procedures. Further randomised studies comparing treatment effects on DWI lesions and clinical stroke are needed to fully establish surrogacy.

Influence of stenting with open-cell stents vs close-cell stents on the outcomes of patients with bilateral carotid stenosis

BACKGROUND

Carotid artery stenting (CAS) is an effective way to prevent stroke in patients with severe carotid stenosis. However, several studies comparing the outcomes of stenting with open-cell stents (OCS) vs closed-cell stents (CCS) have yielded inconclusive results. This study aimed to compare the outcomes of CAS with OCS vs CCS in the same patients.

METHODS

From year 2000 to 2016, we included 52 patients with severe bilateral carotid stenosis who underwent OCS deployment in one artery and CCS deployment in the contralateral artery. Stents were selected according to arterial anatomy and lesion morphology, and the peri-procedural and long-term outcomes of treatment with OCS vs CCS, were compared in terms of rates of ischemic spot development on early post-procedural diffusion-weighted imaging (ISDWI), in-stent restenosis (ISR), and recurrent stroke.

RESULTS

After stenting with OCS vs CCS, the number (rate) of arteries with no lesion, < 5 lesions, and ≥ 5 lesions on DWI was 9 (32%) vs 8 (27%), 8 (29%) vs 17 (57%), and 11 (39%) vs 5 (17%) (p = .10); number (rate) of arteries with 0%, < 50%, and >50% ISR was 34 (65%) vs 34 (65%), 9 (17%) vs 11 (21%), and 9 (17%) vs 7 (13%) (p = .71); number (rate) of recurrent strokes after CAS was 2 (4%) vs 0 (0%).

CONCLUSION

The rates of peri-procedural cerebral ischemic insult, long-term stent patency, and stroke recurrence indicate that no one carotid stent cell design is superior to the other. We suggest both OCS and CCS are reasonable options for the treatment of severe carotid stenosis.

Tailored Strategies in Carotid Artery Stenting to Avoid Periprocedural Complications

Carotid artery stenting (CAS) has been widely accepted as a valuable therapeutic alternative to carotid endarterectomy (CEA) for high-grade carotid stenosis. Because carotid revascularization including CAS is usually performed in patients with minimal or no neurological deficits, utmost care should be taken to avoid periprocedural complications. The major concerns associated with CAS are embolic stroke, hyperperfusion syndrome (HPS), and perioperative myocardial infarction.Plaque characteristics, cerebral blood flow (CBF) in the affected cerebral hemisphere, and concomitant coronary artery disease prior to CAS are all important to assess the risks of these complications and are routinely evaluated.Tailored CAS is planned based on findings of preoperative evaluation, as follows. (1) If the plaque component is thought vulnerable, proximal embolic protection methods, use of a closed-cell-type stent, or referral to CEA should be considered to avoid embolic complications. (2) If patients have severe CBF impairment, staged angioplasty is an effective strategy to prevent postoperative HPS. (3) If concomitant cardiac diseases are present, the optimal treatment sequence should be discussed between cardiologists and neurointerventionalists.These tailored strategies based on preoperative risk evaluations may lead to safer procedures and better clinical outcome in CAS patients.

Effect of Open- vs Closed-Cell Stent Design on Periprocedural Outcomes and Restenosis After Carotid Artery Stenting: A Systematic Review and Comprehensive Meta-analysis

Purpose:To compare periprocedural complications and in-stent restenosis rates associated with open- vs closed-cell stent designs used in carotid artery stenting (CAS). Methods: A systematic search was conducted to identify all randomized and observational studies published in English up to October 31, 2017, that compared open- vs closed-cell stent designs in CAS. Identified studies were included if they reported the following outcomes: stroke, transient ischemic attack (TIA), myocardial infarction (MI), hemodynamic depression, new ischemic lesions detected on imaging, and death within 30 days, as well as the incidence of in-stent restenosis. A random-effects model meta-analysis was employed. Model results are reported as the odds ratio (OR) and 95% confidence interval (CI). The I2 statistic was used to assess heterogeneity. Results: Thirty-three studies (2 randomized trials) comprising 20, 291 patients (mean age 71.3±3.0 years; 74.6% men) were included. Patients in the open-cell stent group had a statistically significant lower risk of restenosis ⩾40% (OR 0.42, 95% CI 0.19 to 0.92; I2=0%) and ⩾70% (OR 0.23, 95% CI 0.10 to 0.52; I2=0%) at a mean follow-up of 24 months. No statistically significant differences were identified for periprocedural stroke, TIA, new ischemic lesions, MI, hemodynamic depression, or death within 30 days after CAS. Sensitivity analysis of the 2 randomized controlled trials only did not point to any significant differences either. Conclusion: Use of open-cell stent design in CAS is associated with a decreased risk for restenosis when compared to the closed-cell stent, without significant differences in periprocedural outcomes.

Predictors of Perioperative Stroke/Death after Carotid Artery Stenting: A Review Article

Carotid artery stenting (CAS) has been recommended as an alternative treatment to carotid endarterectomy for patients with significant carotid stenosis. Only a few studies have analyzed clinical/anatomical and technical variables that affect perioperative outcomes of CAS. Following a comprehensive Medline search, it was reported that clinical factors, including age of >80 years, chronic renal failure, diabetes mellitus, symptomatic indications, and procedures performed within 2 weeks of transient ischemic attack symptoms, are associated with high perioperative stroke and death rates. They also highlighted that angiographic variables, e.g., ulcerated and calcified plaques, left carotid intervention, >90% stenosis, >10-mm target lesion length, ostial involvement, type III aortic arch, and >60°-angulated internal carotid and common carotid arteries, are predictors of increased stroke rates. Technical factors associated with increased perioperative risk of stroke include percutaneous transluminal angioplasty (PTA) without embolic protection devices, PTA before stent placement, and the use of multiple stents. This review describes the most widely quoted data in defining various predictors of perioperative stroke and death after CAS. (This is a review article based on the invited lecture of the 45th Annual Meeting of Japanese Society for Vascular Surgery.)

Anatomical and technical predictors of perioperative clinical outcomes after carotid artery stenting

BACKGROUND

A few other studies have reported the effects of anatomical and technical factors on clinical outcomes of carotid artery stenting (CAS). This study analyzed the effect of these factors on perioperative stroke/myocardial infarction/death after CAS.

METHODS

This was a retrospective analysis of prospectively collected data of 409 of 456 patients who underwent CAS during the study period. A logistic regression analysis was used to determine the effects of anatomical and technical factors on perioperative stroke, death, and myocardial infarction (major adverse events [MAEs]).

RESULTS

The MAE rate for the entire series was 4.7% (19 of 409), and the stroke rate was 2.2% (9 of 409). The stroke rate for asymptomatic patients was 0.46% (1 of 218; P = .01). The MAE rates for patients with transient ischemic attack (TIA) were 7% (11 of 158) vs 3.2% (8 of 251) for other indications (P = .077). The stroke rates for heavily calcified lesions were 6.3% (3 of 48) vs 1.2% (4 of 332) for mildly calcified/noncalcified lesions (P = .046). Differences in stroke and MAE rates regarding other anatomical features were not significant. The stroke rate for patients with percutaneous transluminal angioplasty (PTA) before embolic protection device (EPD) insertion was 9.1% (2 of 22) vs 1.8% (7 of 387) for patients without (P = .07) and 2.6% (9 of 341) for patients with poststenting PTA vs 0% (0 of 68) for patients without. The MAE rate for patients with poststenting PTA was 5.6% (19 of 341) vs 0% (0 of 68) for patients without (P = .0536). The MAE rate for patients with the ACCUNET (Abbott, Abbott Park, Ill) EPD was 1.9% (3 of 158) vs 6.7% (16 of 240) for others (P = .029). The differences between stroke and MAE rates for other technical features were not significant. A regression analysis showed that the odds ratio for stroke was 0.1 (P = .031) for asymptomatic indications, 13.7 (P = .014) for TIA indications, 6.1 (P = .0303) for PTA performed before EPD insertion, 1.7 for PTA performed before stenting, and 5.4 (P = .0315) for heavily calcified lesions. The MAE odds ratio was 0.46 (P = .0858) for asymptomatic indications, 2.1 for PTAs performed before EPD insertion, 2.2 for poststent PTAs, and 2.2 (P = .1888) for heavily calcified lesions. A multivariate analysis showed that patients with TIA had an odds ratio of stroke of 11.05 (P = .029). Patients with PTAs performed before EPD insertion had an OR of 6.15 (P = .062). Patients with heavily calcified lesions had an odds ratio of stroke of 4.25 (P = .0871). The MAE odds ratio for ACCUNET vs others was 0.27 (P = .0389).

CONCLUSIONS

Calcific lesions and PTA before EPD insertion or after stenting were associated with higher stroke or MAE rates, or both. The ACCUNET EPD was associated with lower MAE rates. There was no correlation between other anatomical/technical variables and CAS outcome.

The effect of increasing operator experience on procedure-related characteristics in patients undergoing carotid artery stenting

Objectives To evaluate the efficacy and safety of carotid artery stenting for the treatment of severe carotid artery disease in our department and to investigate the effect of increasing operator experience on perioperative and procedure-related characteristics. Methods From January 2007 to February 2015 200 patients underwent 207 endovascular procedures for carotid artery stenosis. Of all, 113 arteries (56.5%) were symptomatic. Significant changes across time were calculated with the use of Change Point analysis using bootstrap and mean squared error estimates. Results The technical success was 98.6% (204/207 cases). Thirty-day neurological events included stroke in four patients (2%) and transient ischemic attack in two (1%). None of the patients died during the first 30 days. The most significant change of radiation duration occurred after the 33rd patient with a decrease from 25.31 min to 12.31 min, while for the total operative time that change occurred between the 31st and 33rd patient where mean operation time decreased from 88.89 min to 49.22 min. The most significant change of contrast media used occurred at the 40th patient with a decrease from 91.58 ml to 62 ml. During a mean follow-up period of 42 ± 20.02 months none of the patients experienced any cerebrovascular event. There was one case of significant recurrent stenosis, which was successfully treated by endovascular means. Conclusions Endovascular treatment of carotid artery stenosis performed in a single center with the use of a cerebral protection device seems to consist a safe therapeutic choice with acceptable results, within the referenced benchmarks proposed in the latest guidelines. Certain perioperative parameters such as the amount of contrast media used, the fluoroscopy and operation time, seem to decline overtime indicating increasing operator's experience. A number of performed cases above 40 was related to the significant decrease of those parameters and may represent the learning curve of the procedure.

Incidence and risk factors of embolized particles in carotid artery stenting and association with clinical outcome

BACKGROUND

One of the mechanisms for periprocedural neurologic events in carotid artery stenting (CAS) is catheter manipulation within the aorta and supraaortic arteries causing plaque embolization. Therefore, the present analysis sought to determine risk factors for embolic particle dimensions and their relationship with adverse clinical events after CAS.

METHODS

Between 1999 and 2015 embolic protection devices (EPD) of a total of 944 CAS procedures were evaluated regarding the occurrence and size of captured particles.

RESULTS

Particles were found in 819 of 944 (87%) EPDs. Larger particles were detected in procedures using open cell stents (150±282μm vs. 107±177μm; p=0.005) and longer stents (≥40mm) (165±315μm vs. 122±215μm; p=0.026). With increasing learning curve, particle size was continually reduced (168±282μm in the first third of the cohort vs. 127±309μm in the second third vs. 108±114μm in the last third; p=0.009). Longer stents and use of Acculink stent were found to be independent predictors for particle diameter. In patients who died or sustained a stroke during long-term follow-up (median 5.5years [IQR 2.6-7.9]) significantly larger particles were captured during CAS compared to those patients with an uneventful follow-up (160±330μm vs. 121±195μm; p=0.047).

CONCLUSIONS

In the vast majority of CAS procedures particles could be retrieved from the EPDs used. Procedural characteristics such as stent type and stent length were associated with larger particles.

Comparison of Open-Cell Stent and Closed-Cell Stent for Treatment of Central Vein Stenosis or Occlusion in Hemodialysis Patients

Background

Central vein stenosis or occlusion is a common complication that can lead to significant morbidity and dysfunction of access in the hemodialysis patient. More lesions can develop over time, and preserving access becomes a challenge as life expectancy of the hemodialysis patient increases.

Objectives

The goal was to compare long-term results and determine the outcomes of open-cell stent versus closed-cell stent for central vein stenosis or occlusion in hemodialysis patients.

Patients and Methods

From 1997 to 2015, in 401 hemodialysis patients, stent placement for central vein stenosis or occlusion was performed if balloon angioplasty was unsatisfactory, due to elastic recoil or occurrence of restenosis within 3 months. When thrombus was present, primary stenting was performed. A total of 257 open-cell stents and 144 closed-cell stents were used. Angiographic findings including lesion site, central vein stenosis or occlusion, and presence of thrombosis and complication were evaluated. Primary patency rate and mean patency rate of the stent were compared between two stent groups by Kaplan-Meier survival analysis.

Results

For the open-cell stent group, 159 patients were diagnosed as central vein stenosis and 98 were occlusion. For the closed-cell stent group, 78 were stenosis and 66 were occlusion. There were two complications for central migration and two for procedure-related vein rupture. Open-cell stents and closed-cell stents had mean patency rates of 10.9 ± 0.80 months and 8.5 ± 10.87 months, respectively (P = 0.002).

Conclusion

The open-cell stent is effective and its performance is higher than that obtained with the closed-cell stent for treating central vein stenosis or occlusion in hemodialysis patients.

In-Stent Restenosis After Carotid Artery Stenting: From Diagnosis to Treatment

Although carotid artery stenting is a safe and effective treatment for preventing ischaemic stroke in significant carotid atherosclerotic disease, it can be complicated by in-stent restenosis (ISR). Factors involved in the ISR process are both mechanical and patient-related, but the most important is the neointimal thickening within stent struts, leading to lumen reduction. Overall incidence of carotid ISR is low and related embolic risk seems to be lower than native disease. Digital subtraction angiography is the gold standard for diagnosis. Nowadays, Doppler ultrasound should be considered the first-line investigation, due to its non-invasiveness and reproducibility. Computed tomography angiography remains useful when Doppler ultrasound is inconclusive. Indication and modality of treatment of ISR are still debated: both surgery (carotid endarterectomy with stent removal in most cases) or interventional procedures such as percutaneous transluminal angioplasty with simple balloon, cutting-balloon, drug-eluting balloon, and stenting, showed safety and efficacy in follow-up. Surgery is currently reserved for selected cases. Carotid ISR is an overall rare complication which can be easily identified at routine follow-up. This paper is a literature review and state-of-the-art assessment of ISR, clinical features, diagnosis, and treatment.

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.

A comparative analysis of transcranial Doppler parameters acquired during carotid stenting and semi-eversion carotid endarterectomy

Background

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) have both been proposed for treatment of critical atherosclerotic stenosis located at the carotid bifurcation. Monitoring of hyperintense microembolic signals (MES) by transcranial Doppler ultrasound (TCD) is considered a method of quality control, both in CEA and in CAS.

Objective

To analyze temporal distribution of MES throughout both semi-eversion CEA and CAS procedures and to evaluate changes in mean velocity of blood flow through the ipsilateral middle cerebral artery (MCA).

Method

Thirty-three procedures (17 CEA and 16 CAS) were prospectively monitored using TCD and the data were related to three different stages of surgery (pre-cerebral protection, during cerebral protection and post-cerebral protection). Chi-square, Mann-Whitney, ANOVA and contrast tests were used for statistical analysis.

Results

The MES were uniformly distributed in the CEA group, but not in the CAS group (p = 0.208). The number of MES was higher in the CAS group in all stages. The average flow in the MCA was similarly lower in both groups during the protection stage.

Conclusion

CEA provoked a lower incidence of MES per procedure than CAS in all stages. The behavior of the averages of the mean of blood flow through the MCA was similar in both groups.

Perioperative and follow-up results in carotid artery stenting with contralateral carotid occlusion

PURPOSE

Contralateral carotid occlusion (CCO) increases the risk of carotid endarterectomy (CEA). We determined the outcome of carotid angioplasty and stenting (CAS), an alternative to CEA, in the setting of CCO through an independent analysis of imaging and clinical outcome.

MATERIALS AND METHODS

Medical records of 26 consecutive patients with CCO who underwent CAS by a single operator using the same procedural protocol (with distal protection and closed-cell stents) were retrospectively evaluated. National Institutes of Health Stroke Scale (NIHSS) and Modified Rankin Scale (mRS) scores before and after CAS, periprocedural complications, and the restenosis rate were analyzed by independent stroke neurologists who were not involved in the care of the patients.

RESULTS

The median mRS score for the 26 patients was 1 (range 0-5) before and after CAS. All of the patients underwent clinical and imaging follow-up (mean 19.5 ± 14.3 and 11.6 ± 11.2 months, respectively). Thirty-day mortality/permanent morbidity rates were 0 %. One patient had hyperperfusion syndrome and was managed medically without sequelae; however, he had stent occlusion after 30 days, resulting in a decline in his mRS from 4 (preprocedure) to 5. Otherwise, there was no decline in mRS during the post-discharge follow-up.

CONCLUSION

According to an independent analysis of this single-operator series, CAS is safe and effective for the treatment of patients with CCO.

Interventions for Extracranial Carotid Artery Stenosis: An Update

OPINION STATEMENT

Clinical trials demonstrate that stroke risk after the periprocedural period is similar for carotid angioplasty and stenting (CAS) and carotid endarterectomy (CEA), making CAS an acceptable alternative to CEA. However, there tends to be a higher procedural risk of stroke for CAS than for CEA and a potentially higher rate of myocardial infarction in patients undergoing CEA as compared to CAS. Furthermore, lower rates of complications with revascularization and of post-revascularization stroke have been attributed to advances in medical management, improved surgical technique, and new devices. We discuss identifying patients who may have higher complication rates and recent clinical studies and medical advances directed at reducing stroke risk in patients with extracranial carotid stenosis.

Outcomes of 1000 Carotid Wallstent Implantations

Purpose: To evaluate the outcomes of carotid artery stenting (CAS) with Wallstents in a single-center experience. Methods: From January 2003 to December 2013, 1000 carotid artery lesions were treated with Carotid Wallstents under cerebral protection in 877 patients (mean age 71.7±8 years; 621 men). Indications for treatment were de novo lesions (>70% asymptomatic and >60% symptomatic); stenoses following carotid endarterectomy, radiation, or neck surgery; contralateral laryngeal nerve palsy; and high surgical risk. All the patients underwent duplex ultrasound and clinical evaluation during follow-up; radiography was performed when fracture or stent migration was suggested by ultrasound. Results: Procedure success was achieved in 99.3% of patients. Major and minor 30-day adverse events occurred in 2.1% of patients, including stroke (1.8%: 1.3% minor, 0.5% major), myocardial infarction (0.1%), and death (0.2%). Plaque morphology, nature of stenosis, and symptomatic status were significantly associated with the risk of postoperative neurologic events. Restenosis occurred in 3.2% at a mean 45.5-month follow-up and was significantly associated with diabetes, smoking, symptomatic stenosis, de novo stenosis, and calcification (plaque III/IV). No fracture or migration was registered during follow-up. Conclusion: CAS is a valid method for treating carotid artery disease, with very low rates of major adverse events and neurologic complications. The Carotid Wallstent seems to have excellent results, even with complex plaque morphology, and a low incidence of restenosis at follow-up.

Meta-analysis of the Effect of Stent Design on 30-Day Outcome After Carotid Artery Stenting

Purpose: To review the contemporary literature and analyze whether stent cell design plays a role in 30-day outcomes after carotid artery stenting (CAS). Methods: A systematic review of the literature was undertaken that identified 9 studies comparing the effect of different cell design on 30-day outcome in patients undergoing CAS. Random-effects models were applied to calculate pooled outcome data for mortality and cerebrovascular morbidity. Results are reported as the odds ratio (OR) and 95% confidence interval (CI). Results: The 9 studies included 8018 patients who underwent 8028 CAS procedures (4018 open-cell stents, 4010 closed-cell stents). Six studies were retrospective in design, one was a registry, and only two studies prospectively compared the effect of different cell designs. Nearly half of the patients (3452, 43.1%) were symptomatic, with no significant difference between the closed- and open-cell stent groups (p=0.93). During the first month after the procedure, there were no significant differences in mortality (OR 0.69, 95% CI 0.39 to 1.24, p=0.21), transient ischemic attacks (OR 0.95, 95% CI 0.69 to 1.30, p=0.74), or strokes (OR 1.17, 95% CI 0.83 to 1.66, p=0.37). Conclusion: This meta-analysis showed that 30-day cerebrovascular complications after CAS were not significantly different for the open-cell group in comparison to the closed-cell group. Future prospective clinical trials comparing different free cell areas and other stent design properties are still needed to further investigate whether stent design plays a significant role in the results of carotid stenting.

Evaluation and management of plaque protrusion or thrombus following carotid artery stenting

Carotid artery stenting (CAS) has become a common treatment for carotid artery stenosis. However, complications, such as an ischemic event, can occur with CAS during intra- and post-operative periods. Among these ischemic complications, plaque protrusion into the stent and thrombus on the stent have occurred after CAS. We retrospectively evaluated the temporal profile and treatment options for these complications in 32 consecutive cases who underwent CAS at our hospital between April 2009 and December 2011. The cases were evaluated pre-operatively for risk factors, as well as the plaque morphology and characteristics using computed tomographic angiography (CTA), ultrasound (US), and magnetic resonance imaging (MRI). Post-operatively, lesions were examined by CTA and/or US within 1 week of CAS. As a result, among the 32 cases, 8 experienced plaque protrusions or thrombus, which were treated with medication (anti-platelet and/or anti-coagulation reinforcement). In 7 of these 8 cases, the plaque protrusion or thrombus was stabilized with medication alone. However, the remaining case showed growth and migration of the plaque protrusion or thrombus when treated with medication alone, and therefore, required further endovascular treatment. We identified that a history of symptomatic cerebral infarction and plaques with ulceration were risk factors for plaque protrusion or thrombus formation after CAS, and pre dilatation can decrease the risk of these complications. Medication was effective in most cases of plaque protrusion or thrombus; however, further endovascular treatment was required when medication alone was unsuccessful.