New ischemic brain lesions on diffusion-weighted MRI after carotid artery stenting with filter protection: frequency and relationship with plaque morphology

Hematological predictors of silent new cerebral ischemic lesions in carotid artery stenting: A retrospective study

BACKGROUND

Silent new cerebral ischemic lesions (sNCIL) are a common complication of carotid artery stenting (CAS) that can lead to an increase in morbidity and mortality. We aimed to evaluate the impact of hematological parameters on sNCIL in patients undergoing CAS.

METHODS

We retrospectively evaluated 103 patients who underwent CAS, with a mean age of 70.5 ± 6.7 years, and 31 (20.1 %) of whom were female. Stents were placed for internal carotid artery revascularization. The presence of new hyperintense lesions on diffusion-weighted imaging (DWI) without neurological symptoms was considered as sNCIL in cases without apparent neurological findings. Patients were categorized into two groups based on DWI results: positive (29) and negative (74).

RESULTS

In the study population, sNCIL was observed in 29 patients (28.2 %). The DWI-positive group exhibited significantly higher Plateletcrit (PCT) levels, advanced age, and a lack of embolic protection device usage compared to the DWI-negative group. The Receiver Operating Characteristic (ROC) analysis identified a PCT value of 0.26 as the optimal threshold, detecting the development of sNCIL with a sensitivity of 75.9 % and specificity of 59.1 % (AUC: 0.700; 95 % CI: 0.594-0.806, p = 0.002).

CONCLUSION

To be determined by a simple blood parameter, PCT can predict the risk of sNCIL before CAS and holds clinical value in the treatment of patients with carotid artery stenosis.

Effect of plaque morphological characteristics on the outcomes of carotid artery stenting

Carotid artery stenting (CAS) represents today an accepted option for the treatment of severe carotid artery stenosis. The evolution of materials, techniques, perioperative medical management and patients' selection, has allowed to progressively reduce CAS complications. However, the main drawback of CAS is still represented by the risk of cerebral embolization, that may occur during several steps of the procedure and also in the early postoperative period. Preoperative carotid plaque morphological characteristics may have a great role in determining the risk of embolization during CAS. This review summarizes the current knowledge on carotid plaque characteristics that may influence the risk of complication during CAS. This information may be important for the optimization of CAS patients' selection and adaptation of the materials and techniques.

The correlation between the cardiovascular instability and the size of the developed ischaemic lesions in patients who underwent carotid stenting

AIMS

In this study we investigated the relationship between cardiovascular instability and the size of the developed ischaemic lesions during carotid stent implantation by diffusion-weighted (DWI) magnetic resonance (MR) examination.

MATERIAL AND METHODS

We retrospectively analyzed anaesthesia reports and follow-up MR examinations after stent implantation of 192 patients in a 3-year period. Nineteen aspects of cardiovascular status were analyzed. We registered the duration of the intervention, low and high blood pressure (BP) values during anaesthesia and heart rates. The fluctuations of BP and heart rate and the time of their compensations after the stent expansion were also recorded. Values were compared with the number and the size of ischaemic lesions on DWI scans. We used Spearman and Kendall rank correlations and Welch's tests for statistical analysis. Values of p ≤ 0.05 were considered as statistically significant.

RESULTS

Decreased heart rate significantly correlated with the number (p = 0.0123) and size (p = 0.00323) of ischaemic lesions during stent expansion. Other cardiovascular parameters did not show any significant correlations.

CONCLUSIONS

Our results indicate that only heart rate attenuation affects the size of ischaemic lesions; thus the prevention of bradycardia is highly important.

Age and the risk of new ischemic lesions on diffusion weighted imaging after carotid artery stenting: A systematic review and meta-analysis

To perform a systematic review and meta-analysis to show the association between age and the risk of new ischemic lesions on diffusion-weighted magnetic resonance imaging (DWI) after carotid artery stenting in patients with carotid artery stenosis. We searched PubMed and EMBASE from their dates of inception to March 14, 2019 for eligible studies. Standardized mean difference (SMD) and pooled odds ratio (OR) with 95% confidence interval (CI) was used to evaluate the association between age and new DWI lesions. Sensitivity analysis was performed to detect the possible source of heterogeneity. Twenty-three studies enrolling 2127 patients were included. The incidence of new DWI lesions was 62% in older patients and 41% in younger patient (OR 2.44, 95%CI 1.57-3.79; p < 0.0001). The patients with new DWI lesions were older than those without (SMD 0.24, 95% CI 0.08-0.39; p = 0.003). The risk of new DWI lesions increased by 1.07 per added year (95%CI 1.04-1.11, p < 0.0001). The results remained stable in sensitivity analyses and after adjusting for publication bias. It was concluded that older age was at higher risk of new DWI lesions after stenting in patients with carotid artery stenosis.

Relationship between carotid plaque characteristics and new ischemic lesions after stenting detected by computed tomography angiography

Background

Although carotid artery stenting achieves definite benefits, it carries a higher rate of embolization compared with carotid endarterectomy. The incidence of embolization may be related to plaque stability.

Purpose

To assess for any relationship between plaque characteristics and cerebral emboli following carotid artery stenting.

Material and Methods

Sixty-three patients with severe carotid stenosis underwent carotid artery stenting. They were divided into two groups according to whether new ischemic lesions were detected on diffusion-weighted imaging after carotid artery stenting. We evaluated the types and locations of calcification in plaques and extent of calcification. We then assessed for a correlation between each of these factors and occurrence of new lesions on diffusion-weighted imaging after carotid artery stenting.

Results

The locations of calcification, percentage of plaque enhancement, and the number of plaques with irregular surface or ulceration were significantly different between the two groups. A peripheral position of calcification (close to the adventitia), enhancing plaques, and plaques with irregular surfaces or ulceration were statistically significant predictors of intracerebral embolization after carotid artery stenting. No significant differences in type of plaque or degree of calcification were found between two groups.

Conclusion

Peripheral calcification, enhancing plaques, and plaques with irregular surfaces were risk factors for intracerebral embolization after carotid artery stenting. These plaque characteristics should be considered when choosing the optimal treatment for patients.

Association between high sensitivity C-reactive protein (hs-CRP) levels and the risk of major adverse cardiovascular events (MACE) and/or microembolic signals after carotid angioplasty and stenting

Background

To evaluate the association between pre/post-procedural high sensitive C-reactive protein (hs-CRP) level and hs-CRP difference, and the risk of major adverse cardiovascular events (MACE) or new diffusion-weighted MRI lesions after carotid angioplasty and stenting (CAS).

Methods

In this study, conducted in 2016 in Shiraz (Iran), patients who underwent diagnostic angiography and CAS were recruited. CAS was performed with distal embolic protection device on patients with both standard and high risk of endarterectomy. Pre/post-procedural hs-CRP, and hs-CRP difference were determined by immunoenzymometric assay method.

Results

A total of 50 patients with diagnostic angiography and 60 patients with CAS were enrolled. No death, myocardial infarction, ischemic or hemorrhagic stroke, and need to revascularization occurred during the 30-days of the post-procedural period. Accordingly, the statistical evaluation in associating MACE and hs-CRP levels was impossible. Angioplasty was associated with higher frequency of elevated post-procedural hs-CRP in comparison to angiography (P=0.003). The higher age, symptomatic lesions, negative history of hypertension, and hs-CRP difference had significant association with the presence of new DWI lesions in univariate analysis (all P<0.05). Angioplasty of left carotid bulb and post-procedural hs-CRP levels was very close to the level of significance (P=0.06). But only left sided lesions had positive association (P=0.037) and hypertension had negative association (P=0.037) in multivariate regression analysis. There were significant association between post-procedural hs-CRP level (P=0.02) and hs-CRP difference (P=0.003), and the number of new lesions; and the hs-CRP difference and the accumulated lesion surface area (P=0.009).

Conclusion

Post-procedural hs-CRP and hs-CRP difference may predict embolic complications of CAS.

Reduction of cerebral DWI lesion burden after carotid artery stenting using the CASPER stent system

INTRODUCTION

Despite various measures to protect against distal embolization during carotid artery stenting (CAS), periprocedural ischemic lesions are still encountered.

OBJECTIVE

To evaluate the periprocedural cerebral diffusion weighted imaging (DWI) lesion burden after CASPER stent placement.

METHODS

Patients who underwent CAS using the CASPER stent system were reviewed. Degrees of carotid stenosis and plaque configuration were determined. All patients were pretreated with dual antiplatelet agents and cerebral pre- and postprocedural MRI was obtained. All CAS procedures were performed by a single operator.

RESULTS

A total of 110 patients with severe carotid artery stenosis (median degree of stenosis 80%, median length of stenosis 10 mm) were treated with CAS. Hypoechogenic or heterogeneous, mostly hypoechogenic, plaques were documented in 48.6% (52/107) of patients. Carotid ulceration was present in 15.9% (17/107). Postprocedurally, 7.3% (8/110) of patients were found to have ischemic DWI lesions. They were asymptomatic in all patients. Follow-up at 90 days was available in 88.2% (97/110) of patients with excellent functional outcome (modified Rankin Scale score 0-1) in 95.9% (93/97).

CONCLUSION

Carotid artery stenting using the new CASPER stent in combination with a distal embolic protection device is safe and results in a lower rate of periprocedural DWI lesion burden compared with reported results for historic controls.

Short-Term Results of Carotid Endarterectomy and Stenting After the Introduction of Carotid Magnetic Resonance Imaging: A Single-Institution Retrospective Study

OBJECTIVE

Although carotid artery stenting (CAS) has been gaining popularity as an alternative to carotid endarterectomy (CEA), perioperative stroke rate following contemporary CAS remains significantly higher than stroke rate after CEA. The purpose of this study was to assess perioperative (within 30 days) therapeutic results in patients with carotid stenosis (CS) after introduction of preoperative carotid magnetic resonance imaging plaque evaluation in a single center performing both CEA and CAS.

METHODS

Based on prospectively collected data for patients with CS who were scheduled for carotid revascularization, retrospective analysis was conducted of 295 consecutive patients with CS. An intervention was selected after consideration of periprocedural risks for both CEA and CAS. Concerning risk factors for CAS, results of magnetic resonance imaging plaque evaluation were emphasized with a view toward reducing embolic complications.

RESULTS

CAS was performed in 114 patients, and CEA was performed in 181 patients. Comparing baseline characteristics of the 295 patients, age, T1 signal intensity of plaque, symptomatic CS, urgent intervention, and diabetes mellitus differed significantly between CAS and CEA groups. Among patients who underwent CAS, new hyperintense lesions on diffusion-weighted imaging were confirmed in 47 patients. New hyperintense lesions on diffusion-weighted imaging were recognized in 21.4% of patients who underwent CEA (n = 39), significantly less frequent than in patients who underwent CAS.

CONCLUSIONS

The overall short-term outcome of CEA and CAS is acceptable. Preoperative carotid magnetic resonance imaging evaluation of plaque might contribute to low rates of ischemic complications in CAS.

The Role of White Matter Damage in the Risk of Periprocedural Diffusion-Weighted Lesions after Carotid Artery Stenting

Background

White matter hyperintensities (WMH) are a common finding in aged individuals affected by carotid artery disease and are a risk factor for first-ever and recurrent stroke. We investigated if white matter damage increases the risk of brain microembolism during carotid artery stenting (CAS), as evaluated by the appearance of new areas of restricted diffusion on diffusion-weighted images (DWI).

Methods

We evaluated 47 patients with severe internal carotid artery (ICA) stenosis undergoing CAS, comparing preprocedural clinical, ultrasound and radiological characteristics. WMH volume was computed on FLAIR images before CAS. After CAS, the DWI scan was looked over for areas of restricted diffusion (DWI lesions). A first univariate analysis was adopted to compare groups according to the occurrence of DWI lesions. Then, the variable DWI lesion was modelled by means of a logistic regression model.

Results

Seventeen patients developed at least 1 DWI lesion after CAS. Compared with non-DWI, DWI patients were more commonly treated in the left ICA (p = 0.007) and had a more severe WMH damage (p = 0.027). Indeed, the risk of a DWI lesion was higher in left versus right stenosis (OR = 9.0, 95% CI 1.9-42.7, p = 0.005) and increased for each log-unit of WMH lesion load (OR = 7.05, 95% CI 1.07-46.49, p = 0.042). A WMH lesion load of at least 5.25 cm³ had a 50% probability of occurrence of a new DWI lesion.

Conclusions

Treated side and preexisting white matter damage are risk conditions for brain microembolism during CAS. This should be taken into account to optimize severe carotid artery disease management.

Aortic arch and common carotid artery plaques with soft components pose a substantial risk of cerebral embolization during carotid stenting

OBJECTIVES

A higher rate of embolization is considered a disadvantage of carotid stenting (CAS), when compared with carotid endarterectomy. Plaques in the aortic arch (AA) and the common carotid artery (CCA) may be additional sources of embolization to stented internal carotid plaques during CAS. In this study, we aimed to investigate the relationship between these plaques and intracerebral embolization.

METHODS

We analyzed the occurrence and composition of plaques in the AA and CCA by computed tomography angiography (CTA) in 101 consecutive cases of CAS. Cases of peri-procedural embolization were detected on diffusion-weighted imaging as lesions demonstrating diffusion restriction. We applied the χ(2) and Fisher's exact tests, as well as logistic regression models.

RESULTS

The occurrence of plaques in the AA and CCA was significantly related to the appearance of new diffusion-weighted imaging lesions (p = 0.013 and p = 0.004, respectively). Patients with soft plaques in the AA or CCA had a significantly higher risk of embolization than those without plaques (p = 0.012 and p = 0.006, respectively). In contrast, homogeneously calcified plaques did not pose significantly higher risks.

CONCLUSIONS

Soft plaques in the AA and CCA result in a substantial risk of embolization during CAS. Use of a CTA examination of the AA and the CCA in patients with carotid stenosis may help to select lower-risk patients for CAS.

Follow-up after undersized dilatation of targeted lesions in carotid artery stenting

BACKGROUND AND PURPOSE

We assessed whether intentional undersized dilatation of targeted lesions during carotid artery stenting (CAS) carried a higher risk of in-stent restenosis (ISR) and correlation to subsequent ischemic stroke in qualifying arteries in the follow-up period.

METHODS

Consecutive patients undergoing CAS between April 2003 and May 2010 were retrospectively reviewed. The use of a filter device as a distal embolic protection device (EPD) was first approved by Japanese governmental health insurance in April 2008; previously, transient balloon occlusion was used off-label. Until March 2008 (Group A), the target diameter of balloon dilatation was 80-100% of the normal vessel diameter just distal to the stenotic lesion. Moderately undersized dilatation (70-80% of the normal vessel diameter) using the distal EPD was adopted in April 2008 (Group B) in an attempt to reduce the amount of released plaque debris.

RESULTS

We analyzed 132 CAS procedures (125 patients) in Group A and 53 CAS procedures (52 patients) in Group B. The mean follow-up period was 35.4 months (35.3 months in Group A and 36.0 months in Group B). Eight lesions (4.3%; 7 in Group A and 1 in Group B) developed ISR. None of the patients had symptomatic ISR, and ISR did not increase in Group B (odds ratio, 0.34; 95% confidence interval, 0.04-2.86; p = 0.32).

CONCLUSIONS

Undersized dilatation of targeted lesions did not increase the risk of developing ISR, and we suggest it as a viable treatment option to prevent ischemic events during CAS.

Nε-(carboxymethyl)lysine in debris from carotid artery stenting: multiple versus nonmultiple postoperative lesions

BACKGROUND

No predictor of postoperative ischemic events has been identified in patients undergoing carotid artery stenting (CAS). We aimed to determine whether N(ε)-(carboxymethyl)lysine (CML) in debris trapped by an embolic protection filter device is a predictor of postoperative ischemic events.

METHODS

We enrolled 27 patients (73.4 ± 7.2 years; 22 male, 5 female) who underwent CAS for carotid artery stenosis. Diffusion-weighted magnetic resonance imaging was performed before and after the procedure. Protein samples were extracted from the debris. CML and myeloperoxidase were examined by solid phase enzyme-linked immunosorbent assay and Western blot analysis.

RESULTS

Seventeen patients had 0 or 1 new lesion (nonmultiple lesions) postoperatively, whereas 10 patients had 2 or more new lesions postoperatively (multiple lesions). The CML concentration of the protein sample was significantly higher in patients with multiple lesions than in those with nonmultiple lesions (6.26 ± 2.77 ng/mg protein and 3.36 ± 1.57 ng/mg protein, respectively; P = .010). Statin therapy for dyslipidemia was associated with a lower incidence of multiple lesions and a lower concentration of CML in the protein sample (P = .004 and P = .02, respectively). Receiver operating characteristic analysis showed that the area under the curve for CML was significantly greater than .5 (.877; 95% confidence interval, .742-1.00).

CONCLUSIONS

CML derived from debris may distinguish between patients with postoperative multiple ischemic lesions and those with postoperative nonmultiple lesions who undergo CAS.

Cerebral embolic lesions detected with diffusion-weighted magnetic resonance imaging following carotid artery stenting: a meta-analysis of 8 studies comparing filter cerebral protection and proximal balloon occlusion. JACC Cardiovasc Interv. 2014;7:1177-1183. [PMID: 25240544 DOI: 10.1016/j.jcin.2014.05.019]

OBJECTIVES

The aim of this meta-analysis was to evaluate and compare the efficacy of the 2 different neuroprotection systems in preventing embolization during carotid artery stenting (CAS), as detected by diffusion-weighted magnetic resonance imaging (DW-MRI).

BACKGROUND

Data from randomized and nonrandomized studies comparing both types of embolic protection devices revealed contrasting evidence about their efficacy in neuroprotection, as assessed by the incidence of new ischemic lesions detected by DW-MRI.

METHODS

Eight studies, enrolling 357 patients, were included in the meta-analysis. Our study analyzed the incidence of new ischemic lesions/patient, comparing filter cerebral protection and proximal balloon occlusion.

RESULTS

Following CAS, the incidence of new ischemic lesions/patient detected by DW-MRI was significantly lower in the proximal balloon occlusion group (effect size [ES]: -0.43; 95% confidence interval [CI]: -0.84 to -0.02, I(2) = 70.08, Q = 23.40). Furthermore, following CAS, the incidence of lesions at the contralateral site was significantly lower in the proximal protection group (ES: -0.50; 95% CI: -0.72 to -0.27, I(2) = 0.00, Q = 3.80).

CONCLUSIONS

Our meta-analysis supports the concept that the use of proximal balloon occlusion compared with filter cerebral protection is associated with a reduction of the amount of CAS-related brain embolization. The data should be confirmed by a randomized clinical trial.

Can Doppler flow parameters of carotid stenosis predict the occurrence of new ischemic brain lesions detected by diffusion-weighted MR imaging after filter-protected internal carotid artery stenting?

BACKGROUND AND PURPOSE

Carotid angioplasty and stent placement are increasingly being used for the treatment of symptomatic and asymptomatic carotid artery disease. Carotid angioplasty and stent placement carry an inherent risk of distal cerebral embolization, precipitating new brain ischemic lesions and neurologic symptoms. Our purpose was to evaluate the frequency of new ischemic lesions found on diffusion-weighted imaging after protected carotid angioplasty and stent placement and to determine the association of new lesions with ICA Doppler flow parameters.

MATERIALS AND METHODS

Fifty-two patients (mean age, 68 ± 11 years) with 50%-69% (n = 20, group 1) and ≥70% (n = 32, group 2) internal carotid artery stenosis underwent carotid angioplasty and stent placement with distal filter protection. DWI was performed before and 48 hours after carotid angioplasty and stent placement.

RESULTS

Thirty-three (63.4%) patients showed new lesions. The average number of new postprocedural lesions was 3.4 per patient. Most of the postprocedural lesions were <5 mm (range, 3-23 mm), cortical and corticosubcortical, and clinically silent. Group 2 had a significantly higher number of new lesions compared with group 1 (P < .001). A significant relationship was found between ICA Doppler flow parameters and the appearance of new lesions.

CONCLUSIONS

The appearance of new ischemic lesions was significantly related to the Doppler flow parameters, particularly peak systolic velocity.

Plaque morphology detected with Duplex ultrasound before carotid angioplasty and stenting (CAS) is not a predictor of carotid artery in-stent restenosis, a case control study

Background

In-stent restenosis (ISR) is an important factor endangering the long-term safety and efficacy of carotid artery angioplasty and stenting (CAS). It is plausible that soft vulnerable plaques are more likely to be injured during CAS procedure and are therefore more likely to initiate the cascade finally leading to ISR. The aim of this study was to investigate if plaque morphology detected by a simple applicable Duplex ultrasound score before CAS can be used as a predictor for ISR.

Methods

Within a prospectively collected single-centre CAS database of 281 patients (comprising 300 arteries) with high-grade carotid artery stenosis, who underwent CAS between May 2003 and January 2013, we conducted a nested case–control study. Plaque morphology before CAS was analysed by a blinded investigator and each parameter of the Total Plaque Risk Score (TPRS) as well as the whole score was evaluated with regard to its diagnostic validity for ISR.

Results

We analysed the data of 10 patients with ISR and 50 patients without ISR. There were no significant differences with respect to baseline characteristics, vascular risk factors, and degree of stenosis between patients with and without ISR. The duration of follow-up was longer in patients with ISR (p = 0.024) and these patients were more likely to show increased PSV (p = 0.012) immediately after CAS than patients without ISR. Neither individual parameters of the TPRS score nor the score as a whole were suitable as a diagnostic test for ISR development.

Conclusions

In the present study we could demonstrate that the non-contrast enhanced DUS of the pre-interventional plaque formation cannot be used as a predictor for the development of ISR. Evaluating a more sophisticated, but not routinely available approach e.g. by ultrasound based plaque perfusion imaging or CT based plaque analysis could be helpful in the future in order to assess the role of plaque morphology in the context of ISR development.

Flow reversal versus filter protection: a pilot carotid artery stenting randomized trial

BACKGROUND

Carotid artery stenting (CAS) has become an alternative treatment for patients presenting symptomatic carotid artery stenosis. The improvement in clinical outcomes with CAS has been associated with the development of embolic protection devices. The trial aim is to compare flow reversal versus filter protection during CAS through femoral access.

METHODS AND RESULTS

Patients were randomly enrolled in CAS using flow reversal or filter protection. The primary end points were the incidence, number, and size of new ischemic brain lesions after CAS. The secondary end points included major adverse cardiac and cerebrovascular events, transient ischemic attack, and definitive ischemic brain lesions on fluid-attenuated inversion recovery magnetic resonance image at a 3-month follow-up. Ischemic brain lesions were assessed by a 3T magnetic resonance image. Neurological outcomes were evaluated by means of the National Institutes of Health Stroke Scale and the modified Rankin Scale (mRS). Forty consecutive patients were randomly assigned. Compared with flow reversal (n=21), filter protection (n=19) resulted in a significant reduction in the incidence (15.8% versus 47.6%, P=0.03), number (0.73 versus 2.6, P=0.05), and size (0.81 versus 2.23 mm, P=0.05) of new ischemic brain lesions. Two patients, 1 from each group, presented transient ischemic attack at 3-month follow-up. There were no major adverse cardiac and cerebrovascular events in the hospital or at 3-month follow-up.

CONCLUSIONS

In this small sample size trial, filter protection was more effective than flow reversal in reducing ischemic brain lesions during CAS through femoral approach.

CLINICAL TRIAL REGISTRATION URL

http://portal2.saude.gov.br/sisnep/. Unique identifier: 0538.0.004.000-10.