Predictors of carotid stent restenosis

Outcomes Following Carotid Revascularization in Patients with Prior Ipsilateral Carotid Artery Stenting in the Vascular Quality Initiative

OBJECTIVES

The outcomes of carotid revascularization in patients with prior carotid artery stenting remain understudied. Prior research has not reported the outcomes after Transcarotid artery revascularization (TCAR) in patients with previous carotid artery stenting. In this study, we compared the peri-operative outcomes of TCAR, tfCAS and CEA in patients with prior ipsilateral CAS using the VQI.

METHODS

Using the Vascular Quality Initiative data from 2016 to 2023, we identified patients who underwent TCAR, tfCAS, or CEA following prior ipsilateral carotid artery stenting. We included covariates such as age, race, sex, BMI, comorbidities (hypertension, diabetes, prior CAD, prior CABG/PCI, CHF, renal dysfunction, smoking, COPD, anemia), symptom status, urgency, ipsilateral stenosis, and contralateral occlusion into a regression model to compute propensity scores for treatment assignment. We then used the propensity scores for inverse probability-weighting and weighted logistic regression to compare in-hospital stroke, in-hospital death, stroke/death, postoperative myocardial infarction (MI), stroke/death/MI, 30-day mortality and cranial nerve injury (CNI) following TCAR, tfCAS, and CEA. We also analyzed trends in the proportions of patients undergoing the three revascularization procedures over time using Cochrane-Armitage trend testing.

RESULTS

We identified 2,137 patients undergoing revascularization following prior ipsilateral carotid stenting: 668 TCAR patients (31%), 1128 tfCAS patients (53%) and 341 CEA patients (16%). In asymptomatic patients, TCAR was associated with a lower yet not statistically significant in-hospital stroke/death than tfCAS (TCAR vs tfCAS: 0.7% vs 2.0%,aOR:0.33[0.11-1.05]; p=0.06), and similar odds of stroke/death with CEA (TCAR vs CEA: 0.7% vs 0.9%,aOR:0.80[0.16-3.98]; p=0.8). Compared with CEA, TCAR was associated with lower odds of post-operative MI (0.1% vs 14%,aOR:0.02[0.00-0.10]; p<0.001), stroke/death/MI (0.8% vs 15%,aOR:0.05[0.01-0.25]; p<0.001), and CNI (0.1% vs 3.8%,aOR:0.04[0.00-0.30]; p=0.002) in this patient population. In symptomatic patients, TCAR had an unacceptably elevated in-hospital stroke/death rate of 5.1% with lower rates of CNI than CEA. We also found an increasing trend in the proportion of patients undergoing TCAR following prior ipsilateral carotid stenting (2016 to 2023: 14% to 41%), with a relative decrease in proportions of tfCAS (61% to 45%) and CEA (25% to 14%) (p<.001).

CONCLUSIONS

In asymptomatic patients with prior ipsilateral carotid artery stenting, TCAR was associated with lower odds of in-hospital stroke/death compared with tfCAS, with comparable stroke/death but lower postoperative MI and CNI rates compared with CEA. In symptomatic patients, TCAR was associated with unacceptably elevated in-hospital stroke/death rates. In line with the post-procedure outcomes, there has been a steady increase in the proportion of patients with prior ipsilateral stenting undergoing TCAR over time.

Treatment Results of Carotid Artery Stenting with an Open-Cell Stent: Analysis of 734 Consecutive Cases at a Single Center

OBJECTIVE

In carotid artery stenting (CAS) for internal carotid artery stenosis, the stent is often selected according to the plaque properties and arterial tortuosity. In our institute, an open-cell stent is used as the first-line stent regardless of the characteristics of the lesion. This study was performed to examine the outcome of CAS with an open-cell stent as the real-world results.

METHODS

In total, 811 CAS procedures using open-cell stents were performed for internal carotid artery stenosis from April 2002 to December 2019. Of these patients, we excluded those with hyperacute conditions for which CAS was performed within 3 days of onset, those in whom acute mechanical thrombectomy was performed simultaneously with CAS, and those with stenosis due to arterial dissection. Thus, 734 patients were retrospectively analyzed. Perioperative and long-term outcomes and risk factors for perioperative infarction were investigated.

RESULTS

The periprocedural stroke rate and mortality rate were 3.7% (27/734) and 0.4% (3/734), respectively. Low-echoic plaque was a significant risk factor for periprocedural stroke in both univariate (P < 0.03) and multivariate (odds ratio, 2.69; 95% confidence interval, 1.14-6.66; P = 0.02) analyses. Cerebral infarction and high grade restenosis were observed in 15 (2.0%) and 17 (2.3%) patients during a median 50-month follow-up.

CONCLUSIONS

CAS with open-cell stents showed good results in terms of both the postoperative stroke incidence and long-term severe restenosis rate. However, low-echoic plaque was a risk factor for perioperative stroke incidence, which should be considered when deciding on the indication for CAS with an open-cell stent.

Late Outcomes of Carotid Artery Stenting for Radiation Therapy-Induced Carotid Stenosis

PURPOSE

Carotid artery stenting (CAS) appears as a promising alternative treatment to carotid endarterectomy for radiation therapy (RT)-induced carotid stenosis. However, this is based on a poor level of evidence studies (small sample size, primarily single institution reports, few long-term data). The purpose of this study was to report the long-term outcomes of a multicentric series of CAS for RT-induced stenosis.

METHODS

All CAS for RT-induced stenosis performed in 11 French academic institutions from 2005 to 2017 were collected in this retrospective study. Patient demographics, clinical risk factors, elapsed time from RT, clinical presentation and imaging parameters of carotid stenosis were preoperatively gathered. Long-term outcomes were determined by clinical follow-up and duplex ultrasound. The primary endpoint was the occurrence of cerebrovascular events during follow-up. Secondary endpoints included perioperative morbidity and mortality rate, long-term mortality rate, primary patency, and target lesion revascularization.

RESULTS

One hundred and twenty-one CAS procedures were performed in 112 patients. The mean interval between irradiation and CAS was 15 ± 12 years. In 31.4% of cases, the lesion was symptomatic. Mean follow-up was 42.5 ± 32.6 months (range 1-141 months). The mortality rate at 5 years was 23%. The neurologic event-free survival and the in-stent restenosis rates at 5 years were 87.8% and 38.9%, respectively. Diabetes mellitus (p=0.02) and single postoperative antiplatelet therapy (p=0.001) were found to be significant predictors of in-stent restenosis. Freedom from target lesion revascularization was 91.9% at 5 years.

CONCLUSION

This study showed that CAS is an effective option for RT-induced stenosis in patients not favorable to carotid endarterectomy. The CAS was associated with a low rate of neurological events and reinterventions at long-term follow-up.

Treatment of the Carotid In-stent Restenosis: A Systematic Review

Background and Purpose: In-stent restenosis (ISR) after carotid artery stent (CAS) is not uncommon. We aimed to evaluate therapeutic options for ISR after CAS. Methods: We searched PubMed and EMBASE until November 2, 2020 for studies including the treatment for ISR after CAS. Results: In total, 35 studies, covering 1,374 procedures in 1,359 patients, were included in this review. Most cases (66.3%) were treated with repeat CAS (rCAS), followed by percutaneous transluminal angioplasty (PTA) (17.5%), carotid endarterectomy (CEA) (14.3%), carotid artery bypass (1.5%), and external beam radiotherapy (0.4%). The rates of stroke & TIA within the postoperative period were similar in three groups (PTA 1.1%, rCAS 1.1%, CEA 1.5%). CEA (2.5%) was associated with a slightly higher rate of postoperative death than rCAS (0.7%, P = 0.046). Furthermore, the rate of long-term stroke & TIA in PTA was 5.7%, significantly higher than rCAS (1.8%, P = 0.036). PTA (27.8%) was also associated with a significantly higher recurrent restenosis rate than rCAS (8.2%, P = 0.002) and CEA (1.6%, P < 0.001). The long-term stroke & TIA and recurrent restenosis rates showed no significant difference between rCAS and CEA. Conclusions: rCAS is the most common treatment for ISR, with low postoperative risk and low long-term risk. CEA is an important alternative for rCAS. PTA may be less recommended due to the relatively high long-term risks of stroke & TIA and recurrent restenosis.

Estimated Glomerular Filtration Rate as a Predictor of Restenosis After Carotid Stenting Using First-Generation Stents

This study evaluated the impact of the baseline estimated glomerular filtration rate (eGFR) on clinical and angiographic outcomes and long-term in-stent restenosis (ISR) rates in patients undergoing elective carotid artery stenting (CAS) procedures. Consecutive patients who underwent CAS were retrospectively enrolled (n = 456). At the end of 3 years of follow-up, patients who had died or were lost follow-up were excluded from the study and a final analysis was performed using data from the remaining 405 patients. The study population (n = 405) was divided into 3 tertiles based on the tertile values of the eGFR level (T1, T2, and T3); then, clinical and procedural characteristics and 3-year ISR rates were compared between the groups. An ISR of 50% was detected in 49 (12%) surviving patients. The 3-year ISR was higher among patients with the lowest eGFR values (T1) by 3.7 times (95% CI: 2.01-11.38) than that among patients with the highest eGFR values (T3). These significant relationships persisted following adjustment for confounders. A lower baseline eGFR level was significantly associated with an increased ISR rate. Decreased renal function may be a predictor of ISR after CAS using first-generation stents.

A meta-analysis of the effect of stent design on clinical and radiologic outcomes of carotid artery stenting

OBJECTIVE

Procedural characteristics, including stent design, may influence the outcome of carotid artery stenting (CAS). A thorough comparison of the effect of stent design on outcome of CAS is thus warranted to allow for optimal evidence-based clinical decision making. This study sought to evaluate the effect of stent design on clinical and radiologic outcomes of CAS.

METHODS

A systematic search was conducted in MEDLINE, Embase, and Cochrane databases in May 2018. Included were articles reporting on the occurrence of clinical short- and intermediate-term major adverse events (MAEs; any stroke or death) or radiologic adverse events (new ischemic lesions on postprocedural magnetic resonance diffusion-weighted imaging [MR-DWI], restenosis, or stent fracture) in different stent designs used to treat carotid artery stenosis. Random effects models were used to calculate combined overall effect sizes. Metaregression was performed to identify the effect of specific stents on MAE rates.

RESULTS

From 2654 unique identified articles, two randomized, controlled trials and 66 cohort studies were eligible for analysis (including 46,728 procedures). Short-term clinical MAE rates were similar for patients treated with open cell vs closed cell or hybrid stents. Use of an Acculink stent was associated with a higher risk of short-term MAE compared with a Wallstent (risk ratio [RR], 1.51; P = .03), as was true for use of Precise stent vs Xact stent (RR, 1.55; P < .001). Intermediate-term clinical MAE rates were similar for open vs closed cell stents. Use of open cell stents predisposed to a 25% higher chance (RR, 1.25; P = .03) of developing postprocedural new ischemic lesions on MR-DWI. No differences were observed in the incidence of restenosis, stent fracture, or intraprocedural hemodynamic depression with respect to different stent design.

CONCLUSIONS

Stent design is not associated with short- or intermediate-term clinical MAE rates in patients undergoing CAS. Furthermore, the division in open and closed cell stent design might conceal true differences in single stent efficacy. Nevertheless, open cell stenting resulted in a significantly higher number of subclinical postprocedural new ischemic lesions detected on MR-DWI compared with closed cell stenting. An individualized patient data meta-analysis, including future studies with prospective homogenous study design, is required to adequately correct for known risk factors and to provide definite conclusions with respect to carotid stent design for specific subgroups.

Systematic and Comprehensive Comparison of Incidence of Restenosis Between Carotid Endarterectomy and Carotid Artery Stenting in Patients with Atherosclerotic Carotid Stenosis

OBJECTIVE

The purpose of the present study was to conduct a meta-analysis to systematically compare the incidence rates of in-stent restenosis after carotid artery stenting (CAS) and restenosis after carotid endarterectomy (CEA) for patients with atherosclerotic carotid stenosis.

METHODS

We retrieved potential academic reports comparing restenosis between CEA and CAS from the MEDLINE, PubMed, and EMBASE databases and the Cochrane Library from the date of the first CEA (January 1951) to July 20, 2018. The references of the identified studies were carefully reviewed to ensure that all available reports were included in the present study.

RESULTS

Our meta-analysis included 27 studies (15 randomized controlled trials, 12 nonrandomized controlled trials) and 20,479 participants with atherosclerotic carotid stenosis. A statistically significant difference was found in the cumulative incidence of restenosis >70% between CEA and CAS (risk difference, -0.033, 95% confidence interval [CI] -0.054 to -0.013; P = 0.002). For the restenosis >70% outcomes, although CEA was relevant with a lower rate of restenosis than CAS within 6 months (odds ratio [OR], 0.495; 95% CI, 0.285-0.861; P = 0.013) and 1 year (OR, 0.626; 95% CI, 0.483-0.811; P < 0.001), no statistically significant differences were found at 1.5 years (P = 0.210), 2 years (P = 0.123), 4 years (P = 0.124), 5 years (P = 0.327), or 10 years (P = 0.839). For the restenosis >50% outcomes, a significant difference was found in the rate of restenosis between the CEA and CAS groups within 1 year (OR, 0.317; 95% CI, 0.228-0.441; P < 0.001) but not at 1.5 years (P = 0.301), 2 years (P = 0.686), or 5 years (P = 0.920). No nominally significant effects were demonstrated with respect to the cumulative incidence of occlusion (P = 0.195) or the cumulative incidence of restenosis for symptomatic patients (P = 0.170) between CEA and CAS.

CONCLUSIONS

Although CAS was preferred over CEA, regardless of restenosis >50% or >70% after revascularization within 1 year, no significant difference was observed with extension of the follow-up period to >1 year. CAS was not associated with a greater cumulative incidence of occlusion or the cumulative incidence of restenosis for symptomatic patients.

Effect of Open- vs Closed-Cell Stent Design on Periprocedural Outcomes and Restenosis After Carotid Artery Stenting: A Systematic Review and Comprehensive Meta-analysis

Purpose:To compare periprocedural complications and in-stent restenosis rates associated with open- vs closed-cell stent designs used in carotid artery stenting (CAS). Methods: A systematic search was conducted to identify all randomized and observational studies published in English up to October 31, 2017, that compared open- vs closed-cell stent designs in CAS. Identified studies were included if they reported the following outcomes: stroke, transient ischemic attack (TIA), myocardial infarction (MI), hemodynamic depression, new ischemic lesions detected on imaging, and death within 30 days, as well as the incidence of in-stent restenosis. A random-effects model meta-analysis was employed. Model results are reported as the odds ratio (OR) and 95% confidence interval (CI). The I2 statistic was used to assess heterogeneity. Results: Thirty-three studies (2 randomized trials) comprising 20, 291 patients (mean age 71.3±3.0 years; 74.6% men) were included. Patients in the open-cell stent group had a statistically significant lower risk of restenosis ⩾40% (OR 0.42, 95% CI 0.19 to 0.92; I2=0%) and ⩾70% (OR 0.23, 95% CI 0.10 to 0.52; I2=0%) at a mean follow-up of 24 months. No statistically significant differences were identified for periprocedural stroke, TIA, new ischemic lesions, MI, hemodynamic depression, or death within 30 days after CAS. Sensitivity analysis of the 2 randomized controlled trials only did not point to any significant differences either. Conclusion: Use of open-cell stent design in CAS is associated with a decreased risk for restenosis when compared to the closed-cell stent, without significant differences in periprocedural outcomes.

Seven years' follow-up of comparative study between stenting and medication for treatment of symptomatic vertebrobasilar artery stenosis

Objective Endovascular stent-assistant angioplasty (ESAA) is a valid treatment for symptomatic vertebrobasilar artery stenosis (SVAS), but the long-term effect and the improvement of condition compared with medication treatment are unknown. This study investigated the long-term efficacy of ESAA in patients with moderate and severe SVAS, and compared the efficacy with medication treatment. Materials and methods We conducted a retrospective analysis of clinical data of 43 patients with moderate and severe SVAS hospitalized in our department. According to different treatment methods they were divided into 29 cases in an ESAA group and 14 cases in a medication treatment group. During the follow-up period, the degree of vascular stenosis, vascular blood flow velocity, restenosis rate, recovery of neurological function and the incidence of cerebral ischemic events in the two groups were analyzed. Results The average clinical follow-up period was 89.4 ± 10.2 months. Before treatment, the stenosis rate and average blood flow velocity of the two groups were not statistically significant ( p > 0.05). During the follow-up period, both were significantly lower than the medication treatment group ( p < 0.01). In the ESAA group, three cases of stent stenosis, and three cases in the medication treatment group were completely occluded. The total ischemic events in ESAA group were three cases, compared with nine cases in the medication treatment group; the difference was statistically significant ( p < 0.05). Conclusion ESAA has a long-term effect in the treatment of symptomatic moderate and severe vertebrobasilar artery stenosis. It is superior to medication therapy in preventing posterior circulation ischemia (PCI), but a larger sample size is still needed to confirm the study.

Selective-versus-Standard Poststent Dilation for Carotid Artery Disease: A Systematic Review and Meta-Analysis

BACKROUND

The safety and efficacy of standard poststent angioplasty in patients undergoing carotid artery stent placement have not been well-established.

PURPOSE

We conducted a systematic review of the literature to evaluate the safety and efficacy of carotid artery stent placement and analyzed outcomes of standard-versus-selective poststent angioplasty.

DATA SOURCES

A systematic search of MEDLINE, EMBASE, Scopus, and the Web of Science was performed for studies published between January 2000 and January 2015.

STUDY SELECTION

We included studies with >30 patients describing standard or selective poststent angioplasty during carotid artery stent placement.

DATA ANALYSIS

A random-effects meta-analysis was used to pool the following outcomes: periprocedural stroke/TIA, procedure-related neurologic/cardiovascular morbidity/mortality, bradycardia/hypotension, long-term stroke at last follow-up, long-term primary patency, and technical success.

DATA SYNTHESIS

We included 87 studies with 19,684 patients with 20,378 carotid artery stenoses. There was no difference in clinical (P = .49) or angiographic outcomes (P = .93) in carotid artery stent placement treatment with selective or standard poststent balloon angioplasty. Both selective and standard poststent angioplasty groups had a very high technical success of >98% and a low procedure-related mortality of 0.9%. There were no significant differences between both groups in the incidence of restenosis (P = .93) or procedure-related complications (P = .37).

LIMITATIONS

No comparison to a patient group without poststent dilation could be performed.

CONCLUSIONS

Our meta-analysis demonstrated no significant difference in angiographic and clinical outcomes among series that performed standard poststent angioplasty and those that performed poststent angioplasty in only select patients.

Prediction of carotid artery in-stent restenosis by quantitative assessment of vulnerable plaque using computed tomography

BACKGROUND AND PURPOSE

To assess the relationship between plaque volume evaluated by multidetector computed tomographic angiography (MDCT) and in-stent restenosis (ISR) after carotid artery stenting (CAS).

MATERIALS AND METHODS

From a retrospectively maintained database, data were collected for 52patients with carotid artery stenosis treated with CAS between 2007 and 2012. We defined ISR of≥50% as a peak systolic velocity≥200cm/s on echo-duplex scan. Carotid plaques were subdivided into four components according to radiodensity in Hounsfield units (HU) as follows: <0, 0-60, 60-130, and>600HU. Risk factors that influenced ISR were compared using univariate and multivariate Cox regression analyses.

RESULTS

During a median follow-up period of 36months, ISR of≥50% was detected in five patients (9.6%). In the univariate Cox proportional hazard regression analysis, renal insufficiency, coronary artery disease, total plaque volume, and plaque volumes with radiodensities<0 and≥600HU increased the risk for ISR (P<0.10). When the significant risk factors determined from the univariate analysis were subjected to a multivariate analysis, only the volumes of the plaque components with radiodensities<0 HU independently predicted the development of ISR (hazard ratio: 1.041; 95% confidence interval: 1.006-1.078; P=0.021).

CONCLUSION

Our data suggest that the high volume of the plaque components with radiodensities<0HU was independently associated with the increased risk of ISR after CAS. Quantitative and qualitative tissue characterizations of carotid plaques using MDCT might be a useful predictive tool of the development of ISR.

The myth of restenosis after carotid angioplasty and stenting

BACKGROUND AND PURPOSE

Reported rates of in-stent restenosis after carotid artery stenting (CAS) vary, and restenosis risk factors are poorly understood. We evaluated restenosis rates and risk factors, and compared patients with 'hostile-neck' carotids (a history of ipsilateral neck surgery or irradiation) and atherosclerotic lesions.

METHODS

Demographic, clinical, and radiological characteristics of patients undergoing cervical CAS between 1995 and 2010 with at least 1 month of follow-up were reviewed. Patients with substantial (≥50%) radiographic restenosis were compared with those without significant restenosis to identify restenosis risk factors.

RESULTS

The analysis included 121 patients with 133 stented vessels; 91 (68.4%) lesions were symptomatic. Indications for stent placement included hostile-neck lesions, substantial surgical comorbidities, inclusion in a randomized carotid stenting trial, acute carotid occlusion, tandem stenosis, large pseudoaneurysm, high carotid bifurcation, and contralateral laryngeal nerve palsy. Procedures were technically successful in all but one lesion (99.2%). Perioperative stroke occurred in four cases (3.0%). Mean follow-up was 38 months (range 1-204 months), during which 23 vessels (17.3%) developed restenosis. Hostile-neck carotids (n=57) comprised 42.9% of all vessels treated and were responsible for 15 of 23 restenosis cases, resulting in a significantly higher restenosis rate than that of primary atherosclerotic lesions (26.3% vs 10.5%, p=0.017). By univariate analysis, the presence of calcified plaque was significantly associated with the incidence of in-stent restenosis (p=0.02).

CONCLUSIONS

Restenosis rates after carotid angioplasty and stenting are low. Patients with a history of ipsilateral neck surgery or irradiation are at higher risk for substantial radiographic and symptomatic restenosis.

Predictors of restenosis after carotid artery stenting in 241 cases

Background

Variable rates of restenosis after carotid artery stenting (CAS) have been reported, and few predictors have been suggested. Because CAS is being performed with increasing frequency, more data are needed to evaluate the rate and predictors of restenosis and possibly identify new risk factors for restenosis after CAS. The aim of this study was to analyze the rate and predictors of restenosis after CAS.

Methods

241 patients with carotid artery stenosis treated with stenting were analyzed retrospectively to identify patients who had restenosis after stenting. Univariate analysis and multivariate logistic regression were conducted to determine the predictors of restenosis.

Results

Mean patient age was 67.5 years. 8.3% of patients who underwent CAS had carotid restenosis of ≥50% during follow-up. 3.7% of patients required retreatment. Mean duration from CAS to retreatment was 11 months. In multivariate analysis, the predictors of restenosis included history of cardiovascular disease (OR=8.88, p<0.001) and having a cerebrovascular accident (CVA) prior to stenting (OR=1.87, p=0.034). A higher percentage of preoperative carotid stenosis was associated with higher odds of restenosis in univariate analysis (p=0.04, OR stenosis ≥80%=5.7).

Conclusions

Our results suggest that the rate of carotid restenosis after stenting is low. Patients with cardiovascular disease, patients who had a CVA prior to stenting, and patients with higher percentages of preoperative stenosis had higher odds of restenosis. Higher rates of restenosis should be kept in mind when opting for CAS in these patients.

Relationship between histologic features and outcomes of carotid revascularization for radiation-induced stenosis

OBJECTIVE

This study aimed to elucidate the relationships between preoperative carotid imaging results, histologic characteristics, and surgical treatment outcomes of radiation-induced carotid stenosis (RICS), using control subjects without RICS for comparison.

METHODS

We retrospectively reviewed records of 17 patients who underwent carotid revascularization for 22 instances of RICS, including 10 cases of carotid artery stenting (CAS), 11 cases of carotid endarterectomy (CEA), and 1 case of CEA with retrograde CAS, between July 2004 and April 2013. The controls were 475 patients with no history of radiation therapy who underwent carotid revascularization in a similar period. Preoperative magnetic resonance imaging (MRI), ultrasonography (US), and computed tomography angiography results were correlated with outcomes of histologic analysis of CEA specimens. End points included ipsilateral and contralateral stroke, myocardial infarction, restenosis, in-stent thrombosis, and target lesion revascularization.

RESULTS

Vulnerable plaques on carotid MRI (86% vs 64.2%; P = .010) and mobile (27% vs 8.0%; P = .008) and ulcerative (50% vs 15.8%; P < .001) plaques on US were more frequent in the RICS group. All revascularization procedures were successful, and no occlusion occurred. Adverse events in the CAS group, including one minor stroke and one transient ischemic attack within 30 days as well as five ipsilateral neurologic events after 30 days, including three minor strokes and two transient ischemic attacks, were significantly more frequent than in the CEA group. All three cases of late ipsilateral stroke displayed vulnerable plaque on preoperative MRI and late in-stent thrombosis or restenosis on US.

CONCLUSIONS

Our radiologic and histologic analyses revealed that advanced RICS is often accompanied by formation of vulnerable plaque. CEA can prevent undesirable late outcomes in such cases.

Management of extracranial carotid artery disease

Stroke is the third leading cause of death in developed nations. Up to 88% of strokes are ischemic in nature. Extracranial carotid artery atherosclerotic disease is the third leading cause of ischemic stroke in the general population and the second most common nontraumatic cause among adults younger than 45 years. This article provides comprehensive, evidence-based recommendations for the management of extracranial atherosclerotic disease, including imaging for screening and diagnosis, medical management, and interventional management.

Periprocedural outcomes after surgical revascularization and stenting for postradiotherapy carotid stenosis

BACKGROUND

Treatment of head and neck malignancy commonly involves radiotherapy, which is associated with the development of carotid artery stenosis. There is little evidence to guide clinicians on how to intervene in significant postradiotherapy carotid stenosis. This systematic review collated data pertaining to perioperative outcomes of carotid artery surgery and carotid stenting in postradiotherapy carotid stenosis to aid the clinical decision-making process.

METHODS

A systematic review of the literature, adhering to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2009 guidelines, was performed. We screened 575 articles related to carotid artery surgery or stenting in postradiotherapy carotid stenosis, from which 21 studies were included for quantitative analysis. The primary outcome was stroke or death ≤ 30 days of the procedure. Secondary outcomes included cranial nerve injury, restenosis, stroke, and death at >30 days.

RESULTS

Nine publications recorded 211 surgical procedures in 179 patients. In symptomatic patients, the 30-day mortality rate was 2.6% and the stroke or death rate was 2.7%. In asymptomatic patients, the 30-day mortality rate was 0% and the stroke or death rate was 1.1%. Permanent cranial nerve palsy was experienced by 0.6% of patients. Twelve publications recorded 510 carotid artery stenting procedures in 482 patients. In symptomatic patients, the 30-day mortality rate was 5.1%, and the stroke or death rate was 5.1%. In asymptomatic patients, the 30-day mortality rate was 1.4%, and the stroke or death rate was 2.1%. There was no statistically significant difference in 30-day stroke or death rate between surgical revascularization and carotid artery stenting in all (odds ratio [OR], 0.54; 95% confidence interval [CI] 0.17-1.70; P = .43), symptomatic (OR, 0.52; 95% CI, 0.14-1.98; P = .38), or asymptomatic patients (OR, 0.55; 95% CI, 0.06-5.42; P = .99).

CONCLUSIONS

The published outcomes from high-volume centers demonstrate that surgical revascularization and stenting are both technically feasible in postradiotherapy carotid stenosis and have similar safety profiles to nonirradiated necks. Radiation should therefore not be considered a contraindication to surgical intervention.

Article Commentary: Late Outcomes of Carotid Artery Stenting: A Critical Review

The role of carotid artery stenting (CAS) as an alternative to carotid endarterectomy for the treatment of extracranial carotid occlusive disease for stroke prevention continues to evolve. Although technical and device refinements aimed at making CAS safer continue to this day, safety as measured by 30-day and 1-year outcomes has been the primary recipient of regulatory and practice attention. Relatively less emphasis has been placed on the incidence of recurrent stenosis after CAS and the efficacy of CAS in late stroke prevention. Data on late outcomes of CAS, including factors of potential influence, have been emerging and are addressed in this review.

Carotid artery stenting: what you need to know

Carotid stenting has become an accepted alternative in patients with carotid stenosis. The purpose of this article is to review the relevant trials, describe the different devices available for stenting, the devices for cerebral protection, as well as describe techniques and tricks for successful carotid artery stenting. Understanding how to appropriately preoperatively evaluate patients and intra- and postoperative procedures, carotid artery stenting can be a safe procedure.

Carotid stenting for restenosis after endarterectomy

INTRODUCTION

Restenosis after carotid endarterectomy (CEA) has been described in 8-19% of patients, 14-23% of whom become symptomatic. This study analyzes our experience with carotid artery stenting (CAS) for post-CEA recurrent stenoses.

METHOD

Retrospective database and case-note review.

RESULTS

Between January 2000 and September 2008, a total of 27 patients (15 symptomatic) with hemodynamically significant internal carotid artery post-CEA restenosis underwent CAS. Median stenosis of target vessels was 90% (range 75-95%). There was one periprocedural death (3.7%); no others occurred during the median 34-month follow-up (range 0.1-84 months). There was one late transient ischemic attack 12 months after CAS that was not associated with in-stent restenosis. One 90% restenosis and one occlusion were detected during follow-up at 38 and 57 months after CAS. The remaining patients had no evidence of further restenosis and remained free from cerebrovascular symptoms.

CONCLUSION

CAS offers a feasible option for the management of carefully selected patients with symptomatic and asymptomatic restenosis after CEA.

Follow-up Outcomes of Self-Expanding Stents for Carotid Artery Angioplasty at a Single Hospital

Carotid artery angioplasty and stent placement (CASP) is widely accepted as a valuable alternative to carotid endarterectomy, particularly among high-risk patient populations. We analyzed the follow-up data of patients who underwent CASP with self-expanding stents for carotid lesions. Since 2001, self-expanding stents have been deployed in 59 lesions in 56 patients. Forty-seven patients were male, and nine were female. The median age was 73 years, ranging 50 to 83 years. There were 31 asymptomatic lesions and 28 symptomatic lesions. The median follow-up period was 27 months, ranging six to 102 months. All lesions received stents and technical success was achieved in 58 (98.3%) out of 59 lesions. The 30-day transient ischemic attack rate was 8.6%, the stroke rate was 3.4%, and the death rate was 0%. No ischemic attack was observed on the ipsilateral side after 30 days. Recurrent stenosis (>50%) was observed in three patients (5.1%) and in two (3.4%) of these, revascularization was performed. Kaplan-Meier analysis showed that the rates for one year and two year freedom from any stroke or death were 93.1% and 90.9%, respectively. The incidence of recurrent carotid stenosis is acceptably low after CASP. CASP is effective to prevent ipsilateral ischemic stroke in symptomatic and asymptomatic patients.

Periprocedural cilostazol treatment and restenosis after carotid artery stenting: the Retrospective Study of In-Stent Restenosis after Carotid Artery Stenting (ReSISteR-CAS)

Restenosis after carotid artery stenting (CAS) is a critical issue. Cilostazol can reduce restenosis after interventions in coronary or femoropopliteal arteries. We investigated whether periprocedural cilostazol treatment was related to the incidence of in-stent restenosis (ISR) or target vessel revascularization (TVR) after CAS. The study group comprised 553 of 580 patients who underwent CAS between April 2003 and August 2006 and were followed for 30 months after the procedure. ISR was defined as stenosis of at least 50% detected on angiography or ultrasonography. TVR was defined as revascularization of the treated carotid artery. During CAS, 207 patients (37.4%) were treated with cilostazol. Over 30 months, ISR occurred in 23 patients (4.2%), TVR occurred in 16 patients (2.9%), and either ISR or TVR occurred in 25 patients (4.5%). The incidence of ISR or TVR was significantly lower in the cilostazol-treated group than in the untreated group (1.4% vs 6.4%; log-rank P = .006). In a multivariate analysis, cilostazol treatment (hazard ratio [HR], 0.28; 95% confidence interval [CI], 0.08-0.95; P = .041) and stent diameter (HR, 0.73/1-mm increase; 95% CI, 0.54-0.99; P = .044) were independent factors for the occurrence of ISR or TVR. The incidence of a composite of events, including thromboembolism, hemorrhage, death, and TVR, tended to be lower in the cilostazol-treated group than in the untreated group (15.0% vs 19.9%; log-rank P = .17). Periprocedural cilostazol treatment was associated with lower rates of ISR and retreatment after CAS. A prospective randomized controlled trial is needed to clarify the effect of cilostazol on ISR after CAS.

The Relation Between the Arterial Stress and Restenosis Rate After Coronary Stenting

Two commercially available stents (the Palmaz–Schatz (PS) and S670 stents) with reported high and low restenosis rates, respectively, have been investigated in this paper. Finite element models simulating the stent, plaque, and artery interactions in 3 mm stenosed right coronary arteries were developed. These models were used to determine the stress field in artery walls after stent implantation. The material properties of porcine arteries were measured and implemented in the numerical models. The stress concentration induced in the artery by the PS stent was found to be more than double that of the S670 stent. It demonstrated a good correlation with the reported restenosis rate. The effects of stent structures, compliance mismatch, plaque geometry, and level of stenosis were studied. Results suggested that stent designs and tissue properties cause alterations in vascular anatomy that adversely affect arterial stress distributions within the wall, which impact vessel responses such as restenosis. Appropriate modeling of stent, plaque, and artery interactions provided insights for evaluating alterations to the arterial mechanical environment, as well as biomechanical factors leading to restenosis.

Multidisciplinary approach to carotid stenting

BACKGROUND

Stroke neurologists, vascular surgeons, interventional neuroradiologists and interventional cardiologists have embraced carotid angioplasty and stenting (CAS) because of potential advantages over carotid endarterectomy (CEA). At Austin Health, a multidisciplinary neuro-interventional group was formed to standardise indications and facilitate training. The aims of this study were to describe our organisational model and to determine whether 30-day complications and early outcomes were similar to those of major trials.

METHODS

A clinical protocol was developed to ensure optimal management. CAS was performed on patients with high medical risk for CEA, with technically difficult anatomy for CEA, or who were randomised to CAS in a trial.

RESULTS

From October 2003 to May 2008, 47 patients (34 male, mean age 71.5) underwent CAS of 50 carotid arteries. Forty-three cases had ipsilateral carotid territory symptoms within the previous 12 months. The main indications for CAS were high risk for CEA (n= 17) and randomised to CAS (n= 21). Interventionists were proctored in 27 cases. The procedural success rate was 94% with two cases abandoned because of anatomical problems and one because of on-table angina. Hypotension requiring vasopressor therapy occurred in 12 cases (24%). The duration of follow up was one to 44 months (mean 6.8 months). The 30-day rate of peri-procedural stroke or death was 6% and the one-year rate of peri-procedural stroke or death or subsequent ipsilateral stroke was 10.6%. Restenosis occurred in 13% (all asymptomatic).

CONCLUSION

A multidisciplinary approach is a useful strategy for initiating and sustaining a CAS programme.

Society of vascular surgery vascular registry comparison of carotid artery stenting outcomes for atherosclerotic vs nonatherosclerotic carotid artery disease

OBJECTIVE

The Vascular Registry (VR) on carotid procedures collects long-term outcomes on carotid artery stenting (CAS) and carotid endarterectomy (CEA) patients. The purpose of this report is to describe in-hospital and 30-day CAS outcomes in patients with atherosclerotic carotid artery disease (CAD; atherosclerosis [ATH]) compared to recurrent carotid stenosis (RES) and radiation-induced stenosis (RAD).

METHODS

The VR collects provider-reported data on CAS using a Web-based data management system. For this report, data were analyzed at the preprocedure, procedure, predischarge, and 30-day intervals.

RESULTS

As of November 20, 2008, there were 4017 patients with CAS with discharge data, of which 72% were due to ATH. A total of 2321 patients were available for 30-day outcomes analysis (1623 ATH, 529 restenosis, 119 radiation, 17 dissection, 3 trauma, and 30 other). Baseline demographics showed that ATH occurred in older patients (72-years-old), had the greatest history of coronary artery disease (CAD; 62%), myocardial infarction (MI; 24%), valvular heart disease (8%), arrhythmia (16%), congestive heart failure (CHF; 16%), diabetes mellitus (DM; 35%), and chronic obstructive pulmonary disease (COPD; 20%). RES had a higher degree of baseline stenosis (87.0 vs 85.8 ATH; P = .010), were less likely to be symptomatic (35.5% vs 46.3% ATH; P < .001), but had a greater history of hypertension, peripheral vascular disease (PVD), and smoking. RAD was seen in younger patients (66.6 vs 71.7 ATH; P < .001), were more likely to be male (78.2% vs 60.9% ATH; P < .001), and had less comorbidities overall, with the exception of amaurosis fugax, smoking, and cancer. The only statistically significant difference in perioperative rates was in transient ischemic attack (TIA; 2.7% ATH vs 0.9% RES; P = .02). There were no statistically significant differences in in-hospital death/stroke/MI (ATH 5.4%, RES 3.8%, RAD 4.2%) or at 30 days (ATH 7.1%, RES 5.1%, RAD 5.0%). Even after adjusting for age, gender, symptomatology, CHF, and renal failure, the only statistically significant difference at 30 days was amaurosis fugax between ATH and RAD (odds ratio [OR] 0.13; P = .01).

CONCLUSION

Although patients with ATH have statistically significant comorbidities, they did not have statistically significant increased rates of death/stroke/MI during hospitalization or within 30 days after discharge when compared to RES or RAD. The CAS event rates for ATH vs RES and RAD are similar, despite prior published reports. Symptomatic ATH have statistically significant higher rates of death/stroke/MI compared to asymptomatic cohort. Finally, consistent and accurate entry of long-term data beyond initial hospitalization is essential to fully assess CAS outcomes since a significant number of adverse events occur in the interval from hospital discharge to 30 days.

An old problem, a new solution

A 75-year-old woman with painful visual loss was diagnosed with ocular ischemic syndrome secondary to restenosis of the carotid artery following endarterectomy. She underwent carotid artery stenting, which has become an alternative to carotid endarectomy for primary carotid stenosis but is now also becoming more popular for recurrent carotid artery stenosis.

Long-term risk of carotid restenosis in patients randomly assigned to endovascular treatment or endarterectomy in the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS): long-term follow-up of a randomised trial

Background

In the Carotid and Vertebral Artery Transluminal Angioplasty Study (CAVATAS), early recurrent carotid stenosis was more common in patients assigned to endovascular treatment than it was in patients assigned to endarterectomy (CEA), raising concerns about the long-term effectiveness of endovascular treatment. We aimed to investigate the long-term risks of restenosis in patients included in CAVATAS.

Methods

413 patients who were randomly assigned in CAVATAS and completed treatment for carotid stenosis (200 patients had endovascular treatment and 213 patients had endarterectomy) had prospective clinical follow-up at a median of 5 years and carotid duplex ultrasound at a median of 4 years. We investigated the cumulative long-term incidence of carotid restenosis after endovascular treatment and endarterectomy, the effect of the use of stents on restenosis after endovascular treatment, risk factors for the development of restenosis, and the effect of carotid restenosis on the risk of recurrent cerebrovascular events. Analysis was by intention to treat. This study is registered, number ISRCTN01425573.

Findings

Severe carotid restenosis (≥70%) or occlusion occurred significantly more often in patients in the endovascular arm than in patients in the endarterectomy arm (adjusted hazard ratio [HR] 3·17, 95% CI 1·89–5·32; p<0·0001). The estimated 5-year incidence of restenosis was 30·7% in the endovascular arm and 10·5% in the endarterectomy arm. Patients in the endovascular arm who were treated with a stent (n=50) had a significantly lower risk of developing restenosis of 70% or greater compared with those treated with balloon angioplasty alone (n=145; HR 0·43, 0·19–0·97; p=0·04). Current smoking or a history of smoking was a predictor of restenosis of 70% or more (2·32, 1·19–4·54; p=0·01) and the early finding of moderate stenosis (50–69%) up to 60 days after treatment was associated with the risk of progression to restenosis of 70% or more (3·76, 1·88–7·52; p=0·0002). The composite endpoint of ipsilateral non-perioperative stroke or transient ischaemic attack occurred more often in patients in whom restenosis of 70% or more was diagnosed in the first year after treatment compared with patients without restenosis of 70% or more (5-year incidence 23% vs 11%; HR 2·18, 1·04–4·54; p=0·04), but the increase in ipsilateral stroke alone was not significant (10% vs 5%; 1·67, 0·54–5·11).

Interpretation

Restenosis is about three times more common after endovascular treatment than after endarterectomy and is associated with recurrent ipsilateral cerebrovascular symptoms; however, the risk of recurrent ipsilateral stroke is low. Further data are required from on-going trials of stenting versus endarterectomy to ascertain whether long-term ultrasound follow-up is necessary after carotid revascularisation.

Funding

British Heart Foundation; UK National Health Service Management Executive; UK Stroke Association.

Open-cell versus closed-cell stent design differences in blood flow velocities after carotid stenting

OBJECTIVE

The differential effect of open-cell vs closed-cell stent design configuration on carotid velocities detected by duplex ultrasound (DUS) imaging has not been established. To identify possible stent design differences in carotid velocities, we analyzed DUS studies obtained before and immediately after carotid artery stenting (CAS).

METHODS

In a series of 141 CAS procedures performed during a 3-year period, data from the first postinterventional DUS images and carotid angiograms were evaluated for each patient. Peak systolic velocities (PSV), end-diastolic velocities (EDV), and internal carotid artery/common carotid artery (ICA/CCA) PSV ratios were compared according to stent design. Differences in carotid velocities were analyzed using nonparametric statistical tests.

RESULTS

Completion angiograms revealed successful revascularization and <30% residual stenosis in each case. The 30-day stroke-death rate in this series was 1.6% and was unrelated to stent type. Postintervention DUS images were obtained a median of 5 days (interquartile range [IQR], 1-25 days) after CAS. Closed-cell stents were used in 41 procedures (29%) and open-cell stents in 100 (71%). The median PSV was 95.9 cm/s (IQR, 77-123 cm/s) for open-cell stents and 122 cm/s (IQR, 89-143 cm/s) for closed-cell stents, which was significantly higher (P = .007). Closed-cell stents also had significantly higher median EDVs (36 vs 29 cm/s; P =.006) and ICA/CCA PSV ratios (1.6 vs 1.1; P =.017). By DUS criteria, the carotid velocities in 45% of closed-cell stents exceeded the threshold of 50% stenosis for a nonstented artery compared with 26% of open-cell stents (P =.04). Closed-cell stents had a 2.2-fold increased risk of yielding abnormally elevated carotid velocities after CAS compared with open-cell stents (odds ratio, 2.2; 95% confidence interval, 1.02-4.9).

CONCLUSIONS

Carotid velocities are disproportionately elevated after CAS with closed-cell stents compared with open-cell stents. This suggests that the velocity criteria for quantifying stenosis may require modification according to stent design. The importance of these differences in carotid velocities related to stent design and the potential relationship with recurrent stenosis remains to be established.

Refractory In-stent Restenosis Following Carotid Artery Stenting: A Case Report and Review of Operative Management

In-stent restenosis following carotid artery stenting is a challenging problem that vascular surgeons will likely encounter with increasing frequency. The following describes a patient who developed progressive in-stent restenosis 3 years after carotid artery stenting, which was treated with operative therapy after failed balloon angioplasty. A review of the literature describing surgical approaches to the treatment of in-stent restenosis was also performed.

Carotid stenting with embolic protection: evolutionary advances

Stroke is one of the most significant causes of death and morbidity worldwide. Atherosclerotic stenosis of the extracranial internal carotid artery has been invoked as a common causative factor for stroke in over 20% of patients. Although medical therapy can help to prevent the onset and progression of carotid arteriosclerosis, open surgical carotid endarterectomy has been the gold standard for treating severe blockage. Carotid artery stenting has recently demonstrated efficacy in stroke prevention from atherosclerosis, and in high-risk surgical subgroups, has been shown to be associated with a reduction in the risk of myocardial infarction. The controversy for carotid stenting surrounds the incidence of periprocedural stroke. Will embolic protection devices (EPDs) decrease this risk? EPDs continue to evolve with various engineering strategies directed at increasing the efficiency of protection. There are two major categories of EPDs: distal occlusion, either with balloons (e.g., Percusurge, Medtronic Corporation, MN, USA); or distal filtration (e.g., Angioguard, Cordis Corporation, NJ, USA). The second method is proximal protection (e.g., MoMA device, Invatec Corporation, Brescia, Italy). We review the results of trials currently evaluating carotid stenting with both distal and proximal embolic protection.