Carotid artery stenting: patient, lesion, and procedural characteristics that increase procedural complications

Thirty-day outcomes of carotid endarterectomy versus carotid artery stenting in asymptomatic and symptomatic patients: a propensity score-matched analysis

BACKGROUND

Technological and surgical approaches to carotid artery stenting (CAS) have evolved. Modern randomised controlled trials comparing CAS and carotid endarterectomy (CEA) are limited, and information about updated post-intervention outcomes are mostly from retrospective, small studies.

AIMS

This study aims to compare the 30-day outcomes of stroke, transient ischaemic attack (TIA), acute myocardial infarction (AMI) and death with propensity-matched groups of CEA and CAS in asymptomatic and symptomatic patients over a recent study period of new CAS technologies and approaches.

METHODS

A retrospective, observational, multicentre analysis was conducted including consecutive symptomatic and asymptomatic patients treated with either primary CEA or CAS for internal carotid artery stenosis, between 2015 and 2022. Patients were propensity score-matched based on comorbidities and assessed according to symptom status. Primary endpoints include composite ipsilateral stroke, TIA, AMI and death within 30 days. Secondary endpoints include technical success and length of hospital stay.

RESULTS

From a cohort of 1,110 patients, propensity matching produced 269 distinct treatment pairs (n=538). Most patients were asymptomatic (n=456, 85%). All 6 strokes were minor (CEA=2; CAS=4) and registered among asymptomatic patients. One AMI (CEA) and 1 patient death (CAS) were reported among symptomatic patients. Composite stroke/AMI/death were not significantly different between both types of symptom status and both revascularisation techniques (p=0.44 and p=1, respectively). Technical success was 100%. The length of hospital stay was significantly shorter in asymptomatic patients treated with CAS compared to those treated with CEA (p=0.05), but no difference was registered among symptomatic patients (p=0.32).

CONCLUSIONS

Propensity-matched analysis suggests that CAS has similar postprocedural outcomes for stroke, AMI and death at 30 days compared to CEA.

Association of stroke or death with severity of carotid lesion calcification in patients undergoing carotid artery stenting

OBJECTIVE

Carotid artery stenting (CAS) for heavily calcified lesions is controversial due to concern for stent failure and increased perioperative stroke risk. However, the degree to which calcification affects outcomes is poorly understood, particularly in transcarotid artery revascularization (TCAR). With the precipitous increase in TCAR use and its expansion to standard surgical-risk patients, we aimed to determine the impact of lesion calcification on CAS outcomes to ensure its safe and appropriate use.

METHODS

We identified patients in the Vascular Quality Initiative who underwent first-time transfemoral CAS (tfCAS) and TCAR between 2016 and 2021. Patients were stratified into groups based on degree of lesion calcification: no calcification, 1% to 50% calcification, 51% to 99% calcification, and 100% circumferential calcification or intraluminal protrusion. Outcomes included in-hospital and 1-year composite stroke/death, as well as individual stroke, death, and myocardial infarction outcomes. Logistic regression was used to evaluate associations between degree of calcification and these outcomes.

RESULTS

Among 21,860 patients undergoing CAS, 28% patients had no calcification, 34% had 1% to 50% calcification, 35% had 51% to 99% calcification, and 3% had 100% circumferential calcification/protrusion. Patients with 51% to 99% and circumferential calcification/protrusion had higher odds of in-hospital stroke/death (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.02-1.6; P = .034; OR, 1.9; 95% CI, 1.1-2.9; P = .004, respectively) compared with those with no calcification. Circumferential calcification was also associated with increased risk for in-hospital myocardial infarction (OR, 3.5; 95% CI, 1.5-8.0; P = .003). In tfCAS patients, only circumferential calcification/protrusion was associated with higher in-hospital stroke/death odds (OR, 2.0; 95% CI, 1.2-3.4; P = .013), whereas for TCAR patients, 51% to 99% calcification was associated with increased odds of in-hospital stroke/death (OR, 1.5; 95% CI, 1.1-2.2; P = .025). At 1 year, circumferential calcification/protrusion was associated with higher odds of ipsilateral stroke/death (12.4% vs 6.6%; hazard ratio, 1.64; P = .002).

CONCLUSIONS

Among patients undergoing CAS, there is an increased risk of in-hospital stroke/death for lesions with >50% calcification or circumferential/protruding plaques. Increasing severity of carotid lesion calcification is a significant risk factor for stroke/death in patients undergoing CAS, regardless of approach.

Intravascular lithotripsy for severely calcified carotid artery stenosis - A new frontier in carotid artery stenting?

Carotid stenosis due to severely calcified plaque can pose a significant therapeutic challenge. Extremely calcified scars/stenosis plaques can be challenging from an endovascular treatment perspective as severely calcified lesions are prone to technical failure, stent re-coil and restenosis. Intravascular lithotripsy, approved for treatment of severely calcified coronary lesions, can be used for breaking up the calcium build up in the intimal and medial layers of the vessel wall prior to stenting. This was designated as a breakthrough device innovation by the Food and Drug Administration. This new technique addresses the challenge of the disease without compromising patient safety during the procedure. We here report procedural set-up, execution and early patient follow up from our first use of this emerging technology in a neurointerventional practice setting.

Dual- vs single-layer stents for endovascular treatment of symptomatic and asymptomatic internal carotid artery stenosis

BACKGROUNDS

Plaque protrusion is a common event among carotid artery stenting (CAS) patients and increases ischemic complication risk. Dual-layer stents (DLS) with micromesh technology may offer greater plaque protection compared to single-layer stents (SLS), but few data are available. The aim of the study is to compare clinical outcomes at 12 months for asymptomatic and symptomatic patients treated for primary CAS with DLS or SLS in a high-volume center.

METHODS

A retrospective analysis of consecutive symptomatic and asymptomatic patients treated with primary CAS for internal carotid artery (ICA) stenosis, with either DLS or SLS between 2015 and 2019, was performed. Primary endpoints included rates of ipsilateral transient ischemic attacks (TIA)/stroke and death within 1-year from CAS. Secondary endpoints included patency rates and survival according to stent type.

RESULTS

Of the 301 patients who met inclusion criteria (74.8 % male; 73.6 mean age ± 8.7 years), most patients were asymptomatic (77.4 %). Among all patients DLS was most frequently deployed (66 %); also, among asymptomatic (62 %) and symptomatic patients (81 %), p < 0.01. Symptomatic patients had less comorbidities and severe disease than asymptomatic patients. Six peri-operative strokes were recorded and, within 1 year, 2 additional strokes were registered among symptomatic patients treated with SLS. No post-operative strokes were encountered in the DLS group (p = 0.04) among symptomatic patients. Higher rates of TIA were observed among asymptomatic patients treated with DLS compared to SLS while rates of TIA were reduced among symptomatic patients treated with DLS. There were no differences in patency rates for DLS and SLS in symptomatic and asymptomatic patients. Primary patency was similar among DLS stent types but differed among SLS stent types (p = 0.01). At a mean follow-up of 27 months ±17.6, survival was comparable between DLS and SLS groups (p = 0.98).

CONCLUSION

CAS with DLS seems to reduce the risk of post-procedural stroke for symptomatic patients compared to SLS whilst the choice of stent did not influence ipsilateral TIA, survival or patency rates. These data require confirmation from larger, randomized, prospective studies.

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.

Characteristics and outcomes of elderly patients undergoing carotid stenting: Experience of a high-volume interventional cardiology center

BACKGROUND

Carotid artery stenting (CAS) is an attractive option in order to treat carotid artery stenosis. However, its safety in elderly patients is questioned. Aim of this single-center retrospective study was to assess data of elderly patients undergoing CAS, and to compare them with those of the younger (< 75 years).

METHODS

We collected data of 580 consecutive patients undergoing CAS between December 2007 and June 2020 and compared clinical and procedural characteristics as well as in-hospital major adverse events (MACCE) and long-term mortality between patients < 75 years and patients ≥ 75 years old.

RESULTS

There were 272 patients (46.9%) with age ≥ 75 years and 308 patients (53.1%) with age < 75 years. The median follow-up was 48 months (range 2-144). There was no significant difference about in-hospital MACCE between the two groups (4.7% in the older vs. 3.5% in the younger group, p = 0.9), but a higher rate of cerebral hemorrhage occurred in the older group (1.8% vs. = 0.3%, p = 0.07), even if not significant. Long-term mortality was significantly higher in the older group (27.9 vs. 20.1%, p = 0.027). Multivariate predictors of 12-months mortality were neurologic symptoms within 6 months (OR: 4.83; 95% CI: 2.04-11.42; p ≤ 0.001), smoking status (OR: 2.84; 95% CI: 1.17-6.86; p = 0.02) and age ≥ 75 years (OR: 2.78; 95% CI: 1.14-6.76; p = 0.024).

CONCLUSIONS

In elderly patients, CAS can be carried out efficaciously with acceptable procedural risks, if performed by expert operators and after a correct selection by a multidisciplinary team.

The impact of carotid lesion calcification on outcomes of carotid artery stenting

OBJECTIVE

The impact of carotid artery lesion calcification on adverse events following carotid artery stenting is not well-studied. Few reports associated heavily calcified lesions with high risk of perioperative stroke following transfemoral carotid artery stenting (TFCAS). With the advent of transcarotid artery revascularization (TCAR), we aimed to compare the outcomes of these two procedures stratified by the degree of lesion calcification.

METHODS

Our cohort was derived from the Vascular Quality Initiative database for carotid artery stenting. Patients with missing information on the degree of carotid artery calcification were excluded. Patients were stratified into two groups: >50% (heavy) calcification and ≤50% (no/mild) calcification. The Student t test and the χ² test were used to compare patients' baseline characteristics and crude outcomes, as appropriate. Clinically relevant and statistically significantly variables on univariable analysis were added to a logistic regression model clustered by center identifier.

RESULTS

A total of 11,342 patients were included. Patients with >50% calcification were older, had more comorbidities, and more contralateral occlusion. There were more patients with prior ipsilateral carotid endarterectomy in the ≤50% calcification group. In patients who underwent TCAR, there were no significant differences between those who had >50% vs ≤50% carotid calcification in the odds of in-hospital adverse outcomes. However, in patients with heavy calcification who underwent TFCAS, there was a 50% to 60% increase in the odds of stroke (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.04-2.5; P = .03), stroke/transient ischemic attack (TIA) (OR, 1.6; 95% CI, 1.1-2.3; P = .013), and stroke/death (OR, 1.5; 95% CI, 1.02-2.08; P = .039). Compared with TFCAS in patients with heavy calcification, TCAR was associated with a 40% to 90% reduction in the odds of contralateral stroke (OR, 0.13; 95% CI, 0.04-0.4; P = .001), contralateral stroke/TIA (OR, 0.3; 95% CI, 0.1-0.87; P = .024), any stroke/TIA (OR, 0.6; 95% CI, 0.38-0.91; P = .02), death (OR, 0.3; 95% CI, 0.13-0.72; P = .006), stroke/death (OR, 0.5; 95% CI, 0.32-0.8; P = .004), and stroke/death/myocardial infarction (OR, 0.58; 95% CI, 0.39-0.87; P = .008). There were no significant differences in the odds of stroke and myocardial infarction.

CONCLUSIONS

In this retrospective analysis of patients undergoing TFCAS vs TCAR in the Vascular Quality Initiative database, TCAR demonstrated favorable outcomes compared with TFCAS among patients with calcification greater than 50% of the carotid circumference. Advance burden of carotid artery calcification was associated with worse outcomes in patients undergoing TFCAS but not TCAR. These results are consistent with previously demonstrated superiority of flow reversal compared with distal embolic protection devices. Further research is needed to assess long-term outcomes and confirm the durability of TCAR in heavily calcified lesions.

Ileal hemorrhagic infarction after carotid artery stenting: A case report and review of the literature

BACKGROUND

Ileal hemorrhagic infarction after carotid artery stenting (CAS) is a fatal complication. The prognosis of ileal hemorrhagic infarction after CAS is very poor if not treated in a timely manner. We describe a rare case of ileal hemorrhagic infarction due to acute embolism of the mesenteric artery after CAS.

CASE SUMMARY

A 67-year-old man with acute ischemic stroke underwent CAS via the right femoral artery approach 21 d after intensive medical treatment. On the first day after surgery, the patient had abdominal distension and abdominal pain. Abdominal enhanced computed tomography revealed intestinal obstruction, severe stenosis of the superior mesenteric artery, and poor distal angiography. An exploratory laparotomy was performed, and pathological examination showed hemorrhagic ileal infarction. It was subsequently found that the patient had intestinal flatulence. With the guidance of an ultrasound scan, the patient underwent abdominal puncture, drainage, and catheterization. After 58 d of treatment, the patient was discharged from hospital with a National Institutes of Health Stroke Scale score of 2 points, and a Modified Rankin Scale score of 1 point. At the 6-mo follow-up, the patient had an excellent functional outcome without stroke or mesenteric ischemia. Furthermore, computed tomography angiography showed that the carotid stent was patent.

CONCLUSION

Ileal hemorrhagic infarction is a fatal complication after CAS, usually caused by mesenteric artery embolism. Thus, more attention should be paid to the complications of embolism in the vascular system as well as the nervous system after CAS, and the complications should be identified and treated as early as possible.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

WIRION™ embolic protection system for carotid artery stenting and lower extremity endovascular intervention

Aim: To summarize all available literature regarding the Wirion™ embolic protection system (EPS) and present examples from our center. Materials & methods: A review of literture was performed about the utilization of Wirion EPS. Results: One study was identified investigating the outcomes of Wirion during carotid artery stenting. The study demonstrated 98.3% procedural success with stroke occurring in only 2.5%. Two single arm studies were identified investigating the efficacy of the Wirion filter during lower extremity endovascular interventions. The reported device success ranged from 95.1 to 97.3%. Conclusion: While carotid artery stenting should always be performed with adjunctive EPS in order to decrease the risk of cerebrovascular accidents, the routine use of EPS in femorpopliteal interventions remains an active area of investigation.

Independent Modular Filter for Embolic Protection in Carotid Stenting

BACKGROUND

Embolic protection during carotid artery stenting reduces the rate of thromboembolic events. The Wirion Embolic Protection System is used to deploy an independent distal filter using any 0.014″ guidewire. WISE study (Wirion Study Europe) evaluated the safety and performance of Wirion Embolic Protection System in patients undergoing carotid artery stenting.

METHODS AND RESULTS

A prospective, multicenter, nonrandomized, open-label, single-arm study of carotid artery stenting in high surgical risk patients was performed. The primary end point, a composite of death, stroke, and myocardial infarction at 30 days, was compared with performance goal derived from historical controls. Secondary end points were components of the primary end point and the device, angiographic, procedural, and clinical success rates. Preplanned interim analysis was performed on the first 120 patients. At interim analysis, the primary end point was significantly lower for the Wirion Embolic Protection System group, compared with historical data (3.3% versus 6.3%, respectively; P value =0.0008). Analysis of primary end point components in the WISE group, compared with the historical control group, shows numerically lower mortality (0% versus 1.7%, respectively; P=0.21), stroke (2.5% versus 4.6%, respectively; P=0.18), and myocardial infarction (0.8% versus 1.5%, respectively; P=0.50). Device, angiographic, procedural, and clinical success was achieved in 99.2%, 99.1%, 98.3%, and 96.6% of cases, respectively.

CONCLUSIONS

The data suggest that independent modular filter use in carotid artery stenting in high surgical risk patients is safe and effective. The outcomes suggest that use of an independent modular filter may be associated with a lower rate of embolic complications associated with carotid stent placement.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01783639.

A Protocol-Based Decision for Choosing a Proper Surgical Treatment Option for Carotid Artery Stenosis

OBJECTIVE

There are two established surgical treatment options for carotid artery stenosis. Carotid endarterectomy (CEA) has been accepted as a gold standard for surgical treatment while carotid artery stenting (CAS) has recently become an alternative option. Each treatment option has advantages and disadvantages for the treatment outcomes. We propose a protocol for selection of a proper surgical treatment option for carotid artery stenosis.

MATERIALS AND METHODS

A total of 192 published articles on management of carotid artery stenosis were reviewed. Preoperatively considerable factors which had been repeatedly noted in those articles for the risk/benefits of CEA or CAS were selected. According to those factors, a protocol with four categories was established.

RESULTS

CEA or CAS is indicated when the patient has a symptomatic stenosis ≥ 50%, or when the patient has an asymptomatic stenosis ≥ 80%. Each treatment option has absolute indications and favorable indications. Each absolute indication is scored with three points, and each favorable indication, one point. Based on the highest scores, a proper treatment option (CEA or CAS) is selected.

CONCLUSION

We have been treating patients according to this protocol and evaluating the outcomes of our protocol-based decision because this protocol might be helpful in assessment of risk/benefit for selection of a proper surgical treatment option in patients with carotid artery stenosis.

Short- and long-term major cardiovascular adverse events in carotid artery interventions: a nationwide population-based cohort study in Taiwan

INTRODUCTION

Carotid artery stenosis is one of the leading causes of ischemic stroke. Carotid artery stenting has become well-established as an effective treatment option for carotid artery stenosis. For this study, we aimed to determine the efficacy and safety of carotid stenting in a population-based large cohort of patients by analyzing the Taiwan National Healthcare Insurance (NHI) database.

METHODS

2,849 patients who received carotid artery stents in the NHI database from 2004 to 2010 were identified. We analyzed the risk factors of outcomes including major adverse cardiovascular events including death, acute myocardial infarction, and cerebral vascular accidents at 30 days, 1 year, and overall period and further evaluated cause of death after carotid artery stenting.

RESULTS

The periprocedural stroke rate was 2.7% and the recurrent stroke rate for the overall follow-up period was 20.3%. Male, diabetes mellitus, and heart failure were significant risk factors for overall recurrent stroke (Hazard Ratio (HR) = 1.35, p = 0.006; HR = 1.23, p = 0.014; HR = 1.61, p < 0.001, respectively). The periprocedural acute myocardial infarction rate was 0.3%. Age and Diabetes mellitus were the significant factors to predict periprocedural myocardial infarction (HR = 3.06, p = 0.019; HR = 1.68, p < 0.001, respectively). Periprocedural and overall mortality rates were 1.9% and 17.3%, respectively. The most significant periprocedural mortality risk factor was acute renal failure. Age, diabetes mellitus, acute or chronic renal failure, heart failure, liver disease, and malignancy were factors correlated to the overall period mortality.

CONCLUSION

Periprocedural acute renal failure significantly increased the mortality rate and the number of major adverse cardiovascular events, and the predict power persisted more than one year after the procedure. Age and diabetes mellitus were significant risk factors to predict acute myocardial infarction after carotid artery stenting.

Anatomical risk factors for ischemic lesions associated with carotid artery stenting

The purpose of this study was to investigate the anatomical risk factors for ischemic lesions detected by diffusion-weighted imaging (DWI) associated with carotid artery stenting (CAS). DWI was performed within four days after CAS in 50 stenotic lesions between January 2008 and September 2013. We retrospectively analyzed the correlation between the anatomical factors and ischemic lesions associated with CAS. Post-procedural DWI revealed new ischemic lesions after 24 (48%) of the 50 CAS procedures. All three patients with common carotid artery tortuosity, defined as the presence of severe angulation (less than 90 degrees) in the common carotid artery, developed new ischemic lesions. However, there were no significant differences between the patients with and without tortuosity, likely due to the small number of cases. Meanwhile, seven of eight patients with internal carotid artery tortuosity, defined as the presence of severe angulation (less than 90 degrees) in the cervical segment of the internal carotid artery, developed new ischemic lesions. A multivariate analysis showed internal carotid artery tortuosity (odds ratio: 11.84, 95% confidence interval: 1.193-117.4, P= 0.035) to be an independent risk factor for the development of ischemic lesions associated with CAS. Anatomical factors, particularly severe angulation of the internal carotid artery, have an impact on the risk of CAS. The indications for CAS should be carefully evaluated in patients with these factors.

Carotid artery stenting

Carotid artery stenting (CAS) has achieved clinical equipoise with carotid endarterectomy (CEA), as evidenced by 2 large U.S. randomized clinical trials, multiple pivotal registry trials, and 2 multispecialty guideline documents endorsed by 14 professional societies. The largest randomized trial conducted in patients at average surgical risk of CEA, CREST (Carotid Revascularization Endarterectomy Versus Stenting Trial) found no difference between CAS and CEA for the combined endpoint of stroke, death, and myocardial infarction (MI) after 4 years of follow-up. The largest randomized trial comparing CAS and CEA in patients at increased surgical risk, SAPPHIRE (Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy), looked at 1-year stroke, death, and MI incidence and found no difference in symptomatic patients, but a significantly better outcome in asymptomatic patients for CAS (9.9% vs. 21.5%; p = 0.02). Given that >70% of carotid revascularization procedures are performed in asymptomatic patients for primary prevention of stroke, it is incumbent upon clinicians to demonstrate that revascularization has an incremental benefit over highly effective modern medical therapy alone.

Carotid artery stenting: current and emerging options

Carotid artery stenting technologies are rapidly evolving. Options for endovascular surgeons and interventionists who treat occlusive carotid disease continue to expand. We here present an update and overview of carotid stenting devices. Evidence supporting carotid stenting includes randomized controlled trials that compare endovascular stenting to open surgical endarterectomy. Carotid technologies addressed include the carotid stents themselves as well as adjunct neuroprotective devices. Aspects of stent technology include bare-metal versus covered stents, stent tapering, and free-cell area. Drug-eluting and cutting balloon indications are described. Embolization protection options and new direct carotid access strategies are reviewed. Adjunct technologies, such as intravascular ultrasound imaging and risk stratification algorithms, are discussed. Bare-metal and covered stents provide unique advantages and disadvantages. Stent tapering may allow for a more fitted contour to the caliber decrement between the common carotid and internal carotid arteries but also introduces new technical challenges. Studies regarding free-cell area are conflicting with respect to benefits and associated risk; clinical relevance of associated adverse effects associated with either type is unclear. Embolization protection strategies include distal filter protection and flow reversal. Though flow reversal was initially met with some skepticism, it has gained wider acceptance and may provide the advantage of not crossing the carotid lesion before protection is established. New direct carotid access techniques address difficult anatomy and incorporate sophisticated flow-reversal embolization protection techniques. Carotid stenting is a new and exciting field with rapidly advancing technologies. Embolization protection, low-risk deployment, and lesion assessment and stratification are active areas of research. Ample room remains for further innovations and developments.

State of the art in carotid artery stenting: trial data, technical aspects, and limitations

The volume of carotid artery stenting (CAS) safety and efficacy data has grown exponentially over the last decade. Recent comparative data with carotid endarterectomy, the utility of embolic protection devices, peri-procedural medications, basic technical aspects of CAS, developments in carotid stent design, potential complications of CAS, and complication risk factors are discussed in this review.

Patient, Anatomic, and Procedural Characteristics That Increase the Risk of Carotid Interventions

Subjective characteristics for increased risk of carotid artery stenting (CAS) have included thrombus-containing lesions, heavily calcified lesions, very tortuous vessels, and near occlusions. More objective high-risk features include contraindications to dual antiplatelet therapy, a history of bleeding complications, and lack of femoral artery vascular access. Variables that increase the risk of CAS complications are attributed to patient characteristics, anatomic features, or procedural factors. Operator and hospital volume affect the risk of complications occurring with CAS. As the complexity and difficulty of CAS patients increases, the need for more highly skilled operators and teams becomes even more necessary to minimize complications.