Editor's Choice - Early and Late Outcomes after Transcarotid Revascularisation for Internal Carotid Artery Stenosis: A Systematic Review and Meta-Analysis

William M. Feinberg Lecture: Asymptomatic Carotid Stenosis: Current and Future Considerations

Asymptomatic high-grade carotid stenosis is an important therapeutic target for stroke prevention. For decades, the ACAS (Asymptomatic Carotid Atherosclerosis Study) and ACST (Asymptomatic Carotid Surgery Trial) trials provided most of the evidence supporting endarterectomy for patients with asymptomatic high-grade stenosis who were otherwise good candidates for surgery. Since then, transfemoral/transradial carotid stenting and transcarotid artery revascularization have emerged as alternatives to endarterectomy for revascularization. Advances in treatments against atherosclerosis have driven down the rates of stroke in patients managed without revascularization. SPACE-2 (Stent-Protected Angioplasty Versus Carotid Endarterectomy-2), a trial that included endarterectomy, stenting, and medical arms, failed to detect significant differences in stroke rates among treatment groups, but the study was stopped well short of its recruitment goal. CREST-2 (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial) will be able to clarify whether revascularization by stenting or endarterectomy remains efficacious under conditions of intensive medical management. Transcarotid artery revascularization has a favorable periprocedural risk profile, but randomized trials comparing it to intensive medical management are lacking. Features like intraplaque hemorrhage on MRI and echolucency on B-mode ultrasonography can identify patients at higher risk of stroke with asymptomatic stenosis. High-grade stenosis with poor collaterals can cause hemispheric hypoperfusion, and unstable plaque can cause microemboli, both of which may be treatable risk factors for cognitive impairment. Evidence that there are patients with carotid stenosis who benefit cognitively from revascularization is presently lacking. New risk factors are emerging, like exposure to microplastics and nanoplastics. Strategies to limit exposure will be important without specific medical therapies.

Next-generation transcarotid artery revascularization: TransCarotid flOw Reversal Cerebral Protection And CGUARD MicroNET-Covered Embolic Prevention Stent System To Reduce Strokes - TOPGUARD Study

BACKGROUND

Stent-assisted carotid artery revascularization employing surgical cutdown for transcervical access and dynamic flow reversal (TCAR) is gaining popularity. TCAR, despite maximized intra-procedural cerebral protection, shows a marked excess of 30-day neurologic complications in symptomatic vs. asymptomatic stenoses. The TCAR conventional single-layer stent (free-cell area 5.89mm2) inability to seal embologenic lesions may be particularly relevant after the flow reversal neuroprotection is terminated.

METHODS

We evaluated peri-procedural and 30-day major adverse cerebral and cardiac events (MACCE) of TCAR (ENROUTE, SilkRoad Medical) paired with MicroNET-covered neuroprotective stent (CGuard, InspireMD) in consecutive patients at elevated risk of complications with transfemoral/transradial filter-protected stenting (increased lesion-related and/or access-related risk). CGuard (MicroNET free cell area ≈0.02-0.03 mm2) has level-1 evidence for reducing intra- and abolishing post-procedural lesion-related cerebral embolism.

RESULTS

One hundred and six increased-risk patients (age 72 [61-76] years, median [Q1-Q3]; 60.4% symptomatic, 49.1% diabetic, 36.8% women, 61.3% left-sided index lesion) were enrolled in three vascular surgery centers. Angiographic stenosis severity was 81 (75-91)%, lesion length 21 (15-26)mm, increased-risk lesional characteristics 87.7%. Study stent use was 100% (no other stent types). 74.5% lesions were predilated; post-dilatation rate was 90.6%. Flow reversal duration was 8 (5-11)min. One stroke (0.9%) occurred in an asymptomatic patient prior to establishing neuroprotection (index lesion disruption with the sheath insertion wire); there were no other peri-procedural MACCE. No further adverse events occurred by 30-days. 30-day stent patency was 100% with normal velocities and absence of any in-stent material by Duplex Doppler.

CONCLUSIONS

Despite a high proportion of increased-risk lesions and clinically symptomatic patients in this study, TCAR employing the MicroNET-covered anti-embolic stent showed 30-day MACCE rate <1%. This suggests a clinical role for combining maximized intra-procedural prevention of cerebral embolism by dynamic flow reversal with anti-embolic stent prevention of peri- and post-procedural cerebral embolism (TOPGUARD NCT04547387).

Preoperative Risk Factors Impacting Length of Stay After Transcarotid Artery Revascularization

BACKGROUND

Transcarotid artery revascularization (TCAR), using interoperative flow reversal is a unique, hybrid operation utilized in treating critical carotid artery stenosis. Over the past decade, TCAR has been increasingly used to treat asymptomatic carotid artery disease and has a similar risk profile to traditional carotid endarterectomy. Postoperative length of stay (LOS) has a significant impact on cost-effectiveness and quality outcomes in this expanded setting. The objective of this study is to develop a multivariate regression model to identify key preoperative variables and their impact factor on LOS after TCAR for asymptomatic carotid artery stenosis. We hypothesized that high-risk preoperative patient factors historically identified in carotid endarterectomy would similarly impact LOS after TCAR.

METHODS

A multi-institution, retrospective study of all adult patients undergoing TCAR with flow-reversal for intraoperative neuroprotection was performed using the Society for Vascular Surgery Vascular Quality Initiative (VQI) from January 2016 to August 2021. Patients with prolonged preoperative hospitalization (preoperative LOS ≥1 day) were excluded to enhance the capture of carotid artery stenosis as the index admission. Univariate analysis was done on preoperative factors against LOS using nonparametric statistical tests. A multivariate model was then constructed using a negative binomial regression. The study population was split into 80% "training" data for model formulation and 20% "test" data for model validation.

RESULTS

Thirteen thousand four hundred eighty-three patients undergoing TCAR for asymptomatic carotid stenosis met the study's inclusion criteria with a median postoperative LOS of 1.82 days. Factors in VQI found to have a significant effect on LOS and retained in the multivariate model were lesion type (restenosis versus atherosclerotic), age, gender, chronic obstructive pulmonary disease, preoperative beta blocker, calcific lesion burden, hypertension status, and race (P < 0.05). The model accurately predicted LOS after TCAR within 1 day for 86.04% and within 2 days for 94.51% of patients in the test population.

CONCLUSIONS

This large-scale analysis from 2016 to 2021 spans a considerable expansion in the practice of TCAR for asymptomatic carotid disease. All preoperative variables shown to significantly increase the postoperative LOS were derived from the VQI data set. As LOS is a measure of health-care efficiency and cost-effectiveness, this model can be used to identify patients at risk for increased postoperative LOS. It has the potential to be incorporated into a patient/physician decision support tool to optimize resource planning and patient selection for elective TCAR.

Surveillance and risk factors for early restenosis following transcarotid artery revascularization

OBJECTIVE

Restenosis after transcarotid artery revascularization (TCAR) is a known complication. When identified in the early postoperative period, it may be related to technique. We evaluated our TCAR experience to identify potentially modifiable factors impacting restenosis.

METHODS

This is a single-institution, retrospective review of patients undergoing TCAR from November 2017 to July 2022. Restenosis was defined as >50% stenosis on duplex ultrasound (DUS) examination or computed tomographic angiography (CTA). Continuous variables were compared using Kruskal-Wallis's test. Categorical variables were compared using the Fisher's exact test.

RESULTS

Of 61 interventions, 11 (18%) developed restenosis within the median follow-up of 345 days (interquartile range, 103-623 days). Among these patients, 82% (9/11) had >50% stenosis, and 18% (2/11) had >80% stenosis. Both patients with high-grade restenosis were symptomatic and underwent revascularization. Diagnosis of post-TCAR restenosis was via DUS examination in 45% (5/11), CTA in 18% (2/11), or both CTA/DUS examination in 36% (4/11). Restenosis occurred within 1 month in 54% (6/11) and 6 months in 72% (8/11) of patients. However, three of the six patients with restenosis within 1 month had discordant findings on CTA vs DUS imaging. Patient comorbidities, degree of preoperative stenosis, medical management, balloon size, stent size, lesion characteristics, and predilatation angioplasty did not differ. Patients with restenosis were younger (P = .02), had prior ipsilateral endarterectomy (odds ratio [OR], 6.5; P = .02), had history of neck radiation (OR, 18.3; P = .01), and lower rate of postdilatation angioplasty (OR, 0.11; P = .04), without an increased risk of neurological events.

CONCLUSIONS

Although post-TCAR restenosis occurred in 18% of patients, only 3% of patients had critical restenosis and required reintervention. Patient factors associated with restenosis were younger age, prior endarterectomy, and history of neck radiation. Although early restenosis may be mitigated by improved technique, the only technical factor associated with restenosis was less use of postdilatation angioplasty. Balancing neurological risk, this factor may have increased application in appropriate patients. Diagnosis of restenosis was inconsistent between imaging modalities; current surveillance paradigms and diagnostic thresholds may warrant reconsideration.

The intracranial effects of flow reversal during transcarotid artery revascularization

Background

This study aimed to assess intraoperative cerebral hemodynamic responses and embolic events during transcarotid artery revascularization via transcranial Doppler, near-infrared spectroscopy, and bispectral index monitoring.

Methods

Twelve patients (7 males, 5 females; mean age: 72.8±9.0 years; range, 63 to 91 years) undergoing transcarotid artery revascularization with simultaneous transcranial Doppler, near-infrared spectroscopy, and bispectral index monitoring were analyzed in this retrospective study between September 2017 and December 2019. The mean flow velocity and pulsatility index of the middle cerebral artery, alongside near-infrared spectroscopy and bispectral index values, before flow reversal, during flow reversal, and after flow reversal phases were investigated. The presence and frequency of high-intensity transient signals were recorded to evaluate embolic incidents.

Results

Significant reductions in middle cerebral artery mean flow velocity were noted during flow reversal (40.58±10.57 cm/sec to 20.58±14.34 cm/sec, p=0.0004), which subsequently returned to and exceeded baseline values after flow reversal cessation (53.33±17.69 cm/sec, p=0.0005). Near-infrared spectroscopy (71±4.4% to 66±6.2%) and bispectral index (45.71±8.5 to 40.14±8.1) values mirrored these hemodynamic changes, with notable decreases during flow reversal, and recoveries after flow reversal. The highest concentration of high-intensity transient signals was observed during stent deployment, signifying a critical embolic phase. No perioperative neurological complications or other significant adverse events were documented.

Conclusion

Transcranial Doppler, near-infrared spectroscopy, and bispectral index effectively monitor cerebral hemodynamics and embolic potential during transcarotid artery revascularization, providing real-time data crucial for optimizing perioperative management. These findings underscore the clinical value of multimodal monitoring in improving patient outcomes in transcarotid artery revascularization procedures.

Determinants of Mortality and Mid-Term Outcomes After Transcarotid Artery Revascularization and Transfemoral Carotid Artery Stenting

OBJECTIVES

The potential benefit of transcarotid artery revascularization (TCAR) over transfemoral carotid artery stenting (tfCAS) has been studied in the perioperative period with lower rates of stroke and death; however, data on mid-term outcomes are limited. We aimed to evaluate 3-year outcomes after TCAR and tfCAS and determine the primary predictors of 30-day and 1-year mortality following TCAR.

METHODS

Data from the Vascular Quality Initiative for patients undergoing TCAR or tfCAS from January 2016 to December 2022 were analyzed. 1:1 propensity score matching using the nearest-neighbor method was used to adjust baseline demographics and clinical characteristics. Kaplan-Meier survival analysis and Cox Proportional Hazard Regression were used to evaluate long-term outcomes. Iterative stepwise multiple logistic regression analysis and Cox Proportional Hazard Regression were used to identify predictors of 30-day and 1-year mortality, respectively, based upon preoperative, intraoperative, and postoperative factors.

RESULTS

A total of 70 237 patients were included in analysis (TCAR=58.7%, tfCAS=41.3%). Transcarotid artery revascularization patients were older and had higher rates of comorbid conditions and high-risk medical and anatomic features than tfCAS patients. Propensity score matching yielded 22 322 pairs with no major differences between groups except that TCAR patients were older (71.6 years vs 70.8 years). At 3 years, TCAR was associated with a 24% reduction in hazard of death compared with tfCAS (hazard ratio [HR]=0.76, 95% confidence interval [CI]=0.71-0.82, p<0.001), for both symptomatic and asymptomatic patients. This survival advantage was established in the first 6 months (HR=0.59, 95% CI=0.53-0.62, p<0.001), with no difference in mortality risk from 6 months to 36 months (HR=0.95, 95% CI=0.86-1.05, p=0.31). Transcarotid artery revascularization was also associated with decreased hazard for 3-year stroke (HR=0.81, 95% CI=0.66-0.99, p=0.04) and stroke or death (HR=0.81, 95% CI=0.76-0.87, p<0.001) compared with tfCAS. The top predictors for 30-day and 1-year mortality were postoperative complications. The primary independent predictor was the occurrence of postoperative stroke.

CONCLUSIONS

Transcarotid artery revascularization had a sustained mid-term survival advantage associated over tfCAS, with the benefit being established primarily within the first 6 months. Notably, our findings highlight the importance of postoperative stroke as the primary independent predictor for 30-day and 1-year mortal.

CLINICAL IMPACT

The ongoing debate over the superiority of TCAR compared to tfCAS and CEA has been limited by a lack of comparative studies examining the impact of pre-operative symptoms on outcomes. Furthermore, data are scarce on mid-term outcomes for TCAR beyond the perioperative period. As a result, it remains uncertain whether the initial benefits of stroke and death reduction observed with TCAR over tfCAS persist beyond one year. Our study addresses these gaps in the literature, offering evidence to enable clinicians to assess the efficacy of TCAR for up to three years. Additionally, our study seeks to identify risk factors for postoperative mortality following TCAR, facilitating optimal patient stratification.

Comparison of Perioperative Safety of Carotid Artery Stenting and Endarterectomy in the Treatment of Carotid Artery Stenosis: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Current management guidelines for the treatment of carotid stenosis are controversial. We performed this meta-analysis to evaluate the perioperative safety of carotid artery stenting (CAS) and endarterectomy.

METHODS

We systematically searched EMBASE, PubMed, Web of Science, and the Cochrane Library from inception to November 10, 2022, for randomized controlled trials that compared CAS with carotid endarterectomy (CEA) among patients with carotid stenosis. The analyzed outcomes mainly included stroke, death, myocardial infarction (MI), cranial nerve palsy, the cumulative incidence of mortality, stroke, or MI and the cumulative incidence of death or stroke in the perioperative periods. The risk ratio (RR) and 95% confidence interval (95% CI) were calculated and pooled. Subgroup analyses were based on whether patients were symptomatic or asymptomatic. We assessed the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework.

RESULTS

Seventeen randomized controlled trials with 12,277 participants (6514 and 5763 in the CAS and CEA groups, respectively) were included. Pooled analysis demonstrated that compared with CEA, CAS was associated with decreased risks of perioperative MI (RR = 0.47, 95% CI = 0.29∼0.77) and perioperative cranial nerve palsy (RR = 0.02, 95% CI = 0.01∼0.06) but higher risks of perioperative stroke (RR = 1.48, 95% CI = 1.18∼1.87) and cumulative incidence of death or stroke (RR = 1.52, 95% CI = 1.20∼1.93).

CONCLUSIONS

The perioperative safety was equivalent between CAS and CEA. However, CEA may be preferred when considering both procedural safety and long-term efficacy in preventing recurrent stroke.

A single-center experience of 30-day perioperative and one year clinical outcomes of transcarotid artery revascularization in 100 consecutive patients

BACKGROUND

Transcarotid Artery Revascularization (TCAR) using the ENROUTE system (Silk Road) has been proposed as a safe and effective alternative to both carotid endarterectomy (CEA) and transfemoral carotid artery stenting (TF-CAS). Two large registries (ROADSTER 1 and ROADSTER 2) have shown that TCAR has acceptable/low rates of perioperative stroke/death. This study will analyze the 30-day perioperative and 1-year clinical outcomes from a single-center.

PATIENT POPULATION AND METHODS

This is a retrospective analysis of prospectively collected data from SVS/VQI TCAR surveillance project (TSP) of 100 consecutive patients (102 TCAR procedures) done in our institution. These procedures were done for high-risk patients for CEA, which included anatomical (previous CEA, high cervical lesion, neck radiation, stoma, arch type, etc.), physiological (CHF, severe coronary artery disease, COPD on O2 therapy, etc.) and combined anatomical/physiological reasons. These procedures were done by vascular surgeons after receiving the appropriate training. The perioperative stroke, death, and MI rates were analyzed. Kaplan Meyer analysis was used to estimate rate of freedom from stroke/death and the incidence of ≥50% and ≥80% in-stent restenosis at 1 year.

RESULTS

100 consecutive high-risk patients for CEA included: 38% anatomical, 44% physiological, and 18% combined anatomical and physiological reasons. The mean age was 72.5 years (range 52-90 years). Indications for TCAR were 34% for symptomatic lesions (TIA/stroke) and 66% for asymptomatic lesions. Mean ipsilateral treated stenosis was 80.4%. Contralateral ≥50% stenosis/occlusion was present in 31% of patients. Technical success rate was 100%. 92% had pre-stenting PTA and 26% had post-stenting PTA. The mean flow reversal time was 8.5 min (range 3-26 min). The 30-day perioperative stroke rate was 2.9% (1/67, 1.5% for asymptomatic patients), the stroke/death rate was 2.9%, and stroke/death and MI rate was 3.9% (4/102). Other perioperative complications included cranial nerve injury 3/102 (2.9%), carotid artery dissection (2%), and major hematoma (necessitated operation evacuation) (5.9%). Freedom from stroke rates and stroke/death rates at 1 year were: 90% and 89%. Freedom from ≥50% and ≥80% in-stent restenosis rates at 1 year were 82% and 90%, respectively. None of these restenosis were symptomatic except two (2/13). Freedom from reintervention rate at 1 year was 98%.

CONCLUSION

Although the perioperative events were somewhat higher than what has been reported in previous registries, TCAR for patients who are high-risk for CEA has a low perioperative stroke and stroke/death rates with satisfactory outcome at 1 year. Further long-term data is probably needed to verify long-term outcome.

The role of post-dilatation in carotid MicroNet-covered stent implantation, evaluated using 3D cone-beam CT angiography

BACKGROUND

This study aims to assess the role and safety of post-dilatation in protected carotid artery stenting (PCAS) using the new MicroNet-covered 2nd-generation stent assessed by cone beam CT scans.

METHODS

From March 2020 to March 2022, patients were enrolled in the study according to CT angiography results based on the following criteria: Evidence of 70% to 99% carotid stenosis in asymptomatic patients and 50% to 99% in symptomatic patients, per the NASCET index. Using a FilterWire EZ™ (Boston Scientific, Natick, MA, USA) embolic protection system (EPS), MicroNet-covered stent PCAS was performed by two interventional radiologists with at least 8 years of experience in endovascular intervention. Each patient underwent post-dilatation following stent placement. Finally, a third radiologist (not participating in the interventional procedures) evaluated the cone beam CT scans and calculated residual stenosis. Major and minor complications were recorded in the 30 days following the procedure.

RESULTS

A total of 192 patients (121 male, mean age 73±10 years) were included in the study, and all patients received post-dilatation following stent implantation. Technical successes were achieved in all procedures. Adverse events noted in this study were limited to periprocedural transient ischemic attacks that occurred in three out of 192 patients (1.6%) and showed a swift complete recovery. The post-dilatation balloon diameters used in the study were: 5.0 mm (30.3%), 5.5 mm (39.3%) and 6 mm (30.3%). Optimized postdilatation resulted in a significant increase in the final luminal area. Similar improvements were observed in all subtypes of plaque.

CONCLUSIONS

Post-dilatation in protected CAS is safe and induces a significant improvement in the cross-sectional area regardless of the stenotic plaque.

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).

Prospective evaluation of acute cerebral injury by DW-MRI following transcarotid artery revascularization using a double-layer micromesh stent

BACKGROUND

Transcervical carotid artery revascularization (TCAR) has demonstrated a low overall stroke rate in carotid artery stenting (CAS). Furthermore, the use of a double-layer micromesh stent is expected to reduce embolization and plaque prolapse. The combination of TCAR and the double layer stent may lead to improved results compared to previously reported outcomes. The objective of this study is to present the findings of a prospective study including patients treated with the Roadsaver stent and TCAR.

METHODS

Between January 2017 and May 2022, 85 patients were enrolled. Every patient underwent TCAR with the Roadsaver stent. As per our protocol, a neurological examination and an ultrasound were performed within 24 hours before and after the procedure, and again 30 days after. A diffusion-weighted magnetic resonance imaging (DW-MRI) was conducted 24 hours before the procedure and 48-72 hours after the procedure. The primary endpoint was the detection of new ischemic lesions on postoperative DW-MRI. The secondary endpoint was a composite of all strokes, death, and myocardial infarction within 30 days.

RESULTS

Sixty-four patients (75.29%) were symptomatic, out of which 25 were treated within 14 days of the onset of the symptoms. Pre and postprocedural DW-MRI were performed in 83 patients. Postprocedural lesions were found in nine patients (10.84%). There were no strokes or death within 30 days, but two patients experienced a myocardial infarction.

CONCLUSIONS

Our study suggests that the use of TCAR and the Roadsaver stent could be a safe alternative to carotid endarterectomy because it entails a low incidence of cerebral embolization, even in recently symptomatic and elderly patients.

Carotid artery interventions - endarterectomy versus stenting

Current management of patients with carotid artery stenosis is based on well-established guidelines, including surgical procedures - carotid endarterectomy (CEA) and endovascular carotid artery stenting (CAS) - and optimal medical treatment alone. Outcomes in the postprocedural period after CAS and CEA are similar, suggesting strong clinical durability for both treatments. Recent advances, which include the emergence of novel endovascular treatment tools and techniques, combined with more recent randomised trial data shed new light on optimal patient selection and treatment in contemporary practice. Improved, modern technologies including enhanced embolic protection devices and dual-layered micromesh stents yield better outcomes and should result in further improvements in CAS. In centres of excellence, nowadays, the majority of patients with severe carotid artery stenosis can be successfully treated with either CEA or CAS.

What Is the Role of Transcarotid Artery Revascularization?

Carotid endarterectomy (CEA) is the gold-standard method of carotid revascularization in symptomatic patients with ≥50% and in asymptomatic patients with ≥70% stenosis. Transfemoral carotid artery stenting (TFCAS) has been associated with higher perioperative stroke rates compared to CEA in several studies. On the other hand, transcarotid artery revascularization (TCAR) has outperformed TFCAS in patients who are considered high risk for surgery. There is increasing data that supports TCAR as a safe and efficient technique with outcomes similar to those of CEA, but additional level-one studies are necessary to evaluate the long-term outcomes of TCAR in high- and standard-risk patients.

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.

Transcarotid Revascularization Timing and Early Postoperative Outcomes in Symptomatic Patients

Objective

Carotid endarterectomy (CEA) performed several days after onset of symptoms has been shown to be optimal in preventing procedure-related stroke. Transcarotid artery revascularization (TCAR) is an alternative hybrid procedure to treat high-risk for CEA patients. In this investigation, our aim is to determine the effect of timing of TCAR in symptomatic patients.

Methods

Procedures were captured prospectively at 2 independent health systems from 2016-2022 within a carotid intervention database. A retrospective analysis of this database was performed to generate cohorts by time to revascularization from onset of symptoms, with the short-interval revascularization (SIR) group defined as having a time to revascularization between 2-5 days; and long-interval revascularization (LIR) group having a time to revascularization of 6-180 days. Univariate analysis was performed comparing the cohorts at an α of .05.

Results

During the study period, 875 TCARs were captured, including 321 procedures performed in symptomatic patients. Of these, 84 had revascularization performed within 6 days after onset of symptoms (SIR) while 237 additional cases were completed 6 or more days after onset of symptoms (LIR). Baseline comorbidities were grossly similar between cohorts. Intraoperatively, SIR patients were less likely to develop bradycardia (4.8% vs 22.2%, P = .01) and experienced a shorter operative time (58 minutes vs 65 minutes, P = .02). Estimated blood loss, flow reversal time, radiation exposure, fluoroscopic time and contrast volume were identical between the groups. Length of stay in SIR patients was longer (1, IQR [1-3] vs 1, IQR [1-2] days, P < .01). Additionally, SIR patients seemed to trend toward a higher rate of reinterventions (3.6% vs .4%, P = .06). The incidence of ipsilateral or contralateral stroke, cranial nerve palsy, myocardial infarction, hematoma, stent thrombosis and death were statistically identical between the 2 groups.

Conclusion

Like the previous results established for CEA, symptomatic patients undergoing TCAR demonstrate similar outcomes if the procedure is performed 48 hours after the neurologic event.

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.

Outcomes and role of shunting during carotid endarterectomy for symptomatic patients

OBJECTIVE

Shunt placement during carotid endarterectomy (CEA) is often advocated to protect the ischemic penumbra in patients with symptomatic carotid stenosis. This study assesses the effect of shunt placement on postoperative stroke risk in symptomatic patients undergoing CEA.

METHODS

We queried the American College of Surgeons National Surgical Quality Improvement Program database (2016-2019) for CEA cases with complete CEA procedure-targeted data. Symptomatic patients were identified as having a preoperative diagnosis of stroke on presentation (DS), transient ischemic attack (TIA), amaurosis fugax (AF), or temporary monocular blindness (TMB). DS patients were further analyzed according to the severity of their stroke based on their modified Rankin Scale (mRS). To better assess the effect of shunt placement on stroke rate, we compared cases of CEA with patch angioplasty technique, with and without the use of intraoperative shunt. Patients who underwent carotid eversion or primary closure were excluded. Baseline demographics and perioperative outcomes were compared using Chi-square and Mann-Whitney U test. Multivariate analysis was performed to identify independent risk factors for postoperative stroke and cranial nerve injury.

RESULTS

We identified 4,652 cases of CEA with patch angioplasty in symptomatic patients, including 1,889 (40.6%) with shunt placement and 2,763 (59.4%) without. Age, race, and sex distributions were similar for both procedures. Compared to patients without shunt, those with shunt had significantly higher rates of emergency (9.1% vs 7.0%, P = .010) and non-elective surgery (40.3% vs 37.2%, P = .035), general anesthesia (97.0% vs 86.3%, P < .001), and bleeding disorders (27.2% vs 22.7%, P < .001). Thirty-day incidence of postoperative stroke was similar between patients who had shunt placement (3.2%) and those who did not (2.6%) (P = .219). Additionally, subgroup analysis failed to show any benefit of shunting on postoperative stroke regardless of preoperative symptoms or neurologic disability. In contrast, shunt placement was associated with increased rate of cranial nerve injury (4.1% vs 2.4%, P = .001). Multivariate analysis revealed that non-elective surgery (OR 1.99, 95% CI 1.36-2.91, P < .001) and DS (vs TIA/AF/TMB) (OR 1.64, 95% CI 1.12-2.41, P = .012) were predictive of 30-day postoperative stroke. After adjusting for confounders, shunt placement had no effect on stroke risk at 30 days but remained an independent risk factor for cranial nerve injury (aOR 1.87, 95% CI 1.32-2.64, P < .001).

CONCLUSIONS

In symptomatic patients undergoing CEA with patch angioplasty, shunting is associated with increased risk of cranial nerve injury without reduction in postoperative stroke risk.

Comparison of Recent Practice Guidelines for the Management of Patients With Asymptomatic Carotid Stenosis

Despite the publication of several national/international guidelines, the optimal management of patients with asymptomatic carotid stenosis (AsxCS) remains controversial. This article compares 3 recently released guidelines (the 2020 German-Austrian, the 2021 European Stroke Organization [ESO], and the 2021 Society for Vascular Surgery [SVS] guidelines) vs the 2017 European Society for Vascular Surgery (ESVS) guidelines regarding the optimal management of AsxCS patients.The 2017 ESVS guidelines defined specific imaging/clinical parameters that may identify patient subgroups at high future stroke risk and recommended that carotid endarterectomy (CEA) should or carotid artery stenting (CAS) may be considered for these individuals. The 2020 German-Austrian guidelines provided similar recommendations with the 2017 ESVS Guidelines. The 2021 ESO Guidelines also recommended CEA for AsxCS patients at high risk for stroke on best medical treatment (BMT), but recommended against routine use of CAS in these patients. Finally, the SVS guidelines provided a strong recommendation for CEA+BMT vs BMT alone for low-surgical risk patients with >70% AsxCS. Thus, the ESVS, German-Austrian, and ESO guidelines concurred that all AsxCS patients should receive risk factor modification and BMT, but CEA should or CAS may also be considered for certain AsxCS patient subgroups at high risk for future ipsilateral ischemic stroke.

New paradigms in minimally-invasive vascular surgery

INTRODUCTION

Vascular surgery has been greatly evolved during the last decades and novel minimally invasive techniques have been introduced. Aim of this review is to briefly present all these advances and compare them with traditional repairs.

AREAS COVERED

The authors have extensively searched literature through the Pubmed and Embase databases. All articles published up to December 2021 referring to minimally invasive techniques used for treatment of peripheral artery disease, carotid disease, aortic aneurysms and venous disease were evaluated. Minimally invasive techniques under investigation included endovascular and hybrid techniques, robot-assisted and laparoscopic approaches.

EXPERT OPINION

Several minimally invasive techniques such as endovascular and hybrid approaches have been extensively used during the last two decades to treat vascular surgery patients offering them lower mortality and morbidity risks. Novel robot assisted techniques have shown promising results in preclinical studies although further clinical evaluation is needed.

Diabetes Mellitus and Clinical Outcomes in Carotid Artery Revascularization Using Second-Generation, MicroNet-Covered Stents: Analysis from the PARADIGM Study

INTRODUCTION

Carotid artery stenting (CAS) using conventional (single-layer) stents is associated with worse clinical outcomes in diabetes mellitus (DM) vs. non-DM patients: an effect driven largely by lesion-related adverse events. CAS outcomes with MicroNet-covered stents (MCS) in diabetic patients have not been evaluated.

AIM

To compare short- and long-term clinical outcomes and restenosis rate in DM vs. non-DM patients with carotid stenosis treated using MCS.

MATERIALS AND METHODS

In a prospective study in all-comer symptomatic and increased-stroke-risk asymptomatic carotid stenosis, 101 consecutive patients (age 51-86 years, 41% diabetics) underwent 106 MCS-CAS. Clinical outcomes and duplex ultrasound velocities were assessed periprocedurally and at 30 days/12 months.

RESULTS

Baseline characteristics of DM vs. non-DM patients were similar except for a higher prevalence of recent cerebral symptoms in DM. Type 1 and type 1+2 plaques were more prevalent in DM patients (26.7% vs. 9.8%, p = 0.02; 62.2% vs. 37.7%, p = 0.01). Proximal embolic protection was more prevalent in DM (60% vs. 36%; p = 0.015). 30-day clinical complications were limited to a single periprocedural minor stroke in DM (2.4% vs. 0%, p = 0.22). 12-month in-stent velocities and clinical outcomes were not different (death rate 4.8% vs. 3.3%; p = 0.69; no new strokes). Restenosis rate was not different (0% vs. 1.7%, p = 0.22).

CONCLUSIONS

MCS may offset the adverse impact of DM on periprocedural, 30-day, and 12-month clinical complications of CAS and minimize the risk of in-stent restenosis. In this increased-stroke-risk cohort, adverse event rate was low both in DM and non-DM. Further larger-scale clinical datasets including extended follow-ups are warranted.

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).