Randomized clinical trial comparing neurological outcomes after carotid endarterectomy or 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.

Transcarotid arterial revascularization is feasible and safe with concomitant inferior vena cava occlusion

Transcarotid artery revascularization (TCAR) has risen as a promising minimally invasive intervention for high-risk patients with favorable anatomy. TCAR's noninferiority to carotid endarterectomy regarding stroke is reliant on its flow reversal technology and lack of aortic arch manipulation. We present the case of a 79-year-old man with a chronically occluded inferior vena cava who safely underwent staged bilateral TCAR for bilateral high-grade carotid artery stenosis. Although chronic inferior vena cava occlusion alters flow mechanics, we suspect that any pressure gradient facilitating retrograde flow from the carotid artery to the femoral vein provides neuroprotective benefits.

Comparison of Perioperative Safety of Carotid Artery Stenting and Endarterectomy in the Treatment of Carotid Artery Stenosis: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Current management guidelines for the treatment of carotid stenosis are controversial. We performed this meta-analysis to evaluate the perioperative safety of carotid artery stenting (CAS) and endarterectomy.

METHODS

We systematically searched EMBASE, PubMed, Web of Science, and the Cochrane Library from inception to November 10, 2022, for randomized controlled trials that compared CAS with carotid endarterectomy (CEA) among patients with carotid stenosis. The analyzed outcomes mainly included stroke, death, myocardial infarction (MI), cranial nerve palsy, the cumulative incidence of mortality, stroke, or MI and the cumulative incidence of death or stroke in the perioperative periods. The risk ratio (RR) and 95% confidence interval (95% CI) were calculated and pooled. Subgroup analyses were based on whether patients were symptomatic or asymptomatic. We assessed the certainty of evidence using the Grading of Recommendations Assessment, Development and Evaluation framework.

RESULTS

Seventeen randomized controlled trials with 12,277 participants (6514 and 5763 in the CAS and CEA groups, respectively) were included. Pooled analysis demonstrated that compared with CEA, CAS was associated with decreased risks of perioperative MI (RR = 0.47, 95% CI = 0.29∼0.77) and perioperative cranial nerve palsy (RR = 0.02, 95% CI = 0.01∼0.06) but higher risks of perioperative stroke (RR = 1.48, 95% CI = 1.18∼1.87) and cumulative incidence of death or stroke (RR = 1.52, 95% CI = 1.20∼1.93).

CONCLUSIONS

The perioperative safety was equivalent between CAS and CEA. However, CEA may be preferred when considering both procedural safety and long-term efficacy in preventing recurrent stroke.

The Height and Mobility of Protruding Plaque After Carotid Artery Stenting Are Associated with Postoperative Ischemic Lesions

BACKGROUND

Tissue protrusion (TP) is a possible cause of cerebral infarction after carotid artery stenting (CAS). Using optical frequency domain imaging (OFDI) and angioscopy, we investigated the relationship between the morphological features of TP and postoperative new ischemic lesions on magnetic resonance imaging (MRI)-diffusion weighted imaging (DWI) after CAS.

METHODS

Fifty patients who underwent CAS and subsequent poststenting intravascular evaluation using both OFDI and angioscopy were included. CAS was performed for proximal protection via the femoral artery approach, and intravascular evaluation with OFDI and angioscopy were performed after stent placement. We compared the background and poststenting intravascular findings between patients with and without postoperative new ischemic lesions on MRI-DWI.

RESULTS

TP was observed in 42 patients (84%), and postoperative new ischemic lesions on MRI-DWI were observed in 32 patients (64%). The frequency of TP did not differ between the 2 groups, but the height of TP was higher in the DWI-positive group (0.62 mm vs. 0.29 mm, P = 0.0028), and mobile TP was observed only in the DWI-positive group. The height of TP (P = 0.023) was an independent predictor of new periprocedural ischemic brain lesions after CAS, and its cut-off value for mobility was 0.55 mm on the receiver operating characteristic curve (area under the curve, 0.93).

CONCLUSIONS

The height of TP on OFDI and mobile-TP on angioscopy after CAS were associated with postoperative new ischemic lesions on MRI-DWI. The intravascular evaluation using OFDI and angioscopy could be helpful for a detailed evaluation of TP.

Periprocedural P2Y12 inhibitors improve perioperative outcomes after carotid stenting by primarily decreasing strokes

OBJECTIVE

The continuation of antiplatelet agents in the periprocedural period around carotid stenting (CAS) procedures is felt to be mandatory to minimize the risk of periprocedural stroke. However, the optimal antiplatelet regimen is unclear, with some advocating dual antiplatelet therapy, and others supporting the use of P2Y₁₂ inhibitors alone. The objective of this study was to evaluate the periprocedural effect of P2Y₁₂ inhibitors for CAS.

METHODS

The Vascular Quality Initiative was used from years 2007 to 2020. All transcarotid artery revascularization (TCAR) and transfemoral carotid artery stenting (TF-CAS) procedures were included. Patients were stratified based on perioperative use of P2Y₁₂ inhibitors as well as symptomatic status. Primary end points were perioperative neurological events (strokes and transient ischemic attacks). Secondary end points were mortality and myocardial infarction.

RESULTS

A total of 31,036 CAS procedures were included for analysis, with 49.8% TCAR and 50.2% TF-CAS cases; 63.8% of patients were male and 82.3% of patients were on a P2Y₁₂ inhibitor. P2Y₁₂ inhibitor use was more common in males, asymptomatic patients, those older than 70 years, and concurrent statin use. P2Y₁₂ inhibitors were more likely to be used in TCAR cases than in TF-CAS cases (87.3% vs 76.8%; P < .001). The rate of periprocedural neurological events in the whole cohort was 2.6%. Patients on P2Y₁₂ inhibitors were significantly less likely to experience a periprocedural neurological event (2.3% vs 3.9%; P < .001) and mortality (0.6% vs 2.1%; P < .001) than those who were not on a P2Y₁₂ inhibitor. There was no effect on the rates of myocardial infarction. On multivariate analysis, both symptomatic and asymptomatic patients on P2Y₁₂ inhibitors were significantly less likely to develop perioperative neurological events. Additionally, the use of P2Y₁₂ inhibitors demonstrated an independent significant effect in reducing of the rate of perioperative stroke (odds ratio, 0.29; 95% confidence interval, 0.25-0.33). Finally, additional analysis of the types of P2Y₁₂ inhibitors used revealed that all seemed to be equally effective in decreasing the periprocedural neurological event rate.

CONCLUSIONS

The use of perioperative P2Y₁₂ inhibitors seems to markedly decrease the perioperative neurological event rate with TCAR and TF-CAS in both symptomatic and asymptomatic patients and should be strongly considered. Patients with contraindications to P2Y₁₂ inhibitors may not be appropriate candidates for any CAS procedure. Additionally, alternative types of P2Y₁₂ inhibitors seem to be equally effective as clopidogrel. Finally, an analysis of the Vascular Quality Initiative demonstrates that, even for TCAR cases, only 87.3% of patients seem to be on P2Y₁₂ inhibitors in the periprocedural period, leaving room for significant improvement.

ANALYSIS OF SPIN IN VASCULAR SURGERY RANDOMIZED CONTROLLED TRIALS WITH NONSIGNIFICANT OUTCOMES

OBJECTIVES

Spin is the manipulation of language that distorts the interpretation of objective findings. The purpose of this study is to describe the characteristics of spin found in statistically nonsignificant randomized controlled trials (RCT) comparing carotid endarterectomy (CEA) to carotid artery stenting (CAS) for carotid stenosis (CS), and endovascular repair (EVAR) to open repair (OR) for abdominal aortic aneurysms (AAA).

METHODS

A search of MEDLINE, EMBASE, and the Cochrane Controlled Register of Trials was performed in June 2020 for studies published describing AAA or CS. All phase three RCTs with nonsignificant primary outcomes comparing OR to EVAR or CEA to CAS were included. Studies were appraised for the characteristics and severity of spin using a validated tool. Binary logistic regression was performed to assess the association of spin grade to (1) funding source (commercial vs non-commercial) and (2) the publishing journal's impact factor.

RESULTS

Thirty-one of 355 articles captured were included for analysis. Spin was identified in nine abstracts (9/18) and 13 main texts (13/18) of AAA articles and seven abstracts (7/13) and ten main texts (10/13) of CS articles. For both AAA and CS articles, spin was most commonly found in the manuscript discussion section, with the most commonly employed strategy being the interpretation of statistically nonsignificant primary results to show treatment equivalence or rule out adverse treatment effects. Increasing journal impact factor was associated with a statistically significant lower likelihood of spin in the study title or abstract conclusion (βOR = 0.96, 95% CI: 0.94 - 0.98, p < 0.01) while no significant association could be found with funding source (βOR = 1.33, 95% CI: 0.30-5.92, p = 0.71).

CONCLUSIONS

A large proportion of statistically nonsignificant RCTs contain interpretations that are inconsistent with their results. These findings should prompt authors and readers to appraise study findings independently and to limit the use of spin in study interpretations.

Actual incidence of cerebral infarction after thoracic endovascular aortic repair: a magnetic resonance imaging study

 

OBJECTIVES

The actual incidence of cerebral infarction (CI), including asymptomatic infarction, owing to thoracic endovascular aortic repair (TEVAR) has not been reported in detail. This study was performed to investigate the incidence of post-TEVAR CI by using diffusion-weighted magnetic resonance imaging (DW-MRI) and to determine the risk factors for both symptomatic and asymptomatic CI.

METHODS

We examined 64 patients undergoing TEVAR at our institute between April 2017 and November 2020. Aortic atheroma was graded from 1 to 5 by preoperative computed tomography. Cerebral DW-MRIs were conducted 2 days after the procedure to diagnose postoperative CI.

RESULTS

A total of 44 new foci were detected by post-interventional cerebral DW-MRI in 22 patients (34.4%). Only one patient developed a symptomatic stroke (1.6%), and TEVAR was successfully completed in all cases. Debranching of the aortic arch and left subclavian artery occlusion with a vascular plug was performed in 19 (29.7%) and 12 (18.8%) patients, respectively. The number of patients with proximal landing zones 0–2 was significantly higher in the CI group than in the non-CI group (68.2% vs 11.9%; P < 0.001). The following risk factors were identified for asymptomatic CI: aortic arch debranching (P < 0.001), left subclavian artery occlusion (P = 0.001) and grade 4/5 aortic arch atheroma (P = 0.048).

CONCLUSIONS

Over one-third of the patients examined by cerebral DW-MRI after TEVAR were diagnosed with CI. High-grade atheroma and TEVAR landing in zone 0–2 were found to be positively associated with asymptomatic CI.

Clinical trial registration

02-014.

European Stroke Organisation guideline on endarterectomy and stenting for carotid artery stenosis

Atherosclerotic stenosis of the internal carotid artery is an important cause of stroke. The aim of this guideline is to analyse the evidence pertaining to medical, surgical and endovascular treatment of patients with carotid stenosis. These guidelines were developed based on the ESO standard operating procedure and followed the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach. The working group identified relevant questions, performed systematic reviews and meta-analyses of the literature, assessed the quality of the available evidence, and wrote recommendations. Based on moderate quality evidence, we recommend carotid endarterectomy (CEA) in patients with ≥60-99% asymptomatic carotid stenosis considered to be at increased risk of stroke on best medical treatment (BMT) alone. We also recommend CEA for patients with ≥70-99% symptomatic stenosis, and we suggest CEA for patients with 50-69% symptomatic stenosis. Based on high quality evidence, we recommend CEA should be performed early, ideally within two weeks of the last retinal or cerebral ischaemic event in patients with ≥50-99% symptomatic stenosis. Based on low quality evidence, carotid artery stenting (CAS) may be considered in patients < 70 years old with symptomatic ≥50-99% carotid stenosis. Several randomised trials supporting these recommendations were started decades ago, and BMT, CEA and CAS have evolved since. The results of another large trial comparing outcomes after CAS versus CEA in patients with asymptomatic stenosis are anticipated in the near future. Further trials are needed to reassess the benefits of carotid revascularisation in combination with modern BMT in subgroups of patients with carotid stenosis.

Outcome differences between carotid artery stenting (CAS) and carotid endarterectomy (CEA) in postoperative ventricular arrhythmia, neurological complications, and in-hospital mortality

Objective: We study whether the carotid artery stenting (CAS) and carotid endarterectomy (CEA) differ from each other in postoperative ventricular arrhythmia, along with neurological complications (perioperative stroke and transient ischemic attack), in-hospital mortality, and estimated medical cost. Methods: This study used data of patients with carotid artery stenosis from the National Inpatient Sample (NIS) database (2011-2014) from the United States of America. Based on the procedure that patients received, individuals were categorized into groups of CAS and CEA. Multilevel analyses were conducted to examine the difference in the following outcomes: postoperative ventricular arrhythmia, neurological complications, in-hospital mortality, and medical costs between CAS and CEA. The patient age, gender, race, Charlson Comorbidity Index, primary payer, emergency department service record, bed size of hospital, region of the hospital, and location of the hospital were adjusted in each model. In addition, preexisting cardiovascular diseases (CVDs) were adjusted for when predicting postoperative ventricular arrhythmia; postoperative CVDs were adjusted for in the model of in-hospital mortality. Results: A total of 127,321 carotid artery stenosis hospitalizations were included in our analyses (n = 17,074 in CAS, n = 110,247 in CEA). Multivariate logistic regressions showed that compared with patients underwent CAS, those with CEA had a lower odds of postoperative ventricular arrhythmia (odds ratio [OR] = 0.81, 95% confidence interval [CI]: [0.66-0.98]), less neurological complications (OR = 0.55, 95% CI: [0.51-0.59] in general; OR = 0.63, 95% CI: [0.57-0.69] in ischemic stroke; OR = 0.26, 95% CI: [0.20-0.32] in hemorrhagic stroke; and OR = 0.58, 95% CI: [0.47-0.71] in transient ischemic attack), and in-hospital mortality (OR = 0.52, 95% CI: [0.42-0.64]). Generalized linear model indicated patients undergoing CEA had lower medical cost (β = -4329.99, 95% CI: [-4552.61, -4107.38]) than patients undergoing CAS. Conclusions: In short-term outcomes, CEA was associated with a lower risk of postoperative ventricular arrhythmia, neurological complications, in-hospital mortality, and lower cost as compared with CAS.

Carotid artery stenting versus endarterectomy for treatment of carotid artery stenosis

BACKGROUND

Carotid artery stenting is an alternative to carotid endarterectomy for the treatment of atherosclerotic carotid artery stenosis. This review updates a previous version first published in 1997 and subsequently updated in 2004, 2007, and 2012.

OBJECTIVES

To assess the benefits and risks of stenting compared with endarterectomy in people with symptomatic or asymptomatic carotid stenosis.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched August 2018) and the following databases: CENTRAL, MEDLINE, Embase, and Science Citation Index to August 2018. We also searched ongoing trials registers (August 2018) and reference lists, and contacted researchers in the field.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing stenting with endarterectomy for symptomatic or asymptomatic atherosclerotic carotid stenosis. In addition, we included RCTs comparing carotid artery stenting with medical therapy alone.

DATA COLLECTION AND ANALYSIS

One review author selected trials for inclusion, assessed trial quality and risk of bias, and extracted data. A second review author independently validated trial selection and a third review author independently validated data extraction. We calculated treatment effects as odds ratios (OR) and 95% confidence intervals (CI), with endarterectomy as the reference group. We quantified heterogeneity using the I² statistic and used GRADE to assess the overall certainty of evidence.

MAIN RESULTS

We included 22 trials involving 9753 participants. In participants with symptomatic carotid stenosis, compared with endarterectomy stenting was associated with a higher risk of periprocedural death or stroke (the primary safety outcome; OR 1.70, 95% CI 1.31 to 2.19; P < 0.0001, I² = 5%; 10 trials, 5396 participants; high-certainty evidence); and periprocedural death, stroke, or myocardial infarction (OR 1.43, 95% CI 1.14 to 1.80; P = 0.002, I² = 0%; 6 trials, 4861 participants; high-certainty evidence). The OR for the primary safety outcome was 1.11 (95% CI 0.74 to 1.64) in participants under 70 years old and 2.23 (95% CI 1.61 to 3.08) in participants 70 years old or more (interaction P = 0.007). There was a non-significant increase in periprocedural death or major or disabling stroke with stenting (OR 1.36, 95% CI 0.97 to 1.91; P = 0.08, I² = 0%; 7 trials, 4983 participants; high-certainty evidence). Compared with endarterectomy, stenting was associated with lower risks of myocardial infarction (OR 0.47, 95% CI 0.24 to 0.94; P = 0.03, I² = 0%), cranial nerve palsy (OR 0.09, 95% CI 0.06 to 0.16; P < 0.00001, I² = 0%), and access site haematoma (OR 0.32, 95% CI 0.15 to 0.68; P = 0.003, I² = 27%). The combination of periprocedural death or stroke or ipsilateral stroke during follow-up (the primary combined safety and efficacy outcome) favoured endarterectomy (OR 1.51, 95% CI 1.24 to 1.85; P < 0.0001, I² = 0%; 8 trials, 5080 participants; high-certainty evidence). The rate of ipsilateral stroke after the periprocedural period did not differ between treatments (OR 1.05, 95% CI 0.75 to 1.47; P = 0.77, I² = 0%). In participants with asymptomatic carotid stenosis, there was a non-significant increase in periprocedural death or stroke with stenting compared with endarterectomy (OR 1.72, 95% CI 1.00 to 2.97; P = 0.05, I² = 0%; 7 trials, 3378 participants; moderate-certainty evidence). The risk of periprocedural death or stroke or ipsilateral stroke during follow-up did not differ significantly between treatments (OR 1.27, 95% CI 0.87 to 1.84; P = 0.22, I² = 0%; 6 trials, 3315 participants; moderate-certainty evidence). Moderate or higher carotid artery restenosis (50% or greater) or occlusion during follow-up was more common after stenting (OR 2.00, 95% CI 1.12 to 3.60; P = 0.02, I² = 44%), but the difference in risk of severe restenosis was not significant (70% or greater; OR 1.26, 95% CI 0.79 to 2.00; P = 0.33, I² = 58%; low-certainty evidence).

AUTHORS' CONCLUSIONS

Stenting for symptomatic carotid stenosis is associated with a higher risk of periprocedural stroke or death than endarterectomy. This extra risk is mostly attributed to an increase in minor, non-disabling strokes occurring in people older than 70 years. Beyond the periprocedural period, carotid stenting is as effective in preventing recurrent stroke as endarterectomy. However, combining procedural safety and long-term efficacy in preventing recurrent stroke still favours endarterectomy. In people with asymptomatic carotid stenosis, there may be a small increase in the risk of periprocedural stroke or death with stenting compared with endarterectomy. However, CIs of treatment effects were wide and further data from randomised trials in people with asymptomatic stenosis are needed.

Editor's Choice - Overview of Primary and Secondary Analyses From 20 Randomised Controlled Trials Comparing Carotid Artery Stenting With Carotid Endarterectomy

OBJECTIVES

The aim of this review was to carry out primary and secondary analyses of 20 randomised controlled trials (RCTs) comparing carotid endarterectomy (CEA) with carotid artery stenting (CAS).

METHODS

A systematic review and meta-analysis of data from 20 RCTs (126 publications) was carried out.

RESULTS

Compared with CEA, the 30 day death/stroke rate was significantly higher after CAS in seven RCTs involving 3467 asymptomatic patients (odds ratio [OR] 1.64, 95% confidence interval [CI] 1.02-2.64) and in 10 RCTs involving 5797 symptomatic patients (OR 1.71, 95% CI 1.38-2.11). Excluding procedural risks, late ipsilateral stroke was about 4% at 9 years for both CEA and CAS, i.e., CAS was durable. Reducing procedural death/stroke after CAS may be achieved through better case selection, e.g., performing CEA in (i) symptomatic patients aged > 70 years; (ii) interventions within 14 days of symptom onset; and (iii) situations where stroke risk after CAS is predicted to be higher (segmental/remote plaques, plaque length > 13 mm, heavy burden of white matter lesions [WMLs], where two or more stents might be needed). New WMLs were significantly more common after CAS (52% vs. 17%) and were associated with higher rates of late stroke/transient ischaemic attack (23% vs. 9%), but there was no evidence that new WMLs predisposed towards late cognitive impairment. Restenoses were more common after CAS (10%) but did not increase late ipsilateral stroke. Restenoses (70%-99%) after CEA were associated with a small but significant increase in late ipsilateral stroke (OR 3.87, 95% CI 1.96-7.67; p < .001).

CONCLUSIONS

CAS confers higher rates of 30 day death/stroke than CEA. After 30 days, ipsilateral stroke is virtually identical for CEA and CAS. Key issues to be resolved include the following: (i) Will newer stent technologies and improved cerebral protection allow CAS to be performed < 14 days after symptom onset with risks similar to CEA? (ii) What is the optimal volume of CAS procedures to maintain competency? (iii) How to deliver better risk factor control and best medical treatment? (iv) Is there a role for CEA/CAS in preventing/reversing cognitive impairment?

Carotid artery stenting: Current state of evidence and future directions

Both carotid endarterectomy (CEA) and carotid artery stenting (CAS) are common treatments for carotid artery stenosis. Several randomized controlled trials (RCTs) have compared CEA to CAS in the treatment of carotid artery stenosis. These studies have suggested that CAS is more strongly associated with periprocedural stroke; however, CEA is more strongly associated with myocardial infarction. Published long-term outcomes report that CAS and CEA are similar. A reduction in complications associated with CAS has also been demonstrated over time. The symptomatic status of the patient and history of previous CEA or cervical radiotherapy are significant factors when deciding between CEA or CAS. Numerous carotid artery stents are available, varying in material, shape and design but with minimal evidence comparing stent types. The role of cerebral protection devices is unclear. Dual antiplatelet therapy is typically prescribed to prevent in-stent thrombosis, and however, evidence comparing periprocedural and postprocedural antiplatelet therapy is scarce, resulting in inconsistent guidelines. Several RCTs are underway that will aim to clarify some of these uncertainties. In this review, we summarize the development of varying techniques of CAS and studies comparing CAS to CEA as treatment options for carotid artery stenosis.

Timing of carotid intervention

Flimsy evidence

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.

Anesthesia type determines risk of cerebral infarction after carotid endarterectomy

OBJECTIVE

Silent and symptomatic cerebral infarctions occur in up to 34% of patients after carotid endarterectomy (CEA). This prospective study compared the risk of new brain infarctions detected by magnetic resonance imaging (MRI) in patients with internal carotid artery stenosis undergoing CEA with local anesthesia (LA) vs general anesthesia (GA).

METHODS

Consecutive patients with internal carotid artery stenosis indicated for CEA were screened at two centers. Patients without contraindication to LA or GA were randomly allocated to the LA or GA group by ZIP code randomization. Brain MRI was performed before and 24 hours after CEA. Neurologic examination was performed before and 24 hours and 30 days after surgery. The occurrence of new infarctions on the control magnetic resonance images, stroke, transient ischemic attack, and other complications was statistically evaluated.

RESULTS

Of 210 randomized patients, 105 underwent CEA with LA (67 men; mean age, 68.3 ± 8.1 years) and 105 with GA (70 men; mean age, 63.4 ± 7.5 years). New infarctions were more frequently detected on control magnetic resonance images in patients after CEA under GA compared with LA (17.1% vs 6.7%; P = .031). Stroke or transient ischemic attack occurred within 30 days of CEA in three patients under GA and in two under LA (P = 1.000). There were no significant differences between the two types of anesthesia in terms of the occurrence of other complications (14.3% for GA and 21.0% for LA; P = .277).

CONCLUSIONS

The risk of silent brain infarction after CEA as detected by MRI is higher under GA than under LA.

Fragility Index in Randomized Controlled Trials of Ischemic Stroke

OBJECTIVE

The fragility index (FI), a minimum number of events in 1 arm of a clinical trial required to revert the statistically significant result to nonsignificant, has recently been developed as an easy-to-understand novel metric to evaluate the robustness of randomized controlled trials (RCTs). Here, we evaluated the FI of RCTs in the field of neurology, particularly in studies of ischemic stroke.

METHODS

Previous literature published between June 1, 2012 and May 31, 2018 were reviewed from the MEDLINE database by the authors. The original article reporting the significant RCT result, of which a dichotomous outcome was set as its primary outcome measure, was included to evaluate the robustness of the result by calculating the FI. In addition, recent studies examining FI in other clinical fields were reviewed and summarized.

RESULTS

In the 25 eligible RCT studies, the median total number of study participants was 206 (inter quartile range: 144-450) and the median FI was 7 (inter quartile range: 4-15.0). The FI showed a strong negative correlation with the observed P value. There was no significant difference in the FI between RCTs with and without acute settings. Our median FI was higher than the median FI of 2.5 of previous studies examining FI in other clinical fields, as only 20% (5 of 25) of studies included in our study had an FI less than 2.5.

CONCLUSION

Our results suggest that many RCTs in the field of ischemic stroke have a fair robustness, when compared to those in other clinical fields.

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.

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.

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

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Lesions from carotid revascularization affect consistent brain targets.

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

Carotid artery stenting vs. carotid endarterectomy in the management of carotid artery stenosis: Lessons learned from randomized controlled trials

Background:

Carotid artery stenosis, both symptomatic and asymptomatic, has been well studied with several multicenter randomized trials. The superiority of carotid endarterectomy (CEA) to medical therapy alone in both symptomatic and asymptomatic carotid artery stenosis has been well established in previous trials in the 1990s. The consequent era of endovascular carotid artery stenting (CAS) has offered another option for treating carotid artery stenosis. A series of randomized trials have now been conducted to compare CEA and CAS in the treatment of carotid artery disease. The large number of similar trials has created some confusion due to inconsistent results. Here, the authors review the trials that compare CEA and CAS in the management of carotid artery stenosis.

Methods:

The PubMed database was searched systematically for randomized controlled trials published in English that compared CEA and CAS. Only human studies on adult patients were assessed. The references of identified articles were reviewed for additional manuscripts to be included if inclusion criteria were met. The following terms were used during search: carotid stenosis, endarterectomy, stenting. Retrospective or single-center studies were excluded from the review.

Results:

Thirteen reports of seven large-scale prospective multicenter studies, comparing both interventions for symptomatic or asymptomatic extracranial carotid artery stenosis, were identified.

Conclusions:

While the superiority of intervention to medical management for symptomatic patients has been well established in the literatures, careful selection of asymptomatic patients for intervention should be undertaken and only be pursued after institution of appropriate medical therapy until further reports on trials comparing medical therapy to intervention in this patient group are available.

Endarterectomy versus stenting for stroke prevention

The European Society for Vascular Surgery (ESVS) has recently prepared updated guidelines for the management of patients with symptomatic and asymptomatic atherosclerotic carotid artery disease, with specific reference to the roles of best medical therapy, carotid endarterectomy (CEA) and carotid artery stenting (CAS). In symptomatic patients, there is a drive towards performing carotid interventions as soon as possible after onset of symptoms. This is because it is now recognised that the highest risk period for recurrent stroke is the first 7–14 days after onset of symptoms. The guidelines advise that there is a role for both CEA and CAS, but the levels of evidence are slightly lower for CAS than for CEA. This is because 30-day risks of death/stroke in the randomised controlled trials (RCTs) were significantly higher than after CEA (especially in the first 7–14 days after onset of symptoms) and there are concerns that the results obtained in the RCTs may not be generalisable into routine clinical practice. In asymptomatic patients, the 2018 ESVS guidelines were the first to recommend that CEA/CAS should be targeted into a smaller cohort of patients who may be ‘higher risk for stroke’ on medical therapy. As with symptomatic patients, the ESVS guidelines advise that there is a potential role for both CEA and CAS, but the levels of evidence are again slightly lower for CAS than for CEA. This is because 30-day risks of death/stroke in the two largest RCTs, which used credentialed (experienced CAS practitioners), were only just within the accepted 3% risk threshold and there remain concerns that the results obtained in RCTs may not be generalisable into routine clinical practice.

Impact of internal carotid endarterectomy on visual fields: a non-randomised prospective cohort study in Austria

PURPOSE

The goal of this study was to determine whether internal carotid endarterectomy is associated with visual field changes.

METHODS

Between March 2007 and December 2010, a cohort study involved 29 patients with stenosis of the carotid artery. All patients underwent ophthalmoscopy and kinetic visual field examination (Goldmann perimetry) preoperatively and postoperatively. Furthermore, a detailed area calculation was performed. On both the operated and the contralateral side, the areas surrounded by the different isopters (isopter areas) were determined and preoperative and postoperative values compared. The three isopters were classified from the centre to the periphery (I, II and III). Isopter area values are given as ratio compared with total perimetric circle. p Values <0.05 were considered to be statistically significant.

RESULTS

1) The ophthalmologists assessment (paragraph is missing in the proof!)Eight of eleven patients with precarotid endarterectomy impairments experienced focal or concentric improvement. Six cases with preoperative concentric narrowing of the isopters returned to normal or improved substantially. Three out of 18 patients with normal preoperative visual field presented with deteriorations after surgery, two cases with ipsilateral and one with contralateral focal impairment. In 15 cases, there was no preoperative or postoperative abnormality.2) Area calculation (preoperative area, postoperative area, P) (paragraph is missing in the proof)Ipsilateral: isopter area I (0.015, 0.018, 0.131), isopter area II (0.107, 0.120, 0.087), isopter area III (0.392, 0.425, 0.015)Contralateral: isopter area I (0.017, 0.021, 0.222), isopter area II (0.119, 0.125, 0.333), isopter area III (0.416, 0.434, 0.171) CONCLUSIONS: We found a statistically significant extension of the ipsilateral peripheral isopter area (III). Further studies will focus on the question which subgroup is most likely to profit from internal carotid endarterectomy with respect to visual field changes.

Radiographic and symptomatic brain ischemia in CEA and CAS: A systematic review and meta-analysis

OBJECTIVE

In a systematic review, we compared ratio of new periprocedural radiographic brain ischemia (RBI) to the number of strokes and TIAs among patients undergoing carotid endarterectomy (CEA) and carotid artery stenting (CAS).

METHODS

We searched 5 databases for entries related to brain ischemia in CEA or CAS from inception through September 2015. We included articles with CEA or CAS and systematic performance of preprocedural and postprocedural brain MRI and reporting of RBI and stroke incidence. We calculated a symptomatic risk ratio of number of strokes and TIAs to RBI. Random effects models were used.

RESULTS

Fifty-nine studies (5,431 participants) met the inclusion criteria. There were 22 cohorts in CEA, 34 in CAS with distal protection, 8 in CAS with proximal protection, 9 in CAS without protection, and 9 in CAS with unspecified devices. Overall, 30.7% (95% confidence interval [CI] 26.6%-34.7%) had RBI, while 3.2% (95% CI 2.6%-3.8%) had clinical strokes or TIAs, with a stroke and TIA to RBI weighted ratio of 0.18 (95% CI 0.15-0.22). CEA had lower incidence of RBI compared to CAS (13.0% vs 37.4%) and also lower number of strokes and TIAs (1.8% vs 4.1%). The stroke and TIA to RBI ratio did not differ across 5 different types of carotid interventions (p = 0.58).

CONCLUSIONS

One in 5 persons with periprocedural radiographic brain ischemia during CEA and CAS had strokes and TIAs. The stable ratio of stroke and TIA to radiographic ischemia suggests that MRI ischemia could serve as a surrogate measure of periprocedural risk.

Endarterectomy achieves lower stroke and death rates compared with stenting in patients with asymptomatic carotid stenosis

BACKGROUND

It is currently unclear if carotid artery stenting (CAS) is as safe as carotid endarterectomy (CEA) for patients with significant asymptomatic stenosis. The aim of our study was to perform a systematic review and meta-analysis of trials comparing CAS with CEA.

METHODS

On March 17, 2017, a search for randomized controlled trials was performed in MEDLINE and Scopus databases with no time limits. We performed meta-analyses with Peto odds ratios (ORs) and 95% confidence intervals (CIs). Quality of evidence was assessed with the Grading of Recommendations Assessment, Development, and Evaluation method. The primary safety and efficacy outcome measures were stroke or death rate at 30 days and ipsilateral stroke at 1 year (including ipsilateral stroke and death rate at 30 days), respectively. Perioperative stroke, ipsilateral stroke, myocardial infarction (MI), and cranial nerve injury (CNI) were all secondary outcome measures.

RESULTS

The systematic review of the literature identified nine randomized controlled trials reporting on 3709 patients allocated into CEA (n = 1479) or CAS (n = 2230). Stroke or death rate at 30 days was significantly higher for CAS (64/2176 [2.94%]) compared with CEA (27/1431 [1.89%]; OR, 1.57; 95% CI, 1.01-2.44; P = .044), with low level of heterogeneity beyond chance (I² = 0%). Also, stroke rate at 30 days was significantly higher for CAS (63/2176 [2.90%]) than for CEA (26/1431 [1.82%]; OR, 1.63; 95% CI, 1.04-2.54; P = .032; I² = 0%). MI at 30 days was nonsignificantly lower for CAS (12/1815 [0.66%]) compared with CEA (16/1070 [1.50%]; OR, 0.53; 95% CI, 0.24-1.14; P = .105; I² = 0%); however, CNI at 30 days was significantly lower for CAS (2/1794 [0.11%]) than for CEA (33/1061 [3.21%]; OR, 0.13; 95% CI, 0.07-0.26; P < .00001; I² = 0%). Regarding the long-term outcome of stroke or death rate at 30 days plus ipsilateral stroke during follow-up, this was significantly higher for CAS (79/2173 [3.64%]) than for CEA (35/1430 [2.45%]; OR, 1.51; 95% CI, 1.02-2.24; P = .04; I² = 0%). Quality of evidence for all stroke outcomes was graded moderate.

CONCLUSIONS

Among patients with asymptomatic stenosis undergoing carotid intervention, there is moderate-quality evidence to suggest that CEA had significantly lower 30-day stroke and also stroke or death rates compared with CAS at the cost of higher CNI and nonsignificantly higher MI rates. The long-term efficacy of CEA in ipsilateral stroke prevention, taking into account perioperative stroke and death, was preserved during follow-up. There is an urgent need for high-quality research before a firm recommendation is made that CAS is inferior or not to CEA.

SONOlysis in prevention of Brain InfaRctions During Internal carotid Endarterectomy (SONOBIRDIE) trial - study protocol for a randomized controlled trial

BACKGROUND

Carotid endarterectomy (CEA) is a beneficial procedure for selected patients with an internal carotid artery (ICA) stenosis. Surgical risk of CEA varies from between 2 and 15%. The aim of the study is to demonstrate the safety and effectiveness of sonolysis (continual transcranial Doppler monitoring, TCD) using a 2-MHz diagnostic probe with maximal diagnostic energy on the reduction of the incidence of stroke, transient ischemic attack (TIA) and brain infarction detected using magnetic resonance imaging (MRI) by the activation of the endogenous fibrinolytic system during CEA.

METHODS/DESIGN

Design: a multicenter, randomized, double-blind, sham-controlled trial.

SCOPE

international, multicenter trial for patients with at least 70% symptomatic or asymptomatic ICA stenosis undergoing CEA.

INCLUSION CRITERIA

patients with symptomatic or asymptomatic ICA stenosis of at least 70% are candidates for CEA; a sufficient temporal bone window for TCD; aged 40-85 years, functionally independent; provision of signed informed consent. Randomization: consecutive patients will be assigned to the sonolysis or control (sham procedure) group by computer-generated 1:1 randomization. Prestudy calculations showed that a minimum of 704 patients in each group is needed to reach a significant difference with an alpha value of 0.05 (two-tailed) and a beta value of 0.8 assuming that 10% would be lost to follow-up or refuse to participate in the study (estimated 39 endpoints).

ENDPOINTS

the primary endpoint is the incidence of stroke or TIA during 30 days after CEA and the incidence of new ischemic lesions on brain MRI performed 24 h after CEA in the sonolysis and control groups. Secondary endpoints are occurrence of death, any stroke, or myocardial infarction within 30 days, changes in cognitive functions 1 year post procedure related to pretreatment scores, and number of new lesions and occurrence of new lesions ≥0.5 mL on post-procedural brain MRI.

ANALYSIS

descriptive statistics and linear/logistic multiple regression models will be performed. Clinical relevance will be measured as relative risk reduction, absolute risk reduction and the number needed to treat.

DISCUSSION

Reduction of the periprocedural complications of CEA using sonolysis as a widely available and cheap method may significantly increase the safety of CEA and extend the indication criteria for CEA.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02398734 . Registered on 20 March 2015.

Analysis of Risk Factors for Cerebral Microinfarcts after Carotid Endarterectomy and the Relevance of Delayed Cerebral Infarction

Background and Purpose

Carotid endarterectomy (CEA) is performed to prevent cerebral infarction, but a common side effect is cerebral microinfarcts. This study aimed to identify the variables related to the production of microinfarcts during CEA as well as determine their association with delayed postoperative infarction.

Methods

This was a retrospective review of data collected prospectively from 548 patients who underwent CEA. The clinical characteristics of the patients and the incidence rates and causes of microinfarcts were analyzed. Microinfarcts were diagnosed by diffusion-weighted magnetic resonance imaging. The presence of delayed postoperative infarction was compared between microinfarct-positive and microinfarct-negative groups.

Results

In total, 76 (13.86%) patients were diagnosed with microinfarcts. Preoperative neurological symptoms were significantly related to the incidence of microinfarcts [odds ratio (OR)=2.93, 95% confidence interval (CI)=1.72–5.00, p<0.001]. Shunt insertion during CEA was the only significant procedure-related risk factor (OR=1.42, 95% CI=1.00–2.19, p=0.05). The presence of microinfarcts did not significantly increase the incidence of delayed postoperative infarction (p=0.204).

Conclusions

In the present study, risk factors for microinfarcts after CEA included preoperative symptoms and intraoperative shunt insertion. Microinfarcts were not associated with delayed postoperative infarction.

Laboratory-Based Markers as Predictors of Brain Infarction During Carotid Stenting: a Prospective Study

AIM

New ischemic lesions in the brain can be detected in approximately 50% of patients undergoing carotid artery stenting (CAS). We wished to discover the laboratory-based predictors of new infarctions in the brain after CAS.

METHODS

All consecutive patients with internal carotid artery stenosis of ≥70% with indication for CAS were enrolled in a prospective study for 16 months. All patients used dual antiplatelet therapy for ≥7 days before CAS. Neurologic examination and magnetic resonance imaging (MRI) of the brain were undertaken before and at 24 h after CAS. Samples of venous blood were collected at ＜24 h before CAS for the evaluation of hematology, reticulocytes, coagulation markers (PT, APTT, Fbg, Clauss), vWF antigen, PAI-1 activity, PAI-1 polymorphism 4G/5G, and the multiplate (aspirin and clopidogrel) resistance test. Blood samples for the assessment of anti-Xa activity were collected during CAS. Differences in the values of laboratory markers between patients with and without new ischemic lesions of the brain on control MRI were evaluated.

RESULTS

The cohort comprised 81 patients (53 males; mean age, 67.3±7.2 years). New ischemic infarctions in the brain on control MRI were found in 46 (56.8%) patients. Three of seven patients with resistance to aspirin or clopidogrel had a new ischemic infarction in the brain. No significant differences for particular markers were found between patients with and without an ischemic lesion in the brain.

CONCLUSION

A high risk of a new ischemic infarction in the brain was detected in patients undergoing CAS, but a laboratory-based predictor of such an infarction could not be identified.

Carotid Endarterectomy: Current Concepts and Practice Patterns

Background Stroke is the number one cause of disability and third leading cause of death among adults in the United States. A major cause of stroke is carotid artery stenosis (CAS) caused by atherosclerotic plaques. Randomized trials have varying results regarding the equivalence and perioperative complication rates of stents versus carotid endarterectomy (CEA) in the management of CAS. Objectives We review the evidence for the current management of CAS and describe the current concepts and practice patterns of CEA. Methods A literature search was conducted using PubMed to identify relevant studies regarding CEA and stenting for the management of CAS. Results The introduction of CAS has led to a decrease in the percentage of CEA and an increase in the number of CAS procedures performed in the context of all revascularization procedures. However, the efficacy of stents in patients with symptomatic CAS remains unclear because of varying results among randomized trials, but the perioperative complication rates exceed those found after CEA. Conclusions Vascular surgeons are uniquely positioned to treat carotid artery disease through medical therapy, CEA, and stenting. Although data from randomized trials differ, it is important for surgeons to make clinical decisions based on the patient. We believe that CAS can be adopted with low complication rate in a selected subgroup of patients, but CEA should remain the standard of care. This current evidence should be incorporated into practice of the modern vascular surgeon.

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.