Proximal embolic protection versus distal filter protection versus combined protection in carotid artery stenting: A systematic review and meta-analysis

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.

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.

CIRSE Standards of Practice on Carotid Artery Stenting

BACKGROUND

Carotid artery stenting has been used effectively to treat internal carotid artery stenosis since 1989 (Mathias et al. in World J Surg. 25(3):328-34, 2001), with refined and expanded techniques and tools presently delivering outstanding results in percutaneous endoluminal treatment of carotid artery stenosis.

PURPOSE

This CIRSE Standards of Practice document is directed at interventional radiologists and details the guidelines for carotid artery stenting, as well as the different implementation techniques. In addition to updating all previously published material on the different clinical indications, it will provide all technical details reflective of European practice for carotid artery stenting. CIRSE Standards of Practice documents do not aim to implement a standard of clinical patient care, but rather to provide a realistic strategy and best practices for the execution of this procedure.

METHODS

The writing group, which was established by the CIRSE Standards of Practice Committee, consisted of five clinicians with internationally recognised expertise in carotid artery stenting procedures. The writing group reviewed existing literature on carotid artery stenting procedures, performing a pragmatic evidence search using PubMed to select relevant publications in the English language from 2006 to 2022.

RESULTS

Carotid artery stenting has an established role in the management of internal carotid artery stenosis; this Standards of Practice document provides up-to-date recommendations for its safe performance.

Safety and Risk Factors of Carotid Artery Stenting with Simple Distal Filter Protection: A Single-Center Retrospective Study

Objective

Carotid artery stenting embolic protection devices offer various options, among which distal filter protection is the simplest and easiest to handle. However, compared to balloon protection systems, distal filter protection has more embolic complications. Therefore, we explored the risk factors of distal filter protection, intending to achieve a safer carotid artery stenting. This retrospective study was conducted to identify prognostic factors following carotid artery stenting with only distal filter protection from July 2010 to June 2021.

Methods

Information on patient background, procedures and devices, and complications was collected using medical records. The data pertaining to 187 patients were analyzed after excluding the data of patients in whom other protection devices (8 cases) were used. We used FilterWire EZ as the first choice for embolic protection device and SpiderFX when the patients had difficult-to-cross lesions.

Results

The patients' mean age was 71.9 ± 6.9 years, and 72 (38.5%) were symptomatic. Symptomatic (odds ratio: 2.02, p = 0.035) and difficult-to-cross lesions (odds ratio: 3.63, p = 0.0013) were factors independently associated with symptomatic complications.

Conclusion

This retrospective single-center study established independent prognostic factors for carotid artery stenting with distal filter protection. For patients with symptomatic lesions and severe stenosis or bends that are difficult to pass through, it is necessary to be careful when performing carotid artery stenting with distal filter protection.

Embolic protection devices for carotid artery stenting: A network meta-analysis

OBJECTIVES

Carotid artery stenting (CAS) is an alternative treatment option for patients at high risk for carotid endarterectomy (CEA) but has been correlated with increased risk for distal embolization and periprocedural stroke despite the use of adjunctive embolic protection devices (EPD). This study compared four types of EPDs and their intra and periprocedural related complications.

METHODS

A systematic review of the literature was conducted in PubMed/Medline to identify studies that investigated the outcomes of CAS with adjuvant use of EPDs, including Proximal Balloon (PB), Distal Filter (DF), and Distal Balloon (DB) strategy. Continuous flow reversal performed via transcarotid approach by a commercially available device as an embolic protection strategy was intentionally excluded based on its distinct procedural characteristics and lack of availability outside of the United States. This network meta-analysis was performed according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines.

RESULTS

Overall, 45 studies, consisting of 7600 participants satisfied the predetermined search criteria and were included in this network meta-analysis. Overall, 13 studies provided data regarding the number of patients with new ischemic lesions detected in the DW-MRI. DF (OR: 3.15; 95% CI: 1.54-6.44; p = 0.002) and DB (OR: 2.28; 95% CI: 1.58-3.29; p < 0.001) were associated with higher odds of new ischemic lesions compared to PB on DW-MRI imaging. No statistical difference was identified between DB versus DF groups (OR: 1.48; 95% CI: 0.73-2.59; p = 0.317). 36 and 27 studies reported on periprocedural stroke and transient ischemic attack (TIA) rates, respectively, showing similar odds of neurologic adverse events between all three groups.

CONCLUSIONS

PB deployment during CAS is superior to DF and DB in preventing distal embolization phenomena. However, no statistically significant difference in TIA and stroke rate was found among any of the analyzed EPD groups. Further research is warranted to investigate the association of embolic phenomena on imaging after CAS with clinically significant neurologic deficits.

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.

Mobile Atheroma in the Left Internal Carotid Artery: A Case of Impending Doom!

A 69-year-old male presented for evaluation of a carotid bruit. Carotid ultrasound demonstrated the unique finding of a large, highly mobile atheroma in the proximal left internal carotid artery. The presence of a mobile atheroma confers an even higher risk of stroke, so this presentation posed a dilemma in terms of endovascular versus open surgical management strategies. In patients with carotid artery disease, the risk of stroke is related to plaque rupture and distal embolization. The patient underwent successful carotid stenting without periprocedural complications. Our case reports the unusual occurrence of a highly mobile atheroma as the initial presentation of carotid artery disease treated safely with percutaneous carotid artery stenting.

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.

Carotid Artery Stenting Using the Walrus Balloon Guide Catheter With Flow Reversal for Proximal Embolic Protection: Technical Description and Single-Center Case Series

BACKGROUND

The use of modern transfemoral balloon guide catheters (BGC) for flow reversal during carotid artery stenting is scarcely described in the literature but represents a promising and efficient technique for embolic protection.

OBJECTIVE

To describe a flow-reversal technique using the Walrus BGC (Q'Apel Medical Inc.) and report our center's experience.

METHODS

We performed a retrospective analysis of data for consecutive patients aged 18 years or older who underwent elective carotid artery stenting with the use of flow reversal through the Walrus BGC between July 2020 and September 2021. Patient characteristics, procedural details, and clinical follow-up were evaluated.

RESULTS

One hundred and five patients were included. Mean age was 69.8 ± 9.4 years, and 36 (34.3%) were women. The most common comorbidities were hyperlipidemia (76.2%) and hypertension (57.1%). Fifty-nine (56.2%) patients were symptomatic. Ninety-nine (94.3%) patients had stenosis ≥70%. Contralateral stenosis ≥50% was present in 44 patients (41.9%). Distal filters were used after flow reversal was established in 90 patients (85.7%). Angioplasty was performed in 85 patients (80.9%). Stenting was successful in 100% of cases. No periprocedural transient ischemic attacks (TIAs) or strokes occurred. Stroke occurred in 2 patients (1.9%) during the 30-day follow-up period, resulting in 1 (0.9%) death.

CONCLUSION

In our experience, this technique was safe, feasible, and efficient, with 100% technical success and no periprocedural thromboembolic complications. More extensive studies are needed to establish the role of proximal protection with flow reversal using modern BGCs.

Not a trifecta: complementary use of carotid artery revascularization techniques in the era of hybrid neurosurgery

OBJECTIVE

Carotid stenosis is currently treated by carotid endarterectomy (CEA), carotid artery stenting (CAS), or transcarotid artery revascularization (TCAR). This study sought to add to the literature by providing real-world data comparing the safety and effectiveness associated with the performance of these carotid revascularization techniques by dual-trained neurosurgeons.

METHODS

The authors performed a retrospective review of carotid stenosis databases at two US centers. Patients treated by CEA, transfemoral CAS, or TCAR for atherosclerotic carotid artery disease were included. Clinical outcomes were compared at 30 days after the procedure.

RESULTS

Seven hundred eighty patients were included (583 with CAS, 165 with CEA, and 32 with TCAR). Overall, 486 patients (62.3%) were men, and 393 (50.4%) had left-sided carotid stenosis. Most patients (n = 617, 79.1%) had symptomatic disease. Among the three treatment groups, there were no statistically significant differences with respect to 30-day ischemic events (CAS 3.8%, CEA 1.8%, TCAR 6.3%; p = 0.267) or 30-day mortality rates (CAS 3.6%, CEA 2.4%, TCAR 3.1%; p = 0.857). Male sex had significantly lower odds of 30-day transient ischemic attack (TIA) or stroke in both univariable (p = 0.024) and multivariable (p = 0.023) regression models. Increasing age had significantly higher odds of 30-day mortality on univariable (p = 0.006) and multivariable (p = 0.003) regression. Patients with the occurrence of 30-day TIA or stroke also had significantly higher odds of 30-day mortality on univariable (p < 0.001) and multivariable (p < 0.001) regression.

CONCLUSIONS

This real-world experience reflects the current practice of hybrid neurosurgery at two high-volume tertiary care centers and suggests that all three treatment modalities have comparable safety and effectiveness if patients are properly selected.

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.

From surgical clamping to endovascular flow arrest/reversal: the concept behind the system

Carotid artery lesions are frequently composed of friable, thrombotic, ulcerated and/or hemorrhagic materials which can embolize during surgical or endovascular interventions. The use of embolic protection devices (EPD) during carotid angioplasty and stenting (CAS) has been proven to be associated with a reduction of the embolic load. Many studies indicate that the clinical results of CAS are comparable with the best surgical series, when EPD are routinely applied. The proximal EPD work by interrupting or reversing the blood flow in the common carotid artery/internal carotid artery (CCA/ICA). Once established the endovascular flow arrest/reversal, these systems have the advantages of promoting a protected crossing of the lesion and blocking both macro-emboli and micro-emboli. Moreover, proximal neuroprotection implies no manipulation of the device in the distal ICA, neither during device deployment nor during device retrieval, and reduces the risk of arterial spasm, dissection, or intimal damage. The choice between transfemoral and transcervical proximal EPD should account for different factors: local availability, operator expertise, and patient characteristics including anatomical features precluding flow arrest/reversal (e.g., incomplete circle of Willis), femoral access (e.g., unfavorable aortic arch anatomy), or transcervical access (e.g., diseased CCA).

CaRotid Artery Filtering Technique (CRAFT): A Technique for Carotid Artery Stenting with Intrinsic Embolic Protection

Purpose

Carotid artery stenting (CAS) is an established treatment for symptomatic carotid artery stenosis as an alternative to carotid endarterectomy. A variety of techniques and devices have been devised to minimise periprocedural stroke risk using either proximal or distal embolic protection. This study presents a method of embolic protection during CAS–the CaRotid Artery Filtering Technique (CRAFT).

Materials and Methods

The CRAFT technique employs aspects of both proximal and distal embolic protection. The CASPER RX stent (MicroVention, Tustin, CA, USA), which is a double-layered, closed-cell, micromesh nitinol stent, is deployed across the carotid artery stenosis with the assistance of a FlowGate balloon guide catheter (Stryker Neurovascular, Fremont, CA, USA). The partially deployed stent acts as a distal filter while the balloon guide is deflated midway during stent deployment to prevent distal plaque embolisation, followed by completion of stent deployment and angioplasty.

Results

A total of 94 patients underwent CAS using the CRAFT technique between June 2016 and March 2021. Successful stent deployment was achieved in all patients. Preliminary results demonstrated acute stent occlusion in 6 patients (6.4%) and distal embolic stroke in 5 patients (5.3%). The median procedural fluoroscopy time was 34 minutes with an interquartile range of 22 to 55 minutes.

Conclusion

The CRAFT technique of CAS presented by this study can be applied in the treatment of symptomatic carotid artery stenosis in both emergency and elective procedure settings with a high technical success and low distal embolic stroke risk.

Transcervical carotid artery revascularization: A systematic review and meta-analysis of outcomes

OBJECTIVE

Carotid artery stenosis is considered a determinant factor for cerebrovascular events, estimated to be the cause of 10% to 20% of all ischemic strokes. Transcervical carotid artery revascularization (TCAR) has been offered as an alternative to transfemoral carotid artery stenting and carotid endarterectomy to treat carotid artery stenosis.

METHODS

We performed a systematic review and meta-analysis of prospective and retrospective studies reporting the outcomes of patients who had undergone TCAR for carotid artery stenosis. The incidence of periprocedural adverse events was calculated.

RESULTS

A total of 45 studies with 14,588 patients met the predefined eligibility criteria and were included in the present meta-analysis. The technical success rate was 99% (95% confidence interval [CI], 98%-99%). The reasons for technical failure included an inability to cross the lesion and/or failure to deploy the stent. Access site complications occurred in 2% of all cases (95% CI, 1%-2%; 30 studies). Overall, the incidence of cranial nerve (CN) injuries was very rare, with only 33 of 8994 patients experiencing neurologic deficits attributed to CN involvement. Bleeding complications were reported by 20 studies and occurred in 2% (95% CI, 1%-3%) of all cases. The overall periprocedural all-cause mortality and stroke rate was 0.5% and 1.3%, respectively. In-stent restenosis was observed in 4 of 260 patients (1.5%; 7 studies), and early (30-day) reocclusion or acute thrombosis of the target lesion occurred in 12 of 1243 patients (∼1%; 11 studies).

CONCLUSIONS

The results from the present study have provided significant evidence that TCAR is a very promising and safe carotid revascularization approach with favorable technical success rates associated with low periprocedural stroke and CN injury rates.

Carotid Stenting without Embolic Protection Increases Major Adverse Events: Analysis of the National Surgical Quality Improvement Program

BACKGROUND AND PURPOSE

Published data regarding embolic protection device efficacy is mixed, and its use during carotid artery stent placement remains variable. We, therefore, examined the frequency of embolic protection device use and its association with outcomes after carotid artery stent placement using a national quality improvement data base.

MATERIALS AND METHODS

Patients undergoing carotid artery stent placement with or without embolic protection devices were identified in the American College of Surgeons National Surgical Quality Improvement Program data base. The primary outcome was the incidence of major adverse cardiovascular events (defined as death, stroke, or myocardial infarction/arrhythmia) within 30 days. Propensity scoring was used to create 2 matching cohorts of patients using demographic and baseline variables.

RESULTS

Between 2011 and 2018, among 1200 adult patients undergoing carotid artery stent placement, 23.8% did not have embolic protection devices. There was no trend toward increased embolic protection device use with time. Patients without embolic protection device use received preoperative antiplatelets less frequently (90.6% versus 94.6%, P = .02), underwent more emergent carotid artery stent placement (7.2% versus 3.6%, P = .01), and had a higher incidence of major adverse cardiovascular events (OR = 1.81; 95% CI, 1.11-2.94) and stroke (OR = 3.31; 95% CI, 1.71-6.39). After compensating for baseline imbalances using propensity-matched cohorts (n = 261 for both), carotid artery stent placement without an embolic protection device remained associated with increased major adverse cardiovascular events (9.2% versus 4.2%; OR = 2.30; 95% CI, 1.10-4.80) and stroke (6.5% versus 1.5%; OR = 4.48; 95% CI, 1.49-13.49).

CONCLUSIONS

Lack of embolic protection device use during carotid artery stent placement is associated with a 4-fold increase in the likelihood of perioperative stroke. Nevertheless, nearly one-quarter of patients in the American College of Surgeons National Surgical Quality Improvement Program underwent unprotected carotid artery stent placement. Efforts targeting improved embolic protection device use during carotid artery stent placement are warranted.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

WIRION™ embolic protection system for carotid artery stenting and lower extremity endovascular intervention

Aim: To summarize all available literature regarding the Wirion™ embolic protection system (EPS) and present examples from our center. Materials & methods: A review of literture was performed about the utilization of Wirion EPS. Results: One study was identified investigating the outcomes of Wirion during carotid artery stenting. The study demonstrated 98.3% procedural success with stroke occurring in only 2.5%. Two single arm studies were identified investigating the efficacy of the Wirion filter during lower extremity endovascular interventions. The reported device success ranged from 95.1 to 97.3%. Conclusion: While carotid artery stenting should always be performed with adjunctive EPS in order to decrease the risk of cerebrovascular accidents, the routine use of EPS in femorpopliteal interventions remains an active area of investigation.

Presence of Contralateral Carotid Occlusion Is Associated With Increased Periprocedural Stroke Risk Following CEA but Not CAS: A Meta-analysis and Meta-regression Analysis of 43 Studies and 96,658 Patients

Purpose: To investigate the prognostic role of contralateral carotid artery occlusion (CCO) in perioperative outcomes of patients undergoing carotid artery endarterectomy (CEA) vs carotid artery stenting (CAS). Materials and Methods: The PubMed, Scopus, and Cochrane databases were searched up to September 2018 to identify observational or randomized studies that compared outcomes of carotid revascularization in patients with vs without CCO. Forty-three studies (46 arms) comprising 96,658 patients were selected (75,857 CEA and 20,801 CAS). The CCO group included 9258 patients. Heterogeneity was assessed with the Higgins I² test. I²>75% indicated significant heterogeneity. A random effects model was used to account for heterogeneity among studies. The results were reported as the odds ratios (ORs) with the 95% confidence intervals (CIs). Meta-regression analysis examined potential confounders. Publication bias was quantified by the Egger method. Results: Carotid revascularization in patients with CCO was associated with an increased risk of 30-day mortality (OR 1.75, 95% CI 1.38 to 2.23, p<0.001; I²=0%), stroke (OR 1.77, 95% CI 1.41 to 2.22, p<0.001; I²=46%), transient ischemic attack (TIA) (OR 2.10, 95% CI 1.34 to 3.27, p=0.001; I²=15%), and the composite endpoint of stroke/death (OR 1.78, 95% CI 1.54 to 2.05, p<0.001; I²=0%). No difference was noted in the risk of perioperative myocardial infarction (OR 0.81, 95% CI 0.50 to 1.31; p=0.388; I²=0%). Subgroup analysis demonstrated that CEA in patients with CCO was associated with an increased risk of stroke (OR 2.07, 95% CI 1.72 to 2.49, p<0.001; I²=14%), death (OR 1.80, 95% CI 1.55 to 2.10, p<0.001; I²=0%), TIA (OR 2.18, 95% CI 1.38 to 3.45, p<0.001; I²=13%), and stroke/death (OR 1.80, 95% CI 1.55 to 2.10, p<0.001; I²=0%), whereas CCO patients who were treated with CAS were at an increased risk for death (OR 1.65, 95% CI 1.07 to 2.60, p=0.023; I²=0%) but not stroke (OR 0.94, 95% CI 0.61 to 1.47; p=0.080; I²=31%) or TIA (OR 1.18, 95% CI 0.18 to 7.55; p=0.861; I²=43%). The meta-regression analysis did not find any significant association for any of the outcomes, and there was no evidence of publication bias. Conclusion: Carotid revascularization outcomes are adversely affected by the presence of CCO. Patients with CCO have a significantly higher risk of periprocedural stroke, death, and TIA. CEA in patients with CCO is associated with an increased risk of perioperative stroke, death, TIA, and death/stroke, while CAS in the presence of a CCO is associated with an increased risk of periprocedural death but not stroke or TIA.

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.

Massive Cerebral Microemboli after Protected Carotid Artery Angioplasty and Stenting Using a Distal Filter Embolic Protection Device for a Vulnerable Plaque with a Lipid Rich Necrotic Core and Intraplaque Hemorrhage: A Case Report

A major concern associated with carotid artery angioplasty and stenting (CAS) is a periprocedural distal cerebral embolization. To prevent distal embolization, embolic protection devices (EPDs) have been developed. However, the risk of cerebral embolism after protected CAS in patents with a vulnerable plaque is controversial and either a silent or a symptomatic stroke can occur despite the use of EPDs. Here, we report a case of a massive cerebral microemboli after a protected CAS using a distal filter EPD for a vulnerable plaque with a lipid rich necrotic core and intraplaque hemorrhage.

Utility of Intravascular Ultrasound During Carotid Angioplasty and Stenting with Proximal Protection

Carotid artery stenting (CAS) is an established treatment for patients at high-risk for endarterectomy. Patients who undergo CAS have been shown to have periprocedural microembolic events on transcranial Doppler ultrasonography. Flow reversal is often applied in these situations to prevent distal emboli and concurrently allow blood to flush into the common carotid artery. Patients who demonstrate soft plaque morphology that may embolize distally during CAS benefit from flow reversal. Even so, the all-stroke risk in these patients is nearly 1.4%. High-risk patients typically have more difficult plaque morphology; flow reversal decreases the rate of distal emboli but does not offer the intraprocedural visualization seen with intravascular ultrasound (IVUS). In this paper, we illustrate potential periprocedural outcomes associated with stenting of the stenotic carotid bifurcation under flow reversal and how IVUS influenced endovascular management. Three high-risk patients who underwent CAS with direct common carotid artery cutdown approaches due to common carotid ostia disease with flow-reversal proximal embolic protection also had intraprocedural IVUS performed to evaluate plaque morphology and stability before the protection system was removed. Case 1 illustrates no intraluminal thrombus on IVUS, requiring no further intervention after stent placement. Case 2 demonstrates intraluminal thrombus on IVUS requiring a second stent to stabilize plaque. Case 3 shows the inadequate resolution of thrombus after a second stent, which was addressed with balloon angioplasty. In our experience, using IVUS as an adjunct to CAS under proximal embolic protection helped demonstrate plaque morphology and plaque fragmentation after stent placement. These cases illustrate the potential benefit of allowing stabilization of the plaque before flow reversal is stopped.

Direct Transcervical Access vs the Transfemoral Approach for Carotid Artery Stenting: A Systematic Review and Meta-Analysis

PURPOSE

To examine the safety profile of transcervical access (TCA) in comparison with the transfemoral approach (TFA) in carotid artery stenting.

MATERIALS AND METHODS

A systematic review and meta-analysis was performed according to current guidelines. Eleven eligible studies including 11,592 patients (10,736 in the TFA group and 856 in the TCA group) were identified through a search of the PubMed, Scopus, and Cochrane databases up to October 2018. A random effects model meta-analysis was conducted, and the I2 statistic was used to assess heterogeneity. Publication bias was assessed using funnel plots and quantified using the Egger method.

RESULTS

The TFA group had a statistically significantly higher risk of periprocedural (30-day) stroke compared with the TCA group (OR 1.98, 95% CI 1.08 to 3.63, p=0.027; I2=0%). Also, patients in the TFA group had a significantly higher risk of developing new ischemic lesions (OR 2.97, 95% CI 1.48 to 5.96, p=0.002; I2=0%) on diffusion-weighted magnetic resonance imaging (DW-MRI). No differences in terms of transient ischemic attack (OR 1.50, 95% CI 0.73 to 3.10, p=0.268; I2=5.9%), myocardial infarction (OR 0.64, 95% CI 0.30 to 1.35; p=0.242; I2=0%), local hematoma (OR 0.53, 95% CI 0.12 to 2.25, p=0.389; I2=0%), or mortality (OR 1.35, 95% CI 0.62 to 2.92, p=0.449; I2=0%) were identified between the groups.

CONCLUSION

TCA is associated with a significantly lower risk for periprocedural stroke and DW-MRI ischemic lesions compared with TFA. Other periprocedural outcomes were similar between the groups.

Editorial comment: sandwich carotid stenting: too much of a good thing?

This editorial comment refers to the article "Detection of in-stent protrusion (ISP) by intravascular ultrasound during carotid stenting: usefulness of stent-in-stent placement for ISP" by Okazaki T et al Eur Radiol., July 2018.