Effects of uncomplicated carotid endarterectomy on cognitive function and brain perfusion in patients with unilateral asymptomatic severe stenosis of the internal carotid artery by comparison with unoperated patients

Objective: The purpose of the present exploratory study was to evaluate the effects of uncomplicated carotid endarterectomy (CEA) on cognitive function and brain perfusion in patients with unilateral asymptomatic severe stenosis of the internal carotid artery (ICA) by comparison with unoperated patients.

Methods: Patients with age ≤75 years and unilateral asymptomatic severe stenosis (≥70%) of the cervical ICA underwent CEA with antiplatelet therapy (surgically treated group: 116 patients) or antiplatelet therapy alone or neither (medically treated group: 45 patients). For the surgically treated group, neuropsychological testing and brain perfusion measurement using single-photon emission computed tomography were performed within one month before surgery and one month after surgery. For the medically treated group, the same testing and measurement were performed twice at an interval of 1 to 2 months.

Results: None of the operated patients developed new major ischemic events after surgery or intraoperative cerebral hyperperfusion. None of the patients in the medically treated group experienced neurological deficits including transient ischemic attacks during the study period. The incidence of patients with interval cognitive improvement was significantly greater in the surgically treated group (11 patients: 9%) than in the medically treated group (0%) (p = 0.0352). The incidence of patients with interval brain perfusion improvement in the ipsilateral cerebral hemisphere was significantly greater in the surgically treated group (24 patients: 21%) than in the medically treated group (0%) (p = 0.0003).

Conclusions: Uncomplicated CEA may improve cognitive function and brain perfusion in patients with unilateral asymptomatic severe stenosis of the ICA when compared with unoperated patients.     

Elevated Neutrophil to Lymphocyte Ratio is Associated with Worse Outcomes after Carotid Endarterectomy in Asymptomatic Patients

ObjectiveManagement of carotid artery stenosis (CAS) remains controversial and proper patient selection critical. Elevated neutrophil to lymphocyte ratio (NLR) has been associated with poor outcomes after vascular procedures. The effect of NLR on outcomes after carotid endarterectomy (CEA) in asymptomatic and symptomatic patients is assessed.Materials and MethodsA retrospective review was conducted of all patients between 2010 and 2018 with carotid stenosis >70% as defined by CREST 2 criteria. A total of 922 patients were identified, of whom 806 were treated with CEA and 116 non-operatively with best medical therapy (BMT). Of patients undergoing CEA, 401 patients (290 asymptomatic [aCEA], 111 symptomatic [sCEA]) also had an available NLR calculated from a complete blood count with differential. All patients treated with BMT were asymptomatic and had a baseline NLR available. Kaplan-Meier analysis assessed composite ipsilateral stroke or death over 3 years.ResultsIn sCEA group, the 3-year composite stroke/death rates did not differ between NLR < 3.0 (22.9%) vs NLR > 3.0 (38.1%) (P=.10). In aCEA group, patients with a baseline NLR >3.0 had an increased risk of 3-year stroke/death (42.6%) compared to both those with NLR <3.0 (9.3%, P<.0001) and those treated with BMT (23.6%, P=.003). In patients with NLR <3.0, aCEA showed a superior benefit over BMT with regard to stroke or death (9.3% vs. 26.2%, P=.02). However, in patients with NLR >3.0, there was no longer a benefit to prophylactic CEA compared to BMT (42.6% vs. 22.2%, P=.05). Multivariable analysis identified NLR >3.0 (HR, 3.23; 95% CI, 1.93-5.42; P<.001) and congestive heart failure (HR, 2.18; 95% CI, 1.33-3.58; P=.002) as independent risk factors for stroke/death in patients with asymptomatic carotid artery stenosis.ConclusionsNLR >3.0 is associated with an increased risk of late stroke/death after prophylactic CEA for asymptomatic carotid artery stenosis, with benefits not superior to BMT. NLR may be used to help with selecting asymptomatic patients for CEA. The effect of NLR and outcomes in symptomatic patients requires further study. Better understanding of the mechanism(s) for NLR elevation and medical intervention strategies are needed to modulate outcome risk in these patients.     

Time delay between symptom and surgery in patients with carotid artery stenosis

Andgren S, Sjöberg L, Norrving B, Lindgren A. Time delay between symptom and surgery in patients with carotid artery stenosis.
Acta Neurol Scand: 2011: 124: 329–333.
© 2011 John Wiley & Sons A/S. Objectives – Many severe strokes are preceded by warning signs such as a transient ischemic attack or stroke with minor deficits. Carotid endarterectomy (CEA) of a symptomatic carotid artery stenosis can prevent future strokes, but should be performed within 2 weeks after the initial symptom to maximize the benefit. The aim of this study was to determine the time delays between symptom and CEA. Methods – We performed a single center observational retrospective study at a tertiary stroke center. A total of 142 carotids in 139 patients with symptomatic stenoses between 2002 and 2006 were included. The main outcome measure was time between qualifying cerebrovascular symptom and CEA. Results – The median time between symptom and CEA was 26 days. The longest delays were between the last diagnostic examination and carotid conference, and between carotid conference and surgery. The median time was shorter for those who received emergency medical care (median 21 days) and for those who were admitted immediately to hospital (median 20 days). Conclusions – The time between symptom and surgery is often longer than desirable. There are several measures to improve the chain of procedures for patients with carotid artery stenosis. These may include omitting the formal carotid conference for uncomplicated cases and minimizing waiting time for surgery.     

Clinical features and long-term outcomes of symptomatic low-grade carotid stenosis

ObjectiveIn symptomatic low-grade stenosis, most of the reports did not clarify the long-term outcome. This study aims to clarify the clinical features and long-term outcomes of symptomatic low-grade stenosis cases.Materials and methodsWe included 123 symptomatic patients with low-grade (<50%) carotid stenosis. The relative plaque signal intensity (rSI) and expansive remodeling rate (ERR) were measured using carotid magnetic resonance imaging (MRI). Antiplatelet therapy and treatment for atherosclerosis risk factors were administered in all cases. Carotid endarterectomy (CEA) was performed when ischemic symptoms appeared, or the percent stenosis progressed despite medical treatment.ResultsThe mean percent stenosis, rSI, and ERR on admission were 22.3, 1.70, and 2.01, respectively. The mean volume of the hyperintense plaque on carotid MRI was 641.4± 540 mm3. Sixty percent of cases involved intraplaque hemorrhage and expansive remodeling. During a mean follow-up of 52 months, recurrence of ischemic events was confirmed in 45 cases (36.6%). Of the 67 cases performed follow-up MRI, 34 cases (50%) had an increased volume of T1-hyperintense plaque. CEA or carotid artery stenting was performed in 49 cases. During a mean follow-up of 57.8 months after CEA, two cases of death (fatal intracerebral hemorrhage and asphyxia) and one case of brain stem lacunar infarction were observed, but ipsilateral ischemic events were not.ConclusionMost of the symptomatic patients with low-grade stenosis had both intraplaque hemorrhage and expansive remodeling and presented a high risk of recurrence and stenosis progression. CEA may have preventive effects against ischemic events in low-grade stenosis.     

The short-term effect of atorvastatin on carotid plaque morphology assessed by computer-assisted gray-scale densitometry: a pilot study

Abstract

Soft, lipid-containing carotid plaques, which appear echolucent on ultrasound imaging, have been associated with increased risk of ischemic stroke. We sought to investigate the effect of short-term treatment with atorvastatin on the change of carotid plaque echodensity. We treated 40 stroke-free and statin-naive subjects with 80 mg atorvastatin daily for 30 days. Computer assisted gray-scale densitometry (GSD) index was calculated at baseline and 30 days after treatment from the normalized plaque images. A multiple logistic regression was used to assess the effect modification of low-density lipoprotein (LDL) cholesterol on plaque stabilization after adjusting for age, sex, and smoking. The average number of carotid plaques at baseline was 2 (range: 0-5; 27 subjects with carotid plaque) and did not change 30 days following atorvastatin treatment. The mean GSD index significantly increased from 73±16 (range: 1-125) at baseline to 89±15 (range: 1-137) at 30 days after treatment (P<0·05). The adjusted odds ratio for the positive GSD plaque index change (vs. no change or decreased gray-scale median (GSM) index) was 1·71 (95% confidence interval: 1·1-7·6, P<0·01). In conclusion, we observed decreased echolucency (increased echodensity) of carotid artery plaques after short-term treatment with atorvastatin.     

The Clinical Outcomes of 75 Consecutive Patients with Cervical Carotid Artery Stenosis Treated by Carotid Artery Stenting

Objective

The purpose of this study was to analyze the clinical outcome of 75 consecutive patients with cervical carotid artery stenosis and who were treated by carotid artery stenting (CAS) only.

Methods

From February 2003 to June 2008, there were 78 stents placed in 75 symptomatic patients (mean age : 67.3 years); 69 patients had carotid stenosis ≥70%, and 6 patients had asymptomatic stenosis ≥80%. No carotid endarterectomy (CEA) was performed during the same period. The patients were clinically followed-up for a mean of 20.1 months.

Results

The procedures were technically successful in all cases. Three (3.8%) patients had procedure-related complications. During the 30-day postprocedural period, there were no restenosis or major stroke. Minor stroke was noticed in 3 (3.8%) patients and 1 (1.3%) of the 75 patients suddenly expired 2 days after discharge. There were no new neurological symptoms that developed during the clinical follow-up period. The results of our series were not inferior to those the previously published in CAS studies, and in fact they were better.

Conclusion

Our results suggest that CAS may be safe and useful for the treatment of cervical carotid artery stenosis when it is used as the first line treatment in those institutions that lack enough experience with CEA.     

Quantitative evaluation of cerebral metabolites and cerebral blood flow in patients with carotid stenosis

Abstract

We examined the metabolic and hemodynamic status of patients with severe carotid stenosis and evaluated the effectiveness of carotid endarterectomy (CEA) by comparing pre- and post-operative results of quantitative proton magnetic resonance spectroscopy (¹H-MRS) and single-photon emission computed tomography (SPECT). Quantitative ¹H-MRS and SPECT were performed in 17 patients with severe carotid stenosis before CEA; in 10 patients the examinations were repeated after CEA. There was a significant correlation between the degree of internal carotid artery (ICA) stenosis and the N-acetyl-aspartate (NAA) concentration, and between CBF and NAA in the basal ganglia. In 10 of the 17 patients (58.8%) we noted a decrease of NAA on ¹H-MRS. After CEA in these patients, NAA was significantly increased, and in 7 of 8 patients whose pre-operative SPECT had indicated impairment of cerebral vasoreactivity, it was improved. Quantitative ¹H-MRS and CBF measurements can indicate the severity of metabolic and hemodynamic impairment in patients with severe carotid stenosis, and can help to assess the effectiveness of CEA. [Neurol Res 2001; 23: 573-580]     

Diagnostic accuracy of somatosensory evoked potential and electroencephalography during carotid endarterectomy

Background and Purpose: Perioperative stroke risk following carotid endarterectomy (CEA) is reported to be approximately 2–3%. The diagnostic accuracies of intraoperative EEG and SSEP monitoring during CEA have been studied separately. However, to date, the effectiveness of simultaneous EEG and SSEP monitoring during CEA has only been evaluated in small study populations. This study examined the diagnostic accuracy of combined EEG and SSEP monitoring in a large (N = 1165) patient population.

Methods: This study included 1165 patients who underwent CEA from 2000 to 2012 at the University of Pittsburgh Medical Center. The sensitivities, specificities, and diagnostic odds ratio of EEG and SSEP monitoring methods were examined separately and together. Receiver operating characteristic curves were plotted to assess sensitivity and specificity of single and combined Intraoperative monitoring (IONM) methods.

Results: Maximum sensitivity was obtained with multimodality monitoring with an IONM change in either EEG or SSEP of 50.00 (95% CI, 30.66–69.34). The specificity of simultaneous EEG and SSEP changes was 93.95 (95% CI, 92.28–95.35%). Maximum area under ROC curve obtained for IONM change in either EEG or SSEP was 0.660 (95% CI, 0.547–0.773, p-value 0.004).

Conclusion: The diagnostic accuracy of multimodality IONM during CEA is higher than an approach using single modality IONM. Simultaneous EEG and SSEP monitoring improves the likelihood of detecting periprocedural strokes after CEA. Neuro protective therapies to prevent periprocedural strokes can be based on changes in SSEP and EEG during CEA.     

血管成形术治疗症状性重度颈动脉狭窄的临床研究

目的 探讨颈动脉内膜剥脱术(carotid endarterectomy,CEA)和颈动脉支架成形术(carotid artery stenting,CAS)治疗症状性重度颈动脉狭窄的近期和中期临床效果.方法 回顾性地分析了2016年1月至2018年12月在我院接受CEA或CAS治疗的203例症状性重度颈动脉狭窄患者的...     

Symptomatic nonstenotic carotid disease: Evaluation of a proposed classification scheme in a prospective cohort

IntroductionUnraveling symptomatic nonstenotic carotid disease (SyNC) as a stroke etiology from other cryptogenic stroke may have important implications for defining natural history and for tailoring secondary prevention strategies. We aim to describe the characteristics of the plaques in a prospectively-collected cohort of patients with non-invasive imaging suggesting symptomatic carotid stenosis but whose DSA demonstrated nonstenotic atheromatous disease, and to evaluate the recurrence rate depending on the type of SyNC.MethodsWe reviewed prospectively-collected data for patients presenting with new neurologic events and non-invasive imaging suggestive of moderate or severe (≥50%) carotid stenosis between July 2016 and October 2018. Patients were included in the present study if the degree of stenosis on DSA was < 50%. We assigned these patients into groups based on a previously-proposed working definition of SyNC, and analyzed the rate of recurrent stroke in the following 6 months.Results28 patients had DSA-confirmed < 50% stenosis and constituted the study cohort. The median age was 73 years and 64% were male; median presenting NIHSS was 1 (IQR 0–3). The great majority (86%) of carotid plaques had high-risk features including ulcerated plaque (n = 21, 75%) and plaque > 3 mm thick (n = 18, 64%). 17 of 28 patients (61%) met classification criteria for “definite” or “probable” SyNC. Three of five patients in the “definite SyNC” group experienced recurrent neurologic events.ConclusionThe majority of patients with non-invasive imaging suggesting carotid stenosis harbor symptomatic carotid disease per current classifications despite DSA stenosis < 50%. Current classification schema may allow for risk stratification of SyNC patients and these findings warrant further study.     

Combining carotid endarterectomy with off-pump coronary artery bypass graft surgery is safe and effective

Background:

We, as neurologists, are frequently consulted to give neurological clearance for surgery in patients who are undergoing coronary artery bypass graft (CABG) surgery and have suffered from stroke or transient ischemic attack (TIA) in past. Similarly clearance is also sought in another group of patients who, though have not suffered from stroke or TIA, but found to have significant carotid stenosis on routine screening prior to surgery. Cardiac surgeons and anesthetists want to know the risk of perioperative stroke in such patients and should carotid endarterectomy (CEA) be done along with CABG. In absence of any clear-cut guideline, neurologists often fail to give any specific recommendation.

Aim:

To find out safety and efficacy of synchronous CEA in patients undergoing CABG.

Design:

Retrospective study.

Materials and Methods:

Out of 3,700 patients who underwent CABG, 150 were found to have severe carotid stenosis of >70%. Out of this, 46 patients with >80% stenosis (three symptomatic and 43 asymptomatic) and one patient with >70% symptomatic carotid stenosis (TIA within last 2 weeks) were taken for simultaneous CEA along with CABG. These three symptomatic carotid patients had suffered from stroke within last 6 months.

Results:

One patient with asymptomatic near total occlusion of carotid artery suffered from hyperperfusion syndrome. None suffered from ischemic stroke, myocardial infarction (MI), or death during perioperative period.

Conclusion:

Combining CEA along with CABG is a safe and effective procedure.     

Preoperative antithrombotic treatment in acutely symptomatic carotid artery stenosis

ObjectivesEarly recurrence of cerebral ischemia in acutely symptomatic carotid artery stenosis can precede revascularization. The optimal antithrombotic regimen for this high-risk population is not well established. Although antiplatelet agents are commonly used, there is limited evidence for the use of anticoagulants. We sought to understand the safety and efficacy of short-term preoperative anticoagulants in secondary prevention of recurrent cerebral ischemic events from acutely symptomatic carotid stenosis in patients awaiting carotid endarterectomy (CEA).Materials and MethodsA retrospective query of a prospective single institution registry of carotid revascularization was performed. Patients who presented with acute ischemic stroke or transient ischemic attack (TIA) attributable to an ipsilateral internal carotid artery stenosis (ICA) were included. Antiplatelet (AP) only and anticoagulation (AC) treatment arms were compared. The primary outcome was a composite of preoperative recurrent ischemic stroke or TIA. The primary safety outcome was symptomatic intracranial hemorrhage.ResultsOut of 443 CEA patients, 342 were in the AC group and 101 in the AP group. Baseline characteristics between groups (AC vs AP) were similar apart from age (71±10.5 vs 73±9.5, p=0.04), premorbid modified Rankin scale (mRS) score (1.0±1.2 vs 1.4±1.3, p=0.03) and stroke as presenting symptom (65.8 vs 53.5%, p=0.02). Patients in the AC group had a lower incidence of recurrent stroke/TIA (3.8 vs 10.9%, p=0.006). One patient had symptomatic intracranial hemorrhage in the AC group, and none in the AP group. In multivariate analysis controlling for age, premorbid mRS, stroke severity, degree of stenosis, presence of intraluminal thrombus (ILT) and time to surgery, AC was protective (OR 0.30, p=0.007). This effect persisted in the cohort exclusively without ILT (OR 0.23, p=0.002).ConclusionsShort term preoperative anticoagulation in patients with acutely symptomatic carotid stenosis appears safe and effective compared to antiplatelet agents alone in the prevention of recurrent cerebral ischemic events while awaiting CEA.     

Influence of internal carotid artery stenosis,blood pressure,glycated hemoglobin,and hemoglobin level on fMRI signals of stroke patients

Abstract

Objectives:

To identify the effect of internal carotid artery (ICA) stenosis, blood pressure (BP), glycated hemoglobin (HbA1c), and hemoglobin level on blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signals in stroke patients.

Methods:

A total of 18 stroke patients with acute cerebral infarction (13 males and 5 females) and 13 age-matched healthy controls (5 males and 8 females) were recruited. Among 18 stroke patients, 8 had significant ICA stenosis (>50%) and 10 had nonsignificant ICA stenosis (<50%). During handgrip task, stroke patients and normal controls were allowed to use their hands coincided with infarction and right hands, respectively.

Results:

The mean BOLD signals in patients with significant ICA stenosis were significantly less than that in patients with nonsignificant ICA stenosis. Mean arterial pressure (MAP) was significantly correlated with activated voxels of Brodmann area 4 (P < 0·01) and total activated voxels (P = 0·007), whereas hemoglobin and HbA1c showed no significant correlation with activated voxels of Brodmann area 4 or total activated voxels (P > 0·05).

Conclusion:

It is suggested that both ICA stenosis and arterial BP could influence BOLD signal, while HbA1c and hemoglobin level had no effect on BOLD signal.     

Association between procalcitonin levels and carotid atherosclerosis in acute ischemic stroke patients

Background and purposes: Procalcitonin has been suggested as a new risk factor in atherosclerotic disease. However, whether procalcitonin levels are associated with the risk of carotid atherosclerosis remains unclear. This study aimed to investigate the relationship between procalcitonin levels and carotid atherosclerosis among patients with first-ever acute ischemic stroke.

Methods: Two hundred and thirty consecutive patients were prospectively enrolled in this study. Serum procalcitonin concentrations were measured at admission for all patients. We also performed ultrasound examination to detect the mean carotid intima-media thickness, presence of carotid-wall thickening, plaque and significant stenosis. Multiple regression analysis was used to estimate the association between procalcitonin levels and carotid atherosclerosis.

Results: The median procalcitonin concentration was 0.051 µg/L (interquartile range, 0.036–0.080 µg/L). Of the 230 patients, 102 (44.3%) had carotid-wall thickening, 113 (49.1%) had plaque and 77 (33.5%) had significant stenosis. After adjusting for all potential confounders by multiple logistic regression analysis, patients with procalcitonin levels in the fourth quartile, compared with the first quartile, were more likely to have carotid-wall thickening [odds ratio 2.288, 95% confidence intervals 1.042–5.021, P = 0.039] and significant stenosis [odds ratio 3.871, 95% confidence intervals 1.690–8.867, P = 0.003]. Furthermore, the linear regression analysis revealed a significant positive correlation between procalcitonin levels and the mean carotid intima-media thickness (β = 0.162, P = 0.012).

Conclusions: Higher procalcitonin concentrations at admission might be associated with carotid-wall thickening and significant stenosis in ischemic stroke patients.     

颈内动脉内膜剥脱术治疗症状性颈内动脉狭窄临床研究

目的探讨颈内动脉内膜剥脱术在症状性颈内动脉狭窄治疗中的临床应用价值。方法对2012年6月~2014年6月间在我院行颈内动脉内膜剥脱术的症状性颈内动脉狭窄病人的23例临床资料进行回顾性研究并随访。结果术后出现暂时性声音嘶哑1例,术侧多发小梗塞灶1例,颈部血肿保守治疗后恢复2例,未见肢体瘫痪、神志不清等严重并发症;术后CTA、DSA检查示颈动脉通畅;随访6月~2年未见血管再狭窄、严重脑缺血表现。结论颈内动脉内膜剥脱术治疗症状性颈内动脉狭窄是一种简单、安全、有效的治疗方法。     

Thirty-day outcomes of carotid endarterectomy in the elderly: A 17-year single-center study

IntroductionCarotid endarterectomy (CEA) has been supported as a durable procedure for treating patients with carotid artery stenosis by many randomized controlled trials (RCTs). The aim of this study was to evaluate the 30-day outcomes and risk factors for CEA in elderly patients with a retrospective single-center study.MethodsOur study sample consisted of patients from 2001 to 2017 CEA-targeted Xuanwu Hospital, Capital Medical University data set. The primary outcome was 30-day postoperative incidence of major adverse clinical events (MACEs; death, myocardial infarction (MI) and ipsilateral stroke). Univariable and multivariable analyses were performed to identify high-risk patients and procedural characteristics associated with MACEs.ResultsA total of 348 elderly patients undergoing CEA for carotid artery stenosis were identified and analyzed. The incidence of postoperative MACEs was 4.6% (16 cases, included 1 death, 14 S, and 1 MI respectively) for elderly patients. Univariate analysis indicated symptomatic lesion (81.3% vs 55.7%, p = 0.044), diabetes mellitus (56.3% vs 26.8%, p = 0.011) and DBP (85.56 ± 11.26 mmHg vs 76.53 ± 9.51 mmHg, p < 0.001) were statistically significant with MACEs. On multivariable analysis, independent predictors of MACEs included diabetes mellitus (DM) (OR = 2.882; 95% CI = 1.005–8.266; P = 0.049) and higher diastolic blood pressure (DBP) (OR = 1.079; 95% CI = 1.025–1.136; P = 0.004). Symptomatic lesion was not an independent risk factor (OR = 2.805; 95% CI = 0.759–10.361; P = 0.122).ConclusionsAccording to our single-center experience, CEA could be safely performed in elderly patients. Risk factors identified for MACEs in this special group patients were DM and higher DBP.     

Diagnostic accuracy of various EEG changes during carotid endarterectomy to detect 30-day perioperative stroke: A systematic review

ObjectivesWe assessed whether significant intraoperative electroencephalography (EEG) changes have predictive value for perioperative stroke within 30 days after carotid endarterectomy (CEA) procedures for carotid stenosis (CS) patients. We also assessed the diagnostic accuracy of various EEG changes in predicting perioperative stroke.MethodsWe searched databases for reports with outcomes of CS patients who underwent CEA with intraoperative EEG monitoring. We calculated the sensitivity, specificity, and diagnostic odds ratio (DOR) of EEG changes for predicting perioperative stroke. Sensitivity and specificity were presented with forest plots and a summary receiver operating characteristic (ROC) curve.ResultsThe meta-analysis included 10,672 patients. Intraoperative EEG changes predicted 30-day stroke with a sensitivity of 46% (95% CI, 38–54%) and specificity of 86% (95% CI, 83–88%). The estimated DOR was 5.79 (95% CI, 3.86–8.69). The estimated DOR for reversible and irreversible EEG changes were 8.25 (95% CI, 3.34–20.34) and 70.84 (95% CI, 36.01–139.37), respectively.ConclusionIntraoperative EEG changes have high specificity but modest sensitivity for predicting perioperative stroke following CEA. Patients with irreversible EEG changes are at high risk for perioperative stroke.SignificanceIntraoperative EEG changes can help surgeons predict the risk of perioperative stroke for CS patients following CEA.     

Overestimation of carotid stenosis on CTA – Real world experience

BackgroundSymptomatic carotid stenosis is responsible for 10% of all strokes. Currently, CT angiography (CTA) is the main diagnostic tool for carotid stenosis. It is frequently the only diagnostic test preceding recommendations for carotid angioplasty and stenting (CAS) or carotid endarterectomy (CEA). However, the specificity of CTA, especially in patients with 50–70% stenosis, was previously reported to be relatively low. Most studies testing the diagnostic accuracy of CTA were published more than a decade ago. Therefore, we aimed to test the diagnostic accuracy of CTA, performed with current available technology, compared with digital subtraction angiography (DSA) in patients with carotid stenosis. This study aims to characterize patients who were candidates for CAS/CEA based on CTA, but may not require it based on DSA.MethodsConsecutive candidates for carotid interventions (CAS or CEA) following CTA were identified from prospectively maintained stroke center registries at two large academic centers. As part of our institutional practice all patients had a routine pre-procedural diagnostic DSA. In each patient, degree of carotid stenosis was compared between CTA and DSA. Patients with concordant degree of stenosis on DSA and CTA (true positive group) were compared to patients with a discordant degree of stenosis with less than 50% on DSA (false positive group).ResultsOut of 90 patients with significant stenosis on CTA, only 70 (78%) were found to have a significant stenosis on DSA. Severe plaque calcification was significantly more common in the false-positive group. In those patients whose CTA reported stenosis of ≥90%, we found a strong agreement between CTA and DSA (positive predictive value [PPV] – 0.9) for a significant stenosis (≥50%). Conversely, the correlation between CTA and DSA in patients with CTA reported 50–70% stenosis was poor (PPV – 0.29) (p < 0.001).ConclusionsOur results suggest that despite ongoing radiological progress, the specificity of CTA in accurately assessing carotid stenosis remains relatively low in patients with both moderate stenosis and heavily calcified plaques. Consequently, patients could possibly be referred for unnecessary CEA surgery and may become exposed to associated potential complications.     

Preoperative brain temperature imaging on proton magnetic resonance spectroscopy predicts hemispheric ischemia during carotid endarterectomy for unilateral carotid stenosis with inadequate collateral blood flow

Objective Preoperative magnetic resonance (MR) angiography sometimes shows the absence of collateral flow via the circle of Willis. This study examined whether brain temperature (BT) imaging on multi-voxel proton MR spectroscopy after this finding increases the accuracy of predicting hemispheric ischemia during internal carotid artery (ICA) clamping during endarterectomy for patients with symptomatic unilateral carotid stenosis.

Methods In 52 patients with ICA stenosis (≥70%) and absence of collateral blood flow via the circle of Willis on preoperative MR angiography, BT imaging was displayed using proton multi-voxel MR spectroscopy. The difference between BTs in the affected and contralateral hemispheres (BT_{affected hemisphere} ? BT_{contralateral hemisphere}) in the deep white matter of the centrum semiovale was calculated and defined as hemispheric ΔBT. Development of cerebral hemispheric ischemia during ICA clamping was determined from intraoperative electroencephalography (EEG).

Results Multivariate analysis revealed that high preoperative hemispheric ΔBT was significantly associated with development of EEG-defined hemispheric ischemia (95% confidence intervals [CIs], 5.376–15.452; p = 0.006). The positive-predictive value for development of EEG-defined hemispheric ischemia was significantly greater for preoperative hemispheric ΔBT following preoperative MR angiography (95%CI, 42–87%) than for preoperative MR angiography alone (95%CI, 13–37%).

Conclusions For patients without collateral flow via the circle of Willis, BT imaging increases the predictive accuracy for development of hemispheric ischemia during ICA clamping during CEA.     

Asymptomatic Carotid Stenosis: Intervention or Best Medical Therapy?

Purpose of Review

Provide a current overview regarding the optimal strategy for managing patients with asymptomatic carotid artery stenosis.

Recent Findings

Carotid endarterectomy (CEA) and carotid artery stenting (CAS) reduce long-term stroke risk in asymptomatic patients. However, CAS is associated with a higher risk of peri-procedural stroke. Improvements in best medical therapy (BMT) have renewed uncertainty regarding the extent to which results from older randomised controlled trials (RCTs) comparing outcomes following carotid intervention can be generalised to modern medical practise.

Summary

‘Average surgical risk’ patients with an asymptomatic carotid artery stenosis of 60–99% and increased risk of late stroke should be considered for either CEA or CAS. In patients deemed ‘high risk’ for surgery, CAS is indicated. Use of an anti-platelet, anti-hypertensive and statin, with strict glycaemic control, is recommended. Results from ongoing large, multicentre RCTs comparing CEA, CAS and BMT will provide clarity regarding the optimal management of patients with asymptomatic carotid artery stenosis.