New brain lesions after carotid revascularization are not associated with cognitive performance

Factors Associated With Silent Brain Infarcts After Middle Cerebral Artery Stenting or Balloon Angioplasty

BACKGROUND AND PURPOSE

Silent brain infarcts (SBIs), which manifest as dot-like lesions on diffusion-weighted imaging (DWI) after endovascular procedures, are associated with an increased risk of stroke, dementia, and cognitive decline. We aimed to identify the factors associated with SBIs following middle cerebral artery (MCA) stenting or balloon angioplasty.

METHODS

We retrospectively reviewed patients who underwent MCA stenting or balloon angioplasty, including those with symptomatic, atherosclerotic MCA stenosis of ≥50%. DWI scans were conducted before and after the procedure, and newly detected DWI lesions were classified as SBIs. We investigated the factors associated with the development of SBIs, and for patients with SBIs, we conducted a detailed analysis based on lesion location (cortex and perforator territory vs. cortex only vs. perforator territory only).

RESULTS

Among 120 patients, 64 (53.3%) exhibited SBIs postprocedure. Factors significantly associated with SBIs included smaller stenosis diameter (odd ratio [95% confidence interval] = 0.03 [0.002-0.35], p = 0.006), longer stenosis length (1.24 [1.02-1.51], p = 0.033), higher MCA tortuosity (1.20 [1.07-1.34], p = 0.002), and diffuse involvement of MCA stenosis (3.99 [1.17-13.62], p = 0.027). Among the patients who exhibited SBIs, D-dimer (p = 0.002), C-reactive protein (p = 0.026), and hemoglobin A1c (p = 0.025) differed according to detailed mechanism.

CONCLUSIONS

Stenosis diameter, stenosis length, and MCA tortuosity were significantly associated with the development of SBIs following MCA stenting.

New Ischemic Cerebral Lesions in Postprocedural Magnetic Resonance Imaging in Carotid Artery Stenting Versus Carotid Endarterectomy: A Systematic Review and Meta-Analysis

BACKGROUND

Recent randomized controlled trials (RCTs) have demonstrated similar outcomes in terms of ischemic stroke incidence after carotid endarterectomy (CEA) or carotid artery stenting (CAS) in asymptomatic carotid disease, while CEA seems to be the first option for symptomatic carotid disease. The aim of this meta-analysis is to assess the incidence of silent cerebral microembolization detected by magnetic resonance imaging (MRI) following these procedures.

METHODS

A systematic search was conducted using PubMed, Scopus, and Cochrane databases, including comparative studies involving symptomatic or asymptomatic patients undergoing either CEA or CAS and reporting on new cerebral ischemic lesions in postoperative MRI. The primary outcome was the newly detected cerebral ischemic lesions. Pooled effect estimates for all outcomes were calculated using the random-effects model. Prespecified random effects metaregression and subgroup analysis were conducted to examine the impact of moderator variables on the presence of new cerebral ischemic lesions.

RESULTS

25 studies reporting on a total of 1827 CEA and 1500 CAS interventions fulfilled the eligibility criteria. The incidence of new cerebral ischemic lesions was significantly lower after CEA compared to CAS, regardless of the time of MRI assessment (first 24 hours; OR: 0.33, 95% CI: 0.17-0.64, P < 0.001), (the first 72 hours, OR: 0.25, 95% CI 0.18-0.36, P < 0.001), (generally within a week after the operation; OR: 0.24, 95% CI: 0.17-0.34, P < 0.001). Also, the rate of stroke (OR: 0.38, 95% CI: 0.23-0.63, P < 0.001) and the presence of contralateral new cerebral ischemic lesions (OR: 0.16, 95% CI 0.08-0.32, P < 0.001) were less frequent after CEA. Subgroup analysis based on the study design and the use of embolic protection device during CAS showed consistently lower rates of new lesions after CEA.

CONCLUSIONS

CEA demonstrates significant lower rates of new silent cerebral microembolization, as detected by MRI in postoperative period compared with CAS.

Cognitive Sequelae of Silent Ischemic Lesions Following Carotid Artery Stenting: Possible Role of Age-Related Moderation

Background: The occurrence of ischemic lesions is common in patients receiving carotid artery stenting (CAS), and most of them are clinically silent. However, few studies have directly addressed the cognitive sequelae of these procedure-related silent ischemic lesions (SILs).

Objective: In this study, we attempted to investigate the effects of SILs on cognition using a comprehensive battery of neuropsychological tests.

Method: Eighty-five patients with unilateral carotid stenosis and 25 age-matched healthy volunteers participated in this study. Brain MRI was performed within 1 week before and 1 week after CAS to monitor the occurrence of post-CAS SILs. A comprehensive battery tapping reading ability, verbal and non-verbal memory, visuospatial function, manual dexterity, executive function, and processing speed was administered 1 week before and 6 months after CAS. To control for practice effects on repeated cognitive testing, the reliable change index (RCI) derived from the healthy volunteers was used to determine the cognitive changes in patients with carotid stenosis.

Results: Among the 85 patients with carotid stenosis, 21 patients received medical treatment (MED group), and procedure-related SILs were noted in 17 patients (SIL+ group) but not observed in 47 patients (SIL– group) after undergoing CAS. Two-way (group × phase) ANOVA revealed that the volunteer group showed improved scores in most cognitive tests while only limited improvement was noted in the SIL– group. The MED and control groups tended to show improvement in the follow-up cognitive testing than the SIL+ group. However, most of the cognitive changes for each patient group did not exceed the upper or lower limits (z = ±1.0) of the RCI.

Conclusions: Although the occurrence of procedure-related SILs is common in patients undergoing CAS, their impacts on cognitive changes after CAS may be limited. The practice effect should be taken into consideration when interpreting cognitive changes following CAS.

Patient risk factors associated with embolic stroke volumes after revascularization

OBJECTIVE

Previous research has shown that subclinical, microembolic infarcts result in long-term cognitive changes. Whereas both carotid endarterectomy (CEA) and carotid artery stenting (CAS) have potential for microembolic events, CAS has been shown to have a larger volume of infarct. We have previously shown that large-volume infarction is associated with long-term memory deterioration. The purpose of this study was to identify independent risk factors that trend toward higher embolic volumes in both procedures.

METHODS

A total of 162 patients who underwent carotid revascularization procedures were prospectively recruited at two separate institutions. Preoperative and postoperative brain magnetic resonance images were compared to identify procedure-related microinfarcts. A novel semiautomated approach was used to define volumes of infarcts for each patient. Patient-related factors including comorbidities, symptomatic status, and medications were analyzed. Tweedie regression analysis was used to identify risk factors associated with procedure-related infarct volume. Variables with an unadjusted P value of ≤ .05 were included in the multivariate analysis.

RESULTS

There were 80 CAS and 82 CEA procedures performed and analyzed for the data set; 81% of CAS patients had procedure-related new infarcts with a mean volume of 388.15 ± 927.90 mm³ compared with 30% of CEA patients with a mean volume of 74.80 ± 225.52 mm³. In the CAS cohort, increasing age (adjusted coefficient ± standard error, 0.06 ± 0.02; P < .01) and obesity (1.14 ± 0.35; P < .01) were positively correlated with infarct volume, whereas antiplatelet use (-1.11 ± 0.33; P < .001) was negatively correlated with infarct volume. For the CEA group, diabetes (adjusted coefficient ± standard error, 1.69 ± 0.65; P < .01) was identified as the only risk factor positively correlated with infarct volume, whereas increasing age (-0.10 ± 0.05; P = .03) was negatively correlated with infarct volume.

CONCLUSIONS

Risk factors for CAS- or CEA-related infarct volumes are identified in our study. Although the result warrants further validation, this study showed that advanced age, obesity, and diabetes independently predicted volume of microinfarcts related to CAS and CEA. These data provide valuable information for patient factor-based risk stratification and preoperative consultation for each procedure.

Clinical and surrogate endpoints in future studies on outcome of carotid revascularization

This paper will provide a comparison of classical endpoints like stroke and mortality versus biochemical (non-STEMI) myocardial infarction and DW-MRI new brain lesions and will discuss the importance of cranial nerve lesion in CEA. An overview of possible endpoints of future randomized clinical trials will be given.

Silent brain infarcts on diffusion-weighted imaging after carotid revascularisation: A surrogate outcome measure for procedural stroke? A systematic review and meta-analysis

Aim

To investigate whether lesions on diffusion-weighted imaging (DWI+) after carotid artery stenting (CAS) or endarterectomy (CEA) might provide a surrogate outcome measure for procedural stroke.

Materials and Methods

Systematic MedLine® database search with selection of all studies published up to the end of 2016 in which DWI scans were obtained before and within seven days after CAS or CEA. The correlation between the underlying log odds of stroke and of DWI+ across all treatment groups (i.e. CAS or CEA groups) from included studies was estimated using a bivariate random effects logistic regression model. Relative risks of DWI+ and stroke in studies comparing CAS vs. CEA were estimated using fixed-effect Mantel-Haenszel models.

Results

We included data of 4871 CAS and 2099 CEA procedures (85 studies). Across all treatment groups (CAS and CEA), the log odds for DWI+ was significantly associated with the log odds for clinically manifest stroke (correlation coefficient 0.61 (95% CI 0.27 to 0.87), p = 0.0012). Across all carotid artery stenting groups, the correlation coefficient was 0.19 (p = 0.074). There were too few CEA groups to reliably estimate a correlation coefficient in this subset alone. In 19 studies comparing CAS vs. CEA, the relative risks (95% confidence intervals) of DWI+ and stroke were 3.83 (3.17-4.63, p < 0.00001) and 2.38 (1.44-3.94, p = 0.0007), respectively.

Discussion

This systematic meta-analysis demonstrates a correlation between the occurrence of silent brain infarcts on diffusion-weighted imaging and the risk of clinically manifest stroke in carotid revascularisation procedures.

Conclusion

Our findings strengthen the evidence base for the use of DWI as a surrogate outcome measure for procedural stroke in carotid revascularisation procedures. Further randomised studies comparing treatment effects on DWI lesions and clinical stroke are needed to fully establish surrogacy.

Neural network imaging to characterize brain injury in cardiac procedures: the emerging utility of connectomics

Cognitive dysfunction is a poorly understood but potentially devastating complication of cardiac surgery. Clinically meaningful assessment of cognitive changes after surgery is problematic because of the absence of a means to obtain reproducible, objective, and quantitative measures of the neural disturbances that cause altered brain function. By using both structural and functional connectivity magnetic resonance imaging data to construct a map of the inter-regional connections within the brain, connectomics has the potential to increase the specificity and sensitivity of perioperative neurological assessment, permitting rational individualized assessment and improvement of surgical techniques.

Convergence Analysis of Micro-Lesions (CAML): An approach to mapping of diffuse lesions from carotid revascularization

Carotid revascularization (endarterectomy, stenting) prevents stroke; however, procedure-related embolization is common and results in small brain lesions easily identified by diffusion weighted magnetic resonance imaging (DWI). A crucial barrier to understanding the clinical significance of these lesions has been the lack of a statistical approach to identify vulnerable brain areas. The problem is that the lesions are small, numerous, and non-overlapping. Here we address this problem with a new method, the Convergence Analysis of Micro-Lesions (CAML) technique, an extension of the Anatomic Likelihood Analysis (ALE). The method combines manual lesion tracing, constraints based on known lesion patterns, and convergence analysis to represent regions vulnerable to lesions as probabilistic brain atlases. Two studies were conducted over the course of 12 years in an active, vascular surgery clinic. An analysis in an initial group of 126 patients at 1.5 T MRI was cross-validated in a second group of 80 patients at 3T MRI. In CAML, lesions were manually defined and center points identified. Brains were aligned according to side of surgery since this factor powerfully determines lesion distribution. A convergence based analysis, was performed on each of these groups. Results indicated the most consistent region of vulnerability was in motor and premotor cortex regions. Smaller regions common to both groups included the dorsolateral prefrontal cortex and medial parietal regions. Vulnerability of motor cortex is consistent with previous work showing changes in hand dexterity associated with these procedures. The consistency of CAML also demonstrates the feasibility of this new approach to characterize small, diffuse, non-overlapping lesions in patients with multifocal pathologies.

•

Convergence Analysis of Micro-Lesions technique finds patterns in diffuse lesions.

•

Lesions from carotid revascularization affect consistent brain targets.

•

Motor cortex is the most vulnerable brain region to these lesions.

Diffusion-weighted imaging detects early brain injury after hypothermic circulatory arrest in pigs

OBJECTIVES

Cerebral injury is a complication of surgery with deep hypothermic circulatory arrest (DHCA). This study aimed to evaluate diffusion-weighted imaging (DWI) for the early detection of brain injury after DHCA in an animal model.

METHODS

Twelve healthy, adult, male miniature pigs were randomly divided into the DHCA (to receive DHCA; n = 6) and the control (sham surgery under anaesthesia; n = 6) groups. All animals received DWI, T1-weighted imaging (T1WI) and T2WI the day before surgery, 7 h postoperatively and 24 h postoperatively. Histopathological evaluation of the brain tissues was performed in the DHCA group using the Fluoro-Jade C staining to detect neuronal degeneration, the Nissl staining to show neuronal morphology and the TUNEL assay for apoptosis. The Cohen's kappa coefficient was used to compare the results of DWI with those of the histopathological evaluation.

RESULTS

All animals survived surgery. In the control group, no new focal brain lesions were detected by postoperative DWI, T1WI or T2WI. In the DHCA group, new focal brain lesions were detected as early as 7 h postoperatively by DWI but not T1WI or T2WI. All three imaging sequences revealed abnormalities 24 h after surgery. In sections from areas showing abnormalities on DWI, the Fluoro-Jade C staining detected neuronal degeneration, the Nissl staining showed morphological abnormalities and the TUNEL assay demonstrated apoptotic cells. The Cohen's kappa statistics showed agreement between DWI findings and the results of all 3 histopathological examinations (TUNEL: kappa = 0.553; Nissl: kappa = 0.652; Fluoro-Jade C: kappa = 0.778; all P < 0.001).

CONCLUSIONS

DWI is superior to T1WI or T2WI for the early detection of neurological lesions after DHCA in pigs.

Harmony as a convergence attractor that minimizes the energy expenditure and variability in physiological gait and the loss of harmony in cerebellar ataxia

BACKGROUND

The harmony of the human gait was recently found to be related to the golden ratio value (ϕ). The ratio between the duration of the stance and that of the swing phases of a gait cycle was in fact found to be close to ϕ, which implies that, because of the fractal property of autosimilarity of that number, the gait ratios stride/stance, stance/swing, swing/double support, were not significantly different from one another. We studied a group of patients with cerebellar ataxia to investigate how the differences between their gait ratios and the golden ratio are related to efficiency and stability of their gait, assessed by energy expenditure and stride-to-stride variability, respectively.

METHODS

The gait of 28 patients who were affected by degenerative cerebellar ataxia and of 28 healthy controls was studied using a stereophotogrammetric system. The above mentioned gait ratios, the energy expenditure estimated using the pelvis reconstructed method and the gait variability in terms of the stride length were computed, and their relationships were analyzed. Matching procedures have also been used to avoid multicollinearity biases.

FINDINGS

The gait ratio values of the patients were farther from the controls (and hence from ϕ), even in speed matched conditions (P=0.011, Cohen's D=0.76), but not when the variability and energy expenditure were matched between the two groups (Cohen's D=0.49). In patients with cerebellar ataxia, the farther the stance-swing ratio was from ϕ, the larger the total mechanical work (R²_adj=0.64). Further, a significant positive correlation was observed between the difference of the gait ratio from the golden ratio and the severity of the disease (R=0.421, P=0.026).

INTERPRETATION

Harmony of gait appears to be a benchmark of physiological gait leading to physiological energy recovery and gait reliability. Neurorehabilitation of patients with ataxia might benefit from the restoration of harmony of their locomotor patterns.

Volume of subclinical embolic infarct correlates to long-term cognitive changes after carotid revascularization

OBJECTIVE

Carotid intervention is safe and effective in stroke prevention in appropriately selected patients. Despite minimal neurologic complications, procedure-related subclinical microemboli are common and their cognitive effects are largely unknown. In this prospective longitudinal study, we sought to determine long-term cognitive effects of embolic infarcts.

METHODS

The study recruited 119 patients including 46% symptomatic patients who underwent carotid revascularization. Neuropsychological testing was administered preoperatively and at 1 month, 6 months, and 12 months postoperatively. Rey Auditory Verbal Learning Test (RAVLT) was the primary cognitive measure with parallel forms to avoid practice effect. All patients also received 3T brain magnetic resonance imaging with a diffusion-weighted imaging (DWI) sequence preoperatively and within 48 hours postoperatively to identify procedure-related new embolic lesions. Each DWI lesion was manually traced and input into a neuroimaging program to define volume. Embolic infarct volumes were correlated with cognitive measures. Regression models were used to identify relationships between infarct volumes and cognitive measures.

RESULTS

A total of 587 DWI lesions were identified on 3T magnetic resonance imaging in 81.7% of carotid artery stenting (CAS) and 36.4% of carotid endarterectomy patients with a total volume of 29,327 mm³. Among them, 54 DWI lesions were found in carotid endarterectomy patients and 533 in the CAS patients. Four patients had transient postoperative neurologic symptoms and one had a stroke. CAS was an independent predictor of embolic infarction (odds ratio, 6.6 [2.1-20.4]; P < .01) and infarct volume (P = .004). Diabetes and contralateral carotid severe stenosis or occlusion had a trend of positive association with infarct volume, whereas systolic blood pressure ≥140 mm Hg had a negative association (P = .1, .09, and .1, respectively). There was a trend of improved RAVLT scores overall after carotid revascularization. Significantly higher infarct volumes were observed among those with RAVLT decline. Within the CAS cohort, infarct volume was negatively correlated with short- and long-term RAVLT changes (P < .05).

CONCLUSIONS

Cognitive assessment of procedure-related subclinical microemboli is challenging. Volumes of embolic infarct correlate with long-term cognitive changes, suggesting that microembolization should be considered a surrogate measure for carotid disease management.

Gait Patterns in Patients with Hereditary Spastic Paraparesis

Background

Spastic gait is a key feature in patients with hereditary spastic paraparesis, but the gait characterization and the relationship between the gait impairment and clinical characteristics have not been investigated.

Objectives

To describe the gait patterns in hereditary spastic paraparesis and to identify subgroups of patients according to specific kinematic features of walking.

Methods

We evaluated fifty patients by computerized gait analysis and compared them to healthy participants. We computed time-distance parameters of walking and the range of angular motion at hip, knee, and ankle joints, and at the trunk and pelvis. Lower limb joint moments and muscle co-activation values were also evaluated.

Results

We identified three distinct subgroups of patients based on the range of motion values. Subgroup one was characterized by reduced hip, knee, and ankle joint range of motion. These patients were the most severely affected from a clinical standpoint, had the highest spasticity, and walked at the slowest speed. Subgroup three was characterized by an increased hip joint range of motion, but knee and ankle joint range of motion values close to control values. These patients were the most mildly affected and had the highest walking speed. Finally, subgroup two showed reduced knee and ankle joint range of motion, and hip range of motion values close to control values. Disease severity and gait speed in subgroup two were between those of subgroups one and three.

Conclusions

We identified three distinctive gait patterns in patients with hereditary spastic paraparesis that correlated robustly with clinical data. Distinguishing specific features in the gait patterns of these patients may help tailor pharmacological and rehabilitative treatments and may help evaluate therapeutic effects over time.

Microembolization is associated with transient cognitive decline in patients undergoing carotid interventions

OBJECTIVE

Carotid interventions are important in helping to reduce the risk of stroke for patients with high-grade carotid artery stenosis; however, subclinical cerebral microemboli can occur during these procedures. Associations have been found between the incidence of microemboli and postoperative decline in memory. We therefore sought to determine whether this decline persisted long-term and to assess changes in other cognitive domains.

METHODS

Patients were prospectively recruited under an Institutional Review Board-approved protocol at a single academic center. Neuropsychological testing was administered preoperatively and at 1-month and 6-month intervals postoperatively. Cognitive domains that were evaluated included verbal memory, visual memory, psychomotor speed, dexterity, and executive function. Diffusion-weighted magnetic resonance imaging sequencing was performed preoperatively and ≤48 hours postoperatively to identify procedure-related microemboli. Univariate and multivariate regression models were used to identify relationships among microembolization, demographics, and cognition.

RESULTS

Included were 80 male patients with an average age of 69 years. Forty patients underwent carotid artery stenting and 40 underwent carotid endarterectomy. Comorbidities included diabetes in 45%, coronary artery disease in 50%, and prior neurologic symptoms in 41%. New postoperative microemboli were found in 45 patients (56%). Microembolization was significantly more common in the carotid artery stenting cohort (P < .005). Univariate analysis demonstrated that patients with procedurally related embolization showed decline 1 month postoperatively in verbal memory and Trail Making A measures. Multivariate analysis demonstrated that procedurally related embolization (odds ratio [OR], 2.8; P = .04) and preoperative symptomatic stenosis (OR, 3.2; P = .026) were independent predictors of decline for the Rey Auditory Verbal Learning Test Short Delay measure at 1 month. At 6 months, no significant relationship was found between emboli and decline on Rey Auditory Verbal Learning Test Short Delay, but age (OR, 1.1, P = .005) and chronic obstructive pulmonary disease (OR, 7.1, P = .018) were significantly associated with decline at 6 months after the intervention.

CONCLUSIONS

Microembolization that is associated with carotid artery intervention predicts short-term cognitive decline. However, some of these cognitive deficits persist at 6 months after the intervention, and further investigation is warranted to determine individual patient risk factors that may affect recovery.

New cerebral lesions at magnetic resonance imaging after carotid artery stenting versus endarterectomy: an updated meta-analysis

Background

Carotid endarterectomy (CEA) or stenting (CAS) are associated with a relatively low rate of clinical events, but diffusion-weighted imaging (DWI) is increasingly being used to compare the incidence of new ischemic lesions. Therefore, we conducted an updated meta-analysis on the occurrence of post-procedural new DWI lesions after CAS versus CEA.

Methods and Results

MEDLINE, Cochrane, ISI Web of Science and SCOPUS databases were searched and 20 studies (2 randomized and 18 non-randomized) with a total of 2104 procedures (CAS = 989; CEA = 1115) were included. The incidence of new DWI cerebral lesions was significantly greater after CAS than CEA (40.3% vs 12.2%; 20 studies; 2104 patients; odds ratio [OR] 5.17; 95% confidence interval [CI], 3.31-8.06; p<0.00001). Also peri-procedural stroke (17 studies; 1833 patients; OR 2.01; 95% CI, 1.14-3.55; p=0.02) and stroke or TIA (17 studies; 1833 patients; OR 2.40; 95% CI, 1.42-4.08; p=0.001) were significantly increased after CAS. This latter clinical advantage in the CEA group over CAS was tempered when CEA procedures were performed with shunting in all instead of selective shunting or when CAS was performed with only closed cell stents instead of both closed and open cell stents, however, no significant differences between subgroups emerged.

Conclusions

CAS is associated with an increased incidence of post-procedural brain DWI lesions. This greater amount of ischemic burden may also reflect a higher rate of cerebral events after CAS. However, whether recent technical advances mainly for CAS could potentially reduce these ischemic events still remains to be evaluated.

Ischemic brain lesions after carotid artery stenting increase future cerebrovascular risk

Background

Brain lesions on diffusion-weighted imaging (DWI) are frequently found after carotid artery stenting (CAS), but their clinical relevance remains unclear.

Objectives

This study sought to investigate whether periprocedural ischemic DWI lesions after CAS or carotid endarterectomy (CEA) are associated with an increased risk of recurrent cerebrovascular events.

Methods

In the magnetic resonance imaging (MRI) substudy of ICSS (International Carotid Stenting Study), 231 patients with symptomatic carotid stenosis were randomized to undergo CAS (n = 124) or CEA (n = 107). MRIs were performed 1 to 7 days before and 1 to 3 days after treatment. The primary outcome event was stroke or transient ischemic attack in any territory occurring between the post-treatment MRI and the end of follow-up. Time to occurrence of the primary outcome event was compared between patients with (DWI+) and without (DWI–) new DWI lesions on the post-treatment scan in the CAS and CEA groups separately.

Results

Median time of follow-up was 4.1 years (interquartile range: 3.0 to 5.2). In the CAS group, recurrent stroke or transient ischemic attack occurred more often among DWI+ patients (12 of 62) than among DWI– patients (6 of 62), with a cumulative 5-year incidence of 22.8% (standard error [SE]: 7.1%) and 8.8% (SE: 3.8%), respectively (unadjusted hazard ratio: 2.85; 95% confidence interval: 1.05 to 7.72; p = 0.04). In DWI+ and DWI– patients, 8 and 2 events, respectively, occurred within 6 months after treatment. In the CEA group, there was no difference in recurrent cerebrovascular events between DWI+ and DWI– patients.

Conclusions

Ischemic brain lesions discovered on DWI after CAS seem to be a marker of increased risk for recurrent cerebrovascular events. Patients with periprocedural DWI lesions might benefit from more aggressive and prolonged antiplatelet therapy after CAS. (A Randomised Comparison of the Risks, Benefits and Cost Effectiveness of Primary Carotid Stenting With Carotid Endarterectomy: International Carotid Stenting Study; ISRCTN25337470)

The impact of carotid artery stenting on cognitive function in patients with extracranial carotid artery stenosis

BACKGROUND

The effect of carotid artery stenting (CAS) on cognitive function in patients with extracranial carotid artery stenosis is equivocal. The aim of this study was to examine the impact of CAS on various domains of cognitive function.

METHODS

We performed a meta-analysis of the studies evaluating various domains of cognitive function before and after CAS, namely, (1) global cognition using Mini-Mental State Examination (MMSE) and Rey Auditory Verbal Learning Test (RAVLT), (2) executive function using Trail Making Test (TMT) A or Color Trails Test (CTT) A and TMT B or CTT B, (3) language ability using Boston Naming Test (BNT), (4) memory, (5) attention/psychomotor speed, and (6) functional ability, using various cognitive tests. Pooled weighted mean differences (WMDs) and standardized mean differences (SMDs) with 95% confidence intervals (95% CIs) were appropriately calculated using fixed or random effects models after assessing between-study heterogeneity. Meta-regression analysis was performed with number of patients per study; mean age (years); follow-up (months); proportion of men; proportion of patients with hypertension, diabetes mellitus, hyperlipidemia, smoking, and coronary artery disease; proportion of symptomatic patients; and degree of ipsilateral and degree of contralateral carotid stenosis as covariates.

RESULTS

Sixteen studies were eligible, including a total of 626 CAS patients. A statistically significant improvement of global cognition was detected with MMSE (WMD = 0.67, 95% CI = 0.29-1.05, P < 0.001; follow-up = 5.6 months), but not with RAVLT (SMD = 0.45, 95% CI = -0.03 to 0.93, P = 0.07; follow-up = 2.4 months). Significant improvement of memory (SMD = 0.33, 95% CI = 0.11-0.55, P < 0.01; follow-up = 4.1 months) and attention/psychomotor speed (SMD = 0.21, 95% CI = 0.04-0.39, P = 0.02; follow-up = 4 months) was also detected. No statistically significant effect on executive function (TMT A/CTT A and TMT B/CTT B; SMD = 0.08, 95% CI = -0.10 to 0.26, P = 0.39; follow-up = 3.9 months and SMD = -0.02, 95% CI = -0.20 to 0.16, P = 0.82, respectively; follow-up = 3.9 months), language ability (BNT; SMD = 0.24, 95% CI = -0.05 to 0.54, P = 0.10; follow-up = 4 months), and functional ability (SMD = -0.05, 95% CI = -0.25 to 0.15, P = 0.63; follow-up = 3.8 months) was observed. No significant effects of the examined covariates were demonstrated in the meta-regression analyses.

CONCLUSIONS

CAS may be associated with improvement in global cognition, memory, and attention/psychomotor speed. There was no positive effect on executive function, language, and functional ability, but CAS was not associated with a decline in any area of cognitive function. Future studies in larger groups of patients are probably needed to fully investigate the long-term effect of CAS on cognition in patients with carotid artery stenosis.

Incidence and risk factors for diffusion-weighted imaging (+) lesions after intracranial stenting and its relationship with symptomatic ischemic complications

BACKGROUND AND PURPOSE

Little is known about high-signal lesions in magnetic resonance diffusion-weighted imaging (DWI [+]) after stenting for intracranial atherosclerotic stenosis. This study aimed to evaluate the incidence, distribution, risk factors, and clinical implications of DWI (+) after intracranial stenting.

METHODS

A total of 123 patients (male:female=88:35, mean age, 64.1 years) with symptomatic intracranial atherosclerotic stenosis (mean stenosis, 76.1±7.7%) underwent both stenting and poststenting DWI. The incidence, distribution (embolic-alone versus stenosis-associated perforator/mixed), and risk factors of DWI (+) and its relationship with symptomatic ischemic complications (SIC, including stroke or transient ischemic attack) were retrospectively evaluated.

RESULTS

Forty-three patients (35.0%) had DWI (+). Middle cerebral artery, smaller distal parent artery, and treatment-related dissection were independent risk factors for DWI (+) (P<0.05). SIC occurred in 4 patients (3.3%), all of whom had DWI (+). Of the patients with DWI (+), neither the number nor the volume of DWI (+) differed significantly between SIC and asymptomatic patients: median number/patient, 3.5 (range, 2-11) versus 2.0 (range, 1-11) and median volume/patient, 329.8 mm(3) (range, 76-883.5 mm(3)) versus 119.5 mm(3) (range, 32.5-873.0 mm(3)). However, SIC occurred more frequently in the stenosis-associated perforator/mixed type (3/11, 27.3%) than in the embolic-alone type (1/32, 3.1%; P<0.05).

CONCLUSIONS

The incidence of DWI (+) after intracranial stenting for intracranial atherosclerotic stenosis was 35.0%. Middle cerebral artery, smaller distal parent artery, and treatment-related dissection were independent risk factors for DWI (+). SIC occurred more frequently in the stenosis-associated perforator/mixed type than in the embolic-alone type.

Neurocognitive functioning after carotid revascularization: a systematic review

BACKGROUND

The objective of this study was to review the recent literature regarding the neurocognitive consequences of carotid endarterectomy (CEA) and carotid stenting (CAS).

METHODS AND RESULTS

A PubMed and Web of Science search was conducted using the key words 'carotid' in combination with 'cognitive', 'cognition', 'neurocognition', 'neurocognitive', 'neuropsychology', and 'neuropsychological'. Bibliographies of relevant articles were cross-referenced. We included 37 studies published since 2007 of which 18 examined CEA, 12 CAS, and 7 compared CEA to CAS. There is a wide variability in the reported neurocognitive outcome following CEA and CAS. Nonetheless, none of the included studies unveiled significant differences between CEA and CAS on postoperative neurocognitive functioning. Postoperative changes observed for CEA and CAS separately seem limited to a small percentage (around 10-15%) of patients and can either present as an improvement or impairment.

KEY MESSAGES

The available data seem to suggest that no obvious cognitive differences between CAS and CEA can be observed after intervention. Both improvement and deterioration in cognitive functioning can be observed following CAS or CEA. Methodological differences such as patient heterogeneity, implementation and type of control groups, type of psychometric tests used, statistical analyses, or timing of the assessments play an important role in explaining the sometimes divergent results of the included studies. Large-scale and methodologically solid studies comparing CEA and CAS on neurocognitive outcome remain warranted. Future studies should implement adequate control groups to correct for practice effects in the target groups.

Predictors of acute and persisting ischemic brain lesions in patients randomized to carotid stenting or endarterectomy

BACKGROUND AND PURPOSE

We investigated predictors for acute and persisting periprocedural ischemic brain lesions among patients with symptomatic carotid stenosis randomized to stenting or endarterectomy in the International Carotid Stenting Study.

METHODS

We assessed acute lesions on diffusion-weighted imaging 1 to 3 days after treatment in 124 stenting and 107 endarterectomy patients and lesions persisting on fluid-attenuated inversion recovery after 1 month in 86 and 75 patients, respectively.

RESULTS

Stenting patients had more acute (relative risk, 8.8; 95% confidence interval, 4.4-17.5; P<0.001) and persisting lesions (relative risk, 4.2; 95% confidence interval, 1.6-11.1; P=0.005) than endarterectomy patients. Acute lesion count was associated with age (by trend), male sex, and stroke as the qualifying event in stenting; high systolic blood pressure in endarterectomy; and white matter disease in both groups. The rate of conversion from acute to persisting lesions was lower in the stenting group (relative risk, 0.4; 95% confidence interval, 0.2-0.8; P=0.007), and was only predicted by acute lesion volume.

CONCLUSIONS

Stenting caused more acute and persisting ischemic brain lesions than endarterectomy. However, the rate of conversion from acute to persisting lesions was lower in the stenting group, most likely attributable to lower acute lesion volumes. Clinical Trial Registration -URL: www.isrctn.org. Unique identifier: ISRCTN25337470.

Stratification of intraoperative ischemic impact by somatosensory evoked potential monitoring, diffusion-weighted imaging and magnetic resonance angiography in carotid endarterectomy with routine shunt use

BACKGROUND

Routine shunting to minimize ischemia during carotid endarterectomy (CEA) is controversial. The aim of this study was to stratify the ischemic parameters associated with CEA and evaluate the effect of routine shunting in attempting to mitigate those ischemia.

METHOD

Data from 248 CEAs with routine shunting were retrospectively evaluated. Our assessment included somatosensory evoked potential (SSEP) amplitude reduction more than 50 % and longer than 5 min (SSEP<50%, >5 min), new postoperative diffusion-weighted imaging lesions (new DWI lesions), and severe stenosis as indicated by reduced ipsilateral middle cerebral artery (MCA) signal on preoperative magnetic resonance angiography (MRA asymmetry), as surrogates of hypoperfusion, microembli, and hemodynamic impairment, respectively.

RESULTS

SSEP<50%, >5 min occurred in 15 % of CEAs during cross-clamping, and shunting reversed the SSEP changes. New DWI lesions were observed in 4.1 %. Pre-clamping the common and external carotid artery during dissection (pre-clamp method) decreased the rate of new DWI lesions compared to without pre-clamping (3.5 % vs. 7.5 %, P = 0.22). Occlusion time was significantly longer in the pre-clamp method than without pre-clamping (P < 0.0001). However, the incidence of SSEP<50%, >5 min was not increased with the pre-clamp method (p = 1.0) when using information regarding SSEP and collaterals to modify the speed of shunt manipulation. MRA asymmetry was identified in 39 CEAs (15.8 %) with correction of asymmetry postoperatively. MRA asymmetry correlated with symptomatic hyperperfusion (P = 0.0034). Only three CEAs had symptomatic hyperperfusion (1.2 %) with minimal symptoms. Ten CEAs sustained transient ischemia, symptomatic hyperperfusion, or 30-day-stroke (composite postoperative ischemic symptoms). Logistic regression analysis confirmed that SSEP<50%, >5 min (p = 0.009), new DWI lesions (p = 0.004) and MRA asymmetry (p = 0.042) were independent predictors of　composite postoperative ischemic symptoms.

CONCLUSIONS

SSEP<50%, >5 min, new DWI lesions, and MRA asymmetry were able to stratify the ischemic impacts in CEA. Meticulous routine shunting could mitigate those appropriately.

[Carotid artery stenting technique]

Over the past 25 years carotid artery stenting (CAS) has emerged as an alternative to carotid endarterectomy (CEA). Most of all younger patients and symptomatic patients with contralateral carotid artery occlusion particularly benefit from CAS. To achieve an optimal result with CAS, patient selection and even more important, knowledge and experience of the interventionist is crucial. The periprocedural complication rate of CAS in large experienced centers is lower (2-3%) than those in randomized trials. Several different devices are now available which allow the procedure to be tailored according to patient anatomy and lesion complexity. Complications like hyperperfusion syndrome and intracerebral bleeding, rupture of side branches of the external or internal carotid artery as well as problems caused by slow flow can be widely avoided by adequate experience.

Subclinical ischemia verified by somatosensory evoked potential amplitude reduction during carotid endarterectomy: negative effects on cognitive performance

OBJECT

Although the mechanisms underlying neurocognitive changes after carotid endarterectomy (CEA) are poorly understood, intraoperative ischemia and postoperative hemodynamic changes may play a role.

METHODS

Data from 81 patients who underwent unilateral CEA with routine shunt use for carotid artery stenosis were retrospectively evaluated. These patients underwent neuropsychological examinations (NPEs), including assessment by the Wechsler Adult Intelligence Scale-Third Edition and the Wechsler Memory Scale-Revised before and 6 months after CEA. results of NPEs were converted into z scores, from which pre- and postoperative cognitive composite scores (CSpre and CSpost) were obtained. The association between the change of CS between pre- and postoperative NPEs (that is, CSpost - CSpre [CSpost - pre]) and various variables was assessed. These latter variables included ischemic or hemodynamic parameters such as 1) intraoperative hypoperfusion detected by somatosensory evoked potential (SSEP) change-that is, an SSEP amplitude reduction more than 50% and longer than 5 minutes (SSEP< 50%, > 5 min); 2) new lesions on postoperative diffusion-weighted imaging studies; and 3) preexisting hemodynamic impairment. Paired t-tests of the NPE scores were performed to determine the net effect of these factors on neurocognitive function at 6 months.

RESULTS

A significant CSpost - pre decrease was observed in patients with SSEP< 50%, > 5 min when compared with those without SSEP< 50%, > 5 min (-0.225 vs 0.018; p = 0.012). Multiple regression analysis demonstrated that SSEP< 50%, > 5 min independently and negatively correlated with CSpost - pre (p = 0.0020). In the group-rate analysis, postoperative NPE scores were significantly improved relative to preoperative scores.

CONCLUSIONS

Hypoperfusion during cross-clamping, as verified by SSEP amplitude reduction, plays a significant role in the subtle decline in cognition following CEA. However, this detrimental effect was small, and various confounding factors were present. Based on these observations and the group-rate analysis, the authors conclude that successful unilateral CEA with routine shunt use does not adversely affect postoperative cognitive function.

Characteristics of Ischemic Brain Lesions After Stenting or Endarterectomy for Symptomatic Carotid Artery Stenosis

Background and Purpose—

In a substudy of the International Carotid Stenting Study (ICSS), more patients had new ischemic brain lesions on diffusion-weighted magnetic resonance imaging (MRI) after stenting (CAS) than after endarterectomy (CEA). In the present analysis, we compared characteristics of diffusion-weighted MRI lesions.

Methods—

Number, individual and total volumes, and location of new diffusion-weighted MRI lesions were compared in patients with symptomatic carotid stenosis randomized to CAS (n=124) or CEA (n=107) in the ICSS-MRI substudy.

Results—

CAS patients had higher lesion numbers than CEA patients (1 lesion, 15% vs 8%; 2–5 lesions, 19% vs 5%; >5 lesions, 16% vs 4%). The overall risk ratio for the expected lesion count with CAS versus CEA was 8.8 (95% confidence interval, 4.4–17.5; P <0.0001) and significantly increased among patients with lower blood pressure at randomization, diabetes mellitus, stroke as the qualifying event, left-side stenosis, and if patients were treated at centers routinely using filter-type protection devices during CAS. Individual lesions were smaller in the CAS group than in the CEA group ( P <0.0001). Total lesion volume per patient did not differ significantly. Lesions in the CAS group were more likely to occur in cortical areas and subjacent white matter supplied by leptomeningeal arteries than lesions in the CEA group (odds ratio, 4.2; 95% confidence interval, 1.7–10.2; P =0.002).

Conclusions—

Compared with patients undergoing CEA, patients treated with CAS had higher numbers of periprocedural ischemic brain lesions, and lesions were smaller and more likely to occur in cortical areas and subjacent white matter. These findings may reflect differences in underlying mechanisms of cerebral ischemia.

Clinical Trial Registration—

URL: http://www.isrctn.org . Unique identifier: ISRCTN25337470.

A diffusion-weighted magnetic resonance imaging-based study of transcervical carotid stenting with flow reversal versus transfemoral filter protection

BACKGROUND

Transfemoral carotid artery stenting (CAS) has been associated with a high incidence of embolic phenomena and silent brain infarction. The goal of this study was to compare the incidence of new ischemic cerebral lesions on diffusion-perfusion magnetic resonance imaging (MRI) sequences after transcervical CAS performed with carotid flow reversal vs stenting via transfemoral approach with distal filter protection.

METHODS

During a 26-month period, 64 consecutive patients diagnosed with significant carotid stenosis by ultrasound imaging were assigned to transcervical CAS with carotid flow reversal or a transfemoral approach with a distal filter. The Rankin stroke scale was administered by an independent neurologist, and diffusion-weighted MRI (DW-MRI) studies were performed ≤24 hours before and ≤24 to 48 hours after the procedure. DW-MRI studies were compared by two neuroradiologists not involved in the study and blinded for time, clinical status, and treatment option. Hyperintense DW-MRI signals found after the procedure were interpreted as postoperative ischemic infarcts. All patients were assessed at 1, 6, and 12 months after the intervention.

RESULTS

The distribution of demographic and pathologic variables was similar in both groups. All procedures were technically successful, with a mean carotid flow reversal time of 22 minutes. Twenty-one (70%) and 23 patients (69.69%) were symptomatic in the transcervical and transfemoral groups, respectively (P=.869). After intervention, new postprocedural DW-MRI ischemic infarcts were found in four transcervical (12.9%) and in 11 transfemoral (33.3%) patients (P=.03), without new neurologic symptoms. No major adverse events occurred at 30 days after the intervention. All patients remained neurologically intact, without an increase in stroke scale scoring. All stents remained patent, and all patients remained stroke-free during follow-up. In multivariate analysis, age (relative risk [RR], 1.022; P<.001), symptomatic status (RR, 4.109; P<.001), and open-cell vs closed-cell stent design (RR, 2.01; P<.001) were associated with a higher risk of embolization in the transfemoral group but not in the transcervical group.

CONCLUSIONS

These data suggest that transcervical carotid stenting with carotid flow reversal carries a significantly lower incidence of new ischemic brain infarcts than that resulting from transfemoral CAS with a distal filter. The transcervical approach with carotid flow reversal may improve the safety of CAS and has the potential to improve results in especially vulnerable patients such as the elderly and symptomatic.

Prospective neurocognitive evaluation of patients undergoing carotid interventions

OBJECTIVE

Distal cerebral embolization is a known complication of carotid interventions. We prospectively investigated whether subclinical microembolization seen on postoperative magnetic resonance imaging (MRI) leads to cognitive deficits in patients undergoing carotid revascularization procedures.

METHODS

Patients undergoing carotid interventions and eligible for MRI scanning were recruited. Among 247 patients who received preoperative and postoperative MRI evaluations, 51 also completed neuropsychologic testing before and at 1 month after their procedure. Cognitive evaluation included the Rey Auditory Verbal Learning Test (RAVLT) for memory evaluation and the Mini-Mental State Examination (MMSE) for general cognitive impairment screening.

RESULTS

The 51 patients (all men), comprising 16 with carotid artery stenting (CAS) and 35 with carotid endarterectomy (CEA), were a mean age of 71 years (range, 54-89 years). Among them, 27 patients (53%) were symptomatic preoperatively, including 11 who had prior stroke and 16 who had prior preoperative transient ischemic attack symptoms. Most patients had significant medical comorbidities, including hypertension (96%), diabetes (31.3%), coronary artery disease (47%), and chronic obstructive pulmonary disease (15.7%). Two patients (4%) had prior ipsilateral CEA and eight had contralateral carotid occlusion (15.7%). Memory decline evident on RAVLT was identified in eight CAS patients and 13 CEA patients. Eleven patients had evidence of procedure-related microemboli. Although there was no significant difference in baseline cognitive function or memory change between the CEA and CAS cohorts, the CAS cohort had a significantly higher incidence of microembolic lesions. Multivariate regression analysis showed that procedure-related microembolization was associated with memory decline (P = .016) as evident by change in RAVLT. A history of neurologic symptoms was significantly associated with poor baseline cognitive function (MMSE; P = .03) and overall cognitive deterioration (change in MMSE; P = .026), as determined by Wilcoxon rank sum test and linear regression analysis, respectively.

CONCLUSIONS

Although CEA and CAS are effective in stroke prevention, with minimal neurologic complication, neurocognitive effects remain uncertain. Procedure-associated microembolization and pre-existing neurologic symptoms are associated with poor baseline cognitive function and memory decline after the procedures. Further comprehensive cognitive evaluation to determine the benefit of carotid interventions is warranted.

Reperfusion does not improve impaired rapid-onset cortical plasticity in patients with severe stenosis of the internal carotid artery

Background

Severe stenosis of the internal carotid artery (ICA) has been associated with impaired cognition in patients, but its effect on rapid-onset cortical plasticity is not known. Carotid endarterectomy (CEA) in patients with severe ICA stenosis reduces stroke risk, but the impact on cognition or physiology of the respective hemisphere remains controversial.

Methods/Results

16 patients with severe stenosis of the ICA and 16 age and sex matched controls were included. Rapid-onset cortical plasticity was assessed using the paired-associative stimulation (PAS) protocol. PAS models long-term synaptic potentiation in human motor cortex, combining repetitive stimulation of the peripheral ulnar nerve with transcranial magnetic stimulation of the contralateral motor cortex. Cognitive status was assessed with a neuropsychological test battery. In patients, verbal learning and rapid-onset cortical plasticity were significantly reduced as compared to controls. Identical follow-up tests in 9 of the 16 patients six months after CEA revealed no improvement of cognitive parameters or cortical plasticity.

Conclusions

Decreased rapid-onset cortical plasticity in patients with severe stenosis of the ICA was not improved by reperfusion. Thus, other strategies known to increase plasticity should be tested for their potential to improve cortical plasticity and subsequently cognition in these patients.

Age-dependent effects of carotid endarterectomy or stenting on cognitive performance

Although evidence is accumulating that age modifies the risk of carotid angioplasty and stenting (CAS) versus endarterectomy (CEA) for patients with significant carotid stenosis, the impact of age on cognition after either CEA or CAS remains unclear. In this study, we analyzed the effects of age on cognitive performance after either CEA or CAS using a comprehensive neuropsychological test battery with parallel test forms and a control group to exclude a learning effect. The neuropsychological outcomes after revascularization were determined in 19 CAS and 27 CEA patients with severe carotid stenosis. The patients were subdivided according to their median age (<68 years and ≥68 years); 27 healthy subjects served as a control group. In all patients clinical examinations, MRI scans and a neuropsychological test battery that assessed four major cognitive domains were performed immediately before, within 72 h, and 3 months after CEA or CAS. While patients <68 years of age showed no significant cognitive alteration after either CEA or CAS, a significant cognitive decline was observed in patients ≥68 years in both treatment groups (p = 0.001). Notably, this cognitive deterioration persisted in patients after CEA, whereas it was only transient in patients treated with CAS. These results demonstrate an age-dependent effect of CEA and CAS on cognitive functions. In contrast to the recently observed increased clinical complication rates in older subjects after CAS compared with CEA, CEA appears to be associated with a greater, persistent decline in cognitive performance than CAS in this subgroup of patients.

Safety of embolic protection device-assisted and unprotected intravascular ultrasound in evaluating carotid artery atherosclerotic lesions

BACKGROUND

Significant atherosclerotic stenosis of internal carotid artery (ICA) origin is common (5-10% at ≥ 60 years). Intravascular ultrasound (IVUS) enables high-resolution (120 µm) plaque imaging, and IVUS-elucidated features of the coronary plaque were recently shown to be associated with its symptomatic rupture/thrombosis risk. Safety of the significant carotid plaque IVUS imaging in a large unselected population is unknown.

MATERIAL/METHODS

We prospectively evaluated the safety of embolic protection device (EPD)-assisted vs. unprotected ICA-IVUS in a series of consecutive subjects with ≥ 50% ICA stenosis referred for carotid artery stenting (CAS), including 104 asymptomatic (aS) and 187 symptomatic (S) subjects (age 47-83 y, 187 men). EPD use was optional for IVUS, but mandatory for CAS.

RESULTS

Evaluation was performed of 107 ICAs (36.8%) without EPD and 184 with EPD. Lesions imaged under EPD were overall more severe (peak-systolic velocity 2.97 ± 0.08 vs. 2.20 ± 0.08 m/s, end-diastolic velocity 1.0 ± 0.04 vs. 0.7 ± 0.03 m/s, stenosis severity of 85.7 ± 0.5% vs. 77.7 ± 0.6% by catheter angiography; mean ± SEM; p<0.01 for all comparisons) and more frequently S (50.0% vs. 34.6%, p=0.01). No ICA perforation or dissection, and no major stroke or death occurred. There was no IVUS-triggered cerebral embolization. In the procedures of (i) unprotected IVUS and no CAS, (ii) unprotected IVUS followed by CAS (filters - 39, flow reversal/blockade - 3), (iii) EPD-protected (filters - 135, flow reversal/blockade - 48) IVUS + CAS, TIA occurred in 1.5% vs. 4.8% vs. 2.7%, respectively, and minor stroke in 0% vs. 2.4% vs. 2.1%, respectively. EPD intolerance (on-filter ICA spasm or flow reversal/blockade intolerance) occurred in 9/225 (4.0%). IVUS increased the procedure duration by 7.27 ± 0.19 min.

CONCLUSIONS

Carotid IVUS is safe and, for the less severe lesions in particular, it may not require mandatory EPD use. High-risk lesions can be safely evaluated with IVUS under flow reversal/blockade.

The PROFI study (Prevention of Cerebral Embolization by Proximal Balloon Occlusion Compared to Filter Protection During Carotid Artery Stenting): a prospective randomized trial

OBJECTIVES

The objective of this study was to compare the cerebral embolic load of filter-protected versus proximal balloon-protected carotid artery stenting (CAS).

BACKGROUND

Randomized trials comparing filter-protected CAS with carotid endarterectomy revealed a higher periprocedural stroke rate after CAS. Proximal balloon occlusion may be more effective in preventing cerebral embolization during CAS than filters.

METHODS

Patients undergoing CAS with cerebral embolic protection for internal carotid artery stenosis were randomly assigned to proximal balloon occlusion or filter protection. The primary endpoint was the incidence of new cerebral ischemic lesions assessed by diffusion-weighted magnetic resonance imaging. Secondary endpoints were the number and volume of new ischemic lesions and major adverse cardiovascular and cerebral events (MACCE).

RESULTS

Sixty-two consecutive patients (mean age: 71.7 years, 76.4% male) were randomized. Compared with filter protection (n = 31), proximal balloon occlusion (n = 31) resulted in a significant reduction in the incidence of new cerebral ischemic lesions (45.2% vs. 87.1%, p = 0.001). The number (median [range]: 2 [0 to 13] vs. 0 [0 to 4], p = 0.0001) and the volume (0.47 [0 to 2.4] cm(3) vs. 0 [0 to 0.84] cm(3), p = 0.0001) of new cerebral ischemic lesions were significantly reduced by proximal balloon occlusion. Lesions in the contralateral hemisphere were found in 29.0% and 6.5% of patients (filter vs. balloon occlusion, respectively, p = 0.047). The 30-day MACCE rate was 3.2% and 0% for filter versus balloon occlusion, respectively (p = NS).

CONCLUSIONS

In this randomized trial of patients undergoing CAS, proximal balloon occlusion as compared with filter protection significantly reduced the embolic load to the brain.

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

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