The ICAROS registry of carotid artery stenting. Imaging in Carotid Angioplasties and Risk of Stroke

Novel Imaging-Based Biomarkers for Identifying Carotid Plaque Vulnerability

Carotid artery disease has traditionally been assessed based on the degree of luminal narrowing. However, this approach, which solely relies on carotid stenosis, is currently being questioned with regard to modern risk stratification approaches. Recent guidelines have introduced the concept of the "vulnerable plaque," emphasizing specific features such as thin fibrous caps, large lipid cores, intraplaque hemorrhage, plaque rupture, macrophage infiltration, and neovascularization. In this context, imaging-based biomarkers have emerged as valuable tools for identifying higher-risk patients. Non-invasive imaging modalities and intravascular techniques, including ultrasound, computed tomography, magnetic resonance imaging, intravascular ultrasound, optical coherence tomography, and near-infrared spectroscopy, have played pivotal roles in characterizing and detecting unstable carotid plaques. The aim of this review is to provide an overview of the evolving understanding of carotid artery disease and highlight the significance of imaging techniques in assessing plaque vulnerability and informing clinical decision-making.

Vascular Imaging: An Unparalleled Decade

Vascular imaging techniques, such as catheter angiography, ultrasound, computed tomography (CT), and magnetic resonance (MR), have all undergone unprecedented innovation and incredible technological leaps in the last 10 years. Ultrasound, CT, and MR have progressed in acquisition speed, resolution, and accuracy to the point that they have now supplanted the former mainstay, invasive catheter-based angiography, despite the advent of digitized angiographic image recording. This review explores the advantages and shortcomings of each technique and how they have changed the diagnosis and assessment of the cardiovascular system for endovascular intervention.

Carotid Artery Dynamics during Head Movements: A Reason for Concern with Regard to Carotid Stenting?

Purpose:

To evaluate carotid artery mobility patterns during head movements following carotid angioplasty/stenting (CAS).

Methods:

In 7 patients (all men; mean age 69 years, range 65–76) who had undergone unilateral CAS, 3D time-of-flight magnetic resonance angiography was performed, visualizing both carotid arteries in 5 different head positions (neutral, turned left and right, and bent forward and backward). Maximum intensity projection reconstructions were obtained to measure angulation at the proximal and distal stent junction. Configuration changes of the stented section of the carotid artery and the unstented contralateral artery were judged. Secondly, transverse sections at the level of the carotid bifurcation and at the skull base were used to calculate torsion shear in the common and internal carotid arteries (CCA, ICA) during turned left and right head position. Results were expressed as median (range).

Results:

In neutral head position, maximal angulation at the distal stent junction was 34.3° (32.3°–55.6°). With the head bent forward, this angulation changed to 47.6° (42.6°–85.2°, p=0.028) and when bent backward to 26.5° (25.0°–48.7°, p=0.027). In all patients, configuration changes of the stented sections were absent. The contralateral unstented side showed diffuse configuration changes without specific angulation at one location. With the head turned left and right, the CCA on the stented side was subjected to 28.6° (13.6°–53.7°) and 24.9° (2.0°–50.6°) of torsion shear, respectively. Torsion of the ICA was subsequently 18.1° (12.7°–40.5°) and 15.2° (2.9°–69.4°).

Conclusions:

Following carotid stenting, sharp ICA angulations that are aggravated by forward bending of the head occur at the distal stent junction. The stented section of the carotid artery shows complete lack of flexibility despite highly flexible features of the stents ex vivo. Both the CCA and ICA are subjected to considerable torsion shear with the head turned left and right. This shear is not accommodated by the current stent designs.

How to avoid complications associated with carotid angioplasty and stenting

Carotid angioplasty and stenting (CAS) has been proposed as an alternative to surgery and is now performed more frequently and is well accepted, at least for high surgical risk patients. However, complications and particularly embolic strokes, even with a meticulous technique, can occur at any step of the procedure. Silent embolism is detected after CAS and may be a problem that needs to be discussed. To avoid and reduce these complications associated with CAS, it is important to have good indications dependent upon on good patient and lesions selection, as well as correct technique. New parameters have been proposed, particularly for asymptomatic lesions. The authors consider that embolic protection devices (EPDs) are mandatory for CAS, and new techniques will be presented. The choice of the EPD depends on the clinical status of the patient, the lesion morphology and characteristics, and the anatomy of the artery. All stents are not equivalent and so a good choice of the stent is necessary to avoid and reduce the complications associated with CAS, and experienced operators are also needed. With all these considerations, CAS can now be performed with acceptable outcomes and in certain population the results are comparable or superior to surgery. The results of ongoing randomized trials are awaited.

The capture of visible debris by distal cerebral protection filters during carotid artery stenting: Is it predictable?

OBJECTIVES

Neurologic complications during carotid artery stenting (CAS) are most clearly associated with embolization of visible debris. Distal filter devices may provide cerebral protection by capturing clinically significant debris. However, they increase procedural time and expense and have their own set of complications. The current study was undertaken to identify the clinical factors predictive for the presence or absence of visible debris captured by distal filter devices during CAS.

METHODS

Patients undergoing CAS with use of a distal filter device (n = 279) were prospectively entered into an investigational carotid registry. Recorded variables were classified as patient-, lesion-, or procedure-related. The filter was assessed for visible debris in each case. The odds ratio (OR) and 95% confidence interval (CI) were determined for each variable to predict visible debris. The ability of each variable to predict the absence of visible debris was assessed by calculating the individual negative predictive value (NPV).

RESULTS

Visible debris was present in 169 filters (60.3%). There was an increased risk of visible debris found with several variables (OR, 95% CI): hypertension (2.9, 1.7 to 5.2), hypercholesterolemia (2.3, 1.4 to 3.9), stent diameter >9 mm (16.6, 9.0 to 30.0), and any neurologic event (4.2, 1.5 to 9.9). The NPV failed to exceed 0.80 (80%) for any variable. The NPV of the variables with a significantly elevated OR was as follows: hypertension (0.60), hypercholesterolemia (0.52), stent diameter >9 mm (0.75), and any neurologic event (0.38).

CONCLUSIONS

Several clinical variables are associated with the presence of visible debris captured by distal filter devices. The current study failed to identify any variables capable of consistently predicting the absence of visible debris. These findings support the routine rather than the selective use of cerebral protection during CAS.

Vascular imaging: an unparalleled decade

Vascular imaging techniques, such as catheter angiography, ultrasound, computed tomography (CT), and magnetic resonance (MR), have all undergone unprecedented innovation and incredible technological leaps in the last 10 years. Ultrasound, CT, and MR have progressed in acquisition speed, resolution, and accuracy to the point that they have now supplanted the former mainstay, invasive catheter-based angiography, despite the advent of digitized angiographic image recording. This review explores the advantages and shortcomings of each technique and how they have changed the diagnosis and assessment of the cardiovascular system for endovascular intervention.

Carotid Plaque Echolucency Increases the Risk of Stroke in Carotid Stenting

Background— Carotid artery stenting (CAS) has recently emerged as a potential alternative to carotid endarterectomy. Cerebral embolization is the most devastating complication of CAS, and the echogenicity of carotid plaque has been indicated as one of the risk factors involved. This is the first study to analyze the role of a computer-assisted highly reproducible index of echogenicity, namely the gray-scale median (GSM), on the risk of stroke during CAS.

Methods and Results— The Imaging in Carotid Angioplasty and Risk of Stroke (ICAROS) registry included 418 cases of CAS collected from 11 international centers. An echographic evaluation of carotid plaque with GSM measurement was made preprocedurally. The onset of neurological deficits during the procedure and the postprocedural period was recorded. The overall rate of neurological complications was 3.6%: minor strokes, 2.2%, and major stroke, 1.4%. There were 11 of 155 strokes (7.1%) in patients with GSM ≤25 and 4 of 263 (1.5%) in patients with GSM >25 ( P =0.005). Patients with severe stenosis (≥85%) had a higher rate of stroke ( P =0.03). The effectiveness of brain protection devices was confirmed in those with GSM >25 ( P =0.01) but not in those with GSM ≤25. Multivariate analysis revealed that GSM (OR, 7.11; P =0.002) and rate of stenosis (OR, 5.76; P =0.010) are independent predictors of stroke.

Conclusions— Carotid plaque echolucency, as measured by GSM ≤25, increases the risk of stroke in CAS. The inclusion of echolucency measured as GSM in the planning of any endovascular procedure of carotid lesions allows stratification of patients at different risks of complications in CAS.

Carotid angioplasty under cerebral protection with the percusurge guardwire system

The purpose of this study was to examine the possible beneficial effect of the PercuSurge GuardWire cerebral protection device based on balloon occlusion of the distal internal carotid artery and debris aspiration for patients undergoing carotid artery stenting (CAS). A total of 268 CAS procedures were attempted under cerebral protection using the PercuSurge GuardWire system in 242 patients (194 men; mean age, 71.2 +/- 9.4 years; range, 40-91). The lesions were mainly atherosclerotic; 64% were symptomatic. Technical success was 99.3%. All lesions were stented except three postangioplasty restenoses. Prophylactic occlusion during balloon dilatation and stenting was well tolerated in 255 patients (95.9%). Microscopic analysis of the aspirated blood showed different types of particles numbering between 7 and 145 per procedure, with a mean diameter of 250 microm (mean, 56-2,652 microm). The 30-day stroke and death rate was 2.3%, with four periprocedural complications at < 48 hr (one retinal embolism and three transient ischemic attacks), one intracerebral hemorrhage at 3 days, and one death of cardiac failure at 3 weeks. This technique appears safe and efficient with a low rate of periprocedural embolic events. Protection devices seem indispensable to perform CAS and expand the applicability of the procedure. Randomized studies (surgery vs. CAS with and without cerebral protection) are awaited.

Recent developments in vascular surgery

The authors of this review discuss the changing role of vascular surgery and the impact of developments such as endovascular interventions and new techniques for treating varicose veins

Percutaneous access and closure of femoral artery access sites associated with endoluminal repair of abdominal aortic aneurysms

PURPOSE

To report longer follow-up and further experience using the Prostar XL Percutaneous Vascular Surgery (PVS) device for access and closure of large bore femoral artery access sites during endovascular repair of abdominal aortic aneurysms (AAAs).

METHODS

One hundred forty-four patients (128 men; mean age 72 years, range 56-89) undergoing endovascular AAA repair had percutaneous access and closure of their 16-F femoral artery access sites using a 10-F PVS device. The first 54 patients were enrolled in the phase III trial of the AneuRx stent-graft for AAA treatment.

RESULTS

The femoral artery access site was successfully closed in 136 (94.4%) patients, with only 8 patients in whom adequate hemostasis could not be obtained. One-month follow-up was available in 144 patients, 6-month in 100, and 1-year in 59. No groin or lower extremity complications have been observed in any patient who had successful closure of the femoral artery access site.

CONCLUSIONS

Large-bore femoral artery access sites can be percutaneously repaired using this device, which minimizes the invasiveness of the endograft procedure.