Gender-specific 30-day outcomes after carotid endarterectomy and carotid artery stenting in the Society for Vascular Surgery Vascular Registry

Sex disparities in outcomes after carotid artery interventions: A systematic review

This systematic review aimed to identify sex-specific outcomes in men and women after carotid endarterectomy (CEA) and carotid artery stenting (CAS), including transfemoral and transcarotid. A search of literature published from January 2000 through December 2022 was conducted using key terms attributed to carotid interventions on PubMed. Studies comparing outcome metrics post intervention (ie, myocardial infarction [MI], cerebral vascular accident [CVA] or stroke, and long-term mortality) among male and female patients were reviewed. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Overall, all studies reported low rates of perioperative complications. Among the studies that did not stratify outcomes by the preoperative symptom status, there were no significant sex differences in rates of perioperative strokes or MIs. Two studies, however, noted a higher rate of 30-day mortality in male patients undergoing CEA than in female patients. Analysis of asymptomatic patients undergoing CEA revealed no difference in perioperative MIs (female: 0% to 1.8% v male: 0.4% to 4.3%), similar rates of CVAs (female: 0.8% to 5% v male: 0.8% to 4.9%), and no significant differences in the long-term mortality outcomes. Alternatively, symptomatic patients undergoing CEA reported a higher rate of CVAs in female patients vs. male patients (7.7% v 6.2%) and showed a higher rate of death in female patients (1% v 0.7%). Among studies that did not stratify outcome by symptomatology, there was no difference in the 30-day outcomes between sexes for patients undergoing CAS. Asymptomatic patients undergoing CAS demonstrated similar incident rates across perioperative MIs (female: 0% to 5.9% v male: 0.28% to 3.3%), CVAs (female: 0.5% to 4.1% v male: 0.4% to 6.2%), and long-term mortality outcomes (female: 0% to 1.75% v male: 0.2% to 1.5%). Symptomatic patients undergoing CAS similarly reported higher incidences of perioperative MIs (female: 0.3% to 7.1% v male: 0% to 5.5%), CVAs (female: 0% to 9.9% v male: 0% to 7.6%), and long-term mortality outcomes (female: 0.6% to 7.1% v male: 0.5% to 8.2%). Sex-specific differences in outcomes after major vascular procedures are well recognized. Our review suggests that symptomatic female patients have a higher incidence of neurologic and cardiac events after carotid interventions, but that asymptomatic patients do not.

Sex differences in outcome after carotid revascularization in symptomatic and asymptomatic carotid artery stenosis

OBJECTIVE

Sex differences regarding the safety and efficacy of carotid revascularization in carotid artery stenosis have been addressed in several studies with conflicting results. Moreover, women are underrepresented in clinical trials, leading to limited conclusions regarding the safety and efficacy of acute stroke treatments.

METHODS

A systematic review and meta-analysis was performed by literature search including four databases from January 1985 to December 2021. Sex differences in the efficacy and safety of revascularization procedures, including carotid endarterectomy (CEA) and carotid artery stenting (CAS), for symptomatic and asymptomatic carotid artery stenoses were analyzed.

RESULTS

Regarding CEA in symptomatic carotid artery stenosis, the stroke risk in men (3.6%) and women (3.9%) based on 99,495 patients (30 studies) did not differ (P = .16). There was also no difference in the stroke risk by different time frames up to 10 years. Compared with men, women treated with CEA had a significantly higher stroke or death rate at 4 months (2 studies, 2565 patients; 7.2% vs 5.0%; odds ratio [OR], 1.49; 95% confidence interval [CI], 1.04-2.12; I2 = 0%; P = .03), and a significantly higher rate of restenosis (1 study, 615; 17.2% vs 6.7%; OR, 2.81; 95% CI, 1.66-4.75; P = .0001). For CAS in symptomatic artery stenosis, data showed a non-significant tendency toward higher peri-procedural stroke in women, whereas for asymptomatic carotid artery stenosis, data based on 332,344 patients showed that women (compared with men) after CEA had similar rates of stroke, stroke or death, and the composite outcome stroke/death/myocardial infarction. The rate of restenosis at 1 year was significantly higher in women compared with men (1 study, 372 patients; 10.8% vs 3.2%; OR, 3.71; 95% CI, 1.49-9.2; P = .005). Furthermore, CAS in asymptomatic patients was associated with low risk of a postprocedural stroke in both sexes, but a significantly higher risk of in-hospital myocardial infarction in women than men (8445 patients, 1.2% vs 0.6%; OR, 2.01; 95% CI, 1.23-3.28; I2 = 0%; P = .005).

CONCLUSIONS

A few sex-differences in short-term outcomes after carotid revascularization for symptomatic and asymptomatic carotid artery stenosis were found, although there were no significant differences in the overall stroke. This indicates a need for larger multicenter prospective studies to evaluate these sex-specific differences. More women, including those aged over 80 years, need to be enrolled in randomized controlled trials, to better understand if sex differences exist and to tailor carotid revascularization accordingly.

Influences of age and gender on operative risks following carotid endarterectomy: A systematic review and meta-analysis

OBJECTIVES

This review aims to undertake a comprehensive review of the literature and investigate associations of age and gender on 30 days post carotid endarterectomy (CEA) and up to 5 years post CEA stroke, death, and combined stroke and death.

DESIGN

A systematic review and meta-analysis.

METHODS

Three main electronic databases including the Cochrane Library, MEDLINE, and Embase were searched from their inception to July 2022. Studies examining operative risks (i.e., stroke, death, and combined stroke and death following CEA) linked to age or gender were included. Two independent reviewers were responsible for study selection, quality assessment, and data extraction. Odds ratio (OR) and 95% confidence interval (CI) of all outcomes were calculated.

RESULTS

44609 studies were retrieved from the search. There were 127 eligible studies (80 studies of age, 72 studies of gender, 25 studies of age and gender) for pooling in the meta-analysis. With regards to stroke and death risks within 30 days post CEA; patients aged ≥75 had higher death (OR 1.38; 95% CI 1.10-1.75) than patients aged <75. Patients aged ≥80 had higher stroke risk (OR 1.17; 95% CI 1.07-1.27) and death risk (OR 1.85; 95% CI 1.48-2.30) particular in asymptomatic patients (OR 2.4; 95% CI 1.56-3.81). Pooled effect estimates by gender, at 30 days post CEA, showed that female was associated with increased risk of stroke (OR 1.28; 95% CI 1.16-1.40), with more risk in asymptomatic female patients (OR 1.51; 95% CI 1.14-1.99).

CONCLUSIONS

This meta-analysis highlights that older people is associated with increased stroke risk, particularly asymptomatic octogenarians who had higher likelihood of death within 30 days post CEA. In addition, female especially those with asymptomatic carotid stenosis had greater likelihood of stroke within 30 days post CEA surgery.

Gender Disparities in Aortoiliac Revascularization in Patients with Aortoiliac Occlusive Disease

BACKGROUND

Gender disparities have been previously reported in aortic aneurysm and critical limb ischemia outcomes; however, limited info is known about disparities in aortoiliac occlusive disease. We sought to characterize potential disparities in this specific population.

MATERIAL AND METHODS

Patients who underwent aortobifemoral bypass and aortic thromboendarterectomy (Current Procedural Terminology codes 35646 and 35331) between 2012 and 2019 were identified in the National Surgical Quality Improvement Program database. A binomial regression model was used to estimate gender differences in 30-day morbidity and mortality. Inverse probability weighting was used to standardize demographic and surgical characteristics.

RESULTS

We identified 1,869 patients, of which 39.8% were female and the median age was 61 years. Age, body composition, and other baseline characteristics were overall similar between genders; however, racial data were missing for 26.1% of patients. Females had a higher prevalence of preexisting chronic obstructive pulmonary disease (20.9% vs. 14.7%, prevalence difference 6.1%, P < 0.01), diabetes mellitus (25.4% vs. 19.4%, prevalence difference 6.0%, P < 0.01), and high-risk anatomical features (39.4% vs. 33.7%, prevalence difference 5.8%, P = 0.01). Preprocedural medications included a statin in only 68.2% of patients and antiplatelet agent in 76.7% of patients. Females also had a higher incidence of bleeding events when compared to males (25.2% vs. 17.5%, standardized risk difference 7.2%, P < 0.01), but were less likely to have a prolonged hospitalization greater than 10 days (18.2% vs. 20.9%, standardized risk difference -5.0%, P = 0.01). The 30-day mortality rate was not significantly different between genders (4.7% vs. 3.6%, standardized risk difference 1.2%, P = 0.25).

CONCLUSIONS

Female patients treated with aortobifemoral bypass or aortic thromboendarterectomy are more likely to have preexisting chronic obstructive pulmonary disease, diabetes mellitus, and high-risk anatomical features. Regardless of a patient's gender, there is poor adherence to preoperative medical optimization with both statins and antiplatelet agents. Female patients are more likely to have postoperative bleeding complications while males are more likely to have a prolonged hospital stay greater than 10 days. Future work could attempt to further delineate disparities using databases with longer follow-up data and seek to create protocols for reducing these observed disparities.

An Analysis of Sex-Based Outcomes Following Transcarotid Artery Revascularization

OBJECTIVE

Several studies suggest that females have higher perioperative adverse events and decreased benefit from carotid artery revascularization with transfemoral carotid artery stenting and carotid endarterectomy (CEA) compared to males. However, there are limited data of sex-based outcomes for transcarotid artery revascularization (TCAR).

METHODS

A retrospective review of prospectively maintained system-wide TCAR databases was performed between December 2015-January 2022. Patients who underwent TCAR were stratified based on sex. Relevant demographics, medical conditions, anatomical characteristics, intra- and postoperative courses, and adverse events were captured.

RESULTS

729 patients underwent TCAR, 486 (66.6%) male and 243 (33.3%) female. Males were more likely to be diagnosed with coronary artery disease (56.9% vs 47.7%, P<.01) and were active smokers (30.4% vs 21.4%, P < .01). Age, symptomatic status, BMI, hypertension, hyperlipidemia, diabetes mellitus, arrhythmia, chronic obstructive pulmonary disease, history of myocardial infarction, heart failure with reduced ejection fraction <30%, end-stage renal disease and Charlson Comorbidity Index were similar. In the perioperative period, there was no significant difference in reintervention rates (1.6% vs 1.2%, P = .75), cranial nerve palsy (.6% vs .4%, P > .99), ipsilateral stroke (1.9% vs 3.3%, P = .29), stent thrombosis (.4% vs .8%, P > .99), myocardial infarction (0% vs 0%, P > .99) and death (1.2% vs 1.2%, P > .99). In follow-up, no significant difference was found in reintervention, ipsilateral stroke, contralateral stroke, myocardial infarction, in-stent restenosis >50%, stent thrombosis, and death.

CONCLUSIONS

Males and females did not have a statistically significant difference in outcomes when comparing ipsilateral stroke, in-stent thrombosis, conversion to CEA, and death after TCAR. However, our cohort comprised predominantly male patients and may conceal statistical significance as the females in our cohort did have a higher tendency toward developing complications. Future studies with a larger female cohort should be conducted to determine whether there is a true disparity of outcomes between the males and females undergoing TCAR.

The impact of sex on outcomes following carotid endarterectomy

BACKGROUND

Previous studies have demonstrated significant sex differences in vascular surgery outcomes. We assessed stroke or death rates following carotid endarterectomy (CEA) in women vs. men.

METHODS

The Vascular Quality Initiative (VQI) was used to identify all patients who underwent CEA between 2010-2019. Demographic, clinical, and procedural characteristics were recorded and differences between women vs. men were assessed using independent t-test and chi-square test. The primary outcomes were 30-day and 1-year stroke or death. Associations between sex and outcomes were assessed using univariate/multivariate logistic regression and Cox proportional hazards analysis.

RESULTS

52,137 women and 79,974 men underwent CEA in VQI sites during the study period. Women were younger (70.3 vs. 70.5 years, p < 0.001) and more likely to have hypertension (89.2% vs. 88.9%, p < 0.05) and diabetes (36.2% vs. 35.8%, p < 0.001), but less likely to be diagnosed with coronary artery disease (23.2% vs. 31.0%, p < 0.001). A greater proportion of men were receiving cardiovascular risk reduction medications and had symptomatic carotid stenosis (28.5% vs. 26.7%, p < 0.001). Women had shorter procedure times (113 vs. 122 minutes, p < 0.001) and were less likely to receive electroencephalography neuromonitoring (27.9% vs. 28.8%, p < 0.001), drain (35.9% vs. 37.3%, p < 0.001), and protamine (67.4% vs. 68.0%, p < 0.01). Stroke or death at 30 days (1.9% vs. 1.8%, p = 0.60) and 1 year (HR 0.98 [95% CI 0.94 - 1.01], p = 0.20) were similar between groups, which persisted in asymptomatic patients (HR 0.97 [95% CI 0.93 - 1.01], p = 0.17) and symptomatic patients (HR 0.99 [95% CI 0.93 - 1.05], p = 0.71). The similarities in 1-year stroke or death rates existed in both the US (HR 0.96 [95% CI 0.92 - 1.01], p = 0.09) and Canada (HR 1.21 [95% CI 0.47 - 3.11], p = 0.70).

CONCLUSIONS

Despite sex differences in clinical and procedural characteristics, women and men have similar 30-day and 1-year outcomes following carotid endarterectomy.

[Carotid endarterectomy with stent removal in a patient with early bilateral restenosis of the internal carotid arteries in the acute period of recurrent ischemic stroke]

We present a rare clinical observation of a patient with an early reoperation performed up to 2 weeks after a recurrent stroke. Carotid endarterectomy with removal of previously installed stents for critical stenoses of the internal carotid arteries after the first stroke was performed. Early bilateral restenosis up to 80-90% of the lumen in the stents of both internal carotid arteries was observed 6 months after stenting. Open interventions were performed in the acute period of recurrent ischemic stroke in two stages with a favorable outcome. No data on the increase of neurological symptoms were obtained for 2 years of observation. Treatment and application of early rehabilitation methods, improved the patient's general condition, strength in the left extremities increased up to 4.5 points, left-sided hemihypesthesia decreased, speech disorders regressed. The patient walks and serves himself independently.

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.

Female Gender Increases Risk of Stroke and Readmission after CEA and CAS

OBJECTIVES

Carotid endarterectomy (CEA) has historically demonstrated a higher rate of perioperative adverse events for female patients. However, recent evidence suggests similar outcomes for CEA between genders. In contrast, fewer studies have examined gender in carotid artery stenting (CAS). Using contemporary data from the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database, we aim to determine if gender impacts differences in postoperative complications in patients who undergo CEA or CAS.

METHODS

The ACS NSQIP database was queried from 2005-2017 using Current Procedural Terminology (CPT) and International Classification of Diseases (ICD) codes for retrospective review. Patients with carotid intervention (CEA or CAS) were stratified into asymptomatic vs symptomatic cohorts to determine the effect of gender on 30-day postoperative outcomes. Symptomatic patients were defined as those with perioperative transient cerebral ischemic attack or stenosis of carotid artery with cerebral infarction. Descriptive statistics were calculated. Risk-adjusted odds of 30-day postoperative outcomes were calculated using multivariate regression analysis with fixed effects for age, race, and comorbidities.

RESULTS

There were 106,568 patients with CEA or CAS (104,412 CEA and 2,156 CAS). Average age was 70.9 years old and female patients accounted for 39.9% of the population. For asymptomatic patients that underwent CEA or CAS, female gender was associated with significantly higher rates of CVA/stroke (13%, p=0.005), readmission (10%, p=0.004), bleeding complication (32%, p=0.001), and UTI (54%, p=0.001) as well as less infection (26%, p=0.001). In the symptomatic cohort, female gender was associated with significantly higher rates of CVA/stroke (32%, p=0.034), bleeding complication (203%, p=0.001), and UTI (70%, p=0.011), while female gender was associated with a lower rate of pneumonia (39%, p=0.039). Subset analysis found that, compared to male patients, female patients <75yo have an increased rate of CVA/stroke (21%, p=0.001) and readmission (15%, p<0.001), while female patients ≥75yo did not. In asymptomatic and symptomatic patients that underwent CEA, female gender was associated with significantly higher rates of CVA/stroke (13%, p=0.006 and 31%, p=0.044, respectively), but this finding was present not in patients undergoing CAS.

CONCLUSION

In patients undergoing carotid intervention, female gender was associated with significantly increased rates of postoperative CVA/stroke in the asymptomatic and symptomatic cohorts as well as readmission in the asymptomatic cohort. Female gender was associated with higher rates of CVA/stroke following CEA, but not CAS. We recommend that randomized control trials ensure adequate representation of female patients to better understand gender-based disparities in carotid intervention.

Experimental comparative assay of tensile resistance of greater saphenous vein from ankle and groin

Background

The great saphenous vein is used as patch material in several types of arterial reconstruction, including trauma and carotid and femoral endarterectomy. There have been reports of saphenous patch blowout, particularly of patches constructed with veins harvested from the ankle. There is a need for objective measurement of the resistance of saphenous vein tissues.

Objectives

To measure the tensile strength of the great saphenous vein harvested at the ankle and groin and analyze the correlation between diameter and tissue strength.

Methods

Venous samples were harvested during elective saphenous stripping in patients with symptomatic varicose veins. Only segments without reflux were included. Ten limbs from eight patients were studied, providing 20 samples in total. Venous segments were opened along their longitudinal axis and fitted to electronic traction assay equipment to obtain values for material maximum tension in kilograms-force per square centimeter (kgf/cm²; the maximum force resisted by the segment, divided by its cross-sectional area).

Results

The average maximum tension in the ankle saphenous vein group ranged from 74.02 to 190.10 kgf/cm² and from 13.53 to 69.45 kgf/cm2 in the groin saphenous vein group (p < 0.0001). The Pearson coefficient for the correlation between vein diameter and maximum tension was -0.852 (moderate to strong inverse correlation).

Conclusions

Ankle saphenous vein tissue from female patients operated for varicose veins has significantly higher resistance than saphenous vein tissue from the groin and there is an inverse relation between vein diameter and resistance of tissue from the same population.

Sex-related disparities in intervention rates and type of intervention in patients with aortic and peripheral arterial diseases in the National Inpatient Sample Database

OBJECTIVE

The first annual Women's Vascular Summit highlighted sex- and gender-related knowledge gaps in vascular disease diagnosis and treatment. This finding suggests an opportunity for further research to improve care and outcomes in people who identify as women, specifically. The purpose of this study was to a large national dataset to identify all operations performed for abdominal aortic aneurysm (AAA), carotid artery stenosis (CAS), and peripheral arterial disease (PAD) in the United States, and to provide data on sex-related disparities in treatment.

METHODS

All hospitalizations of adult patients (≥18 years old) diagnosed with AAA, CAS, or PAD who underwent vascular surgery from 2000 to 2016 were identified in the Healthcare Cost and Utilization Project National Inpatient Sample. Sex-stratified U.S. Census data and sex-specific population disease prevalence estimates from the National Institute of Health and Agency for Healthcare Research and Quality were used to calculate the number of U.S. adults with AAA, CAS, and PAD. Sex-stratified rates of surgery and incidence rate ratios were estimated using Poisson regression. Among those undergoing surgery, multivariable logistic regression was used to assess differences in endovascular vs open approach.

RESULTS

Over 16 years, there were 1,021,684 hospitalizations for vascular surgery: 13% AAA (21% female, 79% male), 40% CAS (42% female, 58% male), and 47% PAD (42% female, 58% male). Females were older than males at time of surgery (median age, 71.3 years vs 69.7 years) and less likely to have private insurance (18% vs 23%); minimal differences were seen across race/ethnicity, comorbidities, and hospital characteristics. After accounting for disease prevalence, females were still 25% less likely to undergo surgery for AAA and 30% less likely to undergo surgery for PAD compared with males with the same disease. These results were consistent over time. After adjustment, females, compared with males, were less likely to receive an endovascular procedure compared with open for AAA or CAS, and more likely to receive one for PAD.

CONCLUSIONS

From 2000 to 2016 in the United States, females were less likely to undergo intervention for AAA and PAD than males. This finding is particularly significant for PAD, because the prevalence is the same for both sexes, indicating that females are likely undertreated for PAD. Additionally, females were less likely to undergo endovascular surgery for AAA and more likely to undergo endovascular surgery for PAD than males. These findings suggest that improvement in AAA and PAD identification and management in females may improve outcomes.

Carotid artery stenting has similar outcomes in men and women

Background

The aim of carotid interventions is to prevent cerebrovascular events. Endovascular treatment (carotid-artery-stenting/CAS) has become established as an alternative to open surgery in some cases. Historically, female sex has been considered as a perioperative risk factor, however, there are few studies regarding this hypothesis when it comes to CAS.

Objectives

To analyze the CAS results in our center adjusted by sex.

Methods

A retrospective cohort study was designed, including patients with carotid atheromatosis operated at a single center from January 2016 to June 2019. Our objective was to compare cardiovascular risk, including myocardial infarction, stroke, and mortality, by sex. Follow-up rates of stent patency, restenosis, stroke, myocardial infarction, and death were reported.

Results

71 interventions were performed in 50 men (70.42%) and 21 women (29.57%). Mean age was 70.50 ± 10.72 years for men and 73.62 ± 11.78 years for women. Cardiovascular risk factors did not differ significantly between sexes. Mean follow-up was 11.28 ± 11.28 months. There were no significant differences in neurological events during follow-up. No adverse cardiological events were detected at any time. Regarding the mortality rate, during medium-term follow up there were 2 neurological related deaths with no significant differences between sexes (p=0.8432). Neither sex had higher rated of restenosis during long term follow-up (5.63% vs. 1.41%, p = 0.9693) or reoperation (1.41% vs. 1.41%, p = 0.4971). All procedures remained patent (<50% restenosis).

Conclusions

Despite the limitations of our study, CAS is a therapeutic option that is as effective and safe in women as in men. No sex differences were observed.

Editor's Choice - Distribution of Care and Hospital Incidence of Carotid Endarterectomy and Carotid Artery Stenting: A Secondary Analysis of German Hospital Episode Data

OBJECTIVE

This is a description of the German healthcare landscape regarding carotid artery disease, assessment of hospital incidence time courses for carotid endarterectomy (CEA) and carotid artery stenting (CAS), and simulation of potential effects of minimum hospital caseload requirements for CEA and CAS.

METHODS

The study is a secondary data analysis of diagnosis related group statistics data (2005-2016), provided by the German Federal Statistical Office. Cases encoded by German operation procedure codes for CEA or CAS and by International Classification of Diseases (ICD-10) codes for carotid artery disease were included. Hospitals were categorised into quartiles according to annual caseloads. Linear distances to the closest hospital fulfilling hypothetical caseload requirements were calculated.

RESULTS

A total of 132 411 and 33 709 patients treated with CEA and CAS from 2012 to 2016 were included. CEA patients had lower rates of myocardial infarction (1.4% vs. 1.8%) and death (1.2% vs. 4.0%), and CAS patients were more often treated after emergency admission (38.1% vs. 27.1%). Age standardised annual hospital incidences were 67.2 per 100 000 inhabitants for CEA and 16.3 per 100 000 inhabitants for CAS. The incidence for CEA declined from 2005 to 2016, with CAS rising again until 2016 after having declined from 2010 to 2013. Regarding distance from home to hospital, centres offering CEA are distributed more homogeneously across Germany, compared with those performing CAS. Hypothetical introduction of minimum annual caseloads (> 20 for CEA; > 10 for CAS) imply that 75% of the population would reach their hospital after travelling 45 km for CEA and 70 km for CAS.

CONCLUSION

Differences in spatial distribution mean that statutory minimum annual caseloads would have a greater impact on CAS accessibility than CEA in Germany. Presumably because of a decline in carotid artery disease and a transition towards individualised therapy for asymptomatic patients, hospital incidence for CEA has been declining.

Personalized-medicine on carotid endarterectomy and stenting

Evidence based medicine (EBM) is the core of current clinical guidelines and is considered as the gold standard of clinical practice. Despite this, a number of limitations and criticisms are moved to EBM. The major one is that this method privileges randomized controlled trials (RCTs), in which the selection of patients is often based on rigid inclusion criteria. The lack of “pragmatism” of some RCTs sometimes makes it difficult to apply guidelines that derive from them to patients observed in clinical practice, who are often affected by comorbidities and disabilities. The new paradigm to overcome this limitation is personalized medicine (PM), which aims to take into account the particular characteristics displayed by the individual. In order to tailor the best treatment for the patient, PM uses EBM but emphasizes the person's specific information from the assessment of the clinic, lifestyle and risk/benefit scores. This narrative review tries to find the best evidence by analysing subgroups and risk scores of patients from meta-analysis and RCTs in order to try to apply PM and to provide good practice points (GPP) on grey aspects and open questions not fully covered by current guidelines on carotid endarterectomy (CEA) and stenting for stroke prevention.

Carotid Artery Stenting in Asymptomatic Carotid Artery Stenosis: JACC Review Topic of the Week

The advance of therapies to reduce the stroke impact of asymptomatic carotid artery stenosis has proved difficult over the last decade. Disagreement concerning the underlying randomized control trials has limited entry into the care arena of endovascular therapies. Recently, advances in percutaneous therapies for carotid artery disease have been reported and provide a substantial database supporting the further incorporation of endovascular-based therapies in patients who need revascularization and meet selection criteria. With a second randomized control trial now published, it is time for a re-evaluation of endovascular therapy as a component of carotid artery care. This review describes the advances in the field in the last 5 years, clarifying the current position of these therapies in the care of the patient with asymptomatic carotid artery disease.

Clinical impact of sex on carotid revascularization

BACKGROUND

The impact of sex in the management of carotid disease is unclear in the current literature. Therefore, we evaluated the effect of sex on perioperative outcomes following carotid endarterectomy (CEA) and carotid artery stenting (CAS).

METHODS

We included patients who underwent CEA or CAS between 2012 and 2017 in the Vascular Quality Initiative database. Our primary outcome was perioperative stroke/death. Secondary outcomes were in-hospital stroke, 30-day mortality, and in-hospital MI. We compared perioperative outcomes between female and male patients, stratified by treatment modality and symptom status, and used multivariable regression to account for differences in baseline characteristics.

RESULTS

A total of 83,436 patients underwent either a CEA (71,383) or CAS (12,053). Asymptomatic and symptomatic CEA females were less likely to be on a preoperative antiplatelet agent, when compared to males. Females overall, were less likely to be on a preoperative statin and more likely to have chronic obstructive pulmonary disease. Within the CAS cohort, females were more likely to have a previous ipsilateral CEA. There were no differences between males and females in major adverse events following CEA for asymptomatic disease. Following CEA for symptomatic disease, there was no difference in stroke/death rate or in-hospital stroke. However, females experienced a higher 30-mortality after adjustment (univariate: 1.0% vs 0.7%, P = .04; adjusted: odds ratio [OR], 1.4:1.02-1.94). Following CAS for asymptomatic disease, females experienced a higher rate of perioperative stroke/death (2.9% vs 1.9% P = .02; OR, 1.5: 1.05-2.03) and in-hospital stroke (2.1% vs 1.2% P = .01; OR, 1.8: 1.20-2.60). There were no differences in outcomes for symptomatic females vs males undergoing CAS.

CONCLUSIONS

Females with carotid disease less frequently receive optimal medical treatment with antiplatelet agents and statins. This is an important target area for quality improvement issue in both females and males. Furthermore, among symptomatic CEA patients the female sex is associated with higher mortality and among asymptomatic CAS patients, females experience higher rates of stroke/death. These findings suggest that careful patient selection is necessary in the treatment of female patients. Quality improvement projects should be created to further investigate and eliminate the disparities of optimal medical management between the sexes.

Race and sex-based disparities associated with carotid endarterectomy in the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND AND AIMS

The indications for carotid endarterectomy (CEA) are well established. The aim of the current study was to investigate sex and race-based disparities in the incidence of CEA after adjusting for carotid artery stenosis risk factors.

METHODS

We conducted a prospective cohort analysis of 14,492 black and white participants in the Atherosclerosis Risk in Communities (ARIC) study without prevalent stroke at baseline (1987-1989). We used Kaplan-Meier curves and Cox proportional hazards models adjusting for sociodemographic, cardiovascular, and disease severity risk factors to quantify the associations of sex and race with incident CEA.

RESULTS

CEA was performed in 330 of 14,492 ARIC participants during a median of 27 years of follow-up [incidence rate 1.00 (95% CI 0.90-1.12) per 1000 persons-years]. The crude incidence of CEA varied significantly by sex [female vs. male: HR 0.60 (95% CI 0.48-0.74)] and race [black vs. white: HR 0.65 (95% CI 0.49-0.86)]. Adjustment for sociodemographic and cardiovascular risk factors, carotid intima-media thickness, and symptomatic status attenuated the association of sex with CEA [females vs. males HR 0.96 (0.76-1.22)], but black participants had a lower risk of incident CEA after adjustment [HR 0.68 (95% CI 0.49-0.95)].

CONCLUSIONS

We found significant variation in the incidence of CEA procedures based on race that was independent of traditional risk factors and carotid IMT. Whether this disparity is a reflection of differences in disease presentation or access to care deserves investigation.

Effects of patient age on outcomes after carotid endarterectomy: A retrospective, single-center study in Korea

In this single-center, retrospective study, we aimed to compare early and late outcomes after carotid endarterectomy (CEA) between younger and elderly patients and to investigate the impact of patient age on the overall incidence of cardiovascular events after CEA.A total of 613 patients with 675 CEAs between January 2007 and December 2014 were stratified by patient age into 2 groups: younger (≤60 years, n = 103 CEAs, 15.3%) and elderly (>60 years, n = 572 CEAs, 84.7%) groups. The study outcomes were defined as the occurrence of major adverse events (MAEs), including fatal or nonfatal stroke or myocardial infarction (MI), or any-cause mortality, and overall cardiovascular events (meaning the composite incidence of stroke or MI) during the perioperative period and within 4 years after CEA.Although there were no significant differences in the incidence of 30-day MAEs and any of the individual MAE manifestations between the 2 groups, the differences in the MAE incidence (P = .006) and any-cause mortality (P = .023) within 4 years after CEA were significantly greater in patients in the elderly group. For overall incidence of cardiovascular events, no significant difference was noted between the 2 groups (P = .096). On multivariate analysis, older age (>60 years) did not affect the incidence of perioperative MAEs and individual MAE manifestations; however, older age was significantly associated with an increased risk of 4-year MAEs (hazard ratio [HR], 3.68, 95% confidence interval [CI], 1.35-10.0; P = .011) and any-cause mortality (HR, 3.26, 95% CI, 1.02-10.5; P = .047). With regard to the 4-year overall incidence of cardiovascular events, older age was not an independent predictor of increased risk of these cardiovascular events.Our study indicates that the risks of perioperative MAEs and the 4-year overall incidence of cardiovascular events do not significantly differ between younger and elderly Korean patients undergoing CEA, although there was a higher risk of 4-year any-cause mortality in the elderly patients. Older age does not appear to be an independent risk factor for perioperative MAEs and overall cardiovascular events within 4 years after CEA.

Three-year outcomes after carotid artery revascularization: Gender-related differences

Objectives

Carotid artery stenosis is thought to cause up to 10% of ischemic strokes. Historically, carotid artery endarterectomy has shown a higher risk of perioperative adverse events for women. More recent trials reported conflicting results regarding the benefit of carotid artery endarterectomy and carotid artery stenting for men and women. The aim of the present retrospective study was to investigate the influence of gender on the short- (30 days) and long-term (3 years) outcomes of carotid artery endarterectomy and carotid artery stenting in a single centre.

Methods

From 2010 to 2017, 912 consecutive symptomatic and asymptomatic patients who underwent carotid artery endarterectomy (389, 42.7%) or carotid artery stenting (523, 57.3%) in a single institution had been evaluated to determine the influence of sex (540 men, 59.2%, vs. 372 women, 40.8%) on the outcomes after both revascularization procedures during three years of follow-up. The primary endpoint was the incidence of death, stroke, myocardial infarction, and restenosis in the short-term follow-up. The secondary endpoint was the incidence of death, stroke, myocardial infarction, and restenosis in the long-term follow-up.

Results

Mean clinical follow-up was 21.1 (16.1) months. Women had internal and common carotid artery diameters significantly smaller with respect to men. For peri-procedural outcomes, women undergoing carotid artery stenting had a higher risk of moderate (50–70%) restenosis (6 women, 2.9%, vs. 3 men, 1.0%). For long-term outcomes, women undergoing carotid artery endarterectomy had a higher rate of moderate restenosis (16 women, 16.3%, vs. 11 men, 7.6%). No significant differences in long-term outcomes were observed between men and women undergoing carotid artery stenting, even after stratification for baseline risk factors.

Conclusions

Contrary to previous reports, from this single-centre study, long-term risk of events seems to be higher in women who underwent carotid artery endarterectomy than in those who underwent carotid artery stenting, while fewer differences were observed in men.

Computed tomography scan based prediction of the vulnerable carotid plaque

BACKGROUND

Primary to validate a commercial semi-automated computed tomography angiography (CTA) -software for vulnerable plaque detection compared to histology of carotid endarterectomy (CEA) specimens and secondary validating calcifications scores by in vivo CTA with ex vivo non-contrast enhanced computed tomography (NCCT).

METHODS

From January 2014 to October 2016 53 patients were included retrospectively, using a cross-sectional design. All patients underwent both CTA and CEA. Sixteen patients had their CEA specimen NCCT scanned. The semi-automated CTA software analyzed carotid stenosis using different HU values defining plaque components. The predictive values of CTA based detection of vulnerable plaques were calculated. Quantification of calcifications on CTA using region of interest (ROI)-function and mathematical equations was done manually, and validated by NCCT of the CEA specimen.

RESULTS

The semi-automated CTA software had a sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 89.1% (95% CI, 73.6% - 96.4%), 31.3% (95% CI, 12.1% - 58.5%), 75% (95% CI, 59.3% - 86.2%) and 55.6% (95% CI, 22.6% - 84.6%). Strong correlation between in vivo CTA and ex vivo NCCT in quantification of calcification was observed, but CTA systematically underestimated calcificationsscore (CALS) with increasing calcification.

CONCLUSION

The CTA-software cannot be used in risk assessment of patients, due to poor specificity and NPV. The correlation between in vivo CTA and ex vivo NCCT was strong, proposing it to be used in both scientifically and clinical settings, but studies with larger sample sizes are needed.

Surgical and Endovascular Treatment of Extracranial Carotid Stenosis

BACKGROUND

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) can be used to prevent stroke due to arteriosclerotic lesions of the carotid artery. In Germany, legally mandated quality assurance (QA) enables the evaluation of outcome quality after CEA and CAS performed under routine conditions.

METHODS

We analyzed data on all elective CEA and CAS procedures performed over the periods 2009-2014 and 2012-2014, respectively. The endpoints of the study were the combined in-hospital stroke and death rate, stroke rate and mortality separately, local complications, and other complications. We analyzed the raw data with descriptive statistics and carried out a risk-adjusted analysis of the association of clinically unalterable variables with the risk of stroke and death. All analyses were performed separately for CEA and CAS.

RESULTS

Data were analyzed from 142 074 CEA procedures (67.8% of them in men) and 13 086 CAS procedures (69.7% in men). The median age was 72 years (CEA) and 71 years (CAS). The periprocedural rate of stroke and death after CEA was 1.4% for asymptomatic and 2.5% for symptomatic stenoses; the corresponding rates for CAS were 1.7% and 3.7%. Variables associated with increased risk included older age, higher ASA class (ASA = American Society of Anesthesiologists), symptomatic vs. asymptomatic stenosis, 50-69% stenosis, and contralateral carotid occlusion (for CEA only).

CONCLUSION

These data reveal a low periprocedural rate of stroke or death for both CEA and CAS. This study does however not permit any conclusions as to the superiority or inferiority of CEA and CAS.

Symptomatic Carotid Artery Stenosis: Surgery, Stenting, or Medical Therapy?

Symptomatic carotid artery disease is a significant cause of ischemic stroke, and these patients are at high risk for recurrent vascular events. Patients with symptoms of stroke or transient ischemic attack attributable to a significantly stenotic vessel (70–99% luminal narrowing) should be treated with intensive medical therapy. Intensive medical therapy is a combination of pharmacologic and lifestyle interventions consistent with best-known practices as follows: initiation of antiplatelet agent or anticoagulation if medically indicated, high potency statin medication, blood pressure control with goal blood pressure of greater than 140/90, Mediterranean-style diet, exercise, and smoking cessation. Further, patients who have extracranial culprit lesions should be considered for revascularization with either carotid endarterectomy or carotid angioplasty and stenting depending on several factors including the patient’s anatomy, age, gender, and procedural risk. Based on current evidence, patients with symptomatic intracranial stenosis should be managed with intensive medical therapy, including the use of dual antiplatelet therapy with aspirin and clopidogrel for the first 90 days following the ischemic event. While the literature has shown a stronger benefit of revascularization of extracranial symptomatic disease among certain subgroups of patients with greater than 70% stenosis, there is less benefit from revascularization with endarterectomy in patients with moderate stenosis of 50–69% if the surgeon’s risk of perioperative stroke or death rate is greater than 6%.

Intermediate Outcomes of Femoropopliteal Stenting in Women: 3-Year Results of the DURABILITY II Trial

BACKGROUND

This study investigated the effects of gender on the 3-year outcomes of the StuDy for EvalUating EndovasculaR TreAtments of Lesions in the Superficial Femoral Artery and Proximal Popliteal By usIng the Protege EverfLex NitInol STent System II (DURABILITY II) trial.

METHODS

A total of 287 patients enrolled in the DURABILITY II trial (prospective and nonrandomized trial) were stratified by gender and evaluated for primary, primary assisted, and secondary patency at 3 years. Clinical scores including changes in ankle-brachial index (ABI) and walking impairment questionnaire (WIQ) scores were evaluated.

RESULTS

Overall 190 male and 97 female patients were included for analysis. The 3-year primary, assisted primary, and secondary patency rates for women versus men were 62.5% vs. 58.8%, 68.5% vs. 64.9%, and 72.1% vs. 67.2%, respectively (P < 0.05). Although ABIs at presentation were similar between women versus men (0.64 vs. 0.65, P < 0.05), women had lower ABI scores at 3 years compared with men (0.85 vs. 0.92, P = 0.03). Women versus men had inferior walking distance scores at presentation (13.6 vs. 25.7, P < 0.001), scores were equalized by 2 years (51.6 vs. 60.8, P < 0.05); however, 3-year follow-up demonstrated less durable results for women versus men (37.3 vs. 58.8, P < 0.05). In addition, women had worse WIQ scores for pain, walking speed, and stair climbing. However, the relative change in scores between men and women were comparable, with both groups seeing similar improvements from baseline for these parameters.

CONCLUSIONS

Women continue to see clinical improvement after intervention, achieving comparable ABIs and walking distance to men at 2 years. These benefits are diminished at 3-year follow-up with women achieving lower absolute ABI and WIQ parameters compared with men, but improved overall compared with scores at presentation.

Risk Factors For Stroke, Myocardial Infarction, or Death Following Carotid Endarterectomy: Results From the International Carotid Stenting Study

OBJECTIVES

Carotid endarterectomy (CEA) is standard treatment for symptomatic carotid artery stenosis but carries a risk of stroke, myocardial infarction (MI), or death. This study investigated risk factors for these procedural complications occurring within 30 days of endarterectomy in the International Carotid Stenting Study (ICSS).

METHODS

Patients with recently symptomatic carotid stenosis >50% were randomly allocated to endarterectomy or stenting. Analysis is reported of patients in ICSS assigned to endarterectomy and limited to those in whom CEA was initiated. The occurrence of stroke, MI, or death within 30 days of the procedure was reported by investigators and adjudicated. Demographic and technical risk factors for these complications were analysed sequentially in a binomial regression analysis and subsequently in a multivariable model.

RESULTS

Eight-hundred and twenty-one patients were included in the analysis. The risk of stroke, MI, or death within 30 days of CEA was 4.0%. The risk was higher in female patients (risk ratio [RR] 1.98, 95% CI 1.02-3.87, p = .05) and with increasing baseline diastolic blood pressure (dBP) (RR 1.30 per +10 mmHg, 95% CI 1.02-1.66, p = .04). Mean baseline dBP, obtained at the time of randomization in the trial, was 78 mmHg (SD 13 mmHg). In a multivariable model, only dBP remained a significant predictor. The risk was not related to the type of surgical reconstruction, anaesthetic technique, or perioperative medication regimen. Patients undergoing CEA stayed a median of 4 days before discharge, and 21.2% of events occurred on or after the day of discharge.

CONCLUSIONS

Increasing diastolic blood pressure was the only independent risk factor for stroke, MI, or death following CEA. Cautious attention to blood pressure control following symptoms attributable to carotid stenosis could reduce the risks associated with subsequent CEA.

Carotid Endarterectomy: Current Concepts and Practice Patterns

Background Stroke is the number one cause of disability and third leading cause of death among adults in the United States. A major cause of stroke is carotid artery stenosis (CAS) caused by atherosclerotic plaques. Randomized trials have varying results regarding the equivalence and perioperative complication rates of stents versus carotid endarterectomy (CEA) in the management of CAS. Objectives We review the evidence for the current management of CAS and describe the current concepts and practice patterns of CEA. Methods A literature search was conducted using PubMed to identify relevant studies regarding CEA and stenting for the management of CAS. Results The introduction of CAS has led to a decrease in the percentage of CEA and an increase in the number of CAS procedures performed in the context of all revascularization procedures. However, the efficacy of stents in patients with symptomatic CAS remains unclear because of varying results among randomized trials, but the perioperative complication rates exceed those found after CEA. Conclusions Vascular surgeons are uniquely positioned to treat carotid artery disease through medical therapy, CEA, and stenting. Although data from randomized trials differ, it is important for surgeons to make clinical decisions based on the patient. We believe that CAS can be adopted with low complication rate in a selected subgroup of patients, but CEA should remain the standard of care. This current evidence should be incorporated into practice of the modern vascular surgeon.

Meta- analysis and meta-regression analysis of the associations between sex and the operative outcomes of carotid endarterectomy

Background

Subgroup analyses from randomized controlled trials (RCT) of carotid endarterectomy (CEA) for both symptomatic and asymptomatic carotid stenosis suggest less benefit in women compared to men, due partly to higher age-independent peri-operative risk. However, a meta-analysis of case series and databases focussing on CEA-related gender differences has never been investigated.

Methods

A systematic review of all available publications (including case series, databases and RCTs) reporting data on the association between sex and procedural risk of stroke and/or death following CEA from 1980 to 2015 was investigated. Pooled Peto odds ratios of the procedural risk of stroke and/or death were obtained by Mantel-Haenszel random-effects meta-analysis. The I² statistic was used as a measure of heterogeneity. Potential publication bias was assessed with the Egger test and represented graphically with Begg funnel plots of the natural log of the OR versus its standard error. Additional sensitivity analyses were undertaken to evaluate the potential effect of key assumptions and study-level factors on the overall results. Meta-regression models were formed to explore potential heterogeneity as a result of potential risk factors or confounders on outcomes. A tria sequential analysis (TSA) was performed with the aim to maintain an over- all 5 % risk of type I error, being the standard in most meta- analyses and systematic reviews.

Results

58 articles reported combined stroke and mortality rates within 30 days of treatment. In the unselected overall meta-analysis, the incidence of stroke and death in the male and female groups differed significantly (Peto OR, 1,162; 95 % CI, 1.067-1.266; P = .001), revealing a worse outcome for female patients. Moderate heterogeneity among the studies was identified (I² = 36 %), and the possibility of publication bias was low (P = .03). In sensitivity analyses the meta-analysis of case series with gender aspects as a secondary outcome showed a significantly increased risk for 30-day stroke and death in women compared to men (Peto OR, 1.390; 95 % CI, 1.148-1.684; P = .001), In contrast, meta-analysis of databases (Peto OR, 1.025; 95 % CI, 0.958-1.097; P = .474) and case series with gender related outcomes as a primary aim (Peto OR, 1.202; 95 % CI, 0.925-1.561; P = .168) demonstrated no increase in operative risk of stroke and death in women compared to men.

Conclusions

Metanalyses of case series and databases dealing with CEA reveal inconsistent results regarding gender differences related to CEA-procedure and should not be transferred into clinical practice.

Prevention and management of stroke in women

Stroke is the leading cause of acquired disability and the third leading cause of death in women worldwide. Sex differences in risk factors, treatment response and quality of life after stroke complicate stroke management in women. Women have an increased lifetime incidence of stroke compared to men, largely due to a sharp increase in stroke risk in older postmenopausal women. Women also have an increased lifetime prevalence of stroke risk factors, including hypertension and atrial fibrillation in postmenopausal women, as well as abdominal obesity and metabolic syndrome in middle-aged women. Controversy continues over the risks of oral contraceptives, hormone therapy and surgical intervention for carotid stenosis in women. Pregnancy and the postpartum period represent a time of increased risk, presenting challenges to stroke management. Recognition of these issues is critical to improving acute care and functional recovery after stroke in women.

Carotid revascularization: risks and benefits

Despite a decline during the recent decades in stroke-related death, the incidence of stroke has remained unchanged or slightly increased, and extracranial carotid artery stenosis is implicated in 20%–30% of all strokes. Medical therapy and risk factor modification are first-line therapies for all patients with carotid occlusive disease. Evidence for the treatment of patients with symptomatic carotid stenosis greater than 70% with either carotid artery stenting (CAS) or carotid endarterectomy (CEA) is compelling, and several trials have demonstrated a benefit to carotid revascularization in the symptomatic patient population. Asymptomatic carotid stenosis is more controversial, with the largest trials only demonstrating a 1% per year risk stroke reduction with CEA. Although there are sufficient data to advocate for aggressive medical therapy as the primary mode of treatment for asymptomatic carotid stenosis, there are also data to suggest that certain patient populations will benefit from a stroke risk reduction with carotid revascularization. In the United States, consensus and practice guidelines dictate that CEA is reasonable in patients with high-grade asymptomatic stenosis, a reasonable life expectancy, and perioperative risk of less than 3%. Regarding CAS versus CEA, the best-available evidence demonstrates no difference between the two procedures in early perioperative stroke, myocardial infarction, or death, and no difference in 4-year ipsilateral stroke risk. However, because of the higher perioperative risks of stroke in patients undergoing CAS, particularly in symptomatic, female, or elderly patients, it is difficult to recommend CAS over CEA except in populations with prohibitive cardiac risk, previous carotid surgery, or prior neck radiation. Current treatment paradigms are based on identifying the magnitude of perioperative risk in patient subsets and on using predictive factors to stratify patients with high-risk asymptomatic stenosis.