Mechanisms to explain the poor results of carotid artery stenting (CAS) in symptomatic patients to date and options to improve CAS outcomes

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Use of Glycoprotein IIb-IIIa Inhibitors in Patients Undergoing Carotid Artery Stenting in the Vascular Quality Initiative

BACKGROUND

Antiplatelet therapies with thromboxane inhibitors and adenosine 5'-diphosphate antagonists have been widely used following carotid artery stenting (CAS). However, these therapies may not apply to patients who are intolerant or present acutely. Glycoprotein IIb/IIIa inhibitors (GPI) are a proposed alternative therapy in these patients; however, their use has been limited due to concerns of increased risk for intracranial bleeding. Thus, this study aims to assess the safety profile of GPI in patients undergoing CAS.

METHODS

All patients undergoing CAS in the Society of Vascular Surgery - Vascular Quality Initiative database from 2012 to 2021 was included and grouped into GPI versus non-GPI therapy (control). The primary outcome was in-hospital stroke or death, and secondary outcomes included in-hospital stroke/transient ischemic attack (TIA), death, myocardial infarction, and intracranial hemorrhage (ICH)/seizure. Patients were stratified by surgical approach (Transcarotid artery revascularization using flow reversal (TCAR) and transfemoral carotid artery stenting), and stepwise backward logistic regression analysis was conducted to evaluate major primary and secondary outcomes.

RESULTS

A total of 50,628 patients underwent carotid revascularization. Of these, 4.4% of the patients received GPI. Mean age was similar between control versus GPI (71.35(9.67) vs. 71.36(10.20) years). Compared to the control group, patients who receive GPI are less likely to be on optimal medical therapy, including aspirin (83.0% vs. 88.1%), P2Y12 inhibitor (73.0% vs. 82.7%), and statin (82.3% vs. 86.0%) (All P < 0.05). In addition, patients in the GPI group were more likely to undergo TCAR for carotid revascularization (52.2% vs. 48.4%) for emergent/urgent (29.4% vs. 16.8%) and symptomatic indications (55.5% vs. 49.7%) (All P < 0.001). After stratifying by surgical approach, if patients underwent TFCAS and received a GPI, they were at increased odds of developing stroke/death (1.77(1.25-2.51)), death (odds ratio (OR) (95% CI): 1.67(1.07-2.61)), stroke/TIA (OR (95% confidence interval (CI)): 1.65(1.09-2.51)), and ICH/seizure (OR (95% CI): 2.13(1.23-3.68)) (All P < 0.05). No difference was seen in outcomes between the 2 groups if undergoing TCAR.

CONCLUSIONS

Patients who receive GPI were more likely to be symptomatic at presentation and less likely to be medically optimized before their carotid revascularization. Transfemoral access in patients receiving GPI was associated with increased odds of morbidity and mortality. However, this was not observed if undergoing TCAR. TCAR can be considered for its overall favorable results in high-risk patients who are not medically optimized.

Modality-specific outcomes of patients undergoing carotid revascularization in the setting of recent myocardial infarction

OBJECTIVE

Recent myocardial infarction (MI) represents a real challenge in patients requiring any vascular procedure. There is currently a lack of data on the effect of preoperative MI on the outcomes of carotid revascularization methodology (carotid enterectomy [CEA], transfemoral carotid artery stenting [TFCAS], or transcarotid artery revascularization [TCAR]). This study looks to identify modality-specific outcomes for patients with recent MI undergoing carotid revascularization.

METHODS

Data was collected from the Vascular Quality Initiative (2016-2022) for patients with carotid stenosis in the United States and Canada with recent MI (<6 months) undergoing CEA, TFCAS, or TCAR. In-hospital outcomes after TFCAS vs CEA and TCAR vs CEA were compared. TCAR vs TFCAS were compared in a secondary analysis. We used logistic regression models to compare the outcomes of these three procedures in patients with recent MI, adjusting for potential confounders. Primary outcomes included 30-day in-hospital rates of stroke, death, and MI. Secondary outcomes included stroke/death, stroke/death/MI, postoperative hypertension, postoperative hypotension, prolonged length of stay (>2 days), and 30-day mortality.

RESULTS

The final cohort included 1217 CEA (54.2%), 445 TFCAS (19.8%), and 584 TCAR (26.0%) cases. Patients undergoing CEA were more likely to have prior coronary artery bypass graft/percutaneous coronary intervention and to use anticoagulant. Patients undergoing TFCAS were more likely to be symptomatic, have prior congestive heart failure, chronic obstructive pulmonary disease, chronic kidney disease, and undergo urgent operations. Patients undergoing TCAR were more likely to have higher rates of American Society of Anesthesiologists class IV to V, P2Y12 inhibitor, and protamine use. In the univariate analysis, CEA was associated with a lower rate of ipsilateral stroke (P = .079), death (P = .002), and 30-day mortality (P = .007). After adjusting for confounders, TFCAS was associated with increased risk of stroke/death (adjusted odds ratio [aOR], 2.69; 95% confidence interval [CI], 1.36-5.35; P = .005) and stroke/death/MI (aOR, 1.67; 95% CI, 1.07-2.60; P = .025) compared with CEA. However, TCAR had similar outcomes compared with CEA. Both TFCAS and TCAR were associated with increased risk of postoperative hypotension (aOR, 1.62; 95% CI, 1.18-2.23; P = .003 and aOR, 1.74; 95% CI, 1.31-2.32; P ≤ .001, respectively) and decreased risk of postoperative hypertension (aOR, 0.59; 95% CI, 0.36-0.95; P = .029 and aOR, 0.50; 95% CI, 0.36-0.71; P ≤ .001, respectively) compared with CEA.

CONCLUSIONS

Although recent MI has been established as a high-risk criterion for CEA and an approved indication for TFCAS, this study showed that CEA is safer in this population with lower risk of stroke/death and stroke/death/MI compared with TFCAS. TCAR had similar stroke/death/MI outcomes in comparison to CEA in patients with recent MI. Further prospective studies are needed to confirm our findings.

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).

Endovascular carotid revascularization under open-chest extracorporeal circulation combined with cardiac surgery in unstable patients at increased risk of carotid-related stroke: SIMultaneous urgent cardiac surgery and MicroNet-covered stent carotid revascularization in extreme-risk patients-SIMGUARD Study

BACKGROUND

In patients at urgent need for cardiac surgery coexisting with increased-stroke-risk carotid stenosis, any staged intervention increases the risk of complications from the primarily unaddressed pathology. In this challenging cohort, we assessed safety and feasibility of endovascular carotid revascularization under open-chest extracorporeal circulation (ECC) combined with cardiac surgery (hybrid-room true simultaneous treatment).

METHODS

Per-protocol (PP), after general anesthesia induction, chest-opening and ECC stand-by installation, carotid stenting (CAS) was performed (femoral/radial or direct carotid access) with ad-hoc/on-hand switch to ECC cardiac surgery.

RESULTS

Over 78 months, 60 patients (70.7±6.9years, 85% male, all American Society of Anesthesiology grade IV) were enrolled. All were at increased carotid-related stroke risk (ipsilateral recent stroke/transient ischemick attack, asymptomatic cerebral infarct, increased-risk lesion morphology, bilateral severe stenosis). Majority of study procedures involved CAS+coronary bypass surgery or CAS+valve replacement±coronary bypass. 45 (75%) patients were PP- and 15 (25%) not-PP (NPP-) managed (context therapy). CAS was 100% neuroprotected (transient flow reversal-64.4%, filters-35.6%) and employed micronet-covered plaque-sequestrating stents with routine post-dilatation optimization/embedding. 4 deaths (6.7%) and 7 strokes (11.7%) occurred by 30-days. Despite CAS+surgery performed on aspirin and unfractionated heparin-only (delayed clopidogrel-loading), no thrombosis occurred in the stented arteries, and 30-days stent patency was 100%. NPP-management significantly increased the risk of death/ipsilateral stroke (OR 38.5; P<0.001) and death/any stroke (OR 12.3; P=0.002) by 30-days.

CONCLUSIONS

In cardiac unstable patients at increased carotid-related stroke risk who require urgent cardiac surgery, simultaneous cardiac surgery and CAS with micronet-covered stent lesion sequestration is feasible and safe and shows efficacy in minimizing stroke risk. Larger-scale, multicentric evaluation is warranted. (SIMGUARD NCT04973579).

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

The Efficacy of Transcarotid Artery Revascularization With Flow Reversal System Compared to Carotid Endarterectomy: A Systematic Review and Meta-Analysis

Background: Carotid artery stenosis has long been a critical cause of stroke and death, and it can seriously affect the life quality. Transcarotid artery revascularization (TCAR) and carotid endarterectomy (CEA) are both feasible therapies for this disease. This systematic review and meta-analysis aim to evaluate if the efficacy of the two approaches is comparable.

Methods: Clinical studies up to March 2021 were searched through PubMed, Embase, and Scopus from a computer. The screening process was designed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. Newcastle-Ottawa Scale (NOS) was used for methodological quality assessment of works of literature meeting the inclusion criteria, and Review Manager 5.4 was used for data synthesis. The I² statistic was performed to measure the heterogeneity, and M-H/I-V fixed or random model was utilized depending on the I² value. The evidence evaluation was accomplished based on grades of recommendation, assessment, development, and evaluation (GRADE) online tool.

Results: A total of 14,200 subjects (six comparative studies) were finally included in this pooled study. There is no statistical discrepancy between the two treatments on reducing stroke/death/myocardial infarction (odds ratio [OR] 0.85, 95% CI 0.67–1.07), stroke (OR 1.03, 95% CI 0.77–1.37), or death (OR 1.14, 95% CI 0.67–1.94). Besides, TCAR is associated with a lower incidence of myocardial infarction (P = 0.004), cranial nerve injury (P < 0.00001), and shorter procedure time (P < 0.00001) than CEA among the overall cohort.

Conclusions: TCAR is a rapidly developing treatment that reaches a comparable prognosis to CEA and significantly reduces the risk of myocardial infarction under the well-matched condition, which is a dependable choice for patients with carotid stenosis.

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).

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.

Outcomes of Transcarotid Artery Revascularization and Carotid Endarterectomy at a Single Institution

BACKGROUND

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are accepted revascularization modalities to treat carotid artery stenosis. Higher incidences of perioperative adverse neurological events and death have been reported in patients with transfemoral CAS. Transcarotid artery revascularization (TCAR) is a newer operative technique that involves direct transcervical carotid access, mitigating aortic arch manipulation and minimizing the risk of embolic stroke via cerebral blood flow reversal. Perioperative stroke, myocardial infarction (MI), and death rates have been shown to be similar between TCAR and CEA, with TCAR having fewer complications. The objective of this study was to ascertain the safety and viability of TCAR by evaluating perioperative outcomes. We hypothesized that patients undergoing TCAR and CEA have equivalent outcomes.

METHODS

We performed a single-institution retrospective review of a prospectively maintained Vascular Quality Initiative database on patients who underwent TCAR or CEA between 2012 and 2019. A total of 66 TCAR cases from February 2018 to December 2019 and 501 CEA cases from January 2012 to December 2019 were reviewed. Preoperative, intraoperative, and postoperative characteristics as well as perioperative outcomes were captured for the statistical analyses.

RESULTS

From 2012 to 2019, 567 patients underwent TCAR or CEA. Patients who underwent TCAR were found to have higher rates of comorbidities compared with CEA. There were no procedure-related strokes in patients who underwent TCAR. There was no statistically significant difference between TCAR and CEA procedure-related strokes (0% vs. 1.0%, P = 0.42). There were 5 CEA procedure-related strokes because of technical problems resulting in thrombosis of the target vessels. Three patients who underwent CEA had strokes unrelated to the operations. Overall, there were no perioperative deaths, MI, cranial nerve injury (CNI), or hematoma in patients who underwent TCAR. There were no complications of surgical site infection, pseudoaneurysm, or arteriovenous fistula among patients who underwent TCAR or CEA.

CONCLUSIONS

This single-center retrospective analysis of TCAR and CEA for the treatment of carotid artery disease suggests TCAR can result in equivalent perioperative procedure-related stroke as CEA as well as equivalent incidence of perioperative complications including MI, CNI, hematoma, and death in selected patients or patients with proper anatomy. TCAR may be considered a safe, feasible carotid revascularization option for carotid artery stenosis.

The less invasive paradox, why carotid artery stenting is not suitable for the high-risk patient

Carotid artery stenosis causes significant morbidity and mortality accounting for approximately 8% of all ischaemic strokes. Carotid artery stenting (CAS) offers an endovascular alternative to carotid endarterectomy (CEA), suggested as a viable option in those deemed high-risk for open CEA due to comorbidities or operative technical considerations. A number of large randomised-controlled trials (RCTs) and meta-analysis comparing CAS vs. CEA in unselected patient populations support the conclusion that CAS is associated with a higher risk of stroke and CEA is associated with a higher risk of myocardial infraction. Initial promise for CAS in high-risk patients was demonstrated by The Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial that reported CAS was non-inferior to CEA. However, there is evidence to suggest age-related adverse outcome in patients undergoing CAS. There is limited evidence to suggest that CEA could be suitable even in patients deemed high-risk for medical or technical reasons. Further contemporary research on the use of CAS and CEA in high-risk patients is required to re-evaluate current guidelines and high-risk criterion. It is common for a composite outcome of death, ipsilateral stroke and MI which should be questioned as subsequent quality of life is likely to differ after suffering a stroke in comparison to MI. This literature review will discuss the current evidence for CAS and CEA interventions in unselected populations and high-risk patients with carotid disease requiring intervention.

Successful Use of Adjunctive Orbital Atherectomy for Extensively Calcified Carotid Artery Lesions Using Flow Reversal Neuroprotection Technique

The use of transcarotid artery revascularization (TCAR) technique for carotid atherosclerotic disease has become increasingly popular as the endovascular alternative to traditional carotid endarterectomy. TCAR does offer a minimally invasive approach to carotid lesions, however, several technical and anatomic considerations, such as extensive calcification, limit its widespread applicability. Both orbital and rotational atherectomy are commonly used for extensively calcified lesions in the peripheral vasculature with satisfactory results for luminal gain. Herein, we describe the use of orbital atherectomy of a severely calcified ostial carotid lesion using reverse flow technique for neuroprotection during TCAR in a patient considered high risk for carotid endarterectomy.

An updated systematic review and meta-analysis of results of transcervical carotid artery stenting with flow reversal

OBJECTIVE

Transcervical carotid artery stenting (CAS) has emerged as an alternative to transfemoral CAS. An earlier systematic review from our group (n = 12 studies; 739 transcervical CAS procedures [489/739 with flow reversal]) demonstrated that transcervical CAS is a safe procedure associated with a low incidence of stroke and complications. Since then, new studies have been published adding nearly 1600 patients to the literature. We aimed to update our early systematic review and also to perform a meta-analysis to investigate outcomes specifically after transcervical CAS with flow reversal.

METHODS

An electronic search of PubMed/MEDLINE, Embase, and the Cochrane databases was carried out to identify studies reporting outcomes after transcervical CAS with flow reversal. Crude event rates for outcomes of interest were estimated by simple pooling of data. A proportion meta-analysis was also performed to estimate pooled outcome rates.

RESULTS

A total of 18 studies (n = 2110 transcervical CAS procedures with flow reversal) were identified. A high technical success (98.25%) and a low mortality rate (0.48%) were recorded. The crude rates of major stroke, minor stroke, transient ischemic attack, and myocardial infarction (MI) were 0.71%, 0.90%, 0.57%, and 0.57%, respectively; a cranial nerve injury occurred in 0.28% of the procedures. A neck hematoma was reported in 1.04% of the procedures, and a carotid artery dissection occurred in 0.76% of the interventions; in 1.09% of the cases, conversion to carotid endarterectomy was required. After a meta-analysis was undertaken, the pooled technical success rate was 98.69% (95% confidence interval [CI], 97.19-99.70). A pooled mortality rate of 0.04% (95% CI, 0.00-0.29) was recorded. The pooled rate of any type of neurologic complications was 1.88 (95% CI, 1.24-2.61), whereas the pooled rates of major stroke, minor stroke, and transient ischemic attack were 0.12% (95% CI, 0.00-0.46), 0.15% (95% CI, 0.00-0.50), and 0.01% (95% CI, 0.00-0.22), respectively. The pooled rate of bradycardia/hypotension was 10.21% (95% CI, 3.99-18.51), whereas the pooled rate of MI was 0.08% (95% CI, 0.00-0.39). A neck hematoma after transcervical CAS was recorded in 1.51% (95% CI, 0.22-3.54) of the procedures; in 0.74% (95% CI, 0.05-1.95) of the interventions, conversion to CEA was required. Finally, a carotid artery dissection during transcervical CAS occurred in 0.47% (95% CI, 0.00-1.38) of the procedures.

CONCLUSIONS

This updated systematic review and meta-analysis demonstrated that transcervical CAS with flow reversal is associated with high technical success, almost zero mortality, and low rates of major stroke, minor stroke, MI, and complications.

The utility of adjunctive electroencephalography while performing transcarotid artery revascularization

Transcarotid artery revascularization (TCAR) has been used as an alternative to carotid endarterectomy and transfemoral carotid artery stenting. Although TCAR has been associated with a decrease in perioperative strokes compared with transfemoral carotid artery stenting, little is known about the safety of cerebral blood during flow reversal or the value of adjunctive electroencephalography (EEG) monitoring in performing TCAR. We describe two cases of EEG changes in patients undergoing TCAR. These cases highlight the use of adjunctive EEG and provide examples of test clamping to assess for compromised collateral cerebral blood flow in patients undergoing TCAR.

A multi-institutional analysis of transcarotid artery revascularization compared to carotid endarterectomy

OBJECTIVE

Transcarotid artery revascularization (TCAR) is a novel approach to carotid intervention that uses a direct carotid cut-down approach coupled with cerebral blood flow reversal to minimize embolic potential. The initial positive data with TCAR indicates that it may be an attractive alternative to trans-femoral carotid artery stenting and possibly carotid endarterectomy (CEA) for high-risk patients. The purpose of this study was to present 30-day and 1-year outcomes after treatment by TCAR and to compare these outcomes against a matched control group undergoing CEA at the same institutions.

METHODS

A retrospective review of all patients who underwent TCAR at four institutions between 2013 and 2017 was performed to evaluate the use of the ENROUTE Transcarotid Neuroprotection System (Silk Road Medical, Inc, Sunnyvale, Calif). TCAR patients had high-risk factors and were either enrolled in prospective trials or treated with a commercially available TCAR device after US Food and Drug Administration approval. Contemporaneous patients undergoing CEA at each institution were also reviewed. Patients were propensity matched in a 1:1 (CEA:TCAR) fashion with respect to preoperative comorbidities. Data were analyzed using statistical models with a P value of less than .05 considered significant. Individual and composite stroke, myocardial infarction, and death at 30 days and 1 year postoperatively were assessed.

RESULTS

Consecutive patients undergoing TCAR or CEA were identified (n = 663) and compared. Patients undergoing the TCAR procedure (n = 292) had higher rates of diabetes (P = .01), hyperlipidemia (P = .02), coronary artery disease (P < .01), and renal insufficiency (P < .01) compared with unmatched CEA patients (n = 371). Stroke rates were similar at 30 days (1.0% TCAR vs 1.1% CEA) and 1 year (2.8% TCAR vs 3.0% CEA) in the unmatched groups. After propensity matching by baseline characteristics including gender, age, symptom status (36.3%, 35.3%) and diabetes, 292 TCAR patients were compared with 292 CEA patients. TCAR patients were more likely to be treated preoperative and postoperatively with clopidogrel (preoperatively, 82.2% vs 39.4% [P < .01]; postoperatively, 98.3% vs 36.0% [P < .01]) and statins (preoperatively, 88.0% vs 75.0% [P < .01]; postoperatively, 97.8% vs 78.8% [P < .01]). Stroke (1.0% TCAR vs 0.3% CEA; P = .62) and death (0.3% TCAR vs 0.7% CEA; P = NS) rates were similar at 30 days and comparable at 1 year (stroke, 2.8% vs 2.2% [P = .79]; death 1.8% vs 4.5% [P = .09]). The composite end point of stroke/death/myocardial infarction at 1 month postoperatively was 2.1% vs 1.7% (P = NS). TCAR was associated with a decreased rate of cranial nerve injury (0.3% vs 3.8%; P = .01).

CONCLUSIONS

These early data suggest that patients undergoing TCAR, even those with high-risk comorbidities, achieve broadly similar outcomes compared with patients undergoing CEA while mitigating cranial nerve injury. Further comparative studies are warranted.

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

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

Transcervical Carotid Stent Placement in the Setting of a Hostile Neck and a Type III Aortic Arch

Previous radical neck dissection and neck irradiation pose considerable operative risks in patients requiring carotid endarterectomy for symptomatic carotid disease. Carotid stenting is an acceptable alternative for these patients but carries a higher risk of cerebrovascular accidents especially in patients with type III aortic arch anatomy. Herein, we present a technically challenging case of a patient with an irradiated neck and a history of radical neck dissection who presented with a symptomatic high-grade left internal carotid artery stenosis in the setting of a type III aortic arch. He was treated via a hybrid approach for carotid artery stenting.

A Prospective, Multicenter Study of a Novel Mesh-Covered Carotid Stent: The CGuard CARENET Trial (Carotid Embolic Protection Using MicroNet)

OBJECTIVES

This study sought to evaluate the feasibility of the CGuard Carotid Embolic Protective Stent system-a novel thin strut nitinol stent combined with a polyethylene terephthalate mesh covering designed to prevent embolic events from the target lesion in the treatment of carotid artery lesions in consecutive patients suitable for carotid artery stenting.

BACKGROUND

The risk of cerebral embolization persists throughout the carotid artery stenting procedure and remains during the stent healing period.

METHODS

A total of 30 consecutive patients (age 71.6 ± 7.6 years, 63% male) meeting the conventional carotid artery stenting inclusion criteria were enrolled in 4 centers in Germany and Poland.

RESULTS

The primary combined endpoint was the procedure success of the CGuard system and the number and volume of new lesions on the ipsilateral side assessed by diffusion-weighted magnetic resonance imaging at 48 h post-procedure and at 30 days. The secondary endpoint was 30-day major adverse cardiac or cerebrovascular events (death, stroke, or myocardial infarction). Protection devices were used in all procedures. Procedure success was 100%, with 0% procedural complications. The 30-day major adverse cardiac or cerebrovascular events rate was 0%. New ipsilateral ischemic lesions at 48 h occurred in 37.0% of patients and the average lesion volume was 0.039 ± 0.08 cm(3). The 30-day diffusion-weighted magnetic resonance imaging showed complete resolution of all but 1 periprocedural lesion and only 1 new minor (0.116 cm(3)) lesion in relation to the 48-h scan.

CONCLUSIONS

The use of the CGuard system in patients undergoing carotid artery stenting is feasible. In addition, the benefit of using CGuard may extend throughout the stent healing period.

Optimal contemporary management of symptomatic and asymptomatic carotid artery stenosis

This commentary addresses the issue of optimal contemporary management of symptomatic and asymptomatic carotid artery stenosis. Based on current data, carotid endarterectomy (CEA) should be performed in the majority of patients with symptomatic carotid artery stenosis. Carotid artery stenting (CAS) should be reserved for a minority of these symptomatic patients, in whom CEA is contraindicated. In asymptomatic patients, all should be placed on best medical treatment (BMT). With the use of one or more of the proposed stroke risk stratification models or some as yet undetermined method, the identification of those asymptomatic individuals may be possible in whom stroke risk is higher than usual with BMT. This asymptomatic subgroup, which may be small and is yet to be determined with certainty, could be offered an invasive carotid procedure (either CAS or CEA).

Outcomes of carotid stenting among symptomatic patients: a contemporary review

Strokes have an extremely significant socioeconomic impact on the healthcare industry with a resultant poor quality of life. The majority of strokes result from embolic phenomenon, a third originating from carotid atheromatous plaque. The gold-standard treatment for symptomatic carotid artery stenosis has been carotid endarterectomy; however, carotid artery stenting over the last decade has become an increasingly accepted and performed alternative. This article describes the outcomes of carotid stenting among symptomatic patients and examines the trials that have been performed regarding the treatment options.

Article Commentary: Late Outcomes of Carotid Artery Stenting: A Critical Review

The role of carotid artery stenting (CAS) as an alternative to carotid endarterectomy for the treatment of extracranial carotid occlusive disease for stroke prevention continues to evolve. Although technical and device refinements aimed at making CAS safer continue to this day, safety as measured by 30-day and 1-year outcomes has been the primary recipient of regulatory and practice attention. Relatively less emphasis has been placed on the incidence of recurrent stenosis after CAS and the efficacy of CAS in late stroke prevention. Data on late outcomes of CAS, including factors of potential influence, have been emerging and are addressed in this review.

Inflammation as a marker for the prediction of internal carotid artery restenosis following eversion endarterectomy--evidence from clinical studies

The role of inflammation is well established in the pathogenesis of atherosclerosis and an increased level of circulating inflammatory markers may predict the future risk of atherosclerosis progression and plaque rupture. C-reactive protein (CRP) identification by hypersensitive methods (high-sensitivity CRP [hsCRP]) has become a clinical and laboratory inflammation marker. Carotid endarterectomy (CEA) is a well-established procedure for carotid stenosis treatment which can reduce stroke rate. Internal carotid artery (ICA) restenosis reduction may be prevented by the anti-inflammatory effect of statins. This review considers the recent findings on the presence of hsCRP and C3 complement concentration and inflammatory plaque composition as well as their effects on ICA restenosis rate, following eversion CEA with emphasis on human studies.

Carotid artery stenting simulation: from patient-specific images to finite element analysis

The outcome of carotid artery stenting (CAS) depends on a proper selection of patients and devices, requiring dedicated tools able to relate the device features with the target vessel. In the present study, we use finite element analysis to evaluate the performance of three self-expanding stent designs (laser-cut open-cell, laser-cut closed-cell, braided closed-cell) in a carotid artery (CA). We define six stent models considering the three designs in different sizes and configurations (i.e. straight and tapered), evaluating the stress induced in the vessel wall, the lumen gain and the vessel straightening in a patient-specific CA model based on computed angiography tomography (CTA) images. For the considered vascular anatomy and stents, the results suggest that: (i) the laser-cut closed-cell design provides a higher lumen gain; (ii) the impact of the stent configuration and of the stent oversizing is negligible with respect to the lumen gain and relevant with respect to the stress induced in the vessel wall; (iii) stent design, configuration and size have a limited impact on the vessel straightening. The presented numerical model represents a first step towards a quantitative assessment of the relation between a given carotid stent design and a given patient-specific CA anatomy.