Determining in-stent stenosis of carotid arteries by duplex ultrasound criteria

Editor's Choice - Development of a Risk Prediction Nomogram for Carotid Re-Stenosis in the One Year RECAST Registry

OBJECTIVE

The long term benefit of carotid angioplasty and stenting (CAS) can be reduced by recurrent stroke related to in stent re-stenosis (ISR). An individualised predictive tool is needed to identify ISR events. A nomogram for individual risk assessment of ISR ≥ 70% after CAS is proposed.

METHODS

A national observational, prospective, multicentre registry was conducted between January 2015 and December 2020. Cohorts of patients with symptomatic or asymptomatic severe carotid stenosis who underwent CAS with a follow up of at least one year after CAS were included. Duplex ultrasound was used to assess in stent re-stenosis. Pre-operative factors were compared between the non-ISR and ISR groups. Kaplan-Meier and Cox regression were used for variable selection. The nomogram was formulated and validated by concordance indices and calibration curves. An in stent re-stenosis risk table was generated for risk stratification.

RESULTS

A total of 354 patients were included in the analysis. The ISR rate of ≥ 70% was 7.6% (n = 27). Peripheral arterial disease (hazard ratio [HR] 3.18, 95% confidence interval [CI] 1.23 - 8.24, p = .017), anterior communicating artery absence (HR 3.38, 95% CI 1.27 - 8.94, p = .016), diabetes mellitus (HR 3.34, 95% CI 1.21 - 9.26, p = .020), female sex (HR 2.99, 95% CI 1.04 - 8.60, p = .041), and pre-procedure pathological ultrasound vasoreactivity (HR 3.87, 95% CI 1.43 -10.50, p = .008), as independent risk factors for ISR of ≥ 70%, were included in the nomogram. The concordance index at 12 and 24 months was 0.83. In low risk groups, ISR of ≥ 70% occurred in 4.8% of patients during follow up compared with 56.2% of patients in the high risk groups (p < .001).

CONCLUSION

The nomogram and risk evaluation score have good predictive ability for ISR. They can be used as practical clinical tools for individualised risk assessment.

[Role of duplex ultrasonography of the ophthalmic artery in internal carotid artery stenosis]

BACKGROUND

Duplex sonographic visualization of a retrogradely perfused ophthalmic artery (AO) as an expression of an existing collateral supply in high-grade stenosis of the internal carotid artery (ACI) is a widely used and validated tool. After revascularization there may be another reversal of flow. Recently, the question of whether knowledge of the flow direction of the AO before and after implantation of a stent can be used as an outcome predictor has been posed more frequently.

METHODS AND RESULTS

In this article, the method of duplex sonographic assessment of the AO is explained more elaborately and we present a case of a patient with 75% restenosis of the left ACI with contralateral chronic occlusion of the right ACI. We focus on the special aspect that the ipsilateral AO was initially perfused retrogradely and that postinterventionally there was a flow reversal to a physiological anterograde flow. The case report is used to illustrate the value of duplex sonographic visualization of the AO.

CONCLUSION

Our case report is able to illustrate two aspects: On the one hand, the AO can be perfused retrogradely in the specific case of chronic ACI occlusion of the opposite side, even when the ACI stenosis of the considered side is less than 80%. On the other hand, the AO can offer added diagnostic value as a follow-up parameter for re- or in-stent stenoses.

Ultrasound assessment of brain supplying arteries (extracranial)

Ultrasonography of the brain-supplying arteries is a non-invasive and highly efficient technique for the assessment of a stenosis or a vessel occlusion in patients with cerebrovascular diseases. This article reviews the examination technique for a standardized ultrasound assessment of the extracranial carotid and vertebral arteries. It further describes the multiparametric grading criteria of internal carotid artery stenosis and it gives recommendations for a standardised documentation of findings. Additionally, it proposes recommendations for intima-media thickness measurement and for classifying atherosclerotic plaques with B-mode ultrasonography. Moreover, criteria for the diagnosis of in-stent stenoses, vertebral artery dissections and subclavian steal syndrome are provided.

Implantable Self-Reporting Stents for Detecting In-Stent Restenosis and Cardiac Functional Dynamics

Despite the increasing number of stents implanted each year worldwide, patients remain at high risk for developing in-stent restenosis. Various self-reporting stents have been developed to address this challenge, but their practical utility has been limited by low sensitivity and limited data collection. Herein, we propose a next-generation self-reporting stent that can monitor blood pressure and blood flow inside the blood arteries. This proposed self-reporting stent utilizes a larger inductor coil encapsulated on the entire surface of the stent strut, resulting in a 2-fold increase in the sensing resolution and coupling distance between the sensor and external antenna. The dual-pressure sensors enable the detection of blood flow in situ. The feasibility of the proposed self-reporting stent is successfully demonstrated through in vivo analysis in rats, verifying its biocompatibility and multifunctional utilities. This multifunctional self-reporting stent has the potential to greatly improve cardiovascular care by providing real-time monitoring and unprecedented insight into the functional dynamics of the heart.

Role of carotid duplex in the assessment of carotid artery restenosis after endarterectomy or stenting

Introduction

Redo carotid endarterectomy (CEA) and carotid stenting (CAS) are often performed when there is evidence of post-procedural restenosis. The incidence of restenosis after carotid reconstruction is not negligible, ranging from 5 to 33%. The diagnosis of significant internal carotid artery (ICA) restenosis is usually based on duplex ultrasound (US) criteria, mostly on peak-systolic flow velocity (PSV). However, there have been no generally accepted duplex US criteria for carotid restenosis after CAS or CEA.

Methods

In this systematic review, the PubMed/ Medline and Scopus databases were screened to find trials that reported duplex US criteria for significant restenosis after CEA and/or CAS. Only those reports were analyzed in which the restenoses were also assessed by CT/MR or digital subtraction angiography as comparators for duplex US.

Results

Fourteen studies met the predetermined search criteria and were included in this review. In most studies, PSV thresholds for significant in-stent ICA restenosis after CAS were higher than those for significant stenosis in non-procedurally treated (native) ICA. Many fewer studies investigated the US criteria for ICA restenosis after CEA. Despite the heterogeneous data, there is a consensus to use higher flow velocity thresholds for assessment of stenosis in stented ICA than in native ICA; however, there have been insufficient data about the flow velocity criteria for significant restenosis after CEA. Although the flow velocity thresholds for restenosis after CAS and CEA seem to be different, the large studies used the same duplex criteria to define restenosis after the two procedures. Moreover, different studies used different flow velocity thresholds to define ICA restenosis, leading to variable restenosis rates.

Discussion

We conclude that (1) further examinations are warranted to determine appropriate duplex US criteria for restenosis after CAS and CEA, (2) single duplex US parameter cannot be used to reliably determine the degree of ICA restenosis, (3) inappropriate US criteria used in large studies may have led to false restenosis rates, and (4) studies are required to determine if there is a benefit from redo carotid artery procedure, such as redo-CEA or redo-CAS, starting with prospective risk stratification studies using current best practice non-invasive care alone.

Short- and Mid-Term Outcomes of Stenting in Patients with Isolated Distal Internal Carotid Artery Stenosis or Post-Surgical Restenosis

The aim was to evaluate the outcome of stenting in patients with isolated distal internal carotid artery (ICA) stenosis or post-surgical restenosis, as no data are currently available in the literature. Sixty-six patients (men, N = 53; median age: 66 [IQR, 61–73] years) with ≥50% distal ICA (re)stenosis were included in this single-center retrospective study. The narrowest part of the (re)stenosis was at least 20 mm from the bifurcation in all patients. Patients were divided into two etiological groups, atherosclerotic (AS, N = 40) and post-surgical restenotic (RES, N = 26). Postprocedural neurological events were observed in two patients (5%) in the AS group and in two patients (7.7%) in the RES group. The median follow-up time was 40 (IQR, 18–86) months. Three patients (7.5%) in the AS group had an in-stent restenosis (ISR) ≥ 50%, but none in the RES group. Three patients (7.5%) in the AS group and seven patients (26.9%) in the RES group died. None of the deaths in the RES group were directly related to stenting itself. The early neurological complication rate of stenting due to distal ICA (re)stenoses is acceptable. However, the mid-term mortality rate of stenting for distal ICA post-surgical restenoses is high, indicating the vulnerability of this subgroup.

Comparison of Restenosis Risk in Single-Layer versus Dual-Layer Carotid Stents: A Duplex Ultrasound Evaluation

PURPOSE

The aim of this study was to report intermediate-term results of duplex ultrasound follow-up of carotid artery stenting performed with the dual-layer stent as compared to concurrent patients treated with other commercially available single-layer carotid stents.

MATERIALS AND METHODS

A single centre, retrospective, nonrandomized study including 162 non-consecutive patients with 199 implanted carotid stents treated over a 7-year period was conducted. Patients with at least one ultrasound examination after treatment were included. Procedural and follow-up data for patients treated with the dual-layer stent implantation (83 stents) vs first-generation carotid stents implantations (116 stents) were compared.

RESULTS

The median follow-up time was 24.0 months (IQR 10-32 months) for dual-layer stents and 27.5 months (IQR 10.3-59 months) for single-layer stents. The rate of severe restenosis was significantly higher in the dual-layer stent group than in the single-layer group (13.3% [11/83] vs 3.4% [4/116], p = 0.01). Seven reinterventions were performed in 5 patients with dual-layer stents. The rate of reintervention was significantly higher compared to no reinterventions in single-layer stents (6% [5/83] vs 0% [0/116], p = 0.012). Patients with restenosis had significantly higher presence of dyslipidaemia (100% [12/12] vs 63.3% [95/150], p = 0.009).

CONCLUSIONS

In this real-world cohort of patients undergoing carotid artery stenting, the patients treated with low-profile dual-layer micromesh stent showed higher rates of restenosis and reinterventions compared to first-generation single-layer stents.

Restenosis rates in patients with ipsilateral carotid endarterectomy and contralateral carotid artery stenting

Purpose

We aimed to evaluate the long-term outcome of carotid endarterectomy (CEA) and carotid artery stenting (CAS) in patients who underwent both procedures on different sides.

Methods

In this single-center retrospective study (2001–2019), 117 patients (men, N = 78; median age at CEA, 64.4 [interquartile range {IQR}, 57.8–72.2] years; median age at CAS, 68.8 [IQR, 61.0–76.0] years) with ≥50% internal carotid artery stenosis who had CEA on one side and CAS on the other side were included. The risk of restenosis was estimated by treatment adjusted for patient and lesion characteristics.

Results

Neurological symptoms were significantly more common (41.9% vs 16.2%, P<0.001) and patients had a significantly shorter mean duration of smoking (30.2 [standard deviation {SD}, 22.2] years vs 31.8 [SD, 23.4] years, P<0.001), hypertension (10.1 [SD, 9.8] years vs 13.4 [SD, 9.1] years, P<0.001), hyperlipidemia (3.6 [SD, 6.6] years vs 5.0 [SD, 7.3] years, P = 0.001), and diabetes mellitus (3.9 [SD, 6.9] years vs 5.7 [SD, 8.9] years, P<0.001) before CEA compared to those before CAS. While the prevalence of heavily calcified stenoses on the operated side (25.6% vs 6.8%, P<0.001), the incidence of predominantly echogenic/echogenic plaques (53.0% vs 70.1%, P = 0.011) and suprabulbar lesions (1.7% vs 22.2%, P<0.001) on the stented side was significantly higher. Restenosis rates were 10.4% at 1 year, 22.3% at 5 years, and 33.7% at the end of the follow-up (at 11 years) for CEA, while these were 11.4%, 14.7%, and 17.2%, respectively, for CAS. Cox regression analysis revealed a significantly higher risk of restenosis (hazard ratio [HR], 1.80; 95% confidence interval [CI], 1.05–3.10; P = 0.030) for CEA compared to that for CAS. After adjusting for relevant confounding factors (smoking, hypertension, diabetes mellitus, calcification severity, plaque echogenicity, and lesion location), the estimate effect size materially did not change, although it did not remain statistically significant (HR, 1.85; 95% CI, 0.95–3.60; P = 0.070).

Conclusion

Intra-patient comparison of CEA and CAS in terms of restenosis tilts the balance toward CAS.

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.

Endothelial Progenitor Cell-Derived Extracellular Vesicles: Potential Therapeutic Application in Tissue Repair and Regeneration

Recently, many studies investigated the role of a specific type of stem cell named the endothelial progenitor cell (EPC) in tissue regeneration and repair. EPCs represent a heterogeneous population of mononuclear cells resident in the adult bone marrow. EPCs can migrate and differentiate in injured sites or act in a paracrine way. Among the EPCs’ secretome, extracellular vesicles (EVs) gained relevance due to their possible use for cell-free biological therapy. They are more biocompatible, less immunogenic, and present a lower oncological risk compared to cell-based options. EVs can efficiently pass the pulmonary filter and deliver to target tissues different molecules, such as micro-RNA, growth factors, cytokines, chemokines, and non-coding RNAs. Their effects are often analogous to their cellular counterparts, and EPC-derived EVs have been tested in vitro and on animal models to treat several medical conditions, including ischemic stroke, myocardial infarction, diabetes, and acute kidney injury. EPC-derived EVs have also been studied for bone, brain, and lung regeneration and as carriers for drug delivery. This review will discuss the pre-clinical evidence regarding EPC-derived EVs in the different disease models and regenerative settings. Moreover, we will discuss the translation of their use into clinical practice and the possible limitations of this process.

In vitro performance of echoPIV for assessment of laminar flow profiles in a carotid artery stent

Purpose: Detailed blood flow studies may contribute to improvements in carotid artery stenting. High-frame-rate contrast-enhanced ultrasound followed by particle image velocimetry (PIV), also called echoPIV, is a technique to study blood flow patterns in detail. The performance of echoPIV in presence of a stent has not yet been studied extensively. We compared the performance of echoPIV in stented and nonstented regions in an in vitro flow setup.

Approach: A carotid artery stent was deployed in a vessel-mimicking phantom. High-frame-rate contrast-enhanced ultrasound images were acquired with various settings. Signal intensities of the contrast agent, velocity values, and flow profiles were calculated.

Results: The results showed decreased signal intensities and correlation coefficients inside the stent, however, PIV analysis in the stent still resulted in plausible flow vectors.

Conclusions: Velocity values and laminar flow profiles can be measured in vitro in stented arteries using echoPIV.

Follow-up after carotid stenting with the CASPER stent system: A duplex ultrasound evaluation

OBJECTIVE

To report results of duplex ultrasound evaluation of consecutive patients after carotid stenting with the double layer Carotid Artery Stent designed to Prevent Embolic Release (CASPER) stent system.

METHODS

Between January 2014 and June 2017, a single-center, retrospective study of 101 consecutive patients (21.8% female; median age, 72.1 years) was performed. Patients with internal carotid artery stenosis treated with the CASPER stent were included. Eligibility criteria for stenting included stenosis of ≥70% of the vessel diameter (or ≥50% diameter with ulceration) in symptomatic carotid artery stenosis or ≥80% stenosis in asymptomatic patients at the carotid artery bifurcation or the proximal cervical internal carotid artery. Duplex ultrasound examination was performed before and within 24 hours of implantation as well as at 14 days, and 3, 6, and 12 months.

RESULTS

At the 12-month follow-up visit, moderate in-stent restenosis (ISR) (≥50% and <70%) was detected in three stents (2.8%) and severe (≥70%) ISR in two (1.9%; including one case of stent occlusion). All but the two latter patients remained asymptomatic during the follow-up period. One patient required retreatment for ISR after a minor stroke and another patient with stent occlusion also re-presented with a minor stroke. Multivariable logistic regression was unable to detect any significant factors associated with ISR.

CONCLUSIONS

Duplex ultrasound examination after carotid stenting is a useful tool for patient follow-up and determination of ISR. We found a low incidence of ISR assessed by duplex ultrasound examination at 12 months after CASPER stenting, but further studies are warranted.

Follow-up of patients after revascularisation for peripheral arterial diseases: a consensus document from the European Society of Cardiology Working Group on Aorta and Peripheral Vascular Diseases and the European Society for Vascular Surgery

Peripheral arterial diseases comprise different clinical presentations, from cerebrovascular disease down to lower extremity artery disease, from subclinical to disabling symptoms and events. According to clinical presentation, the patient's general condition, anatomical location and extension of lesions, revascularisation may be needed in addition to best medical treatment. The 2017 European Society of Cardiology guidelines in collaboration with the European Society for Vascular Surgery have addressed the indications for revascularisation. While most cases are amenable to either endovascular or surgical revascularisation, maintaining long-term patency is often challenging. Early and late procedural complications, but also local and remote recurrences frequently lead to revascularisation failure. The rationale for surveillance is to propose the accurate implementation of preventive strategies to avoid other cardiovascular events and disease progression and avoid recurrence of symptoms and the need for redo revascularisation. Combined with vascular history and physical examination, duplex ultrasound scanning is the pivotal imaging technique for identifying revascularisation failures. Other non-invasive examinations (ankle and toe brachial index, computed tomography scan, magnetic resonance imaging) at regular intervals can optimise surveillance in specific settings. Currently, optimal revascularisation surveillance programmes are not well defined and systematic reviews addressing long-term results after revascularisation are lacking. We have systematically reviewed the literature addressing follow-up after revascularisation and we propose this consensus document as a complement to the recent guidelines for optimal surveillance of revascularised patients beyond the perioperative period.

Duplex ultrasound surveillance of renal branch grafts after fenestrated endovascular aneurysm repair

OBJECTIVE

The use of duplex ultrasound (DUS) examinations for surveillance after fenestrated endovascular aneurysm repair (FEVAR) is not well-studied. Our objective was to further characterize normal and abnormal duplex findings in renal branch grafts after FEVAR.

METHODS

We retrospectively reviewed a single-center experience involving consecutive patients treated with Cook ZFEN devices between 2012 and 2017. Postoperative imaging consisted of a computed tomography (CT) scan at 1 month, 6 months, 1 year, and annually thereafter. As experienced progressed, DUS examination with or without concurrent CT scans were obtained in a nonstandardized protocol, particularly for patients with decreased renal function. Renal patency loss was defined as occlusion or stenosis of greater than 50% evaluated on 3-day renal artery center-line imaging.

RESULTS

A total of 116 patients were treated with FEVAR, of which 60 (51.7%) had concurrent CT and renal DUS images available for review. Six patients (10%) had limited ultrasound studies owing to bowel gas and were excluded. The study cohort therefore included 54 patients receiving of 94 renal fenestrated stents with a mean follow-up of 23 months. Twelve cases of renal patency loss in 10 patients (9 stenoses, 3 occlusions) were found on CT scanning, 11 (91.6%) of which had concurrent abnormalities found on ultrasound examination. Stents with compression at the junction of the main body exhibited significantly elevated mean Peak systolic velocities (PSV) compared with nonstenosed stents (349.2 cm/s vs 115.3 cm/s; P = .003). Stenosis in the most proximal portion of the stent (ie, within the main body) showed no difference in proximal PSV (86.0 cm/s vs 131.9 cm/s; P = .257); however, dampened PSV showed significant differences in the mid (17.5 cm/s vs 109.9 cm/s; P = .027) and distal (19.0 cm/s vs 78.3 cm/s; P = .028) segments compared with nonstenosed stents. All occluded stents demonstrated no flow detection. Proximal PSV served as a strong classifier for junctional stenosis (area under the curve, 0.98). A combined criterion of proximal PSV of greater than 215 cm/s or distal PSV of less than 25 cm/s resulted in a sensitivity of 91.6% and specificity of 85.3% for detecting patency loss. All stents that were compromised underwent successful secondary reintervention and restoration of patency.

CONCLUSIONS

DUS imaging is a clinically useful modality for surveillance of renal branch grafts after FEVAR. Patterns of segmental velocity elevation (proximal PSV, >215 cm/s) and dampening in the distal renal indicate potential hemodynamic compromise and should prompt more aggressive workup or imaging and likely be considered for secondary intervention.

The incidence of carotid in-stent stenosis is underestimated ≥50% or ≥80% and its clinical implications

BACKGROUND

The incidence of carotid in-stent stenosis has been reported to vary between 1% and 30%. Most published studies have short follow-up, which may lead to underestimation of the incidence of in-stent stenosis. This study analyzed the incidence of ≥50% and ≥80% in-stent stenosis using validated duplex ultrasound criteria and its clinical implications.

METHODS

This is a retrospective analysis of prospectively collected data of 450 carotid artery stenting (CAS) procedures (February 6, 2001-December 19, 2016). All patients had postoperative carotid duplex ultrasound examination, which was repeated at 1 month, 6 months, and every 6 to 12 months thereafter. A Kaplan-Meier analysis was used to estimate rates of freedom from ≥50% in-stent stenosis (internal carotid artery peak systolic velocity of ≥224 cm/s) and ≥80% in-stent stenosis (internal carotid artery peak systolic velocity of ≥325 cm/s), freedom from reintervention, and survival.

RESULTS

The mean age was 68.3 years, with a mean follow-up of 40.3 months. A total of 201 patients (45% [201/450]) had CAS for symptomatic disease. Primary CAS was done in 291 patients (65%); in the remaining 35%, CAS was done for postcarotid endarterectomy (CEA) stenosis. A total of 101 patients (23%) had ≥50% late carotid in-stent stenosis, and of these, 33 (7.4%) had ≥80% in-stent stenosis. Nineteen patients (4.3%) developed late transient ischemic attack and three (0.7%) late stroke. Twenty-three (5.2%) patients had late reintervention. Rates of freedom from ≥50% in-stent stenosis in the whole series were 85%, 79%, 75%, 72%, and 70% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively. The rates of freedom from ≥50% in-stent stenosis for primary CAS and CAS for post-CEA stenosis were not statistically significant (P = .540). The rates of freedom from ≥80% in-stent stenosis for the whole series were 96%, 95%, 93%, 90%, and 89% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively. The rates of freedom from ≥80% in-stent stenosis for primary CAS and CAS for post-CEA stenosis were also not statistically significant (P = .516). Rates of freedom from reintervention were 98%, 96%, 93%, 93%, and 91% at 1 year, 2 years, 3 years, 4 years, and 5 years, respectively, and there were no significant differences between primary CAS and CAS for post-CEA stenosis (P = .939). The overall late survival rates were 99%, 97%, 96%, 94%, and 91% at 1 year, 2 years, 3 years, 4 years, and 5 years.

CONCLUSIONS

The incidence of ≥50% in-stent stenosis is relatively high; however, the rates of ≥80% stenosis and late neurologic events are low. Longer follow-up of patients with ≥50% carotid in-stent stenosis may yield higher incidence of ≥80% stenosis.

The Society for Vascular Surgery practice guidelines on follow-up after vascular surgery arterial procedures

Although follow-up after open surgical and endovascular procedures is generally regarded as an important part of the care provided by vascular surgeons, there are no detailed or comprehensive guidelines that specify the optimal approaches with regard to testing methods, indications for reintervention, and follow-up intervals. To provide guidance to the vascular surgeon, the Clinical Practice Council of the Society for Vascular Surgery appointed an expert panel and a methodologist to review the current clinical evidence and to develop recommendations for follow-up after vascular surgery procedures. For those procedures for which high-quality evidence was not available, recommendations were based on observational studies, committee consensus, and indirect evidence. Recognizing that there are numerous published reports on the role of duplex ultrasound for surveillance of infrainguinal vein bypass grafts, the Society commissioned a systematic review and meta-analysis on this topic. The panel classified the strength of each recommendation and the corresponding quality of evidence on the basis of the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system: recommendations were graded either strong or weak, and the quality of evidence was graded high, moderate, or low. The resulting recommendations represent a wide variety of open surgical and endovascular procedures involving the extracranial carotid artery, thoracic and abdominal aorta, mesenteric and renal arteries, and lower extremity arterial revascularization. The panel also identified many areas in which there was a lack of high-quality evidence to support their recommendations. This suggests that there are opportunities for further clinical research on testing methods, threshold criteria, and the role of surveillance as well as on the modes of failure and indications for reintervention after vascular surgery procedures.

Enabling Angioplasty-Ready "Smart" Stents to Detect In-Stent Restenosis and Occlusion

Despite the multitude of stents implanted annually worldwide, the most common complication called in-stent restenosis still poses a significant risk to patients. Here, a "smart" stent equipped with microscale sensors and wireless interface is developed to enable continuous monitoring of restenosis through the implanted stent. This electrically active stent functions as a radiofrequency wireless pressure transducer to track local hemodynamic changes upon a renarrowing condition. The smart stent is devised and constructed to fulfill both engineering and clinical requirements while proving its compatibility with the standard angioplasty procedure. Prototypes pass testing through assembly on balloon catheters withstanding crimping forces of >100 N and balloon expansion pressure up to 16 atm, and show wireless sensing with a resolution of 12.4 mmHg. In a swine model, this device demonstrates wireless detection of blood clot formation, as well as real-time tracking of local blood pressure change over a range of 108 mmHg that well covers the range involved in human. The demonstrated results are expected to greatly advance smart stent technology toward its clinical practice.

Doppler Characteristics of Recurrent Hepatic Artery Stenosis

OBJECTIVES

We sought to assess midterm sonographic findings in patients after stenting for hepatic artery stenosis.

METHODS

Thirty-nine hepatic artery stent procedures were performed for hepatic artery stenosis after liver transplantation between September 2009 and December 2013. Thirty cases were technically successful and met the minimum follow-up time (76 days, defined by earliest diagnosed stenosis). Routine ultrasound surveillance was obtained on all patients, and statistical analysis of the findings in the patency and restenosis groups was performed.

RESULTS

Of the 30 cases, restenosis occurred 9 times in 6 patients. Mean follow-up was 677 days. Mean time to restenosis was 267 days. Five cases (56%) were identified within the first 6 months after stent placement. Four cases (44%) were recognized in the second year after stent placement. Prior to the sonographic diagnosis of restenosis, the mean resistive indices of the main (.64 versus .57, P < .0001), left (.63 versus .54, P < .0001), right anterior (.60 versus .52, P < .0001), and right posterior (.60 versus .53, P = .001) hepatic artery branches differed among patency and restenosis groups, respectively. The mean peak systolic velocity also differed significantly between the 2 groups: 254 cm/sec in patients with eventual restenosis versus 220 cm/sec in patients without restenosis (P = .02).

CONCLUSIONS

The sonographic evaluation of hepatic artery stenosis remains critical during the first 2 years after stent placement. While the vast majority of patients do not restenose, resistive index and peak systolic velocity differed significantly between the 2 groups and may be prognostic surveillance markers for the development of restenosis.

Optimal cut-off criteria for duplex ultrasound compared with computed tomography angiography for the diagnosis of restenosis in stented carotid arteries in the international carotid stenting study

Introduction

Previous studies that reported duplex-ultrasound cut-off criteria, based on blood velocity parameters, for the degree of stenosis in a stented carotid artery were either retrospective, or the reference test was carried out only when a patient was suspected of having restenosis at duplex ultrasound, which is likely to have resulted in verification bias. We performed a prospective study of diagnostic accuracy to find new blood velocity cut-offs in duplex ultrasound for in-stent restenosis.

Patients and methods

Stented patients within the international carotid stenting study were eligible. Patients had a carotid computed tomography angiography in addition to routine duplex ultrasound performed at a yearly follow-up. Duplex-ultrasound bloodflow velocity parameters were compared to the degree of stenosis on computed tomography angiography. The results were analysed using receiver-operating-characteristic curves.

Results

We included 103 patients in this study. On computed tomography angiography, 30 (29.1%) patients had a 30%-49% in-stent restenosis, 21 (20.4%) patients had 50%-69% in-stent restenosis and 5 (4.9%) patients a ≥70% in-stent restenosis. The cut-off value ≥50% stenosis was a peak systolic velocity of 125 cm/s (sensitivity: 63% (95% CI: 41-79), specificity: 83% (95% CI: 72-90)).

Discussion

This study provides a level 2b evidence for new cut-off values for in-stent restenosis. Unfortunately, we could not say anything about severe stenosis because of the low number of severe stenosis after one year.

Conclusions

The 125 cm/s cut-off value on duplex ultrasound is lower than found in previous studies and equal to unstented arteries. Duplex-ultrasound measurements made in stented carotid arteries should not be corrected for the presence of a stent when determining the degree of stenosis.

CT Angiography of Stented Carotid Arteries: Comparison with Doppler Ultrasonography

Purpose:

To determine whether computed tomographic angiography (CTA) is a feasible modality for assessing stented carotid arteries and whether in-stent restenosis based on CTA concurs with ultrasonography (US).

Methods:

A retrospective review was conducted of 37 follow-up CTA and US images from 27 patients (23 men; median age 70 years, range 56–77) who received 34 nitinol carotid stents. CTA and US images were compared with respect to assessability and percent stenosis. Both visual estimation (≥50% or not) and the NASCET method were used to determine percent stenosis in CTA images. For US, a determination of ≥50% stenosis was based on peak systolic velocity (≥200 cm/s) and an internal carotid artery to common carotid artery ratio ≥2.5. Percent stenosis values by CTA were also compared to values (n=7, 21%) determined by catheter angiography.

Results:

CTA and US images were “totally assessable” in 27 (73%) and 15 (41%), “totally non-assessable” in 0 (0%) and 3 (8%), and “partially assessable” in 10 (27%) and 19 (51%), respectively. Assessability of CTA images was equal to or better than that of US images in 33 (89%). The percent stenoses by CTA and US were comparable in 20 cases. CTA found ≥50% stenosis using the NASCET method in 4 of 20 stents; none of these showed ≥50% stenosis by visual estimation of CTA or by spectral Doppler US. Compared with catheter angiography, CTA overestimated percent stenosis from 34% to 66% (mean 53%). US confirmed 2 angiographically proven restenoses, but CTA identified only 1.

Conclusion:

CTA provides better image quality for stented carotid arteries than US, but it might be inferior to US in determining restenosis in assessable cases. Therefore, CTA is likely to be an alternative to US in cases of non-assessability. A large-scale study including more restenosis cases is warranted to reveal which modality is more reliable for diagnosis of restenosis.

Carotid Artery Stenting with Distal Protection Using the Carotid Wallstent and Filterwire Neuroprotection: Single-Center Experience of 380 Cases with Midterm Outcomes

Emerging data have supported the clinical efficacy of carotid artery stenting (CAS) in stroke prevention in high-risk surgical patients. This study was performed to evaluate the midterm clinical outcome of CAS using the Carotid Wallstent and FilterWire distal protection (both Boston Scientific, Natick, MA) at an academic institution. Risk factors for in-stent restenosis (ISR) were also analyzed. Clinical variables and treatment outcome of high-risk patients who underwent Carotid Wallstent placement with FilterWire EX/EZ neuroprotection were analyzed during a recent 54-month period. Three hundred eighty CAS procedures were performed in 354 patients. Technical success was achieved in 372 cases (98%), and symptomatic lesions existed in 85 (24%) patients. No patient experienced periprocedural mortality or neuroprotective device–related complication. The 30-day stroke and death rate was 2.7%, and the overall complication rate was 6.9%. The overall major or fatal stroke rates in symptomatic and asymptomatic patients were 4.6% and 1.3%, respectively (not significant). The overall stroke and death rates between the symptomatic and asymptomatic groups were 5.8% and 2.4%, respectively (not significant). The median follow-up period was 29 months (range 1–53 months). With Kaplan-Meier analysis, the rates of freedom from 60% or greater ISR after CAS procedures at 12, 24, 36, and 48 months were 97%, 94%, 92%, and 90%, respectively. The rates of freedom from all fatal and nonfatal strokes at 12, 24, 36, and 48 months were 97%, 91%, 89%, and 85%, respectively. Multivariable analysis of significant univariate predictors identified that postendarterectomy stenosis (odds ratio [OR] 3.98, p = .02) and multiple stent placement (OR 3.68, p = .03) were independent predictors of ISR. Our study yielded favorable short-term and midterm clinical results using Carotid Wallstent with FilterWire neuroprotection. Late follow-up results showed low rates of fatal and nonfatal stroke and favorable ISR rates compared with other carotid stent trials. Postendarterectomy and multiple stent placement were associated with subsequent ISR.

Neurosonology and noninvasive imaging of the carotid arteries

In this chapter, we review imaging of the extracranial carotid arteries and the indications for noninvasive carotid artery evaluation, measuring the degree of arterial stenosis and plaque morphology. We also analyze the types of noninvasive imaging, including carotid duplex ultrasound, transcranial Doppler, magnetic resonance angiography, and computer tomography angiography. We look at each of these modalities, briefly discussing techniques, benefits, limitations, and sources of error. Furthermore, we discuss the apparent accuracy and the need for multimodality imaging. Finally, an imaging algorithm for the evaluation of the extracranial carotid arteries is proposed, which is in routine use at our hospital.

Standards in neurosonology. Part I

The paper presents standards related to ultrasound imaging of the cerebral vasculature and structures. The aim of this paper is to standardize both the performance and description of ultrasound imaging of the extracranial and intracranial cerebral arteries as well as a study of a specific brain structure, i.e. substantia nigra hyperechogenicity. The following aspects are included in the description of standards for each ultrasonographic method: equipment requirements, patient preparation, study technique and documentation as well as the required elements of ultrasound description. Practical criteria for the diagnosis of certain pathologies in accordance with the latest literature were also presented. Furthermore, additional comments were included in some of the sections. Part I discusses standards for the performance, documentation and description of different ultrasound methods (Duplex, Doppler). Part II and III are devoted to standards for specific clinical situations (vasospasm, monitoring after the acute stage of stroke, detection of a right-toleft shunts, confirmation of the arrest of the cerebral circulation, an assessment of the functional efficiency of circle of Willis, an assessment of the cerebrovascular vasomotor reserve as well as the measurement of substantia nigra hyperechogenicity).

Surveillance and follow-up after revascularization for critical limb ischemia

The purpose of a structured and cost-effective surveillance program after surgical or endovascular intervention for critical limb ischemia is to optimize limb salvage and preserve arterial repair function. Surveillance programs should include clinical, vascular laboratory, and radiographic follow-up, and, when a high-grade progressive stenosis is identified, appropriately timed intervention should be performed. Because many patients with critical limb ischemia are older and many are frail with limited mobility, optimizing the durability of arterial intervention and keeping these patients ambulatory is an important factor in retaining an independent lifestyle and quality of life. Despite the importance of surveillance after arterial intervention, there is a lack of consensus in the literature regarding the efficacy of surveillance, how it should be performed, and well-defined evidence-based guidelines. This review provides an up-to-date scrutiny on this topic and provides recommendations for optimal testing methods, limitations of surveillance testing, and when and how to intervene. These recommendations should be considered in the care of the patient with critical limb ischemia, but with the understanding that patients vary widely and care should be individualized.

Ultrasound findings after endovascular stent deployment in transplant liver hepatic artery stenosis

OBJECTIVE

Endovascular stenting is a safe, effective treatment of hepatic artery stenosis after liver transplant, but no detailed evaluation has been completed of changes in ultrasound monitoring parameters after stenting. This study aims to improve poststenting surveillance by delineating the expected postoperative findings.

MATERIALS AND METHODS

Thirty-one stent procedures were performed at our institution for hepatic artery stenosis after liver transplant between October 2010 and October 2012. Of these, 28 (90%) were technically successful, of which 23 met the minimum follow-up time (76 days, defined by the earliest diagnosed restenosis). These patients were followed with serial ultrasound, per the following schedule: within 1 week of stenting, 3 months after stenting, 6 months after stenting, and every 6 months thereafter; additional, unscheduled examinations were frequently performed when indicated on the basis of deterioration of clinical and laboratory status. Follow-up examinations (mean, 268 days total follow-up) were compared with prestenting examinations to evaluate changes in peak systolic velocity (PSV), resistive index (RI), and tardus-parvus waveforms. Data were analyzed to determine a normal range for postprocedure values and time course of change in values.

RESULTS

Of the 23 patients, six experienced restenosis. In all patients, mean PSV decreased by 124 cm/s, and mean RI increased by 0.13 within 48 hours after stenting. PSV differed between patency and restenosis groups only at more than 90 days after stenting (mean PSV, 234 and 400 cm/s, respectively), with PSV above 300 cm/s serving as a high-sensitivity threshold for the determination of restenosis. Prestenting RI of below 0.40 had a strong correlation with restenosis. Poststenting RI differed between patency and restenosis groups only at more than 48 hours after stenting, with RI of below 0.55 having a strong correlation with restenosis. Tardus-parvus waveform resolution was often delayed well beyond 48 hours after stenting, and time to tardus-parvus waveform resolution had no correlation with patency or restenosis.

CONCLUSION

Ultrasound is convenient and useful to follow stents in hepatic artery stenosis after liver transplant. Prestenting hemodynamics can have value in predicting restenosis. Diagnosis of restenosis can be made with RI and PSV, whereas resolution time of tardus-parvus waveform is of less concern. These parameters can guide which patients require closer monitoring and aggressive treatment.

Management of carotid stenosis. History and today

Internal carotid stenosis constitutes a significant clinical challenge, since it is the cause of 20–25% of ischemic brain strokes. The management of the internal carotid stenosis for many years has been raising controversies amongst neurologists, vascular surgeons and interventional radiologists mainly due to the introduction of endovascular stenting as an alternative to surgical treatment. Its application, however, requires knowledge of specific selection criteria for this kind of treatment as well as of the methods of monitoring patients after stent implantation into the internal carotid artery. Duplex Doppler ultrasound examination is currently a basis for the diagnosis of the arterial stenosis of precranial segments of the carotid arteries. It allows a reliable assessment of not only the course and morphology of the walls, but also of the hemodynamics of blood flow. Interventional treatment is applicable in patients with internal carotid stenosis of ≥70%, which is accompanied by an increase of the systolic flow velocity above 200 cm/s and the end-diastolic velocity above 50–60 cm/s in the stenotic lumen. In most cases, such a diagnosis in duplex Doppler ultrasound examination does not require any confirmation by additional diagnostic methods and if neurological symptoms are also present, it constitutes a single indication for interventional treatment. When deciding about choice of surgical or endovascular method of treatment, the following factors are of crucial importance: morphology of atherosclerotic plaque, its size, echogenicity, homogeneity of its structure, its surface and outlines. By means of ultrasound examinations, patients can be monitored after endovascular stent implantation. They enable evaluation of the degree of stent patency and allow for an early detection of symptoms indicating stenosis recurrence or presence of in-stent thrombosis. When interpreting the findings of the US checkup, it is essential to refer to the initial examination performed in the first days after the procedure and the next ones conducted during the monitoring period.

Renal artery stenosis: prevalence of, risk factors for, and management of in-stent stenosis

Atherosclerotic renal artery stenosis is common and is associated with hypertension and chronic kidney disease. More frequent use of percutaneous renal artery stent placement for the treatment of renal artery stenosis during the past 2 decades has increased the number of patients with implanted stents. In-stent stenosis is a serious problem, occurring more frequently than earlier reports suggest and potentially resulting in late complications. Currently, there are no guidelines covering the approach to restenosis after renal artery stent placement. This article reviews data on the prevalence of and risk factors for the development of in-stent stenosis and the clinical manifestations, evaluation, and treatment of in-stent stenosis and suggests a strategy for the management of patients after percutaneous renal artery stent placement.

Characteristics of duplex sonographic parameters over time after successful carotid artery stenting

OBJECTIVES

Carotid duplex sonography is the primary tool for surveillance after carotid artery stenting, but the course of sonographic velocities over time after successful stenting is unclear. The purpose of this study was to describe carotid duplex sonographic velocity parameters after successful carotid artery stenting and to determine the predictors of poststent sonographic velocities.

METHODS

We queried institutional carotid stent and noninvasive vascular laboratory databases for internal carotid artery stents placed between January 2004 and June 2007. We included patients with stenosis of 20% or less on completion angiograms who had carotid duplex sonography within 30 days before and 7 days after stenting. The prestent peak systolic velocity (PSV), end-diastolic velocity (EDV), internal-to-common carotid artery PSV ratio, contralateral internal carotid artery velocities, stent type, open- versus closed-cell stent design, and days of follow-up were tested as potential predictors of poststent velocities.

RESULTS

Eighty-two of 498 patients met inclusion criteria. The mean PSV and PSV ratio decreased from 423.6 cm/s and 7.1 before stenting to 98.5 cm/s and 1.3 after stenting (both P < .001). During a median follow-up of 370 days, poststent velocities remained stable. All poststent velocities (PSV, EDV, and PSV ratio) were dependent on prestent ipsilateral and contralateral velocities. The poststent EDV was dependent on the type of stent. The upper range for 0% to 20% stenosis in the stented internal carotid artery was a PSV of 141 cm/s, an EDV of 42 cm/s, and a PSV ratio of 2.1 or lower.

CONCLUSIONS

With a median follow-up of 1 year, the PSV and PSV ratio remained stable over time in successfully stented carotid arteries. Deviations in sonographic parameters after initial poststent carotid duplex sonography should prompt an investigation for possible in-stent restenosis.

Carotid Doppler velocity measurements and anatomic stenosis: correlation is futile

BACKGROUND

Duplex ultrasound with Doppler velocimetry is widely used to evaluate the presence and severity of internal carotid artery stenosis; however, a variety of velocity criteria are currently being applied to classify stenosis severity. The purpose of this study is to compare published Doppler velocity measurements to the severity of internal carotid artery stenosis as assessed by x-ray angiography in order to clarify the relationship between these 2 widely used approaches to assess carotid artery disease.

METHODS

Scatter diagrams or "scattergrams" of correlations between Doppler velocity measurements and stenosis severity as assessed by x-ray contrast angiography were obtained from published articles for native and stented internal carotid arteries. The scattergrams were graphically digitized, combined, and segmented into categories bounded by 50% and 70% diameter reduction. These data were combined and divided into 3 sets representing different velocity parameters: (1) peak systolic velocity, (2) end-diastolic velocity, and (3) the internal carotid artery to common carotid artery peak systolic velocity ratio. The horizontal axis of each scattergram was transformed to form a cumulative distribution function, and thresholds were established for the stenosis categories to assess data variability.

RESULTS

Nineteen publications with 22 data sets were identified and included in this analysis. Wide variability was apparent between all 3 velocity parameters and angiographic percent stenosis. The optimal peak systolic velocity thresholds for stenosis in stented carotid arteries were higher than those for native carotid arteries. Within each category of stenosis, the variability of all 3 velocity parameters was significantly lower in stented arteries than in native arteries.

CONCLUSION

Although Doppler velocity criteria have been successfully used to classify the severity of stenosis in both native and stented carotid arteries, the relationship to angiographic stenosis contains significant variability. This analysis of published studies suggests that further refinements in Doppler velocity criteria will not lead to improved correlation with carotid stenosis as demonstrated by angiography.

Duplex Evaluation Following Femoropopliteal Angioplasty and Stenting: Criteria and Utility of Surveillance

Surveillance following lower extremity bypass, carotid endarterectomy, and endovascular aortic aneurysm repair has become the standard of care at most institutions. Conversely, surveillance following lower extremity endovascular interventions is performed somewhat sporadically in part because the duplex criteria for recurrent stenoses have been ill defined. It appears that duplex surveillance after peripheral endovascular interventions, as with conventional bypass, is beneficial in identifying recurrent lesions which may preclude failure and occlusion. In-stent stenosis following superficial femoral artery angioplasty and stenting can be predicted by both peak systolic velocity and velocity ratio data as measured by duplex ultrasound. Duplex criteria have been defined to determine both ≥50% in-stent stenosis and ≥80% in-stent stenosis. Although not yet well studied, it appears that applying these criteria during routine surveillance may assist in preventing failure of endovascular interventions.

The current role of carotid duplex ultrasonography in the management of carotid atherosclerosis: foundations and advances

The management of atherosclerotic carotid occlusive disease for stroke prevention has entered a time of dramatic change. Improvements in medical management have begun to challenge traditional interventional approaches to asymptomatic carotid stenosis. Simultaneously, carotid artery stenting (CAS) has emerged as an alternative to carotid endarterectomy (CE). Finally, multiple factors beyond degree of stenosis and symptom status now mitigate clinical decision making. These factors include brain perfusion, plaque morphology, and patency of intracranial collaterals (circle of Willis). With all of these changes, it seems prudent to review the role of carotid duplex ultrasonography in the management of atherosclerotic carotid occlusive disease for stroke prevention. Carotid duplex ultrasonography (CDU) for initial and serial imaging of the carotid bifurcation remains an essential component in the management of carotid bifurcation disease. However, correlative axial imaging modalities (computer tomographic angiography (CTA) and contrast-enhanced magnetic resonance angiography (CE-MRA)) increasingly aid in the assessment of individual stroke risk and are important in treatment decisions. The purpose of this paper is twofold: (1) to discuss foundations and advances in CDU and (2) to evaluate the current role of CDU, in light of other imaging modalities, in the clinical management of carotid atherosclerosis.

Duplex velocity criteria for native celiac/superior mesenteric artery stenosis vs in-stent stenosis

BACKGROUND

Duplex velocity criteria (DVC) to identify in-stent celiac artery (CA) and superior mesenteric artery (SMA) stenosis is not well defined. Only one study has been published which concluded that DVC for native SMA stenosis overestimated stenosis in stented SMAs. The purpose of this study was to analyze DVC in detecting CA/SMA in-stent stenosis (ISS).

METHODS

Forty-three patients with 62 stents (32 SMAs and 30 CAs), who had concurrent postoperative duplex ultrasound scan and angiograms for significant ISS by DVC were analyzed. A receiver operator curve (ROC) analysis was used to determine optimal DVC (peak systolic velocity [PSV], end-diastolic velocity [EDV], and CA or SMA/aortic systolic ratios) for detecting ≥50% and ≥70% ISS. These were compared to duplex velocities obtained from 97 native CAs and 74 native SMAs with ≥50% stenosis done in the same study period.

RESULTS

The mean stented celiac PSV (cm/s), EDV, and systolic ratio for ≥50% ISS were 447, 136, and 7.1 vs 379, 104, and 5.2 for ≥50% native stenosis (P = .067, .106, and < .01). The mean stented SMA PSV, EDV, and ratio for ≥50% ISS were 410, 114, and 6.2 vs 405, 76, and 2.0 for ≥50% native stenosis (P = .885, .037, and < .0001). The PSV cutpoints for detecting ≥50% SMA ISS was 325 cm/s (sensitivity 89%, specificity 100%, and overall accuracy 91%) vs 295 cm/s for ≥50% native SMA and for ≥70% SMA ISS was 412 (sensitivity 100%, specificity 95%, and overall accuracy 97%) vs 400 for native stenosis. The PSV cutpoints for ≥50% CA ISS was 274 cm/s (sensitivity 96%, specificity 86%, and overall accuracy 93%) vs 240 cm/s for ≥50% native stenosis and for ≥70% CA ISS was 363 (sensitivity 88%, specificity 92%, and overall accuracy 90%) vs 320 cm/s for native stenosis (sensitivity 80, specificity 89%, and overall accuracy 85%). ROC analysis also showed that both PSVs and EDVs were equal predictors for SMA and CA ≥50% and ≥70% ISS. For ≥50% SMA ISS, the area under the curve (AUC) for PSV equals 0.91, EDV = 0.81, P = .341. For CA, PSV, AUC = 0.99, EDV = 0.88, P = .063.

CONCLUSIONS

There is a tendency toward higher velocities in stented CA/SMAs in comparison to native arteries. Caution must be exercised in using duplex velocity cutoffs for native CA/SMA stenosis for stented CA/SMA. Further prospective validation studies are needed.

Prediction of cardiovascular events by inflammatory markers in patients undergoing carotid stenting

OBJECTIVE

To assess whether inflammatory markers predict atherosclerotic disease activity after carotid treatment in patients with severe carotid stenosis and nonsignificant coronary artery disease undergoing carotid stenting.

PATIENTS AND METHODS

From March 1, 2004, to September 30, 2005, a total of 55 consecutive patients (mean ± SD age, 69±8.3 years; 26 men) with severe carotid stenosis and nonsignificant coronary artery disease were treated with carotid stent implantation. Patients were followed up for a period of 5 years for the occurrence of cardiovascular events.

RESULTS

A significant correlation between quantitative analysis of debris entrapped in the filters and inflammatory markers was found. Moreover, the number of particles per filter, the total particles area, and the mean particle axis per filter were significantly higher in patients with clinical events at the follow-up compared with patients without events (87 vs 32, P=.006; 50,118.7 vs 17,782, P=.002; 33.9 vs 30.2, P=.03). At 5-year follow-up we recorded cardiovascular or neurologic events in 11 of the 55 patients (20%). Higher preprocedural levels of high-sensitivity C-reactive protein, interleukin 6 soluble receptor, and interleukin 6 were significantly associated with clinical events at follow-up (P<.001, P=.05, and P=.02, respectively). In particular high-sensitivity C-reactive protein measured at 24 and 48 hours after carotid stenting showed a significant correlation with clinical events (P=.001). Also preprocedural intracellular adhesion molecule 1 and circulating vascular cell adhesion molecule 1 blood concentrations were significantly correlated with a worse prognosis at follow-up (P=.04 and P=.03, respectively).

CONCLUSION

In patients with severe carotid stenosis and nonsignificant coronary artery disease, inflammation is associated with atherosclerotic disease activity and a worse prognosis. Interleukin 6, interleukin 6 soluble receptor, intracellular adhesion molecule 1, vascular cell adhesion molecule 1, and high-sensitivity C-reactive protein levels at baseline and 24 and 48 hours after carotid stenting are predictive of neurologic and cardiovascular events at follow-up.