Trans-Carotid Artery Revascularization Versus Carotid Endarterectomy in Patients With Carotid Artery Disease: Systematic Review and Meta-analysis of 30-day Outcomes

This systematic review and meta-analysis compared trans-carotid artery revascularization (TCAR) as an alternative approach to carotid endarterectomy (CEA) in patients with carotid artery disease. An electronic search was conducted using PubMed, Scopus, and Cochrane databases including comparative studies with patients who underwent either TCAR or CEA. This meta-analysis is according to the recommendations of the PRISMA statement. Eight studies met our eligibility criteria, incorporating 7,606 and 7,048 patients in the TCAR and CEA groups, respectively. Thirty-day mortality (odds ratio [OR]: 0.94, 95% confidence interval [CI]: 0.56-1.56, P = .81) and stroke (OR: 0.92, 95%CI 0.70-1.22, P = .57) were similar between the two groups, with low heterogeneity. The odds of myocardial infarction (OR: 1.79, 95% CI: 1.18-2.71, P = .01) and cranial nerve injury were significantly higher in patients undergoing CEA compared with TCAR (OR: 4.11, 95% CI: 2.59-6.51, P < .001). The subgroup analysis according to symptomatic pre-intervention status revealed no statistically significant difference regarding 30-day mortality (symptomatic OR: 0.91, 95% CI: 0.40-2.07, P = .82, asymptomatic OR: 0.93, 95% CI: 0.46-1.86, P = .83) and stroke (symptomatic OR: 0.88, 95% CI:0.47-1.64, P = .68, asymptomatic OR: 0.93, 95% CI: 0.64-1.35, P = .70). TCAR offers an alternative treatment for patients with carotid artery stenosis with comparable to CEA mortality and stroke rates during a 30-day post-operative period.

Assessment of Conflicts of Interest in the Transcarotid Artery Revascularization Literature

INTRODUCTION

To systematically review the accuracy of self-reported conflicts of interest (COIs) among transcarotid artery revascularization (TCAR) studies and evaluate factors associated with increased discrepancies.

MATERIALS AND METHODS

A literature search identified all TCAR-related studies with at least one American author published between January 2017 and December 2020. Industry payments from Silk Road Medical, Inc. were collected using the Centers for Medicare and Medicaid Open Payments database. COI discrepancies were identified by comparing author declaration statements with payments found for the year of publication and year prior (24-mo period). Risk factors for COI discrepancy were evaluated at both the study and author level.

RESULTS

A total of 79 studies (472 authors) were identified. Sixty four studies (81%) had at least one author who received payments from Silk Road Medical, Inc. Fifty eight (73%) studies had at least one author who received an undeclared payment. Consulting fees represented the majority of general payment subtype (60%). Authors who accurately disclosed payments received significantly higher median payments compared to authors who did not accurately disclose payments ($37,222 [interquartile range: $28,203-$132,589] versus $1748 [interquartile range $257-$35,041], P < 0.0001). Senior authors were significantly more likely to have a COI discrepancy compared to first authors (P = 0.0219).

CONCLUSIONS

The majority of TCAR-related studies did not accurately declare COI. A multivariate analysis demonstrated no effect of sponsorship on study recommendations or impact factor. This study highlights the need for increased efforts in accountability to improve the transparency of industry sponsorship, especially when consulting authors are reporting their results on patient outcomes.

Association of Year of Surgery and Carotid Stenting Outcomes in High-risk Patients, 2015-2021

This cohort study quantifies the yearly trends and outcomes of transcarotid artery revascularization vs transfemoral carotid artery stenting among high-risk patients from 2015 to 2021.

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.

Impact of Flow Reversal Duration on Neurological Outcomes of Transcarotid Artery Revascularization (TCAR)

BACKGROUNDS

Flow reversal is a key component of transcarotid artery revascularization (TCAR). However, the impact of flow reversal duration on neurological outcomes and the duration of flow reversal which optimizes TCAR's outcomes is not known. We evaluated the association of flow reversal time with the intraoperative and postoperative neurological outcomes of TCAR.

METHODS

We studied all patients undergoing TCAR from September 2016 to October 2021. The exposure of interest was the duration of flow reversal. Multivariable logistic and fractional polynomial models were used to study the impact of flow reversal duration on in-hospital stroke, intraoperative neurological change/intolerance and stroke/death following TCAR and to identify the flow reversal time above which significant perioperative neurological events occur.

RESULTS

The study included 19,462 patients with mean age of 73.4 years who were mostly Caucasian (91%) and male (63%). The mean flow reversal time was 10.7 minutes, and the overall stroke rate was 1.4%. The odds of intraoperative neurological change increased by 3.6% per minute increase in flow reversal time (odds ratio (OR), 1.04; 95%, 1.01-1.06; P < 0.002). Flow reversal duration >10 minutes was associated with 78% increased odds of neurological changes compared to flow reversal duration <10 minutes. There was no significant association between flow reversal duration and stroke, and stroke/death in the first 5 minutes after initiation of flow reversal. The odds of stroke increased by 2.7% per minute increase in flow reversal time >5 minutes (OR, 1.03; 95%, 1.01-1.04; P < 0.001), with flow reversal duration >10 minutes associated with 38% increased odds of stroke compared to flow reversal duration ≤10 minutes (OR, 1.37, 95% confidence interval (CI), 1.09-1.73, P = 0.006). The odds of stroke/death increased by 2.5% per minute increase in flow reversal time >5 minutes (OR, 1.03; 95%, 1.01-1.04; P < 0.001). Flow reversal duration >10 minutes was associated with 25% increased odds of stroke/death compared to flow reversal duration <10 minutes (OR, 1.25, 95% CI, 1.01-1.53, P = 0.038). Symptomatic status did not modify outcomes.

CONCLUSIONS

Our findings suggest that outcomes following TCAR are optimal if the duration of flow reversal is minimized. A clinical cutoff time of 10 minutes is suggested by this study and recommended as a guide. Further studies targeted at the flow reversal component of TCAR are needed to solidify the evidence regarding the clinical effects of temporarily induced retrograde cerebral blood flow during TCAR.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Proximal versus distal protection: dissecting clinical trials

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

Predicting Transcarotid Artery Revascularization adverse outcomes by Imaging Characteristics

OBJECTIVES

Approximately 20-30% of ischemic strokes are caused by internal carotid artery stenosis. Stroke is the leading cause of disability and the second leading cause of death in the United States. Second generation Trans Carotid Arterial Revascularization (TCAR) stenting, using the ENROUTE flow reversal technology to prevent embolic stroke during the stenting process, has demonstrated stroke and death outcomes equivalent to CEA with reduced cranial nerve injury. However, at present, it is not known whether imaging characteristics obtained pre-operatively can predict outcomes of TCAR procedures.

METHODS

This retrospective cohort study included patients who underwent TCAR with flow reversal at 3 hospitals within a single hospital network who had CT angiography, MRI angiography or pre-operative diagnostic angiogram to determine whether carotid and lesion characteristics could predict patients who experienced Major Adverse Critical Events (MACE) versus those who did not. MACE was defined as myocardial infarction at 30 days, restenosis/persistent stenosis (peak systolic velocity within the stent >230cm/sec by post-operative ultrasound), stroke within any time of follow up or death within 1 year of TCAR. Student's t-tests and chi-squared tests were used to compare imaging characteristics, such as presence of pinpoint stenosis, calcification within the common carotid artery (CCA) at the take-off from the aorta, and plaque length in millimeters. Binomial logistic regression was used to examine the likelihood that imaging characteristics were associated with MACE.

RESULTS

Of 220 patients who underwent TCAR in our network, 7 were excluded because flow reversal was not used or appropriate imaging had not been performed prior to TCAR. Of the 213 patients that were included in analysis, the median length of follow up was 10.8 months (IQR: 3.4-33.1 months). Twelve percent (26/213) experienced a MACE, and a model based on imaging characteristics was statistically significant in predicting MACE with 68% accuracy (P=0.005). The presence of pinpoint stenosis was highly predictive of MACE (HR: 3.34, CI: 1.2 to 9.3, P=0.021). A shorter clavicle to carotid bifurcation distance was associated with an increased likelihood of experiencing a MACE (P=0.009), but it was weakly predictive (HR 1.03, CI: 1.01 to 1.05).

CONCLUSIONS

Pre-operative imaging characteristics, such as pinpoint stenosis and clavicle to carotid bifurcation distance, can be used to predict adverse outcomes in TCAR placement.

Transcarotid artery revascularization in reverse for innominate artery stenosis

Stenotic lesions of the supra-aortic vessels have been reported in 2-6% of patients presenting with corresponding symptoms. In the past, these lesions have been treated with open surgical techniques. More recently, endovascular treatment approaches have been proposed for occlusive lesions in the innominate (IA) or common carotid (CCA) arteries. Retrograde stenting of IA and CCA lesions using flow reversal has been described in a retrospective case series; however, a modification of their technique is proposed. Case Presentation: The patient is a 68-year-old male with symptoms of right upper extremity claudication. CT angiogram revealed critical stenosis of the innominate artery and high-grade stenosis of the right subclavian artery. The patient consented to retrograde stenting of the innominate stenosis with neuroprotection using flow reversal or transcarotid revascularization (TCAR) in reverse. Surgical cut-down was performed of the carotid bifurcation, and a U-stitch was placed on the anterior wall of the distal common carotid artery. Flow reversal was achieved by connecting the arterial sheath to the venous sheath. The innominate lesion was crossed, primarily stented with a VBX stent, and post-dilated with a non-compliant balloon. Just prior to crossing the lesion and primary stent placement, the vessel loop around the common carotid and internal carotid arteries were pulled up to ensure neuroprotection while the stent was expanded. This was continued for two minutes before restoring antegrade flow first in the external carotid and then in the internal carotid artery. There were no adverse events. At one month follow-up, the patient reported no right arm claudication symptoms. TCAR for the proximal lesion as described in other case series may not adequately attain flow based neuroprotection. Under that circumstance, the arterial sheath is acting as a conduit to deliver the stent. Risk of embolization to the brain may not be mitigated when the proximal lesion is stented and antegrade flow restored.

Transcarotid artery revascularization (TCAR) stenting or angioplasty for intracranial carotid artery stenosis: Case series and novel application

BACKGROUND

Carotid artery stenting is associated with a higher rate of stroke compared to carotid endarterectomy (CEA). This is likely due to procedural emboli resulting from plaque disruption. The transcarotid artery revascularization (TCAR) method aims to reduce the stroke rate by flow-reversal. TCAR, which has yet to be utilized for intracranial atherosclerotic disease (ICAD), may be particularly valuable given the lack of surgical treatment options for intracranial arterial stenosis.

OBJECTIVE

Presented here are five cases of angioplasty or stenting that demonstrate the feasibility of TCAR for intracranial Internal Carotid Artery (ICA) stenosis treatment.

METHODS

Five cases were reviewed retrospectively and summarized using PROCESS and CARE guidelines.

RESULTS

All patients who underwent intervention between the petrous and ophthalmic segment of the ICA had no new neurologic deficit nor detected embolic stroke. One patient experienced an asymptomatic 5 mm hemorrhage on postoperative routine Computed Tomography (CT) head imaging.

CONCLUSIONS

This highlights a new method for treating intracranial ICA stenosis with a potentially reduced stroke risk. Given the historically higher stroke rates for cervical ICA stenting compared to carotid artery endarterectomy, this method may improve the previously higher stroke rates in endovascular carotid artery treatment, compared to CEA. Although this series is small, it illustrates a novel use for a rising technique that should be further evaluated in a larger study to validate its efficacy as a new treatment modality for surgically inaccessible intracranial disease.

Carotid Interventions for Women: The Hazards and Benefits

The goal of the current review is to examine the hazards and benefits of carotid interventions in women and to provide recommendations for the indications for carotid intervention in female patients. Stroke and cerebrovascular disease are prevalent in women. There are inherent biological and other differences in men and women, which affect the manifestations and outcome of stroke, with women experiencing worse disability and higher mortality following ischemic stroke than men. Due to the underrepresentation of female patients in most clinical trials, the ability to make firm but alternative recommendations for women specifically on the management of carotid stenosis is challenging. Although some data suggest that women might have worse periprocedural outcomes as compared to men following all carotid revascularization procedures, there is also an abundance of data to support a similar risk for carotid procedures in men and women, especially with carotid endarterectomy and transcarotid artery revascularization. Therefore, the indications for carotid revascularization are the same in women as they are in men. The choice of a carotid revascularization procedure in women is based upon the same factors as in men and requires careful evaluation of a particular patient's risk profile, anatomic criteria, plaque morphology, and medical comorbidities that might favor one technique over the other. When performing carotid revascularization procedures in women, tailored techniques and procedures to address the small diameter of the female artery 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.

Performance of Carotid Revascularization Procedures as Modified by Sex

BACKGROUND

Current recommendations on carotid revascularization postulate that women have both increased perioperative risks, such as stroke and death, as well as reduced benefit from intervention. These recommendations do not include data on transcarotid artery revascularization (TCAR). This study strives to compare safety and benefits of TCAR, TFCAS (Transfemoral Carotid Artery Stenting), and CEA (Carotid Endarterectomy) with regard to patient sex.

METHODS

We performed retrospective analysis of the Society for Vascular Surgery (SVS) Vascular Quality Initiative (VQI) CEA and stenting registries, as well as TCAR Surveillance Project data. We compared outcomes after TCAR, TFCAS, and CEA based on sex. The primary outcome was the rate of in-hospital stroke or death. Secondary outcomes included in-hospital stroke, death, transient ischemic attack (TIA), myocardial infarction (MI), stroke/death/MI, stroke/TIA, and recurrent ipsilateral stroke and/or death at 1-year of follow-up.

RESULTS

 A total of 75,538 patients were included, of which 28,960 (38.3%) were female and 46,578 (61.7%) were male. TFCAS females had more than 2 times higher odds of stroke/death (OR:2.85, 95%CI: 2.21-3.67, P < 0.001) and stroke/death/MI (OR:2.23, 95%CI:1.75-2.83, P < 0.001) when compared to CEA females. Odds of TIA were also higher in both TFCAS females (OR:2.01, 95%CI:1.19-3.42, P = 0.010) and TCAR females (OR:1.91, 95%CI:1.09-3.35, P = .023) when compared to CEA females. However, only TFCAS females experienced increased odds of stroke/TIA (OR:1.96, 95%CI:1.45-2.65, P < 0.001) when compared to CEA females. TFCAS males had almost twice the odds of stroke/death (OR:1.74, 95%CI:1.39-2.16, P < 0.001) and 44% higher odds of stroke/death/MI (OR:1.44, 95%CI:1.19-1.75, P < 0.001), and more than 3-times increased odds of death (OR:3.45, 95%CI:2.53-4.71, P < 0.001) when compared to CEA males. Odds of in-hospital stroke were comparable between TFCAS and CEA after adjusting for covariates. TCAR males have half the odds of MI when compared to CEA males (OR:0.52, 95%CI:0.34-0.80, P = 0.003). At 1-year TCAR had comparable risk of stroke/death while TFCAS had increased risk of stroke/death when compared to CEA among both males and females.

CONCLUSION

TCAR performed similarly to CEA in both sexes regardless of symptomatic status. Stroke/death and stroke/death/MI rates were similar in symptomatic and asymptomatic males and females treated by CEA or TCAR. The 1-year outcomes of TCAR were also comparable to CEA in both sexes. It seems that TCAR may be a safe alternative to CEA particularly in women when surgical risk prohibits CEA and while TFCAS is associated with substantial adverse outcomes.

Risk Factors for and Intraoperative Management of Intolerance to Flow Reversal in TCAR

BACKGROUND

In patients deemed high risk for carotid endarterectomy (CEA) who are indicated for treatment of carotid artery stenosis (CAS), transcarotid artery revascularization (TCAR) has been demonstrated as a safe and effective alternative to trans-femoral carotid artery stenting (TF-CAS). Compared to CEA, where approx. 12% of patients undergoing awake intervention do not tolerate internal carotid artery (ICA) clamping, only 1-2% of patients were observed to have intolerance to flow reversal during TCAR based on data from the ROADSTER1/2 trials. This study reviewed awake interventions from those trials to assess factors associated with intolerance to flow reversal and review how those cases were managed.

METHODS

This is a retrospective review of prospectively collected data from Reverse Flow Used During Carotid Artery Stenting Procedure (ROADSTER) multicenter trial along with the subsequent post-approval (ROADSTER-2) trial. The subset of patients from both trials undergoing awake TCAR was analyzed to compare demographics, procedural details, and anatomic factors between patients who did and did not experience intolerance to reversal of flow to assess for predisposing factors. Patients were deemed intolerant to flow reversal at the discretion of the operator, often related to changes in completion of neurologic tasks, hemodynamic stability, or patient reported symptoms.

RESULTS

A total of 103 patients from ROADSTER and 194 patients from ROADSTER-2 underwent TCAR under local/regional anesthesia. Of these, 8 patients had intolerance to flow reversal, though all cases were successfully completed. While intraoperative hemodynamic data was only available for 5 of the 8 intolerant patients, none experienced hypotension. 4 cases were completed under low flow reversal, 3 cases were successfully weaned from low to high flow over several minutes, and 1 case required general anesthesia. No significant association was found between intolerance to flow reversal and comorbidities including diabetes mellitus (DM), hypertension (HTN), hyperlipidemia (HLD), congestive heart failure (CHF), prior MI or angina, pre-op CAS-related symptoms, prior stroke, prior CAS or CEA, prior neck radiation, tandem stenosis, high cervical stenosis, or hostile neck. A trend towards significance was seen with chronic obstructive pulmonary disease (COPD) and contralateral carotid artery occlusion (P = 0.086 and 0.139, respectively).

CONCLUSIONS

Despite intolerance to flow reversal, TCAR cases were successfully completed by adjusting reversal-of-flow rate and do not typically require conversion to GETA. While factors contributing to intolerance of flow reversal during TCAR remain poorly understood, this study identified a trend towards significance with an association of preexisting COPD and contralateral carotid artery occlusion. Given the low number of patients who experienced this issue, a larger sample size is required to better elucidate these trends.

Current evidence for transcarotid artery stenting with flow reversal as the preferred carotid artery stenting approach

Although the transfemoral approach to carotid artery stenting offers a minimally invasive method for treatment of carotid atherosclerotic disease, this technique for carotid revascularization has unfortunately not led to equivalent overall outcomes of stroke or death compared with endarterectomy in symptomatic or high-risk patients. Transcarotid artery revascularization (TCAR) with a flow reversal neuroprotection system was designed to reduce the embolic risk associated with the transfemoral approach, but randomized trials have yet to be published comparing transfemoral carotid artery stenting with TCAR. Regardless, many surgeons and interventionalists have already adopted TCAR as the preferred modality for carotid artery stenting, given the accumulating evidence supporting the reduced stroke or death benefits of TCAR over the transfemoral approach.

Assessing the Suitability of the Carotid Bifurcation for Stenting: Anatomic and Morphologic Considerations

OBJECTIVE

Over the years where stents have been used to treat carotid lesions, a great deal has been learned about which anatomical characteristics lead to adverse outcomes. This review summarizes the anatomic and morphologic characteristics of the carotid vasculature that can help guide patient selection and clinical decision-making.

METHODS

Each of the carotid artery anatomy and lesion characteristics that are relevant to carotid stenting are described in detail. These are accompanied with evidence-based outcomes and results.

RESULTS

Data on the prevalence of carotid artery lesions that are unsuitable for stenting are summarized and the implications of these data for practice are discussed, especially as they pertain to transcarotid artery revascularization.

CONCLUSIONS

CAS can be viable option for carotid revascularization, but the lesion must be acceptable and safe for stent placement. There should be thorough assessment to rule out the presence of severe tortuosity, long-segment disease, severe calcification (circumferential or exophytic), mobile-plaque, swollen ICA sign, and carotid diameters outside the acceptable range. In carefully chosen lesions with the absence of the unfavorable characteristics described-TCAR may offer improved periprocedural success, and CAS may attain better long-term durability.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Carotid stenosis, stroke, and carotid artery revascularization

Atherosclerotic disease of the carotid artery places patients at risk of ischemic stroke and consequently is a target of medical, endovascular and open surgical management. Various imaging modalities are used to characterize anatomy/severity of carotid disease and justify intervention, each having advantages and disadvantages. Carotid revascularization techniques including carotid artery stenting, carotid endarterectomy, and transcarotid artery revascularization vary in invasiveness and are not equally suitable for certain subsets of patients. As such, providing quality care for patients with carotid disease requires a multidisciplinary team of experts in clinical diagnosis, image interpretation, medical management, endovascular intervention, and surgical treatment.

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

OBJECTIVE

Transcarotid/transcervical revascularisation (TCAR) is an alternative to carotid endarterectomy (CEA) and transfemoral carotid stenting (tfCAS). This review aimed to evaluate pooled data on patients undergoing TCAR.

DATA SOURCES

Medline, Embase, Scopus, and Cochrane Library databases were used.

REVIEW METHODS

This systematic review was conducted under Systematic Reviews and Meta-Analysis guidelines. Eligible studies (published online up to September 2020) reported 30 day mortality and stroke/transient ischaemic attack (TIA) rates in patients undergoing TCAR. Data were pooled in a random effects model and weight of effect for each study was also reported. Quality of studies was evaluated according to Newcastle - Ottawa scale.

RESULTS

Eighteen studies (three low, seven medium, and eight high quality) included 4 852 patients (4 867 TCAR procedures). The pooled 30 day mortality rate was 0.7% (n = 32) (95% confidence interval [CI] 0.5 - 1.0), 30 day stroke rate 1.4% (n = 62) (95% CI 1.0 - 1.7), and 30 day stroke/TIA rate 2.0% (n = 92) (95% CI 1.4 - 2.7). Pooled technical success was 97.6% (95% CI 95.9 - 98.8). The cranial nerve injury rate was 1.2% (95% CI 0.7 - 1.9) (n = 14; data from 10 studies) while the early myocardial infarction (MI) rate was 0.4% (95% CI 0.2 - 0.6) (n = 16; data from 17 studies). The haematoma/bleeding rate was 3.4% (95% CI 1.7 - 5.8) (n = 135; data from 10 studies), with one third of these cases needing drainage or intervention. Within a follow up of 3 - 40 months the restenosis rate was 4% (95% CI 0.1 - 13.1) (data from nine studies; n = 64/530 patients) and death/stroke rate 4.5% (95% CI 1.8 - 8.4) (data from five studies; n = 184/3 742 patients). Symptomatic patients had a higher risk of early stroke/TIA than asymptomatic patients (2.5% vs. 1.2%; odds ratio 1.99; 95% CI 1.01 - 3.92); p = .046; data from eight studies).

CONCLUSION

TCAR is associated with promising early and late outcomes, with symptomatic patients having a higher risk of early cerebrovascular events. More prospective comparative studies are needed in order to verify TCAR as an established alternative treatment technique.

Stenting the carotid artery from radial access using a Simmons guide catheter

BACKGROUND

Carotid artery stenting (CAS) is a procedure for stroke prevention, usually done from femoral artery access. Reports of CAS using radial artery access have adopted techniques similar to those used for transfemoral CAS. Initial experience with a simpler and lower profile technique for transradial carotid stenting is described here.

METHODS

Of 55 consecutive elective CAS cases with standard (not bovine) arch anatomy performed during a 15 month time period by the same operator, 20 were selected for transradial treatment using a 6 F Simmons 2 guide catheter. This was a retrospective analysis of those initial 20 patients compared with the 35 patients treated with elective transfemoral CAS. The CAS database was reviewed for clinical indications, technique, procedure and fluoroscopy times, and clinical outcomes.

RESULTS

All procedures were technically successful (no crossovers). No patient had a decline in National Institutes of Health Stroke Scale score or modified Rankin Scale score within 30 days. Mean (95% CI) procedural times for transradial CAS were slightly higher than transfemoral CAS (29.4 (26.0 to 32.7) vs 23.8 (21.2 to 26.4) min, p=0.0098). Mean (95% CI) fluoroscopy times were also higher for transradial CAS compared with transfemoral CAS (9.6 (8.0 to 11.2) vs 6.4 (5.4 to 7.4), p=0.0006). One patient developed a radial artery pseudoaneurysm which required elective surgical repair.

CONCLUSION

Transradial carotid stenting using the described lower profile technique provides another effective option in the array of surgical procedures for the treatment of carotid artery stenosis. Relative procedural and fluoroscopy times may initially be longer compared with transfemoral carotid stenting for experienced CAS operators, although absolute differences are small.

Poststent ballooning during transcarotid artery revascularization

BACKGROUND

Poststent ballooning/angioplasty (post-SB) have been shown to increase the risk of stroke risk after transfemoral carotid artery stenting. With the advancement of transcarotid artery revascularization (TCAR) with dynamic cerebral blood flow reversal, we aimed to study the impact of post-SB during TCAR.

METHODS

Patients undergoing TCAR in the Vascular Quality Initiative between September 2016 and May 2019 were included and were divided into three groups: those who received prestent deployment angioplasty only (pre-SB, reference group), those who received poststent deployment ballooning only (post-SB), and those who received both prestent and poststent deployment ballooning (prepost-SB). Patients who did not receive any angioplasty during their procedure (n = 367 [6.7%]) were excluded because these represent a different group of patients with less complex lesions than those requiring angioplasty. Primary outcome was in-hospital stroke or death. Analysis was performed using univariable and multivariable logistic regression models.

RESULTS

Of 5161 patients undergoing TCAR, 34.7% had pre-SB only, 25% had post-SB only, and 40.3% had both (prepost-SB). No differences in the rates of in-hospital and 30-day stroke, death, and stroke/death were observed among the three groups; in-hospital stroke/death in the pre-SB group was 1.4% (n = 25), post-SB 1.2% (n = 16), and prepost-SB 1.4% (n = 29; P = .92). However, patients undergoing post-SB and prepost-SB had higher rates of in-hospital transient ischemic attacks (TIA) (post-SB, 0.9%; prepost-SB, 1% vs pre-SB, 0.2%, P < .01) and postprocedural hypotension (16.6% and 16.8% vs 13.1%, respectively; P < .001). Post-SB also had longer operative times, as well as flow reversal and fluoroscopy times. On multivariable analysis, no association was seen between post-SB and the primary outcome of in-hospital stroke/death (post-SB odds ratio [OR], 0.88; 95% confidence interval [CI], 0.44-1.73; prepost-SB OR, 0.98; 95% CI, 0.57-1.70). Similarly, no significant differences were noted in terms of postprocedural hemodynamic instability and 30-day outcomes. However, post-SB and prepost-SB were associated with four times the odds of in-hospital TIA compared with pre-SB alone (post-SB OR, 4.24 [95% CI, 1.51-11.8]; prepost-SB OR, 4.76 [95% CI, 1.53-14.79]; P = .01). Symptomatic patients had higher rates of in-hospital stroke/death compared with their asymptomatic counterparts; however, there was no significant interaction between symptomatic status and ballooning in predicting the primary outcome.

CONCLUSIONS

Post-SB was used in 65.3% of TCAR patients. This maneuver seems to be safe without an increase in the odds of postoperative in-hospital stroke/death. However, the increased rates of TIA associated with post-SB requires further investigation.

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.

Duplex Ultrasound Surveillance after Transcarotid Artery Revascularization (TCAR) in Clinical Practice

BACKGROUND

To propose a protocol for the routine clinical use of duplex ultrasound (DUS) assessment after transcarotid artery revascularization (TCAR) procedures, with its specific point of vascular access, based on DUS data from routine clinical practice.

METHODS

DUS data were retrospectively collected at 2 centers from a total of 97 patients who underwent a TCAR procedure with at least 30-day and up to 12-month follow-up. Peak systolic velocity (PSV), end diastolic velocity (EDV), and the internal carotid artery (ICA)/common carotid artery (CCA) PSV ratio were collected at baseline (≤30 days after the procedure) and compared with subsequent measurements.

RESULTS

Baseline data were established within 30 days after the procedure. There were no access site stenoses, pseudoaneurysms, or dissections detected in follow-up. Average hemodynamics measurements at 12 months after the procedure (36% of patients reached this time point to date) were PSV 167 ± 153 cm/sec, EDV 51 ± 55 cm/sec, and ICA/CCA PSV 2.3 ± 1.9. Five patients (5.2%) exhibited velocities indicative of ≥80% in-stent restenosis (ISR) at 12 months after the procedure. Two patients (2.1%) underwent repeat intervention for ISR based on high velocities and before significant clinical consequence. The other 3 patients (3.1%) were asymptomatic and are being managed medically and monitored for neurological symptoms. One intraprocedural stroke (1.0% of total treated) was observed.

CONCLUSIONS

This protocol not only illustrates the utility of using the CCA for the arterial access sheath for carotid stenting, but also successfully identifies patients with clinically significant restenosis >80%-99%. A surveillance regimen of baseline at ≤30 days after the procedure, followed by assessment at 6 and 12 months, and yearly thereafter appears to be a safe and effective protocol, based on the data available to date. A PSV >340 cm/sec and ICA/CCA ratio >4.15 is consistent with an 80-99% restenosis after TCAR. Although a small number, this study serves as a starting point for those who perform TCAR to specifically look at the CCA access site to rule out these potential pitfalls which did occur in the early trials.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Critical Appraisal on the Quality of Reporting on Safety and Efficacy of Transcarotid Artery Stenting With Flow Reversal

Transcarotid revascularization is an alternative to transfemoral carotid artery stenting, designed to avoid aortic arch manipulation and concomitant periprocedural stroke. This article aims to perform a detailed analysis on the quality of the currently available evidence on safety and efficacy of transcarotid artery revascularization. Although current evidence is promising, independent randomized controlled studies comparing transcarotid artery revascularization with carotid endarterectomy in recently symptomatic patients are lacking and will be necessary to establish the true value of transcarotid artery revascularization in carotid artery revascularization.

Outcomes of transcarotid artery revascularization with dynamic flow reversal in patients with contralateral carotid artery occlusion

BACKGROUND

The outcomes of carotid revascularization in patients with contralateral carotid artery occlusion (CCO) are controversial. CCO has been defined by the Centers for Medicare and Medicaid Services as a high-risk criterion and is used as an indication for transfemoral carotid artery stenting. With the promising outcomes associated with transcarotid artery revascularization (TCAR), we aimed to study the perioperative outcomes of TCAR in patients with CCO and to assess the feasibility of TCAR in these high-risk patients.

METHODS

All patients in the Vascular Quality Initiative database who underwent TCAR with flow reversal between September 2016 and May 2019 were included. Patients with trauma, dissection, or more than two treated lesions were excluded. Univariable and multivariable logistic analyses were used to compare the primary outcome of in-hospital stroke or death after TCAR in patients with CCO and those without CCO (patent and <99% stenosis). Secondary outcomes included intraoperative neurologic changes and the individual outcomes of in-hospital stroke, death, and myocardial infarction as well as 30-day mortality.

RESULTS

A total of 5485 TCAR cases were included, of which 593 (10.8%) had CCO. In patients with CCO, mean flow reversal time was shorter (10.1 ± 6.7 minutes vs 11.1 ± 7.8 minutes; P < .01); intraoperative neurologic changes occurred in 1% of these patients compared with 0.7% of those with patent contralateral carotid arteries (P = .43). On univariable analysis, no significant difference in in-hospital stroke or death was shown between patients with and patients without CCO (1.7% vs 1.5%; P = .65). Similarly, no significant differences were noted between the groups in terms of in-hospital death (0.7% vs 0.4%; P = .27), stroke (1.7% vs 1.2%; P = .32), and stroke/death/myocardial infarction (2.2% vs 1.8%; P = .53) as well as 30-day mortality (0.8% vs 0.6%; P = .55). The results remained statistically nonsignificant after adjustment for baseline differences between the groups; the adjusted odds ratio (OR) of in-hospital stroke/death in patients with CCO compared with those with patent contralateral carotid arteries was not significant (OR, 1.39; 95% confidence interval, 0.65-3.0; P = .40). In symptomatic patients presenting with prior stroke, CCO was associated with significantly higher odds of stroke or death (OR, 4.63; 95% confidence interval, 1.39-15.4; P = .01) compared with no CCO. On the other hand, in asymptomatic patients, no significant difference in outcomes was observed between the groups.

CONCLUSIONS

In this analysis, TCAR seems to be safe in patients with CCO. Caution should be taken in symptomatic patients with CCO and a history of prior stroke as they might have worse outcomes compared with patients with patent contralateral carotid arteries. Studies with larger sample size and longer follow-up are needed to assess the perioperative and long-term outcomes of TCAR in patients with CCO in comparison to other procedures.

A systematic review and meta-analysis of carotid artery stenting using the transcervical approach

INTRODUCTION

Carotid artery stenting (CAS) via a transcarotid revascularization (TCAR) approach has emerged as an alternative when carotid endarterectomy or conventional CAS is contraindicated. The present study was conducted to assess the feasibility and safety of TCAR in patients with carotid artery stenosis.

EVIDENCE ACQUISITION

A systematic review of the literature was performed, according to PRISMA guidelines (Preferred Reporting Items for Systematic reviews and Meta-Analyses), using PubMed, EMBASE and CENTRAL databases. The primary outcomes included technical success, perioperative neurological event, myocardial ischemic events, death and their composite. Operational duration, flow reversal time and any local procedure related complication (carotid dissection and cranial nerve injury) were also recorded.

EVIDENCE SYNTHESIS

Twenty-three studies were included, reporting on 3130 patients, undergoing TCAR. Thirty-five per cent of them were symptomatic. Technical success was 98% (95% CI: 0.97-0.99; P=0.11, I²=32%). Early (30-day) new neurological event rate was estimated at 2% (95% CI: 0.01-0.02; P=1.0, I²=0%, respectively) while early death rate was 1% (95% CI: 0.00-0.01; P=1.0, I²=0%). Myocardial ischemic (MI) event rate was 1% (95% CI, 0.00-0.01, P=0.97, I²=6.6%). The composite outcome of neurological event/MI/death at 30-day follow-up was 2% (95% CI: 0.01-0.02, P=0.79, I²=14%). Carotid dissection rate during the intervention was 2% (95% CI: 0.01-0.03, P=0.58, I²=2.9%) while the post-operatively detected cranial nerve injury rate was 1% (95% CI, 0.00-0.01, P=1.0, I²=0%). Regarding the technical aspects of the procedures, operational and flow reversal time were at 73.8 min and 13.7 min, respectively (95% CI: 68.2-79.3, P=0.18, I²=37.6% and 95% CI: 11.3-16.1, P=0.48, I²=0%, respectively).

CONCLUSIONS

TCAR is feasible with high technical success rate. The procedure presents low incidence of local complications, neurological events, myocardial complications and mortality during the early postoperative period and should be considered an acceptable alternative for patients treated for carotid artery stenosis.

A Systematic Review and Meta-Analysis of Transcarotid Artery Revascularization with Dynamic Flow Reversal Versus Transfemoral Carotid Artery Stenting and Carotid Endarterectomy

BACKGROUND

Transfemoral carotid artery stenting (TFCAS) was introduced as a less invasive option for carotid revascularization in patients at high risk for complications from carotid endarterectomy (CEA). The increased perioperative stroke and death risk of TFCAS has however prevented TFCAS from widespread acceptance as an alternative to CEA in high-risk patients. Recent research suggests that transcarotid artery revascularization (TCAR) may be associated with a low stroke and death risk and potentially meet the needs of patients at high surgical risk. We aimed to estimate the 30-day risk of stroke or death of TCAR and compare it to TFCAS and CEA.

METHODS

We searched PubMed, Cochrane, Embase, and Scopus for studies of patients treated with TCAR. Meta-analysis was conducted when appropriate. A logistic-normal random-effects model with logit transformation was used to estimate the pooled event rates after TCAR. Pooled Mantel-Haenszel odds ratios (ORs) of events comparing TCAR to TFCAS and CEA were calculated using a fixed-effects model. Heterogeneity among studies was quantified with the chi-squared statistic of the likelihood ratio (LR) test that compares the random-effects and fixed-effects models.

RESULTS

Nine nonrandomized studies evaluating 4012 patients who underwent TCAR were included. The overall 30-day risks after TCAR were stroke/death, 1.89% (95% confidence interval [CI]: 1.50, 2.37); stroke, 1.34% (95% CI: 1.02,1.75); death, 0.76% (95% CI: 0.56, 1.08); myocardial infarction (MI), 0.60% (95% CI: 0.23, 1.59); stroke/death/MI, 2.20% (95% CI: 1.31, 3.69); cranial nerve injury (CNI), 0.31% (95% CI: 0.12, 0.83). The failure rate of TCAR was 1.27% (95% CI: 0.32, 4.92). Two nonrandomized studies suggested that TCAR was associated with lower risk of stroke and death as compared with TFCAS (1.33% vs. 2.55%, OR: 0.52, 95% CI: 0.36, 0.74 and 0.76% vs. 1.46%, OR: 0.52, 95% CI: 0.32, 0.84, respectively). Four nonrandomized studies suggested that TCAR was associated with a lower risk of CNI (0.54% and 1.84%, OR: 0.52, 95% CI: 0.36, 0.74) than CEA, but no statistically significant difference in the 30-day risk of stroke, stroke/death, or stroke/death/MI.

CONCLUSIONS

Among patients undergoing TCAR with dynamic flow reversal for carotid stenosis the 30-day risk of stroke or death was low. The perioperative stroke/death rate of TCAR was similar to that of CEA while CNI risk was lower. Larger prospective studies are needed to account for confounding factors and provide higher certainty.

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.

Carotid Revascularization: Current Practice and Future Directions

Carotid stenosis is responsible for approximately 15% of ischemic strokes. Carotid revascularization significantly decreases patients' stroke risk. Carotid endarterectomy has first-line therapy for moderate-to-severe carotid stenosis after a series of pivotal randomized controlled trials were published almost 30 years ago. Revascularization with carotid stenting has become a popular and effective alternative in a select subpopulation of patients. We review the current state of the literature regarding revascularization indications, patient selection, advantages of each revascularization approach, timing of intervention, and emerging interventional techniques, such as transcarotid artery revascularization.

Cerebral monitoring during transcarotid artery revascularization with flow reversal via transcranial doppler ultrasound examination

OBJECTIVE

Transcarotid artery revascularization (TCAR) is a hybrid technique for carotid artery revascularization that relies on proximal carotid occlusion with flow reversal for distal embolic protection. The hemodynamic response of the intracranial circulation to flow reversal is unknown. In addition, the rate and pattern of cerebral embolization during flow reversal has yet to be investigated. The aim of this study was to characterize cerebral hemodynamic and embolization patterns during TCAR.

METHODS

A single-institution retrospective study of patients with carotid artery stenosis undergoing TCAR with intraoperative transcranial Doppler (TCD) monitoring of the middle cerebral artery (MCA) was performed. Primary outcomes included changes in MCA velocity and MCA embolic signals observed throughout TCAR.

RESULTS

Eleven patients underwent TCAR with TCD monitoring of the ipsilateral MCA. The average MCA velocity at baseline was 50.6 ± 16.4 cm/s. MCA flow decreased significantly upon initiation of flow reversal (50.5 ± 16.4 cm/s vs 19.1 ± 18.4 cm/s; P = .02). The reinitiation of antegrade flow resulted in a significant increase in the number of embolic events compared with baseline (P = .003), and embolic events were observed in two patients during flow reversal.

CONCLUSIONS

TCD monitoring of patients undergoing TCAR revealed that the initiation of flow reversal results in a decrement in ipsilateral MCA velocity. Furthermore, embolic events can occur during flow reversal and are significantly associated with the reinitiation of antegrade flow in the internal carotid artery. However, both of these hemodynamic events were well-tolerated in our cohort. These findings suggest that TCAR remains a safe neuroprotective strategy for carotid revascularization.

Transcarotid Artery Revascularization Results in Low Rates of Periprocedural Neurologic Events, Myocardial Infarction, and Death

PURPOSE OF REVIEW

Transcarotid artery revascularization (TCAR) is a novel hybrid procedure that reverses carotid flow and places a stent using surgical access of the carotid artery in the neck under local anesthesia. We discuss the indications for carotid revascularization, the clinical rationale for TCAR, and evidence for its potential role in the management of carotid stenosis.

RECENT FINDINGS

Results from pre-clinical studies, prospective single-arm studies, and comparative analyses of registry data indicate that TCAR results in low amounts of periprocedural microembolization, cerebral lesions detectable on magnetic resonance imaging, and neurologic events, myocardial infarctions (MIs), and death. Non-randomized comparisons suggest that TCAR may offer a novel solution to reducing periprocedural stroke, death, and MI in patients with carotid stenosis. A state of equipoise appears to have been reached with TCAR versus the traditional carotid revascularization procedures and a well-controlled randomized trial with careful oversight should be prioritized to obtain level 1 evidence.

CEA vs. stent in patients with acute strokes: are they equally effective?

INTRODUCTION

Stroke is the 3rd leading cause of death worldwide with 15 million strokes annually. Extracranial carotid stenosis contributes to major stroke morbidity and mortality as a significant etiology of ischemic strokes. For acute stroke, in addition to optimal medical management, patients may be candidates for carotid endarterectomy and/or carotid stenting for secondary stroke reduction. This paper set out to review the data currently available regarding equivalency of the two intervention options.

EVIDENCE ACQUISITION

A comprehensive literature review was performed through PubMed and other sources using the key words carotid endarterectomy, carotid artery stent, acute stroke, symptomatic carotid stenosis, flow reversal, TCAR. Studies which solely evaluated patients with asymptomatic disease were ineligible for the study.

EVIDENCE SYNTHESIS

Review of landmark trials such as NASCET and CREST in addition to more recent studies demonstrates the effectiveness of surgical management with carotid endarterectomy of acute stroke. Carotid stenting has also been shown to have acceptable outcomes in certain patient populations.

CONCLUSIONS

Carotid endarterectomy continues to demonstrate effectiveness and safety for management of acute stroke, while carotid stenting has limitations. Carotid artery stenting has been shown to be non-inferior in some patient populations, but more recent and future technologic developments may expand the potential acceptable patient selection criteria.

In-hospital outcomes of transcarotid artery revascularization and carotid endarterectomy in the Society for Vascular Surgery Vascular Quality Initiative

OBJECTIVE

Transcarotid artery revascularization (TCAR) with flow reversal offers a less invasive option for carotid revascularization in high-risk patients and has the lowest reported overall stroke rate for any prospective trial of carotid artery stenting. However, outcome comparisons between TCAR and carotid endarterectomy (CEA) are needed to confirm the safety of TCAR outside of highly selected patients and providers.

METHODS

We compared in-hospital outcomes of patients undergoing TCAR and CEA from January 2016 to March 2018 using the Society for Vascular Surgery Vascular Quality Initiative TCAR Surveillance Project registry and the Society for Vascular Surgery Vascular Quality Initiative CEA database, respectively. The primary outcome was a composite of in-hospital stroke and death.

RESULTS

A total of 1182 patients underwent TCAR compared with 10,797 patients who underwent CEA. Patients undergoing TCAR were older (median age, 74 vs 71 years; P < .001) and more likely to be symptomatic (32% vs 27%; P < .001); they also had more medical comorbidities, including coronary artery disease (55% vs 28%; P < .001), chronic heart failure (20% vs 11%; P < .001), chronic obstructive pulmonary disease (29% vs 23%; P < .001), and chronic kidney disease (39% vs 34%; P = .001). On unadjusted analysis, TCAR had similar rates of in-hospital stroke/death (1.6% vs 1.4%; P = .33) and stroke/death/myocardial infarction (MI; 2.5% vs 1.9%; P = .16) compared with CEA. There was no difference in rates of stroke (1.4% vs 1.2%; P = .68), in-hospital death (0.3% vs 0.3%; P = .88), 30-day death (0.9% vs 0.4%; P = .06), or MI (1.1% vs 0.6%; P = .11). However, on average, TCAR procedures were 33 minutes shorter than CEA (78 ± 33 minutes vs 111 ± 43 minutes; P < .001). Patients undergoing TCAR were also less likely to incur cranial nerve injuries (0.6% vs 1.8%; P < .001) and less likely to have a postoperative length of stay >1 day (27% vs 30%; P = .046). On adjusted analysis, there was no difference in terms of stroke/death (odds ratio, 1.3; 95% confidence interval, 0.8-2.2; P = .28), stroke/death/MI (odds ratio, 1.4; 95% confidence interval, 0.9-2.1, P = .18), or the individual outcomes.

CONCLUSIONS

Despite a substantially higher medical risk in patients undergoing TCAR, in-hospital stroke/death rates were similar between TCAR and CEA. Further comparative studies with larger samples sizes and longer follow-up will be needed to establish the role of TCAR in extracranial carotid disease management.

Anatomic eligibility for transcarotid artery revascularization and transfemoral carotid artery stenting

OBJECTIVE

Transcarotid artery revascularization (TCAR) has emerged as an alternative to transfemoral carotid artery stenting (tfCAS). We investigated the proportion of carotid arteries undergoing revascularization procedures that would be eligible for TCAR based on anatomic criteria and how many arteries at high anatomic risk for tfCAS would be amenable to TCAR.

METHODS

We performed a retrospective review of consecutive patients who underwent carotid endarterectomy or carotid stenting between 2012 and 2015. Patients were excluded if computed tomography angiography of the neck was not performed within 6 months of the procedure. We assessed TCAR eligibility on the basis of the instructions for use of the ENROUTE Transcarotid Neuroprotection System (Silk Road Medical, Sunnyvale, Calif) and high anatomic risk for tfCAS on the basis of anatomic factors known to make carotid cannulation more difficult or hazardous.

RESULTS

Of the 118 patients and 236 carotid arteries identified, 12 carotid arteries were excluded for presence of an occluded internal carotid artery (ICA). Of the remaining 224 carotid arteries, 72% were eligible for TCAR on the basis of the instructions for use criteria; 100% had 4- to 9-mm ICA diameters, 100% had ≥6-mm common carotid artery (CCA) diameter, 75% had ≥5-cm clavicle to carotid bifurcation distance, and 96% lacked significant CCA puncture site plaque. In addition, 7% of carotid arteries had bifurcation anatomy unfavorable for stenting; thus, of the entire cohort of arteries examined, 68% were eligible for TCAR. Hyperlipidemia (odds ratio [OR], 6.7; 95% confidence interval [CI], 1.7-26; P < .01), chronic obstructive pulmonary disease (OR, 3.5; 95% CI, 1.5-8.3; P < .01), and older age (OR, 1.1; 95% CI, 1.0-1.1; P < .01) were independently associated with TCAR ineligibility, whereas white race (OR, 0.2; 95% CI, 0.0-1.0; P = .048) and beta-blocker use (OR, 0.3; 95% CI, 0.1-0.7; P < .01) were independently associated with TCAR eligibility. In addition, 24% of carotid arteries were considered to be at high risk for tfCAS for the presence of a type III aortic arch (7.6%), severe aortic calcification (3.3%), tandem CCA lesions (7.1%), moderate to severe stenosis at the carotid ostium (8.9%), and tortuous distal ICA precluding embolic filter placement (4.5%). Active smoking (OR, 4.4; 95% CI, 1.9-10; P < .01), hyperlipidemia (OR, 4.0; 95% CI, 1.2-14; P = .03), and older age (OR, 1.1; 95% CI, 1.0-1.1; P = .02) were independently associated with tfCAS ineligibility, whereas preoperative aspirin (OR, 0.1; 95% CI, 0.0-0.4; P < .001) or clopidogrel (OR, 0.3; 95% CI, 0.1-0.8; P = .01) use was associated with tfCAS eligibility. Of the arteries that were considered to be at high risk for tfCAS, 69% were eligible for TCAR.

CONCLUSIONS

The majority of carotid arteries in individuals selected for revascularization meet TCAR eligibility, making TCAR a viable treatment option for many patients.

Recent advances in the treatment of carotid artery disease

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