Procedural Safety Comparison Between Transcarotid Artery Revascularization, Carotid Endarterectomy, and Carotid Stenting: Perioperative and 1-Year Rates of Stroke or Death

What the National Coverage Determination for Carotid Artery Stenting Means for the Treatment of Patients with Carotid Artery Disease

OBJECTIVES

In October 2023, the Centers for Medicare & Medicaid Services (CMS) agreed to revisit its national coverage determination (NCD) for carotid artery stenting (CAS). We provide an overview of the arguments presented in favor and against NCD expansion, and discuss the likely ramifications on patient care and outcomes in the future.

METHODS

We completed a narrative review of the arguments presented in favor and against NCD expansion.

RESULTS

Arguments presented in favor of the CAS NCD expansion predominantly focused on the outcomes of four large multicenter randomized controlled trials published between 2010 and 2021 that reported similar outcomes for composite endpoints between patients undergoing CAS and carotid endarterectomy. The main arguments against expanding the CAS NCD centered around higher patient stroke risks with CAS, increasing healthcare costs, premature decision-making, and the lack of a validated shared decision-making tool that can be readily applied to carotid revascularization.

CONCLUSIONS

By expanding the indications for CAS to asymptomatic and standard-risk patients, they will be exposed to excess and unnecessary risks without any evident benefits, potentially leading to widespread adoption of a procedure driven by financial incentives rather than genuine patient benefits.

Racial differences in adoption and outcomes of transcarotid artery revascularization among high-risk adults with carotid artery stenosis

INTRODUCTION

Differential access to new technologies may contribute to racial disparities in surgical outcomes but has not been well-studied in the treatment of carotid artery stenosis. We examined race-based differences in adoption and outcomes of transcarotid artery revascularization (TCAR) among high-risk non-Hispanic (NH) NH Black and NH white adults undergoing carotid revascularization.

METHODS

We conducted a retrospective analysis of TCAR, transfemoral carotid artery stenting (TF-CAS), and carotid endarterectomy (CEA) procedures performed for carotid artery stenosis from 1/2015 to 7/2023 in the Vascular Quality Initiative. NH Black and NH white adults were included if they met Centers for Medicare & Medicaid Services high-risk criteria. Hospitals and physicians were categorized as TCAR-capable if they had previously performed at least one TCAR prior to the time of a given procedure. We fit logistic and linear regressions, adjusted a priori for common demographic, clinical, and disease characteristics, to estimate associations of race with receipt of TCAR (versus CEA or TF-CAS), and to explore associations between race, hospital and physician characteristics, and perioperative composite stroke/death/myocardial infarction.

RESULTS

Of 159,471 high-risk patients undergoing revascularization for carotid artery stenosis (mean age 72 years, 38.5% female, 5.3% NH Black), 28,722 (18.0%) received TCAR, including 16.9% of NH Black adults and 18.1% of NH white adults (P<0.001). After controlling for patient and disease characteristics, NH Black patients were less likely than NH white patients to receive TCAR (aOR 0.92, 95% CI 0.87 to 0.99). The use of TCAR did not vary by race among patients treated at TCAR-capable hospitals (aOR 0.98, 95% CI 0.91 to 1.05) or by TCAR-capable physicians (aOR 1.01, 95% CI 0.93 to 1.10); however, NH Black race was associated with lower odds of receiving treatment in these settings (TCAR-capable hospital: aOR 0.93 [0.88 to 0.98]; TCAR-capable physician: aOR 0.92 [0.87 to 0.98]). NH Black race was associated with higher odds of stroke/death/MI in the full cohort (aOR 1.18, 95% CI 1.03 to 1.36), but not in the subgroup of patients who received TCAR (aOR 0.87, 95% CI 0.56 to 1.34).

CONCLUSIONS

TCAR attenuated racial disparities in perioperative morbidity and mortality associated with carotid revascularization, but NH Black adults were less likely than NH white adults to receive TCAR. Relatively worse access for NH Black adults to technologically-advanced treatment settings may partially explain the broader persistence of race-based differences in carotid revascularization treatment patterns and outcomes.

A Prosthetic Conduit can be Used Safely for TransCarotid Artery Revascularization Under Local Anesthesia in High-Risk Patients

Surgical management of carotid stenosis has evolved from open carotid endarterectomy (CEA) to include multiple alternative procedures including transfemoral carotid artery stenting (tfCAS) and transcarotid artery stenting. In recent years, Transcarotid Artery Revascularization (TCAR) has emerged as a third option, combining open cut down to the common carotid artery (CCA) with endovascular stenting and neuroprotection via reversal of cerebral blood flow. In this case series, a modified TCAR procedure using a prosthetic conduit was successfully performed exclusively under local anesthesia in a total of 10 patients with carotid artery stenosis, high cardiac risk, and anatomical contraindications to a traditional TCAR.

Non-White Patients Have a Higher Risk of Stroke Following Transcarotid Artery Revascularization

INTRODUCTION

Carotid artery revascularization has traditionally been performed by either a carotid endarterectomy or carotid artery stent. Large data analysis has suggested there are differences in perioperative outcomes with regards to race, with non-White patients (NWP) having worse outcomes of stroke, restenosis and return to the operating room (RTOR). The introduction of transcarotid artery revascularization (TCAR) has started to shift the paradigm of carotid disease treatment. However, to date, there have been no studies assessing the difference in postoperative outcomes after TCAR between racial groups.

METHODS

All patients from 2016 to 2021 in the Vascular Quality Initiative who underwent TCAR were included in our analysis. Patients were split into two groups based on race: individuals who identified as White and a second group that comprised all other races. Demographic and clinical variables were compared using Student's t-Test and chi-square test of independence. Logistic regression analysis was performed to determine the impact of race on perioperative outcomes of stroke, myocardial infarction (MI), death, restenosis, RTOR, and transient ischemic attack (TIA).

RESULTS

The cohort consisted of 22,609 patients: 20,424 (90.3%) White patients and 2185 (9.7%) NWP. After adjusting for sex, diabetes, hypertension, coronary artery disease, history of prior stroke or TIA, symptomatic status, and high-risk criteria at time of TCAR, there was a significant difference in postoperative stroke, with 63% increased risk in NWP (odds ratio = 1.63, 95% confidence interval: 1.11-2.40, P = 0.014). However, we found no significant difference in the odds of MI, death, postoperative TIA, restenosis, or RTOR when comparing NWP to White patients.

CONCLUSIONS

This study demonstrates that NWP have increased risk of stroke but similar outcomes of death, MI, RTOR and restenosis following TCAR. Future studies are needed to elucidate and address the underlying causes of racial disparity in carotid revascularization.

Ocular Ischemic Syndrome and the Role of Carotid Artery Revascularization

BACKGROUND

Ocular ischemic syndrome (OIS) is a rare presentation of atherosclerotic carotid artery stenosis that can result in permanent visual loss. This severely disabling syndrome remains under diagnosed and undertreated due to lack of awareness; especially since it requires expedited multidisciplinary care. The relevance of early diagnosis and treatment is increasing due to an increasing prevalence of cerebrovascular disease.

METHODS

The long-term visual and cerebrovascular outcomes following intervention for nonarteritic OIS, remain poorly described and were the objective of this concise review. We conducted a PubMed search to include all English language publications (cohort studies and case reports) between 2002 and 2023.

RESULTS

A total of 33 studies (479 patients) report the outcomes of treatment of OIS with carotid endarterectomy (CEA, 304 patients, 19 studies), and carotid artery stenting (CAS, 175 patients, 14 studies). Visual outcomes were improved or did not worsen in 447 patients (93.3%). No periprocedural stroke was reported. Worsening visual symptoms were rare (35 patients, 7.3%); they occurred in the immediate postoperative period secondary to ocular hypoperfusion (3 patients) and in the late postoperative period due to progression of systemic atherosclerotic disease. Symptomatic recurrence due to recurrent stenosis after CEA was reported in 1 patient (0.21%); this was managed successfully with CAS. None of these studies report the results of transcarotid artery revascularization, the long-term operative outcome or stroke rate.

CONCLUSIONS

OIS remains to be an underdiagnosed condition. Early diagnosis and prompt treatment are crucial in reversal or stabilization of OIS symptoms. An expedited multidisciplinary approach between vascular surgery and ophthalmology services is necessary to facilitate timely treatment and optimize outcome. If diagnosed early, both CEA and CAS have been associated with visual improvement and prevention of progressive visual loss.

Patient decision-making in the era of transcarotid artery revascularization

OBJECTIVE

The National Coverage Determination on carotid stenting by Medicare in October 2023 stipulates that patients participate in a shared decision-making (SDM) conversation with their proceduralist before an intervention. However, to date, there is no validated SDM tool that incorporates transcarotid artery revascularization (TCAR) into its decision platform. Our objective was to elicit patient and surgeon experiences and preferences through a qualitative approach to better inform the SDM process surrounding carotid revascularization.

METHODS

We performed longitudinal perioperative semistructured interviews of 20 participants using purposive maximum variation sampling, a qualitative technique designed for identification and selection of information-rich cases, to define domains important to participants undergoing carotid endarterectomy or TCAR and impressions of SDM. We also performed interviews with nine vascular surgeons to elicit their input on the SDM process surrounding carotid revascularization. Interview data were coded and analyzed using inductive content analysis coding.

RESULTS

We identified three important domains that contribute to the participants' ultimate decision on which procedure to choose: their individual values, their understanding of the disease and each procedure, and how they prefer to make medical decisions. Participant values included themes such as success rates, "wanting to feel better," and the proceduralist's experience. Participants varied in their desired degree of understanding of carotid disease, but all individuals wished to discuss each option with their proceduralist. Participants' desired medical decision-making style varied on a spectrum from complete autonomy to wanting the proceduralist to make the decision for them. Participants who preferred carotid endarterectomy felt outcomes were superior to TCAR and often expressed a desire to eliminate the carotid plaque. Those selecting TCAR felt it was a newer, less invasive option with the shortest procedural and recovery times. Surgeons frequently noted patient factors such as age and anatomy, as well as the availability of long-term data, as reasons to preferentially select one procedure. For most participants, their surgeon was viewed as the most important source of information surrounding their disease and procedure.

CONCLUSIONS

SDM surrounding carotid revascularization is nuanced and marked by variation in patient preferences surrounding autonomy when choosing treatment. Given the mandate by Medicare to participate in a SDM interaction before carotid stenting, this analysis offers critical insights that can help to guide an efficient and effective dialog between patients and providers to arrive at a shared decision surrounding therapeutic intervention for patients with carotid disease.

Sevoflurane-induced regulation of NKCC1/KCC2 phosphorylation through activation of Spak/OSR1 kinase and cognitive impairment in ischemia-reperfusion injury in rats

The occurrence of excitotoxic damage caused by cerebral ischemia-reperfusion (I/R) injury is closely linked to a decrease in central inhibitory function, in which the concentration of chloride inside the cells ([Cl-]i) plays a crucial role. The outflow and inflow of [Cl-]i are controlled by KCC2 and NKCC1, which are cellular cotransporters for K+/Cl- and Na+/K+/Cl-, respectively. NKCC1/KCC2 is regulated by upstream regulators such as SPAK and OSR1, whose activity is influenced by I/R. Sevoflurane is the most commonly used and controversial general anesthetic. To elucidate the impact of sevoflurane on cerebral ischemia-reperfusion (I/R) injury and its underlying mechanism, we investigated its influence on cognitive function and the mechanism of action utilizing a rat model of I/R. By activating the kinase Spak/OSR1, we discovered that I/R damage enhanced the function of NKCC1 and inhibited the function of KCC2, which triggered an imbalance of [Cl-]i concentration, leading to neurological dysfunction and cognitive dysfunction. At the beginning of reperfusion, administration of 1.3 MAC sevoflurane for 3 h increased activation of Spak/OSR1 kinases on day 7 post-perfusion, resulting in an additional dysregulation of NKCC1 and KCC2 activity, which disappeared on day 14. Administration of Closantel, a Spak/OSR1 kinase inhibitor, to animals treated with sevoflurane reverses the additional stimulation. The research revealed that sevoflurane modified the functioning of NKCC1 and KCC2, resulting in cognitive decline by activating Spak/OSR1 kinase. However, this issue could be resolved by inhibiting Spak/OSR1. The research revealed that sevoflurane transiently alters the function of NKCC1 and KCC2, resulting in exacerbating cognitive decline. However, this can be fixed by suppressing Spak/OSR1.

Appropriateness of care: Asymptomatic carotid stenosis including transcarotid artery revascularization

Carotid artery stenosis is one of the most common diagnoses treated by vascular specialists in the United States. The optimal management of carotid stenosis remains controversial, however, with notable variation surrounding diagnostic imaging modalities, longitudinal surveillance, medical therapies, and procedural interventions. Data from high-quality randomized controlled trials and observational studies form the foundation for current management paradigms and societal guidelines that inform clinical practice. Presently, a diagnosis of carotid disease is most often established with duplex ultrasound and supplemental cross-sectional imaging using computed tomography or magnetic resonance angiography as needed to provide additional anatomic information. All patients with documented occlusive disease should receive goal-directed medical therapy with antiplatelet agents and a lipid-reduction strategy, most commonly with a statin. Those with severe carotid stenosis and an acceptable life expectancy may be considered for carotid artery revascularization. The proceduralist should optimally consider a shared decision-making approach in which the tradeoffs of revascularization can be carefully considered with the patient to optimize informed therapeutic decision making. In current practice, three distinct procedure options exist to treat carotid artery stenosis, including carotid endarterectomy, transfemoral carotid artery stenting, and transcarotid artery revascularization. It should be noted that each procedure, although often used interchangeably in most clinical settings, carry technical nuances and outcome disparities. In this review, each of these topics are explored and various approaches are outlined surrounding the appropriate use of treatments for patients with asymptomatic carotid artery stenosis.

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).

Seven years of the transcarotid artery revascularization surveillance project, comparison to transfemoral stenting and endarterectomy

OBJECTIVE

This study utilizes the latest data from the Vascular Quality Initiative (VQI), which now encompasses over 50,000 transcarotid artery revascularization (TCAR) procedures, to offer a sizeable dataset for comparing the effectiveness and safety of TCAR, transfemoral carotid artery stenting (tfCAS), and carotid endarterectomy (CEA). Given this substantial dataset, we are now able to compare outcomes overall and stratified by symptom status across revascularization techniques.

METHODS

Utilizing VQI data from September 2016 to August 2023, we conducted a risk-adjusted analysis by applying inverse probability of treatment weighting to compare in-hospital outcomes between TCAR vs tfCAS, CEA vs tfCAS, and TCAR vs CEA. Our primary outcome measure was in-hospital stroke/death. Secondary outcomes included myocardial infarction and cranial nerve injury.

RESULTS

A total of 50,068 patients underwent TCAR, 25,361 patients underwent tfCAS, and 122,737 patients underwent CEA. TCAR patients were older, more likely to have coronary artery disease, chronic kidney disease, and undergo coronary artery bypass grafting/percutaneous coronary intervention as well as prior contralateral CEA/CAS compared with both CEA and tfCAS. TfCAS had higher odds of stroke/death when compared with TCAR (2.9% vs 1.6%; adjusted odds ratio [aOR], 1.84; 95% confidence interval [CI], 1.65-2.06; P < .001) and CEA (2.9% vs 1.3%; aOR, 2.21; 95% CI, 2.01-2.43; P < .001). CEA had slightly lower odds of stroke/death compared with TCAR (1.3% vs 1.6%; aOR, 0.83; 95% CI, 0.76-0.91; P < .001). TfCAS had lower odds of cranial nerve injury compared with TCAR (0.0% vs 0.3%; aOR, 0.00; 95% CI, 0.00-0.00; P < .001) and CEA (0.0% vs 2.3%; aOR, 0.00; 95% CI, 0.0-0.0; P < .001) as well as lower odds of myocardial infarction compared with CEA (0.4% vs 0.6%; aOR, 0.67; 95% CI, 0.54-0.84; P < .001). CEA compared with TCAR had higher odds of myocardial infarction (0.6% vs 0.5%; aOR, 1.31; 95% CI, 1.13-1.54; P < .001) and cranial nerve injury (2.3% vs 0.3%; aOR, 9.42; 95% CI, 7.78-11.4; P < .001).

CONCLUSIONS

Although tfCAS may be beneficial for select patients, the lower stroke/death rates associated with CEA and TCAR are preferred. When deciding between CEA and TCAR, it is important to weigh additional procedural factors and outcomes such as myocardial infarction and cranial nerve injury, particularly when stroke/death rates are similar. Additionally, evaluating subgroups that may benefit from one procedure over another is essential for informed decision-making and enhanced patient care in the treatment of carotid stenosis.

Effect of Perioperative Stroke on Survival After Carotid Intervention

OBJECTIVES

Perioperative stroke is the most dreaded complication of carotid artery interventions and can severely affect patients' quality of life. This study evaluated the impact of this event on mortality for patients undergoing interventional treatment of carotid artery stenosis with three different modalities.

METHODS

Patients undergoing carotid revascularization at participating Memorial Hermann Health System facilities were captured from 2003-2022. These patients were treated with either carotid endarterectomy (CEA), transfemoral carotid stenting (TF-CAS), or transcarotid artery revascularization (TCAR). Perioperative outcomes, including stroke and mortality, as well as follow-up survival data at 6-month intervals, were analyzed and stratified per treatment modality.

RESULTS

Of the 1681 carotid revascularization patients identified, 992 underwent CEA (59.0%), 524 underwent TCAR (31.2%), and 165 underwent TF-CAS (9.8%). The incidence of stroke was 2.1% (CEA 2.1%, TCAR 1.7%, and TF-CAS 3.6%; P = .326). The perioperative (30-day) death rate was 2.1% (n = 36). The perioperative death rate was higher in patients who suffered from an intraoperative stroke than in those who did not (8.3% vs 1.9%, P = .007). Perioperative death was also different between CEA, TCAR, and TF-CAS for patients who had an intraoperative stroke (.0% vs 33.3% vs .0%, P = .05). TCAR patients were likely to be older (P < .001), have a higher body mass index (P < .001), and have diabetes mellitus (P < .001). Patients who suffered from an intraoperative stroke were more likely to have a symptomatic carotid lesion (58.3% vs 28.8%, P < .001). The TCAR group had a significantly lower survival at 6 months and 12 months when compared to the other two groups (64.9% vs 100% P = .007).

CONCLUSION

Perioperative stroke during carotid interventions significantly impacts early patient survival with otherwise no apparent change in mid-term outcomes at 5 years. This difference appears to be even more significant in patients undergoing TCAR, possibly due to their baseline higher-risk profile and lower functional reserve.

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.

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.

Recent advances and controversial issues in the optimal management of asymptomatic carotid stenosis

OBJECTIVE

The optimal management of patients with asymptomatic carotid stenosis (AsxCS) is enduringly controversial. We updated our 2021 Expert Review and Position Statement, focusing on recent advances in the diagnosis and management of patients with AsxCS.

METHODS

A systematic review of the literature was performed up to August 1, 2023, using PubMed/PubMed Central, EMBASE and Scopus. The following keywords were used in various combinations: "asymptomatic carotid stenosis," "carotid endarterectomy" (CEA), "carotid artery stenting" (CAS), and "transcarotid artery revascularization" (TCAR). Areas covered included (i) improvements in best medical treatment (BMT) for patients with AsxCS and declining stroke risk, (ii) technological advances in surgical/endovascular skills/techniques and outcomes, (iii) risk factors, clinical/imaging characteristics and risk prediction models for the identification of high-risk AsxCS patient subgroups, and (iv) the association between cognitive dysfunction and AsxCS.

RESULTS

BMT is essential for all patients with AsxCS, regardless of whether they will eventually be offered CEA, CAS, or TCAR. Specific patient subgroups at high risk for stroke despite BMT should be considered for a carotid revascularization procedure. These patients include those with severe (≥80%) AsxCS, transcranial Doppler-detected microemboli, plaque echolucency on Duplex ultrasound examination, silent infarcts on brain computed tomography or magnetic resonance angiography scans, decreased cerebrovascular reserve, increased size of juxtaluminal hypoechoic area, AsxCS progression, carotid plaque ulceration, and intraplaque hemorrhage. Treatment of patients with AsxCS should be individualized, taking into consideration individual patient preferences and needs, clinical and imaging characteristics, and cultural, ethnic, and social factors. Solid evidence supporting or refuting an association between AsxCS and cognitive dysfunction is lacking.

CONCLUSIONS

The optimal management of patients with AsxCS should include BMT for all individuals and a prophylactic carotid revascularization procedure (CEA, CAS, or TCAR) for some asymptomatic patient subgroups, additionally taking into consideration individual patient needs and preference, clinical and imaging characteristics, social and cultural factors, and the available stroke risk prediction models. Future studies should investigate the association between AsxCS with cognitive function and the role of carotid revascularization procedures in the progression or reversal of cognitive dysfunction.

Diagnostic accuracy of intraoperative neuromonitoring in transcarotid artery revascularization

BACKGROUND

In recent years, transcarotid artery revascularization (TCAR) has emerged as a safe and effective alternative to carotid artery stenting. While intraoperative neuromonitoring (IONM) techniques such as electroencephalogram (EEG) and somatosensory evoked potentials (SSEPs) are often employed during TCAR, there is limited research on their diagnostic accuracy.

METHODS

The authors retrospectively reviewed a multi-institutional IONM database of TCAR procedures performed with EEG and SSEP monitoring. A total of 516 TCAR procedures were included in this study. Significant changes in EEG and/or SSEPs, surgeon's interventions, resolution of significant changes, and immediate postoperative neurological outcome were documented. Sensitivity, specificity, positive and negative predictive values were calculated.

RESULTS

The incidence of intraoperative onset new neurologic deficit was 0.4%. Significant changes in EEG and/or SSEPs occurred in 5.4% of the cases. Of the cases with IONM alerts, 78.5% returned to baseline with a surgical or hemodynamic intervention. From the cases with unresolved IONM alerts, 33.3% woke up with a new neurological deficit. The overall sensitivity and specificity for IONM was 100% and 99.2%, respectively. The positive predictive value was 33.3% and the negative predictive value was 100%.

CONCLUSIONS

IONM during TCAR offers high sensitivity and specificity in predicting postoperative outcome. Patients with resolved IONM alerts had immediate neurological outcomes that were comparable to those who had no IONM alerts.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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

INTRODUCTION

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

Adoption and Diffusion of Transcarotid Artery Revascularization in Contemporary Practice

BACKGROUND

In 2015, the FDA approved transcarotid artery revascularization (TCAR) as an alternative to carotid endarterectomy (CEA) and transfemoral carotid artery stenting (TF-CAS) for high-risk patients with carotid stenosis. This was granted in the absence of level 1 evidence to support TCAR. We aimed to document trends in TCAR utilization, its diffusion over time, and the clinical phenotypes of patients undergoing TCAR, CEA, and TF-CAS.

METHODS

We used the Vascular Quality Initiative to study patients who underwent TCAR. We calculated the number of TCARs performed and the percent of TCAR utilization versus CEA/TF-CAS. Using data from before TCAR was widespread, we calculated propensity scores for patients to receive CEA. We applied this model to patients undergoing carotid revascularization from 2016 to 2022 and grouped patients by the procedure they ultimately underwent, examining overlap in score distribution to measure patient similarity. We measured the trend of in-hospital stroke/death after TCAR.

RESULTS

We studied 31 447 patients who underwent TCAR from January 1, 2016 to March 31, 2022. The number of centers performing TCAR increased from 29 to 606. In 2021, TCAR represented 22.5% of carotid revascularizations at centers offering all 3 procedures. The percentage of patients that underwent TCAR who met approved high-risk criteria decreased from 88.5% to 80.9% (P<0.001). Those with a prior ipsilateral carotid procedure decreased from 20.6% in 2016 to 12.0% in 2021 (P<0.001). Patients undergoing TCAR after stroke increased from 19.7% to 30.7% (P<0.001). Propensity-score overlap was 55.4% for TCAR/CEA, and 58.6% for TCAR/TF-CAS, demonstrating that TCAR patients have a clinical phenotype mixed between those who undergo CEA and TF-CAS. The average in-hospital stroke/death risk after TCAR was 2.3% in 2016 and 1.7% in 2022 (P trend: 0.954).

CONCLUSIONS

TCAR now represents nearly 1-in-4 procedures at centers offering it. TCAR was increasingly performed among standard-risk patients and as a first-line procedural option after stroke. The absence of level 1 evidence underscores the importance of high-quality registry-based analyses to document TCAR's real-world outcomes and durability.

Impact of calcified plaque volume on technical and 3-year outcomes after transcarotid artery revascularization

OBJECTIVE

We sought to quantify the percent calcification within carotid artery plaques and assess its impact on percent residual stenosis and rate of restenosis in patients undergoing transcarotid artery revascularization for symptomatic and asymptomatic carotid artery stenosis.

METHODS

A retrospective review of prospectively collected institutional Vascular Quality Initiative data was performed to identify all patients undergoing transcarotid artery revascularization from December 2015 to June 2021 (n = 210). Patient and lesion characteristics were extracted. Using a semiautomated workflow, preoperative computed tomography head and neck angiograms were analyzed to determine the calcified plaque volume in distal common carotid artery and internal carotid artery plaques. Intraoperative digital subtraction angiograms were reviewed to calculate the percent residual stenosis post-intervention according to North American Symptomatic Carotid Endarterectomy Trial criteria. Peak systolic velocity and end-diastolic velocity were extracted from outpatient carotid duplex ultrasound examinations. Univariate logistic regression was performed to analyze the relationship of calcium volume percent and Vascular Quality Initiative lesion calcification to percent residual stenosis in completion angiograms. Kaplan-Meier analysis examined the relationship between calcium volume percent and in-stent stenosis over 36 months.

RESULTS

One hundred ninety-seven carotid arteries were preliminarily examined. Predilation was performed in 87.4% of cases with a mean balloon diameter of 5.1 ± 0.7 mm and a mean stent diameter was 8.8 ± 1.1 mm. The mean calcium volume percent was 11.9 ± 12.4% and the mean percent residual stenosis was 16.1 ± 15.6%. Univariate logistic regression demonstrated a statistically significant difference between calcium volume percent and percent residual stenosis (odds ratio [OR], 1.324; 95% confidence interval [CI], 1.005-1.746; P = .046). Stratified by quartile, only the top 25% of calcified plaques (>18.7% calcification) demonstrated a statistically significant association with higher percent residual stenosis (OR, 2.532; 95% CI, 1.049-6.115; P =.039). There was no statistical significance with lesion calcification (OR, 1.298; 95% C,: 0.980-1.718; P = .069). A Kaplan-Meier analysis demonstrated a statistically significant increase in the rate of in-stent stenosis during a 36-month follow-up for lesions containing >8.2% calcium volume (P = .0069).

CONCLUSIONS

A calcium volume percent of >18.7% was associated with a higher percent residual stenosis, and a calcium volume percent of >8.2% was associated with higher in-stent stenosis at 36 months. There was one clinically diagnosed stroke during the follow-up period, demonstrating the overall safety of the procedure.

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.

What Is the Role of Transcarotid Artery Revascularization in the Treatment of Carotid Stenosis?

TCAR for the Treatment of Carotid StenosisTwo carotid revascularization strategies, CEA and TF-CAS, have been informed by high-quality randomized trials. In contrast, no randomized trial evidence exists regarding a newer procedural option, TCAR. The authors discuss these procedures and propose a randomized trial to inform the role of TCAR in the treatment of carotid stenosis.

Update on Management of Symptomatic Carotid Stenosis

Carotid artery stenosis (CAS) is one of the leading causes of cerebral ischemia and stroke.7 When plaque builds up in the internal carotid artery, it blocks blood flow to the brain. Oftentimes, this condition only comes to light after a patient experiences a stroke or stroke-like symptoms. When this occurs, cholesterol-lowering medications and blood thinners can help to increase blood flow to the brain. However, if the plaque is so large that it severely narrows the lumen of the artery, surgery may be required to restore blood flow to the brain. Patients with severe stenosis can undergo procedures such as carotid endarterectomies (CEA), stenting, and transcarotid artery revascularization (TCAR) for this purpose. In this review, we discuss these procedures and which patients warrant which type of intervention. We look at the pathophysiology of internal carotid artery stenosis and current treatment options, while highlighting emerging treatment options. This review aims to increase understanding of the management of symptomatic carotid artery stenosis as well as provide a groundwork for more innovative treatments.

Learning the Treatment Impact on Time-to-Event Outcomes: The Transcarotid Artery Revascularization Simulated Cohort

Proportional hazard Cox regression models are overwhelmingly used for analyzing time-dependent outcomes. Despite their associated hazard ratio is a valuable index for the difference between populations, its strong dependency on the underlying assumptions makes it a source of misinterpretation. Recently, a number of works have dealt with the subtleties and limitations of this interpretation. Besides, a number of alternative indices and different Cox-type models have been proposed. In this work, we use synthetic data, motivated by a real-world problem, for showing the strengths and weaknesses of some of those methods in the analysis of time-dependent outcomes. We use the power of synthetic data for considering observable results but also utopian designs.