Microembolization during carotid artery stenting in patients with high-risk, lipid-rich plaque. A randomized trial of proximal versus distal cerebral protection

New Ischemic Cerebral Lesions in Postprocedural Magnetic Resonance Imaging in Carotid Artery Stenting Versus Carotid Endarterectomy: A Systematic Review and Meta-Analysis

BACKGROUND

Recent randomized controlled trials (RCTs) have demonstrated similar outcomes in terms of ischemic stroke incidence after carotid endarterectomy (CEA) or carotid artery stenting (CAS) in asymptomatic carotid disease, while CEA seems to be the first option for symptomatic carotid disease. The aim of this meta-analysis is to assess the incidence of silent cerebral microembolization detected by magnetic resonance imaging (MRI) following these procedures.

METHODS

A systematic search was conducted using PubMed, Scopus, and Cochrane databases, including comparative studies involving symptomatic or asymptomatic patients undergoing either CEA or CAS and reporting on new cerebral ischemic lesions in postoperative MRI. The primary outcome was the newly detected cerebral ischemic lesions. Pooled effect estimates for all outcomes were calculated using the random-effects model. Prespecified random effects metaregression and subgroup analysis were conducted to examine the impact of moderator variables on the presence of new cerebral ischemic lesions.

RESULTS

25 studies reporting on a total of 1827 CEA and 1500 CAS interventions fulfilled the eligibility criteria. The incidence of new cerebral ischemic lesions was significantly lower after CEA compared to CAS, regardless of the time of MRI assessment (first 24 hours; OR: 0.33, 95% CI: 0.17-0.64, P < 0.001), (the first 72 hours, OR: 0.25, 95% CI 0.18-0.36, P < 0.001), (generally within a week after the operation; OR: 0.24, 95% CI: 0.17-0.34, P < 0.001). Also, the rate of stroke (OR: 0.38, 95% CI: 0.23-0.63, P < 0.001) and the presence of contralateral new cerebral ischemic lesions (OR: 0.16, 95% CI 0.08-0.32, P < 0.001) were less frequent after CEA. Subgroup analysis based on the study design and the use of embolic protection device during CAS showed consistently lower rates of new lesions after CEA.

CONCLUSIONS

CEA demonstrates significant lower rates of new silent cerebral microembolization, as detected by MRI in postoperative period compared with CAS.

Treatment Strategies for Asymptomatic Carotid Stenosis: A Systematic Review and Bayesian Network Meta-Analysis

BACKGROUND AND OBJECTIVES

To compare the safety and efficacy of carotid endarterectomy (CEA), carotid stenting (CAS), and optimal medical therapy (OMT) in patients with asymptomatic carotid stenosis.

METHODS

Relevant randomized controlled trials were researched with PubMed, Web of Science, and the Cochrane Library databases. Fixed-effects model and random-effects model were used to estimate the relative risks and the hazard ratios (HRs). The results of the probabilistic analysis were reported as surfaces under the cumulative ranking curve.

RESULTS

Eight randomized controlled trials were included. Data from 10 348 patients (CEA: n = 4758; CAS: n = 3919; OMT: n = 1673) were evaluated. Compared with the previous OMT, CEA, CAS, and the current OMT (c-OMT) were all effective in reducing the risk of stroke (CEA: HR, 0.52; CI, 0.40-0.66; CAS: HR, 0.58; CI, 0.42-0.81; c-OMT: HR, 0.40; CI, 0.15-0.94); CEA and CAS reduced the risk of ipsilateral stroke (CEA: HR, 0.41; CI, 0.28-0.59; CAS: HR, 0.51; CI, 0.31-0.84), and the risk of fatal or disabling stroke (CEA: HR, 0.59; CI, 0.43-0.81; CAS: HR, 0.57; CI, 0.34-0.95). Regarding reducing the risk of stroke, only CEA was statistically significant in patients with any degree of stenosis compared with the previous medical treatment (<80%: HR, 0.48; CI, 0.33%-0.70%; 80%-99%: HR, 0.53; CI, 0.38-0.73).

CONCLUSION

In the treatment of asymptomatic carotid stenosis, the perioperative outcomes of CAS were similar to that of CEA; CEA, CAS, and c-OMT shared similar long-term outcomes; and CEA and CAS may be more effective in patients with high levels of asymptomatic stenosis.

Treatment Results of Carotid Artery Stenting with an Open-Cell Stent: Analysis of 734 Consecutive Cases at a Single Center

OBJECTIVE

In carotid artery stenting (CAS) for internal carotid artery stenosis, the stent is often selected according to the plaque properties and arterial tortuosity. In our institute, an open-cell stent is used as the first-line stent regardless of the characteristics of the lesion. This study was performed to examine the outcome of CAS with an open-cell stent as the real-world results.

METHODS

In total, 811 CAS procedures using open-cell stents were performed for internal carotid artery stenosis from April 2002 to December 2019. Of these patients, we excluded those with hyperacute conditions for which CAS was performed within 3 days of onset, those in whom acute mechanical thrombectomy was performed simultaneously with CAS, and those with stenosis due to arterial dissection. Thus, 734 patients were retrospectively analyzed. Perioperative and long-term outcomes and risk factors for perioperative infarction were investigated.

RESULTS

The periprocedural stroke rate and mortality rate were 3.7% (27/734) and 0.4% (3/734), respectively. Low-echoic plaque was a significant risk factor for periprocedural stroke in both univariate (P < 0.03) and multivariate (odds ratio, 2.69; 95% confidence interval, 1.14-6.66; P = 0.02) analyses. Cerebral infarction and high grade restenosis were observed in 15 (2.0%) and 17 (2.3%) patients during a median 50-month follow-up.

CONCLUSIONS

CAS with open-cell stents showed good results in terms of both the postoperative stroke incidence and long-term severe restenosis rate. However, low-echoic plaque was a risk factor for perioperative stroke incidence, which should be considered when deciding on the indication for CAS with an open-cell stent.

Use of an embolic protection device during carotid artery stenting is associated with lower periprocedural risk

OBJECTIVE

To investigate associations between individual embolic protection device (EPD) use and respective center policy with periprocedural outcomes after carotid artery stenting (CAS).

METHODS

This analysis is based on the nationwide German statutory quality assurance database and was funded by Germany's Federal Joint Committee Innovation Fund (G-BA Innovationsfonds, 01VSF19016 ISAR-IQ). According to their policy towards EPD use, hospitals were categorized as routine EPD (>90%), selective EPD (10-90%), or sporadic EPD (<10%) centers. Primary study outcome was in-hospital stroke or death. Univariate and multivariate regression analyses were performed.

RESULTS

Overall, 19 302 patients who had undergone CAS between 2013 and 2016 were included. The highest in-hospital stroke or death rate was found in sporadic EPD centers, followed by selective and routine EPD centers (3.1% vs 2.9% vs 1.8%; P<0.001). Across the whole cohort, EPD use was associated with a lower in-hospital stroke or death rate (OR=0.60; 95% CI 0.50 to 0.72). In the multivariate regression analysis, EPD use was independently associated with a lower in-hospital stroke rate (aOR=0.66; 95% CI 0.46 to 0.94). Regarding center policy, routine EPD centers showed a significantly lower in-hospital mortality compared with sporadic EPD centers (aOR=0.44; 95% CI 0.22 to 0.88).

CONCLUSIONS

In a contemporary real-world cohort with low risk of selection bias, EPD use was associated with a lower in-hospital risk of stroke. A center policy of routine EPD use was associated with lower mortality. These data support routine use of EPD during CAS to enhance patient safety.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Evaluation of Robotic-Assisted Carotid Artery Stenting in a Virtual Model Using Motion-Based Performance Metrics

PURPOSE

Robotic-assisted carotid artery stenting (CAS) cases have been demonstrated with promising results. However, no quantitative measurements have been made to compare manual with robotic-assisted CAS. This study aims to quantify surgical performance using tool tip kinematic data and metrics of precision during CAS with manual and robotic control in an ex vivo model.

MATERIALS AND METHODS

Transfemoral CAS cases were performed in a high-fidelity endovascular simulator. Participants completed cases with manual and robotic techniques in 2 different carotid anatomies in random order. C-arm angulations, table position, and endovascular devices were standardized. Endovascular tool tip kinematic data were extracted. We calculated the spectral arc length (SPARC), average velocity, and idle time during navigation in the common carotid artery and lesion crossing. Procedural time, fluoroscopy time, movements of the deployed filter wire, precision of stent, and balloon positioning were recorded. Data were analyzed and compared between the 2 modalities.

RESULTS

Ten participants performed 40 CAS cases with a procedural success of 100% and 0% residual stenosis. The median procedural time was significantly higher during the robotic-assisted cases (seconds, median [interquartile range, IQR]: 128 [49.5] and 161.5 [62.5], p=0.02). Fluoroscopy time differed significantly between manual and robotic-assisted procedures (seconds, median [IQR]: 81.5 [32] and 98.5 [39.5], p=0.1). Movement of the deployed filter wire did not show significant difference between manual and robotic interventions (mm, median [IQR]: 13 [10.5] and 12.5 [11], p=0.5). The postdilation balloon exceeded the margin of the stent with a median of 2 [1] mm in both groups. Navigation with robotic assistance showed significantly lower SPARC values (-5.78±3.14 and -8.63±3.98, p=0.04) and higher idle time values (8.92±8.71 and 3.47±3.9, p=0.02) than those performed manually.

CONCLUSIONS

Robotic-assisted and manual CAS cases are comparable in the precision of stent and balloon positioning. Navigation in the carotid artery is associated with smoother motion and higher idle time values. These findings highlight the accuracy and the motion stabilizing capability of the endovascular robotic system.

CLINICAL IMPACT

Robotic assistance in the treatment of peripheral vascular disease is an emerging field and may be a tool for radiation protection and the geographic distribution of endovascular interventions in the future. This preclinical study compares the characteristics of manual and robotic-assisted carotid stenting (CAS). Our results highlight, that robotic-assisted CAS is associated with precise navigation and device positioning, and smoother navigation compared to manual CAS.

Transradial carotid artery stenting using double layer micromesh stent and novel post-dilation balloon with integrated embolic protection

OBJECTIVES

The highest rate of embolization during carotid artery stenting occurs during post-dilation. We evaluated the ability of the Paladin system (Contego Medical, Raleigh, NC), a novel PTA balloon with an integrated 40-ɥm pore filter, to collect microemboli that may pass into the cerebral circulation when used during post-dilation.

METHODS

25 symptomatic patients underwent transradial CAS using the Paladin system in conjunction with the Roadsaver (Terumo Corporation, Tokyo, Japan) micromesh stent. No additional embolic protection was used. The Paladin filters were collected following the procedure and preserved in formalin for histological analysis. The contents were evaluated for particle count and size. Subjects were followed for 30 days and evaluated for major cardiac adverse events (death, stroke and MI). Secondary endpoints included procedure success, device success, access site complications according to EASY score classification, major vascular or ischemic complications at follow up and in-stent restenosis rate evaluated with duplex ultrasound.

RESULTS

Mean age of patients was 68,5 years. Type 2 aortic arch was present in 77 % of patients and type 1 and type 3 in 12 % and 11 % of patients respectively. Procedural and device success was obtained in all cases without complications. The 30-day MAE rate was 0 %. Twenty-three filters underwent histological analysis. Microscopic debris was present in 100 % of filters, and 75 % of particles were less than 100ɥm in size. The mean number of particles per filter was 3352 ± 1567 (IQR 4300-2343), and the mean number of particles between 40-100ɥm per filter was 2499 ± 1240 (IQR 3227-1575).

CONCLUSION

CAS through radial approach can be safely and effectively performed using the IEP technology Paladin device and double-layer micromesh Roadsaver stent. This strategy can simplify the procedure and decrease peri-procedural complications and procedural time.

Safety of Tailored Transfemoral Carotid Artery Stenting for Symptomatic Elderly Patients: A Single Center Observational Study

OBJECTIVE

Transfemoral carotid artery stenting (TFCAS) in symptomatic elderly patients (≥70 years old) may have a high periprocedural stroke rate. This study was performed to examine whether tailored TFCAS for symptomatic elderly patients is as safe as that for symptomatic nonelderly patients.

METHODS

The subjects were 185 patients with symptomatic internal carotid artery stenosis. Tailored TFCAS including postoperative management was performed based on preoperative examinations of vascular anatomy, plaque imaging, platelet aggregation activity, and cerebral hemodynamic impairment. The major 30-day perioperative stroke rates were examined.

RESULTS

The patients included 51 (27.6%) <70 (group Y) and 134 (72.4%) ≥70 (group E) years old. Group E included significantly more cases with an elongated aortic arch, tortuous target lesion, and longer plaques (all P < 0.05). Among all cases, 181 (97.8%) procedures were performed as per preoperative planning. Group E had more frequent use of a proximal embolic protection device and a closed-cell or dual-layer micromesh stent (all P < 0.05). Seven patients (3.8%) had major stroke. Rates of major ischemic stroke (2.0% vs. 3.0%, P = 1.00) and intracranial hemorrhage (2.0% vs. 0.8%, P = 0.48) were low and did not differ significantly between groups Y and E.

CONCLUSIONS

Symptomatic elderly patients have several unfavorable factors. However, tailored TFCAS for each patient based on preoperative examinations in symptomatic elderly patients may be as safe as that in symptomatic nonelderly patients.

Carotid Artery Stenting versus Carotid Endarterectomy in Terms of Neuroprotection DW-MRI Detected and Neuropsychological Assessment Impairment

BACKGROUND

Carotid artery stenting (CAS) versus carotid endarterectomy (CEA) is well issue known, but the purpose of this study is to compare CAS versus CEA in terms of asymptomatic Diffusion-weighted magnetic resonance imaging (DW-MRI) demonstrated microembolic scattering of infarction and neuropsychological assessment impairment.

METHODS

We performed a prospective, observational, cohort study on 211 consecutive carotid revascularizations at our institution. Patients were divided into 2 different cohorts: CEA was performed in n = 116 patients (Group A); CAS was performed in n = 95 (Group B). Adverse events were collected at 30 days and 6 months postoperative. Differences in terms of DW-MRI demonstrated microembolic scattering of infarction were analyzed and considered significative for P ≤ 0.05. Secondary objectives were: major and minor stroke, neuropsychological assessment impairment, death, myocardial infarction (MI).

RESULTS

CEA was associated with a significative decreased rate of asymptomatic DW-MRI demonstrated microembolic scattering of infarction (13.8% vs. 51%; P = 0.0001) and of 6 months neuropsychological assessments impairment (0.8 vs. 7.4) (P = 0.04) in asymptomatic patients. There was no significant difference between 2 groups in terms of comorbidities. Stroke rates were similar at 30 days (1.7% CEA vs. 4.1% CAS) and 6 months (2.6% CEA vs. 5.3% CAS P = 0.32). There were no differences in terms of central neurological events, death, transient ischemic attack, MI between the groups. The composite end point of stroke/death/MI at 6 months postoperatively was 2.6% vs. 6.3% (P = 0.19).

CONCLUSIONS

According to these results, CEA achieved better outcomes compared to patients treated by CAS with distal filter in terms of asymptomatic microembolic event and impairment National Institutes of Health Stroke Scale scale and neuropsychological assessments. Limitations of the study lead to limited conclusions only in the specific population and not generalized. Further, comparative randomized studies are warranted.

Effect of plaque morphological characteristics on the outcomes of carotid artery stenting

Carotid artery stenting (CAS) represents today an accepted option for the treatment of severe carotid artery stenosis. The evolution of materials, techniques, perioperative medical management and patients' selection, has allowed to progressively reduce CAS complications. However, the main drawback of CAS is still represented by the risk of cerebral embolization, that may occur during several steps of the procedure and also in the early postoperative period. Preoperative carotid plaque morphological characteristics may have a great role in determining the risk of embolization during CAS. This review summarizes the current knowledge on carotid plaque characteristics that may influence the risk of complication during CAS. This information may be important for the optimization of CAS patients' selection and adaptation of the materials and techniques.

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

INTRODUCTION

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

Stenting of the Common Carotid Artery Ostium: Balloon Catheter Lifting-Up Technique With a Gooseneck Snare

Endovascular revascularization of a stenotic lesion requires appropriate stent positioning. In particular, stenting of the common carotid artery (CCA) ostium makes it difficult to avoid proptosis into the aorta. Furthermore, the guiding catheter may become unstable during the stenting because of its position under the aortic arch. To resolve these problems, we performed antegrade stenting for a patient with a symptomatic stenotic left CCA ostium that was treated by lifting a balloon-guiding catheter with a gooseneck snare. Our patient was a 74-year-old man who presented to the hospital with main complaints of right hemiparesis and motor aphasia. A left cerebral infarction due to severe stenotic left CCA ostium was diagnosed. A CT perfusion study showed decreased cerebral blood flow in the left hemisphere. Stenting of the stenotic left CCA ostium was performed using an antegrade approach. A balloon-guiding catheter positioned under the aortic arch was inflated and lifted from the right brachiocephalic artery using a gooseneck snare. The guiding catheter was stabilized during stenting. This method is highly effective for stenting CCA ostium.

Procedural embolic protection strategies for carotid artery stenting: current status and future prospects

INTRODUCTION

Carotid artery angioplasty and stenting (CAS) is an established procedure to treat carotid artery stenosis for either primary or secondary prevention of stroke. Randomized clinical trials have shown an increased risk of periprocedural cerebrovascular events with CAS compared with carotid endarterectomy (CEA). Several strategies have been proposed to mitigate this risk, including alternative vascular access site, proximal/distal embolic protection devices, and dual-layer stents, among others.

AREAS COVERED

This review provides a general overview of current embolic protection strategies for CAS. The phases of the procedure which can affect the early risk of stroke and how to reduce it with novel techniques and devices have been discussed.

EXPERT OPINION

Innovations in device technologies have dramatically improved the safety and efficacy of CAS. To minimize the gap with surgery, a thorough, patient-oriented approach should be pursued. Endovascular technologies and techniques should be selected on an individual basis to address unique lesion characteristics and vascular anatomies. Meticulous pre-procedural planning, both clinical and anatomical, is needed to assess the embolic risk of each procedure. Only by having an in-depth understanding of the wide range of available endovascular devices and techniques, the operator will choose the most appropriate strategy to optimize CAS results.

Results of Angioplasty With Double-Layer Mesh Stent and Protection Systems of the Extra- and Intracranial Dissection of Cephalic Arteries

PURPOSE

Although a majority of cervical artery dissections can be managed conservatively, patients presenting with cerebral embolization or significant stenosis require a more aggressive approach. However, complications associated with endovascular repair are quite frequent and optimal interventional technique still remains to be established.

MATERIALS AND METHODS

The aim of this post hoc survey was to analyze results of endovascular treatments for symptomatic dissections of the internal carotid and vertebral arteries, which were performed under protection and with the use of double-layer mesh stents. During endovascular procedure catheters, stents and protection systems were tailored according to the angioarchitecture of dissection, particularly to its location, length and coexisting stenotic or aneurysmatic lesions. We evaluated retrospectively midterm and late results of endovascular treatment of 25 patients presenting with symptomatic dissection of cervical arteries, including 11 patients with dissections of intracranial segments of the internal carotid artery. Follow-ups were scheduled 1, 3 and 6 after the procedure, and then every 6 months. Control computed tomography (CT) or digital subtraction angiography (DSA) arteriographies were performed 1-6 months and 12 months after endovascular repair.

RESULTS

There were no periprocedural major adverse events. All patients completed the 12-month follow-up. There were neither fatalities nor new neurologic adverse events at the 30-day follow-up, and no such adverse events during long-term follow-up. At 12-month follow-up, in all patients, angiographies revealed patent stents, full coverage of lesions by stents and complete thrombotic closure of the pseudoaneurysms.

CONCLUSIONS

A tailored endovascular management of symptomatic dissection of cervical arteries is safe and efficient, also in a long run.

Impact of residual stenosis on clinical outcomes when performing carotid artery stenting without postdilation

OBJECTIVE

Many centers consider postdilation if the final angiography after carotid artery stenting (CAS) shows residual stenosis of >30% to 40%. Postdilation has been demonstrated to potentially increase the risk of developing neurologic events. This study aimed to investigate the safety of CAS without postdilation regardless of the degree of residual stenosis.

METHODS

We retrospectively investigated 191 patients who underwent transfemoral CAS without postdilation intendedly. All cases underwent mild predilation and self-expanding stent implantation. We divided the patients into a residual stenosis of ≥40% group (n = 69 [36.1%]) and a residual stenosis of <40% group (n = 122 [63.9%]) according to their final angiography. We compared the procedural (within 30 days after CAS) and nonprocedural (afterward) adverse cardiovascular events and in-stent restenosis between the two groups. We also investigated the incidence of perioperative hemodynamic depression between the groups and the changes in residual stenosis over the follow-up time.

RESULTS

Patients in the residual stenosis of ≥40% group had a higher preoperative stenosis rate and a greater proportion of severely calcified lesions than those in the <40% group. There was one procedural cardiac death (0.5%), five strokes (2.6%), and four myocardial infarctions (2.1%). A total of 2.9% had stroke or death procedurally in the residual stenosis of ≥40% group and 3.2% in the residual stenosis of <40% group (P > .950). The median nonprocedural follow-up time was 22 months, with a total of six deaths and four strokes. The cumulative 2-year death or stroke rate was 6.2%, with 5.9% in the residual stenosis of ≥40% group versus 6.7% in the residual stenosis of <40% group (P = .507). There were two cases of in-stent restenosis in the residual stenosis of ≥40% group and three in the residual stenosis of <40% group (P = .927). The difference in the peak systolic velocity of the target lesion between groups at 3 months after CAS was no longer present, and residual stenosis stabilized at 10% to 20% at 6 months in both groups. The patients showed an association between increasing hemodynamic depression incidence and residual stenosis in a significantly graded response (P = .021).

CONCLUSIONS

Residual stenosis after carotid stenting without postdilation is not associated with a risk of postoperative adverse events. This study provides evidence for the feasibility of a no postdilation strategy for CAS.

Proximal versus distal protection: dissecting clinical trials

Carotid artery stenting (CAS) is a valid alternative to conventional carotid endarterectomy for treatment of carotid artery stenosis. Distal embolization of atherosclerotic debris causing cerebrovascular accidents during CAS has been the most significant concern limiting widespread application of CAS technology. A variety of embolic protection devices (EPDs) with different mechanism of action, have been designed to minimize the risk of major embolization causing stroke and their use is recommended by current guidelines. Two general types of EPDs are available: proximal protection devices (PPDs) and distal protection devices (DPDs). However, there is no convincing clinical evidence of the clinical superiority of one device over another. This review will examine the different types of available devices and also innovative devices and techniques, including strengths and weaknesses of each, and present the available evidence and rationale for their routine use during CAS.

Transradial/brachial carotid artery stenting with proximal protection: technical instructions, acute results and long-term outcomes

BACKGROUND

The aim of this study was to evaluate the feasibility, safety and efficacy of transradial/brachial (TR/TB) carotid artery stenting (CAS) with proximal cerebral protection (PCP) as a first line of treatment of carotid artery stenosis.

METHODS

Among 556 patients with significant (>50% if symptomatic or >70% if asymptomatic by Doppler US) unilateral, lipid-rich carotid artery stenosis undergoing TR/TB CAS, 137 (24.5%) deemed at high-risk for periprocedural cerebral embolization were scheduled for PCP with Mo.MA Ultra or Mo.MA mono-balloon. In patients with very complex anatomy the standard technique was modified loading the Mo.MA catheter without mandrel on two-wire system (so called 'No MAndrel 2 wire' technique, No.MA2) to increase support and deliverability. Device, technical and procedural successes both acute and at follow-up were the main outcomes.

RESULTS

Mean patients' age was 74±7 years (93% male), 15% were symptomatic and 59.6% owned 'high-surgical-risk' features. Stenosis degree was 85±7% with soft composition in all (by CT-angiography). TR and TB approach were selected in 92 (67%) and 45 (33%) patients, respectively. Target carotid axes were right, left bovine and left non bovine in 55%, 38% and 7% of patients. Procedures were successfully completed in all patients (intention-to-treat basis) with the standard Mo.MA Ultra system in 129 patients and the Mo.MA mono-balloon in 8 patients. No.MA2 technique was succesfully used in 16 patients as 'bailout' and in 27 patients as 'first line'). Device and technical success was 97% (133/137 patients) due to crossover to femoral access in 3 cases, and Mo.MA too short to engage the ECA in 1 patient. The procedural success was 96.7% (131/137, two minor strokes). Procedural time and fluoroscopy time were increased with No.MA2 technique. One major vascular complication occurred, in the TB group, while chronic radial occlusion was detected by Doppler ultrasound in 7/92 patients (7.1%) at 372±163 days of follow-up. The event-free survival was 91% and the stroke rate was 0%.

CONCLUSIONS

TR/TB CAS with proximal protection is a feasible, safe and effective strategy and may be considered a first line strategy in all comer patients.

Absolute and relative contraindications to proximal protection: do they really matter? A case-illustrative approach

Carotid artery stenting (CAS) is an established technique to treat carotid artery stenosis. Favorable results have been reported in different subsets of patients in both acute and long-term settings. Among the CAS periprocedural variables the type of cerebral protection - distal filter and proximal protection - play a pivot role to reduce cerebral embolization. Accumulating evidence is in favor of better performance of proximal protection vs. distal filters. However, the rate of worldwide penetration of this devise is low. Potential reasons include a lengthy list of technical issues that may account for the reluctance of filter-oriented operators to change systems. This paper shows how to identify, treat, and overcome these technical obstacles.

Intolerance to occlusion during carotid artery stenting with proximal protection: causes, mechanisms, treatment and prevention

Periprocedural cerebral microembolization is the most important complication of carotid artery stenting. Among several variables that play a role to reduce this risk, brain protection (proximal vs. distal) plays a pivot role. Data are accumulating in favor of a better performance of proximal vs. distal especially in symptomatic patients and high-risk carotid plaques. A prerequisite for the technique to be safe and effective is the presence of a valid intracranial collateral circulation to compensate for the target vessel hemisphere avoiding patient intolerance. This complication may occur either soon after the common carotid balloon occlusion or slowly developing during the procedure peaking at the stent post-dilation step. While Willis' circle anatomic variants are the most frequent cause of acute intolerance, a mix of anatomic, hemodynamic and patient cerebral condition play a role for the late developing form. Prevention is the best treatment of intolerance through a pre- and procedural imaging with different techniques (CT angiography, NMR angiography, transcranial Doppler assessment, digital subtraction angiography and back pressure monitoring).

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.

Buddy Catheter Technique: A Method of Guiding the Mo.Ma Ultra into a Left Common Carotid Artery That Branches off the Aortic Arch at a Steep Angle

Objective

The Mo.Ma Ultra is an embolic protection device used in carotid artery stenting (CAS). In cases of left internal carotid artery stenosis (ICS) in which the common carotid artery (CCA) branches off the aortic arch at a steep angle, insertion of the Mo.Ma Ultra into the CCA is sometimes difficult. We introduce a "buddy catheter technique" that helps guide the Mo.Ma Ultra into the CCA, with an additional 4 Fr catheter into the external carotid artery.

Case Presentation

An 84-year-old man with left ICS whose CCA also branched off the aortic arch at a steep angle also underwent CAS. The "buddy catheter technique" was used, and the Mo.Ma Ultra was inserted smoothly. The buddy catheter technique displaces the left CCA upward. Displacement straightens the vessels anatomically, and the ledge effect can be prevented by aligning the course of the vessels with the wire. Nevertheless, this technique requires bilateral femoral puncture, and so, complications can occur.

Conclusion

The buddy catheter technique may be considered in cases in which the left CCA branches off the aortic arch at a steep angle.

Carotid Artery Stenting in Patients With Contralateral Carotid Occlusion Using a Combined Protection Method

BACKGROUND AND PURPOSE

Carotid artery stenting has become widespread as a revascularization method and has increasingly replaced carotid endarterectomy for treating internal carotid artery stenosis with contralateral carotid occlusion. Hence, this study aimed to establish the clinical characteristics and perioperative outcomes of carotid artery stenting for internal carotid artery stenosis in patients with contralateral carotid occlusion using a combined protection method.

METHODS

This retrospective single-center study assessed 218 patients with internal carotid artery stenosis who underwent carotid artery stenting using the dual protection (simultaneous flow reversal and distal filter) and blood aspiration method. We distinguished 2 patient groups: contralateral carotid occlusion (n = 11) and no contralateral carotid occlusion (n = 207). We evaluated the patients' characteristics, intraoperative transient neurological symptoms, hypotension, bradycardia, major adverse events (major stroke, myocardial infarction, and death within 90 days), minor stroke, hyperintensities on diffusion-weighted images after carotid artery stenting, captured visible debris, and restenosis.

RESULTS

In this cohort, 5% of patients with internal carotid artery stenosis had contralateral carotid occlusion. No statistically significant differences in patient characteristics existed between the groups. The success rate of carotid artery stenting was 100%. There were no statistically significant differences in intraoperative complications, postoperative major adverse events, or other outcomes between both groups.

CONCLUSIONS

In this cohort, carotid artery stenting using dual protection combined with blood aspiration was safe and effective in preventing distal embolism in patients with internal carotid artery stenosis and contralateral carotid occlusion.

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.

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

OBJECTIVES

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

In Silico Hemodynamics and Filtering Evaluation of a Commercial Embolic Protection Device

During the last years, several kinds of Embolic Protection Devices (EPD) have been developed, with the aim of minimizing complication caused by thrombi generated during Carotid Artery Stenting (CAS). These devices are capable of capturing small particles generated during the intervention, avoiding cerebral stroke and improving the outcomes of the surgery. However, they have associated complications, like the increase on flow resistance associated by their use or the lack of knowledge on their actual filtration efficiency for thrombi of low size. Current work proposes a validated computational methodology in order to predict the hemodynamic features and filtering efficiency of a commercial EPD. It will be observed how Computational Fluid Dynamics predicts pressure drop with fair agreement with the experimental measurements. Finally, this work analyzes the filtration efficiency and the influence of the distribution of injected particles on this parameter. The capabilities of the filter for retaining particles of diameter below the pore size is, additionally, discussed.

Addition of common carotid intervention increases the risk of stroke and death after carotid artery stenting for asymptomatic patients

BACKGROUND

A recent review of Vascular Study Group of New England data suggested that simultaneous endovascular treatment of tandem carotid lesions (TCAL: common carotid artery + internal carotid artery) is associated with a fourfold increase in perioperative neurologic events and death. However, given the small cohort, the effect of symptomatic status could not be evaluated. This study sought to determine the risk of simultaneous TCAL stenting in cohorts stratified by symptom status.

METHODS

Vascular Quality Initiative data (2005-2020) were queried for carotid stenting procedures (CAS). Emergent and bilateral procedures, patients with prior ipsilateral CAS, internal carotid artery lesions with stenosis <50%, and hybrid transcarotid procedures were excluded. The cohort was stratified by symptomatic status. The primary outcome was the composite of perioperative stroke and death. Predictors of stroke/death were determined with multivariable logistic regression for symptomatic and asymptomatic patients with TCAL forced into the models.

RESULTS

There were 18,886 carotid arteries stented (18,441 patients): 18,077 (96%) with isolated carotid artery lesions and 809 (4%) with TCAL. Mean age was 70.0 ± 9.7. Symptomatic lesions were present in 58.9% of cases (isolated carotid artery lesions: 59.1% vs TCAL: 52.5%; P < .001). More TCAL arteries had a prior carotid endarterectomy (38.3% vs 23.8%; P < .001). TCAL had a higher perioperative stroke/death (3.4% vs 1.8%; P = .026) for asymptomatic lesions, but not symptomatic lesions (4.5% vs 3.7%; P = .41). TCAL were independently associated with stroke/death in asymptomatic patients (odds ratio, 1.85; 95% confidence interval, 1.03-3.33; P = .039) but not symptomatic patients (odds ratio, 1.22; 95% confidence interval, 0.76-1.97; P = .42).

CONCLUSIONS

The addition of endovascular treatment of common carotid artery lesions with CAS is associated with almost double the risk of perioperative stroke/death in asymptomatic patients and should be avoided if possible. Treatment of TCAL is not associated with an increased risk of stroke/death for symptomatic lesions.

Mid-term and late results of endovascular treatment for symptomatic carotid artery stenosis under proximal protection

Introduction

Although filters are still preferred during carotid stenting, proximal protection systems (PPS) are increasingly used during these procedures. PPS seem to be safer than distal systems, especially in symptomatic patients, but evidence supporting their use is limited.

Aim

This was a post hoc survey with 30-day mid-term and long-term follow up, which was aimed at assessment of the safety and efficacy of stenting of the internal carotid artery under PPS in symptomatic patients.

Material and methods

We analysed the results of stenting in 120 symptomatic patients presenting with at least 60% stenosis. Patients were aged 67.9 ±9.8 years, and 12 patients were older than 80 years. An occlusion of contralateral artery was found in 5 patients and bilateral stenosis in 26 patients. The primary endpoint of this study was the proportion of patients who had new neurological events, including transient ischemic attack and minor or major stroke in 30-day follow-up. The secondary endpoint was a composite of technical and clinical success. During long-term follow-up we assessed new neurological events and stenoses of implanted stents.

Results

The incidence of new neurological events during 30-day follow-up was 0.8%. The rate of technical success defined by secondary endpoint was 100%. Mean internal carotid artery stenosis before and after stent implantation was 93.8 ±9% and 8.4 ±6.3%, respectively (p < 0.001). Procedural success was achieved in all cases. During long-term follow-up there were two (1.7%) asymptomatic in-stent stenoses and no (0%) new neurological events.

Conclusions

Endovascular management of symptomatic carotid stenosis under PPS is safe, feasible, and appears to be a good alternative to surgical endarterectomy.

Analysis of postprocedural microembolic infarctions and global oxygen extraction fraction during balloon-protected carotid artery stenting: Preliminary study

Background:

Atherosclerotic carotid stenosis with impaired cerebral perfusion is a risk factor for cerebral ischemia. In major carotid stenoocclusive diseases, increased oxygen extraction fraction (OEF) is associated with ischemic stroke. Balloon-protected carotid artery stenting (CAS) is valuable for high-grade carotid stenosis. However, while balloon-protected CAS can effectively reduce the occurrence of ischemic complications by blocking carotid flow, cerebral hypoperfusion may result in simultaneous cerebral ischemia. We sought to evaluate whether increased OEF during balloon-protected CAS can predict postprocedural microembolic infarction (MI).

Methods:

Eighty-four patients who underwent balloon-protected CAS were enrolled. Initial, intraprocedural, and postprocedural OEFs were calculated from the cerebral arteriovenous oxygen differences obtained from blood sampled just before the temporary occlusion and reperfusion of the internal carotid artery during and after the procedure. MIs were evaluated by diffusion-weighted imaging (DWI). Patients were classified into two groups based on the presence or absence of new MIs, and the relationship between the OEF and postprocedural MIs was analyzed.

Results:

New DWI-positive lesions were found in 37 cases (44.0%). Age, signal intensity ratio (SIR) of carotid plaque on T1-weighted black blood magnetic resonance imaging, and intraprocedural OEF were significantly higher in the DWI-positive group. The high SIR and intraprocedural OEF were significantly associated with the development of postprocedural MIs in multivariate analysis. MIs were correlated with the increase in OEF.

Conclusion:

Increased intraprocedural OEF, obtained by blood sampling during balloon-protected CAS, could predict the incidence of postprocedural MIs. Patients with carotid stenosis could be hemodynamically compromised by carotid flow blockage during balloon-protected CAS.

Common carotid artery endovascular clamping for neuroprotection during carotid stenting: Flow-gate system as an innovative treatment approach

OBJECTIVES

We here report our clinical experience in CAS management through common carotid artery endovascular clamping with FlowGate2 system.

METHODS

Forty-five patients were enrolled with de novo asymptomatic internal carotid artery stenosis ≥70%. Cerebral protection during the stenting procedure was achieved using a unique endovascular clamping technique developed in our Institution which includes: (a) the occlusion of the common carotid artery only, through inflatable balloons integrated in the FlowGate2 Balloon Guide Catheter system; (b) flow inversion connecting catheter to 16 G blood cannula previously placed in arm vein; (c) after the placement of the stent, the flow inversion is maintained for 30 s to allow debris washout. The related primary end-point was the rate of Diffusion-weighted imaging magnetic resonance (DWI) micro-embolic scattering of infarction. The patient's clinical and the neurological status were assessed prior, during and after intervention, at discharge.

RESULTS

Transient clamping intolerance was observed in two patients (2/45; 4%). One minor stroke (1/45; 2%) occurred 8 hr the procedure with DWI ipsilateral micro-embolic lesions. No major strokes or deaths were observed at 3 months follow-up. DWI demonstrated ipsilateral micro-embolic scattering of infarction, in one asymptomatic patient. In all patients, no worst changes in NIHSS scale assessment were recorded at 1, 3, and 6 months.

CONCLUSIONS

Our data confirmed the efficacy of FlowGate2 in terms of neuroprotection during CAS. To our knowledge, these are the first published data on this innovative approach developed in our institution. A large controlled trial is ongoing to confirm preliminary evidences.

Double Filtration During Carotid Artery Stenting Using a Novel Post-Dilation Balloon With Integrated Embolic Protection

OBJECTIVES

This study evaluated the safety and performance of the Paladin System, a novel angioplasty balloon with an integrated embolic protection filter designed to increase embolic protection during post-dilation.

BACKGROUND

The risk of major adverse events during carotid artery stenting (CAS) is equivalent to carotid endarterectomy. However, the risk of minor stroke remains higher with CAS. Much of this risk occurs during post-stent dilation.

METHODS

A total of 106 patients were enrolled in 5 centers in Germany. The study's primary endpoint was all-cause death, myocardial infarction, and stroke at 30 days post-procedure. Pre- and post-procedural diffusion-weighted magnetic resonance imaging evaluated new ischemic lesions in 30 subjects. Filter histomorphometric analysis was performed in 23 patients. Retrospective analyses compared outcome rates to historical controls.

RESULTS

Device and procedural success rates were 100%. The combined major adverse event rate (death, myocardial infarction, and stroke) at discharge and at 30 days was 0% and 1.0%, respectively. The single adverse event was a stroke, which occurred at day 12 and was believed unrelated to the device or procedure. New ischemic lesions were found in 11 (36.7%) patients in the diffusion-weighted magnetic resonance imaging subset. New ipsilateral lesions were seen in 9 (30.0%) patients. Mean lesion volume per patient was 0.010 cm³. Debris was present in all filters, and approximately 90% of captured particles were <100 μm.

CONCLUSIONS

Use of the Paladin System for post-stent dilation during CAS appears safe, and it may effectively decrease the number of embolic particles reaching the brain, which may help reduce the risk of procedure-related stroke. (A Multi-Center Study to Evaluate Acute Safety and Clinical Performance of Paladin® Carotid Post-Dilation Balloon System With Integrated Embolic Protection; NCT02501148).

Carotid, Vertebral, and Brachiocephalic Interventions

Carotid atherosclerosis most frequently manifests in the proximal internal carotid artery and the common carotid artery bifurcations. Subclavian artery atherosclerosis affects the proximal segments with a relatively higher incidence on the left and becomes clinically important in the presence of vertebrobasilar insufficiency or coronary steal. Atherosclerosis of the vertebral artery can lead to posterior circulation stroke. The authors review the major trials on carotid carotid, brachiocephalic and vertebral artery stenosis along with the various available diagnostic and interventional techniques.

Safety of carotid artery stenting for elderly patients with cervical carotid artery stenosis

BACKGROUND

Several recent randomized controlled trials have reported that perioperative complications of carotid artery stenting increase with age, and Japan has the highest proportion of elderly in the world. We retrospectively compared clinical factors, treatment outcomes, and adverse events between younger and elderly carotid artery stenting patients at a single institution in Japan to assess carotid artery stenting safety for the aged population.

METHODS

A total of 150 consecutive patients treated with carotid artery stenting using the dual protection (simultaneous flow reversal and distal filter) and blood aspiration method were enrolled. Patients were classified into an elderly (O) group ≥75 years (54/150, 36.0%) and a younger (Y) group <75 years (96/150, 64%) for comparison of demographics, clinical background, incidence of captured debris during the procedure, outcome, minor stroke, major adverse events (major stroke, myocardial infarction, or death) within 30 days, hyperintense spots on diffusion-weighted images after carotid artery stenting, and postoperative hospitalization days.

RESULTS

The carotid artery stenting procedure was successful in all cases. No major adverse events occurred within 30 days in the Y group, and only one occurred in the O group (P = 0.348). Visible debris was captured in a significantly greater proportion of O group patients than in Y group patients (33/54 (63.5%) vs. 40/96 (42.1%), P = 0.016), but there was no significant difference in the frequency of hyperintense spots on diffusion-weighted images between Y and O groups (23/96 (24.0%) vs. 16/52 (30.8%), P = 0.435).

CONCLUSIONS

Carotid artery stenting using dual protection and blood aspiration is equally safe for younger and elderly patients.

Effect of high-dose strong statin for preventing periprocedural ischemic complications of carotid artery stenting

Statin therapy has been shown to induce carotid atherosclerotic plaque regression and reduce the periprocedural ischemic complications of carotid artery stenting (CAS). This study assessed the safety and usefulness of pretreatment using a high-dose strong statin (HDSS) to reduce the periprocedural ischemic complications of CAS. We analyzed 117 carotid lesions treated by CAS that were evaluated with magnetic resonance imaging (MRI) within 48 h after the procedure. For 67 lesions, an HDSS (rosuvastatin 20 mg or atorvastatin 40 mg daily) were prescribed from at least 14 days before CAS to at least 14 days after procedure (HDSS group). Clinical and angiographic data, as well as in-hospital outcomes, of the HDSS group were retrospectively compared with 50 lesions with conventional treatment without an HDSS (non-HDSS group). There were no significant differences in the baseline clinical and procedural characteristics between the two groups. There was no side effect related to the HDSS. Stroke rates were similar between the two groups (3.0% in HDSS group vs 8.0% in non-HDSS group, p = 0.22). All were minor strokes. Compared to the non-HDSS group, the HDSS group had a lower frequency of new lesions on diffusion-weighted imaging (DWI) with MRI (25.4% vs 44.0%, p = 0.0345). New ipsilateral DWI-positive rate in the HDSS group was significantly lower than in the non-HDSS group (16.4% vs 34.0%, p = 0.0275). Nonipsilateral (contralateral or posterior circulation) DWI-positive rates were similar between the two groups (13.4% vs 20.0%, p = 0.34). Pretreatment with an HDSS might reduce the periprocedural ischemic complications of CAS.

A Case of Carotid Artery Stenting after Aspiration of Thrombus and Unstable Plaque

Objective

There is no established method for carotid artery stenting (CAS) for internal carotid artery stenosis with vulnerable plaque and thrombosis. We report a case in which CAS was performed by aspiration using the Penumbra system for thrombosis that increased in the subacute phase in symptomatic cervical internal carotid artery stenosis.

Case Presentations

A 59-year-old man with a history of lacunar infarction visited the emergency department with weakness in the right upper limb. He was admitted for cerebral infarction in the left corona radiata and basal ganglia. During the course, additional multiple cerebral infarctions developed in the left cerebral hemisphere. The patient was diagnosed with left internal carotid artery stenosis and underwent CAS. As mural thrombus increased compared with preoperative imaging, CAS was performed after thrombus aspiration using the Penumbra system. A large amount of plaque was observed in the aspirated blood.

Conclusion

Thrombus aspiration using the Penumbra system was effective as distal embolic protection during CAS for internal carotid artery stenosis with increased and shape-changing thrombus. The aspirated blood exhibited pathological findings of plaque tissue and thrombus.

Comparison of Embolic Protection with Proximal and Distal Protection Devices: Periprocedural Complications, Clinical Outcomes, and Cerebral Embolic Lesions on Diffusion-Weighted Magnetic Resonance Imaging

OBJECTIVE

Two main types of embolic protection devices have been used during carotid artery stenting (CAS): distal protection devices (DPDs) and proximal protection devices (PPDs). We compared the complications, clinical outcomes, and new ischemic lesions on diffusion-weighted magnetic resonance imaging (DWI) studies between patients who had undergone CAS using a DPD or PPD.

METHODS

We performed a retrospective review of the data from patients who had undergone CAS from March 2010 to January 2016. The periprocedural and 30-day adverse events and new ischemic lesions on DWI studies after CAS were evaluated.

RESULTS

CAS was performed in 103 patients (DPD, n = 60; PPD, n = 43). The number of patients with new ischemic lesions was greater in the DPD than in the PPD group (78% vs. 56%; P = 0.014). Most lesions (>90%) were tiny (≤3 mm), and the average number of new tiny lesions per patient was significantly greater in the DPD than in the PPD group (mean, 9.6 vs. 4.0; P = 0.008). No significant differences in the periprocedural or 30-day adverse rates were noted between the 2 groups. Intolerance during the procedure occurred in 5 patients (12%) in the PPD group, 4 of whom had poor collateral circulation.

CONCLUSIONS

The number of new ischemic lesions per patient and the incidence of ischemic lesions found on DWI were significantly greater in the DPD than in the PPD group. The lack of differences in the periprocedural and 30-day adverse rates between the 2 groups suggests that cerebral microemboli might not be associated with the clinical outcomes. For patients with poor collateral status, DPDs should be used preferentially to avoid the neurologic compromise associated with PPDs.

Risk factors associated with microembolization after carotid intervention

BACKGROUND

Microembolization after carotid artery stenting (CAS) and carotid endarterectomy (CEA) has been documented and may confer risk for neurocognitive impairment. Patients undergoing stenting are known to be at higher risk for microembolization. In this prospective cohort study, we compare the microembolization rates for patients undergoing CAS and CEA and perioperative characteristics that may be associated with microembolization.

METHODS

Patients undergoing CAS and CEA were prospectively recruited under local institutional review board approval from an academic medical center. All patients also received 3T brain magnetic resonance imaging with a diffusion-weighted imaging sequence preoperatively and within 24 hours postoperatively to identify procedure-related new embolic lesions. Preoperative, postoperative, procedural factors, and plaque characteristics were collected. Factors were tested for statistical significance with logistic regression.

RESULTS

A total of 202 patients were enrolled in the study. There were 107 patients who underwent CAS and 95 underwent CEA. Patients undergoing CAS were more likely to have microemboli than patients undergoing CEA (78% vs 27%; P < .0001). For patients undergoing CAS, patency of the external carotid artery (odds ratio [OR], 11.4; 95% confidence interval [CI], 1.11-117.6; P = .04), lesion calcification (OR, 5.68; 95% CI, 1.12-28.79; P = .04), and lesion length (OR, 0.29; 95% CI, 0.08-1.01; P = .05) were all found to be independent risk factors for perioperative embolization. These factors did not confer increased risk to patients undergoing CEA.

CONCLUSIONS

Patients undergoing CAS are at higher risk for perioperative embolization. The risk for perioperative embolization is related to the length of the lesion and calcification. Identifying the preoperative risk factors may help to guide patient selection and, thereby, reduce embolization-related neurocognitive impairment.

National Patterns of Carotid Revascularization Before and After the Carotid Revascularization Endarterectomy vs Stenting Trial (CREST)

Importance

The Carotid Revascularization Endarterectomy vs Stenting Trial (CREST) showed greater safety of carotid artery stenting (CAS) in patients younger than 70 years and carotid endarterectomy (CEA) in those older than 70 years. It is unknown how the result of CREST has influenced carotid revascularization choices in the United States.

Objective

To evaluate national patterns in CAS performance in patients older than 70 years in the post-CREST (2011-2014) compared with the pre-CREST (2007-2010) era.

Design, Setting, and Participants

All adults older than 70 years undergoing carotid revascularization in the United States from 2007 to 2014 were retrospectively identified from the 2007-2014 National Inpatient Sample using International Classification of Disease, Ninth Revision procedural codes. From 61 324 882 unweighted hospitalizations contained in the 2007-2014 National Inpatient Sample, 494 733 weighted carotid revascularization admissions in adults older than 70 years were identified using International Classification of Disease, Ninth Revision procedural codes.

Main Outcomes and Measures

The proportion of CAS performed in all age groups over time was estimated and multivariable-adjusted models were used to compare the odds of receiving CAS in the pre-CREST with those in the post-CREST era in adults older than 70 years.

Results

A total of 41.8% of all patients were women, and mean (SE) age at presentation was 78.1 (0.03) years. A total of 16.3% of CAS and 10.1% of CEA procedures were performed in patients with symptomatic stenosis. The proportion of patients older than 70 years receiving CAS increased from 11.9% in the pre-CREST to 13.8% in the post-CREST era (P = .005). In multivariable models, the odds of receiving CAS increased by 13% in all patients older than 70 years in the post-CREST compared with the pre-CREST period (odds ratio [OR], 1.13, 95% CI, 1.00-1.28, P = .04), including symptomatic women (OR, 1.31, 1.05-1.65, P = .02). Symptomatic stenosis (OR 1.39; 95% CI, 1.27-1.52; P < .001), congestive heart failure (OR, 1.48; 95% CI, 1.35-1.63; P < .001), and peripheral vascular disease (OR, 1.35; 95% CI, 1.27-1.43; P < .001) were associated with higher odds of CAS; comorbid hypertension (OR, 0.70; 95% CI, 0.66-0.74; P < .001), smoking (OR, 0.84; 95% CI, 0.78-0.91; P < .001), and weekend admission (OR, 0.77; 95% CI, 0.68-0.88; P < .001) were negatively associated with the odds of CAS.

Conclusions and Relevance

Despite concerns for higher periprocedural complications with CAS in elderly patients, the odds of CAS increased in the post-CREST compared with pre-CREST era in patients older than 70 years, including symptomatic women.

Efficacy of post-dilatation during carotid artery stenting for unstable plaque using closed-cell design stent evaluated by optical coherence tomography

BACKGROUND AND PURPOSE

This study aimed to use optical coherence tomography (OCT) to evaluate the efficacy of post-dilatation (PD) after stent placement for unstable plaques during carotid artery stenting (CAS) using closed-cell design stent.

MATERIALS AND METHODS

Twelve unstable carotid plaque lesions diagnosed by magnetic resonance imaging were evaluated by OCT during CAS. Pre-procedural minimum lumen diameter and area were 1.5 ± 0.6 mm and 2.6 ± 1.6 mm², respectively. The lesion was pre-dilated with balloon catheters (diameter 4.8 ± 0.3 mm), and closed-cell stent was deployed. PD was performed with balloon catheters of the same size as those used for pre-dilatation. Minimum lumen diameter/area and in-stent tissue prolapse volume after stent placement and after PD were calculated by 2-dimensional cross section images. The number of the stent cells showing tissue prolapse and malapposition after stent-placement and after PD were calculated by 3-dimensional analysis.

RESULTS

Compared to after stent placement, in-stent tissue prolapse volume (0.18 ± 0.10 to 0.22 ± 0.07 mm²/slice, P < 0.01), number of stent cells with any tissue prolapse (12.7 ± 8.2 to 21.0 ± 11.8%, P < 0.001) were significantly increased after PD; stent cells with ≥ 500-µm tissue prolapse (1.6 ± 1.1 to 0.7 ± 0.8%, P < 0.01) and stent malapposition (17.4 ± 7.2 to 14.0 ± 6.3%, P < 0.01) were significantly decreased.

CONCLUSIONS

PD after carotid stent placement caused increase in in-stent tissue prolapse volume and small tissue prolapse, however, the in-stent large tissue prolapse decreased, as the in-stent tissue prolapse may have been crushed into debris.

Real-world Experience of Carotid Artery Stenting in Japan: Analysis of 8458 Cases from the JR-NET3 Nationwide Retrospective Multi-center Registries

We aimed to clarify the outcomes of carotid artery stenting (CAS) in the Japanese population. For this purpose, we reviewed data from the Japanese Registry of NeuroEndovascular Therapy 3 (JR-NET3), a retrospective, nation-wide, multi-center, observational study of neuroendovascular treatments in Japan. Of the 9207 patients who underwent CAS between January 2010 and December 2014, 8458 satisfied the inclusion criteria for our analysis. The outcome statistics of this JR-NET3 cohort were compared to those of JR-NET1 and 2 cohorts fitting the same inclusion criteria. Of the 8458 JR-NET3 patients analyzed, 8042 (95.1%) were treated by surgeons with board certification from the Japanese Society for NeuroEndovascular Therapy. Technical success was achieved in 8417 patients (99.5%), whereas 198 patients (2.3%) had clinically significant complications (CSCs). These findings mirrored those obtained for the JR-NET1 and 2 cohorts. On multivariate analysis, risk factors for CAS-associated CSC included symptomatic lesion [odds ratio (OR), 1.91; 95% confidence interval (CI), 1.23-3.00; P = 0.003] and hypoechoic lesion on carotid artery ultrasound (OR, 1.85; 95% CI, 1.21-2.84; P = 0.005), whereas use of closed-cell stents was a predictor of better outcome (OR, 0.53; 95% CI, 0.35-0.79; P = 0.002). The findings of JR-NET3 reflect good outcomes of CAS, but non-modifiable risk factors reflecting lesion characteristics remain of concern. Using closed-cell stents is advisable. Technological advances such as the introduction of new materials may help further improve CAS outcomes in Japanese patients.

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.

Carotid Artery Stenting Without Embolic Protection Device: A Single-Center Experience

PURPOSE

To evaluate the safety and efficacy of carotid artery stenting (CAS) performed without an embolic protection device (EPD) in a selected group of asymptomatic patients with primary internal carotid artery (ICA) stenosis or restenosis after carotid endarterectomy (CEA).

MATERIALS AND METHODS

Between May 2015 and May 2018, 77 patients (mean age 77 years; 60 men) underwent CAS without any embolic protection device. Forty-seven (61%) patients had primary ICA stenosis and were excluded from CEA because of high surgical risk; the other 30 (39%) patients had post-CEA restenosis (n=26) or a distal ICA flap after eversion CEA (n=4). The mean ICA stenosis was 82%. All procedures were performed from a femoral artery access. Pre- and/or postdilation were used in 64 patients. The primary outcome was the incidence of major complications (death, stroke, or myocardial infarction) during the procedure and within 30 days; the secondary outcome was the incidence of restenosis in follow-up.

RESULTS

No relevant bradycardia was encountered during CAS. The combined rate of stroke, death, or myocardial infarction at 30 days was 1.3%. The single stroke patient recovered fully after 2 months. Over a follow-up that ranged to 3 years (mean 24±18 months), no further neurological events were recorded. One (1.3%) patient had a >70% restenosis after 6 months; the lesion was dilated, successfully restoring the lumen contour.

CONCLUSION

In our series, endovascular treatment of carotid stenosis without the use of protection devices in patients with primary stenosis or postsurgical restenosis can achieve satisfactory safety and efficacy outcomes. The choice of performing CAS without using EPDs should follow a tailored approach based on the appropriate patient anatomy and specific clinical parameters to minimize neurological complications.