Symptomatic High-grade Internal Carotid Artery Research Articles

Reader response: Lower carotid revascularization rates after stroke in racial/ethnic minority-serving US hospitals.

I read the article by Faigle et al.1 about the overall low rates of revascularization for symptomatic carotid stenosis in all groups of patients. Even under the best scenario of whites in a predominantly white-serving hospital, the predicted rates were <25% (table 3),1 suggesting a broad underutilization of this procedure nationwide and even more so in underserved hospitals and groups in the population. Our local practice includes carotid endarterectomy (CEA)/carotid artery stenting (CAS) in all high-grade symptomatic patients within 3 days after an infarct, unless the stroke is major and disabling or the patient refuses. With this in mind, and because rates were so low in this case series, methodologic issues in the study may exist. There likely is misclassification of patients as having symptomatic high-grade internal carotid artery (ICA) stenosis that requires intervention by using International Classification of Diseases, Ninth Revision, Clinical Modification codes 433.11 and 433.31 only—the validity of this code for high-grade symptomatic stenosis was not described, and this would also have been helpful information for codes on CEA/CAS. These codes likely include low-grade stenosis, which can be used by coders to justify 433.xx, as well as potentially intracranial ICA stenosis, for which revascularization is not indicated, and are more likely to be present in nonwhites. The probability of misclassification of mild stenosis or of intracranial artery stenosis (patients who should not be undergoing revascularization; more likely nonwhite), as CEA/CAS candidates, is a likely source of bias and could explain the results. Whites are also more likely to undergo CEA/CAS if asymptomatic,2 potentially due to socioeconomic factors, and the 433.xx has been used for asymptomatic patients to justify treatment or after developing a postoperative stroke.3 Last, patients who were transferred were excluded, but the reason for transfer was not explored; if they had symptomatic disease that needed surgery, they were indeed treated appropriately by the hospital that was otherwise low performing.

Predictors of cognitive functioning after carotid revascularization

PurposeHigh-grade carotid stenosis can affect cognition, but the relationship between stenosis correction and cognitive outcome is not fully understood, yet. The aim of this study was to evaluate the predictors of post-operative neurocognitive functioning in patients with symptomatic severe internal carotid artery (ICA) stenosis undergoing carotid endarterectomy (CEA). Materials and methodsPatients with history of transient ischemic attack within the past 6 months and ipsilateral high-grade stenosis of ICA undergoing CEA were prospectively enrolled. Cerebral hemodynamics was assessed by means of the cerebral vasomotor reactivity (CVR) to hypercapnia measured through transcranial Doppler ultrasonography. Coloured Progressive Matrices plus Complex Figure Copy Test, and phonemic plus categorical (ca) Verbal Fluency tests were performed to assess right and left hemisphere cognitive functions, respectively. Cerebral hemodynamics and cognitive functions were assessed before and 6 months after CEA. ResultsOne hundred and eighty-one patients were included. The mean age was 73.2 (6.9) years and 121 (66.9%) were males. At 6 months from CEA, the scores obtained in the cognitive tests exploring the re-vascularized hemisphere's functions and ipsilateral cerebral hemodynamics were improved. At multivariate linear regression analysis, the 6-month change in cognitive performance was inversely associated with age [ß = −0.17, 95% confidence interval (CI) −0.22 to −0.12; p < .001] and CVR value obtained before CEA on the side of ICA stenosis (ß = −6.25, 95% CI −7.40 to −5.10; p < .001). ConclusionsIn patients with symptomatic high-grade ICA stenosis, age and cerebral hemodynamic status before CEA predicted the neurocognitive performance changes after surgical stenosis correction.

The Probability of Restenosis, Contralateral Disease Progression, and Late Neurologic Events following Carotid Endarterectomy: A Long-Term Follow-Up Study

Background: Most studies that have reported on the progression of ipsilateral and/or contralateral internal carotid artery (ICA) stenosis are restricted to a few years. Methods: Based on a single-center carotid endarterectomy (CEA) registry, we sought all patients with CEA for symptomatic high-grade ICA stenosis between 1970 and 2002. 361 CEA patients (mean age 66 years, 73% male) with annual carotid ultrasound and clinical follow-up were identified. Kaplan-Meier analysis was used to estimate the occurrence of (i) progressive ICA stenosis or restenosis of either the operated or contralateral side, and (ii) cerebrovascular events over time of either the operated or contralateral side. Results: Progressive ICA disease was more likely on the contralateral than on the ipsilateral ICA (hazard ratio 2.71; CI 1.8–4.1, p < 0.001). After 5 years, the probability for progressive ICA disease was 5.2% for the ipsilateral versus 15.8% for the contralateral ICA. After 15 years, the likelihood was 37% for both sides. In the presence of progressive restenosis of the ipsilateral ICA, the 20-year probability of further ischemic cerebrovascular events was 50% compared to 18% in patients without ICA disease progression. For the contralateral ICA, the probability of further ischemic events was 24.5% in patients with ICA disease progression compared to 9.6% without ICA disease progression (15 years). Conclusion: 15 years after CEA, one third of the patients can be expected to develop progressive ICA disease. While ICA disease progression seems to be more prominent on the contralateral ICA within the first years, this difference fades out after 15 years. One out of 2 patients with ipsilateral ICA disease progression can be expected to have a recurrent cerebral ischemic event within 15 years. It remains to be determined whether consequent application of high-dose statins, optimal blood pressure management and antithrombotic therapy can reduce this rate.

Reduced Cerebrovascular Reserve at CO2BOLD MR Imaging Is Associated with Increased Risk of Periinterventional Ischemic Lesions during Carotid Endarterectomy or Stent Placement: Preliminary Results1

To determine whether any initial reductions in cardiovascular reserve (CVR) normalize after carotid revascularization and-because reduced CVR represents a risk factor for ischemic events-whether patients who develop periinterventional infarction have more severely reduced pretreatment CVR than those who do not. Ethics committee approval and informed consent were obtained. Twenty-four consecutive patients with symptomatic high-grade internal carotid artery stenosis (seven women; mean age, 73.1 years +/- 9.4 [standard deviation]) were recruited from a prospective, randomized trial that compared carotid artery stent placement with endarterectomy. Magnetic resonance (MR) imaging, including CO(2) blood oxygen level-dependent (BOLD) MR, was performed 1-3 days before, 1-3 days after, and 1 month after carotid revascularization (carotid artery stent placement, n = 13; carotid endarterectomy, n = 11). Mean CVR in the ipsilateral middle cerebral artery (MCA) territory was reduced prior to treatment (mean DeltaT2* in ipsilateral territory, 1.92% +/- 1.18; mean DeltaT2* in contralateral territory, 2.28% +/- 1.15 [P < .05]) and normalized after treatment (mean DeltaT2* 1-3 days after treatment in ipsilateral territory, 2.66% +/- 1.01; that in contralateral territory, 2.48% +/- 1.27 [P > .05]; mean DeltaT2* 1 month after treatment in ipsilateral territory, 2.27% +/- 1.05; that in contralateral territory, 2.14% +/- 0.96 [P > .05]). Those patients who developed new periinterventional infarcts (n = 7 with punctate foci of restricted diffusion) had greater reduction of CVR in the ipsilateral MCA territory prior to treatment (relative reduction, 32.5% +/- 46.0; P < .05) than those who did not develop infarction (n = 17; relative reduction, 9.2% +/- 55.9). CO(2) BOLD MR imaging could be used successfully to monitor the hemodynamic effects of carotid revascularization; initial reductions in CVR normalized after carotid revascularization. Severely reduced pretreatment CVR was associated with increased occurrence of new periinterventional therapy infarction.

Alert for increased long-term follow-up after carotid artery stenting: Results of a prospective, randomized, single-center trial of carotid artery stenting vs carotid endarterectomy

Carotid endarterectomy (CEA) has been shown to be effective in stroke prevention for patients with symptomatic or asymptomatic carotid artery stenosis. Although several prospective randomized trials indicate that carotid artery stenting (CAS) is an alternative but not superior treatment modality, there is still a significant lack of long-term data comparing CAS with CEA. This study presents long-term results of a prospective, randomized, single-center trial. Between August 1999 and April 2002, 87 patients with a symptomatic high-grade internal carotid artery stenosis (>70%) were randomized to CAS or CEA. After a median observation time of 66 +/- 14.2 months (CAS) and 64 +/- 12.1 months (CEA), 42 patients in each group were re-evaluated retrospectively by clinical examination and documentation of neurologic events. Duplex ultrasound imaging was performed in 61 patients (32 CAS, 29 CEA), and patients with restenosis >70% were re-evaluated by angiography. During the observation period, 23 patients (25.2%) died (10 CAS, 13 CEA), and three were lost to follow up. The incidence of strokes was higher after CAS, with four strokes in 42 CAS patients vs none in 42 CEA patients. One transient ischemic attack occurred in each group. A significantly higher rate of restenosis >70% (6 of 32 vs 0 of 29) occurred after CAS compared with CEA. Five of 32 CAS patients (15.6%) presented with high-grade (>70%) restenosis as an indication for secondary intervention or surgical stent removal, and three presented with neurologic symptoms. No CEA patients required reintervention (P < .05 vs CAS). A medium-grade (<70%) restenosis was detected in eight of 32 CAS patients (25%) and in one of 29 CEA patients (3.4%). In five of 32 CAS (15.6%) and three of 29 CEA patients (10.3%), a high-grade stenosis of the contralateral carotid artery was observed and treated during the observation period. The long-term results of this prospective, randomized, single-center study revealed a high incidence of relevant restenosis and neurologic symptoms after CAS. CEA seems to be superior to CAS concerning the development of restenosis and significant prevention of stroke. However, the long-term results of the ongoing multicenter trials have to be awaited for a final conclusion.

Prevalence of Micro-Emboli in Symptomatic High Grade Carotid Artery Disease: A Transcranial Doppler Study

Background and purpose: Echolucent carotid plaques, as well as downstream micro-embolisation, may be associated with an increased risk of stroke. However, the relationship between carotid plaque ultrasound characteristics and micro-embolic signals (MES) detected in the middle cerebral artery (MCA) is still controversial. The purpose of this study was to investigate the prevalence of MES in patients with symptomatic high-grade internal carotid artery (ICA) stenosis and to identify predisposing factors, such as plaque echogenicity and intra stenotic blood flow velocity pattern. Methods: 197 patients (mean age 69.5 ± 8.6, 161 males) with confirmed symptomatic high-grade ICA stenosis and anti-platelet treatment underwent bilateral MES monitoring for 30 minutes within the anterior circulation, using Power M-mode transcranial Doppler techniques (TCD). Carotid artery plaques were characterized by Gray-Weale scaling. Results: In 32.0% of the patients, we detected MES by TCD within the MCA on the symptomatic side, but the same finding was made in only 4.5% on the corresponding asymptomatic site (p < 0.0001). The presence or absence of MES was associated with neither ultrasonic plaque characteristics nor the intrastenotic blood flow velocities at peak systole and end diastole. The median time since the last ischemic event symptoms was shorter in the patient group with MES [+] than in MES [−] (p = 0.013). Conclusions: Despite optimum standard anti-platelet therapy, cerebral micro-embolisation occurs in 30% of patients with symptomatic carotid artery disease, which might therefore be a possible risk factor for recurrent neurological symptoms. However, the presence of MES is independent of intrastenotic blood flow disturbances and grey scale ultrasound plaque characteristics. The presence of MES as an indicator of unstable plaque and thereby a possible risk factor for stroke should be evaluated prospectively using various algorithms for plaque classifications.

Prevalence of Micro-Emboli in Symptomatic High Grade Carotid Artery Disease: A Transcranial Doppler Study

Echolucent carotid plaques, as well as downstream micro-embolisation, may be associated with an increased risk of stroke. However, the relationship between carotid plaque ultrasound characteristics and micro-embolic signals (MES) detected in the middle cerebral artery (MCA) is still controversial. The purpose of this study was to investigate the prevalence of MES in patients with symptomatic high-grade internal carotid artery (ICA) stenosis and to identify predisposing factors, such as plaque echogenicity and intra stenotic blood flow velocity pattern. 197 patients (mean age 69.5+/-8.6, 161 males) with confirmed symptomatic high-grade ICA stenosis and anti-platelet treatment underwent bilateral MES monitoring for 30 minutes within the anterior circulation, using Power M-mode transcranial Doppler techniques (TCD). Carotid artery plaques were characterized by Gray-Weale scaling. In 32.0% of the patients, we detected MES by TCD within the MCA on the symptomatic side, but the same finding was made in only 4.5% on the corresponding asymptomatic site (p<0.0001). The presence or absence of MES was associated with neither ultrasonic plaque characteristics nor the intrastenotic blood flow velocities at peak systole and end diastole. The median time since the last ischemic event symptoms was shorter in the patient group with MES [+] than in MES [-] (p=0.013). Despite optimum standard anti-platelet therapy, cerebral micro-embolisation occurs in 30% of patients with symptomatic carotid artery disease, which might therefore be a possible risk factor for recurrent neurological symptoms. However, the presence of MES is independent of intrastenotic blood flow disturbances and grey scale ultrasound plaque characteristics. The presence of MES as an indicator of unstable plaque and thereby a possible risk factor for stroke should be evaluated prospectively using various algorithms for plaque classifications.

Immediate CEA for symptomatic carotid disease preferably performed under local anaesthesia is safe

Previous general reservations against carotid endarterectomy (CEA) early after stroke, which were primarily based on concerns of postoperative intracerebral hemorrhage, are resolved. Moreover, a delay of surgery is proofed to be associated with a risk of recurrent cerebral ischemia. However, the complication rate of CEA seems to increase with less time interval to the onset of symptoms. The main purpose of this study was to assess the safety of very early CEA. Patients having a symptomatic high-grade (> 70%) internal carotid artery (ICA) stenosis were referred by neurologists for CEA within different timeframes, so that they were later differentiated depending on whether surgery was performed within 2 days (immediate CEA = iCEA) or 2 weeks (urgent CEA = uCEA) after neurological deficits have occurred primarily. The perioperative complication rate in these groups was than evaluated and compared. From January 2000 until August 2006 130 consecutive patients (median age 68 years, range: 42-90; 66% male, 34%female)presenting with an ipsilateral TIA (n = 80), stroke (n = 50) underwent iCEA (n = 40) or uCEA (n = 90). Demographic and clinical characteristics were equally distributed between treatment groups. Mostly (121/130), CEA was performed under local anaesthesia with selective shunt use which became necessary in 26%. Besides postoperative hemorrhage (n = 4), cardiac complications (n = 2) and temporary cranial nerve lesions (n = 2), new perioperative neurological deficits occurred in total in 8 patients of which 6 were temporary. The other 2 patients developed strokes of which one patient died. Therefore, the combined stroke- and mortality rate was 1.5% (2/130) for the whole study population. With regard to the timing of surgery, a single incident was observed after iCEA (1/40) which also was the only intracerebral hemorrhage. It seems that patients with a symptomatic high-grade ICA stenosis can undergo CEA particularly under local anaesthesia as soon as possible without anticipating an increased complication rate.

Is Ultrasound Examination Sufficient in the Evaluation of Patients with Internal Carotid Artery Severe Stenosis or Occlusion?

Background and Purpose: Carotid endarterectomy (CE) has been shown to be beneficial in patients with symptomatic high-grade internal carotid artery (ICA) stenosis. Some authors have suggested that when ultrasound shows a stenosis 70–99%, CE can be performed without further imaging study. However, ultrasound findings that suggest an ICA occlusion, not confirmed by angiography but which instead show a near-occlusion usually benefit from CE. The objectives of this study are: (1) to evaluate how angiography-obtained information on intracranial arteries affects the treatment decision in patients with 70–99% ICA stenosis, and (2) to evaluate when a symptomatic ICA occlusion shown by ultrasound could actually be a patent artery and therefore benefit from CE. Materials and Methods: We prospectively collected the cerebral angiograms of 133 consecutive patients with TIA or non-disabling stroke due to large artery disease where ultrasound suggested a stenosis ≧70% or occlusion of symptomatic ICA; we calculated the frequency of intracranial vascular malformations and intracranial artery disease (IAD) located in the infraclinoid or supraclinoid portion of the ICA, and in the anterior or middle cerebral artery. Results: Ultrasound showed 31 ICA occlusions and 102 ICA with 70–99% stenosis. All the patients with an ICA stenosis 70–99% on ultrasound examination had the degree of stenosis confirmed by angiography. Two out of 31 patients did not have a complete occlusion but angiography showed a near-occlusion and consequently they underwent CE. Sixty-five (62.5%) out of 104 patients with patent ICA had IAD (mild 26.9%, moderate 21.2%, and severe 14.4%). Five patients (4.8%) had intracranial vascular malformations (4 aneurysms and 1 arteriovenous malformation). One patient had disabling stroke during angiography. Seven patients (6.7%) did not undergo CE after angiography (1 patient had an aneurysm >10 mm, 1 patient had a very tight stenosis of the basilar artery, 5 patients had intracranial stenosis more severe than the extracranial stenosis). Conclusions: In patients that on the basis of ultrasound examination can benefit from CE, information on intracranial arteries is necessary. Moreover, complete occlusion cannot be detected with certainty only by ultrasound examination.

Carotid endarterectomy in octogenarians with symptomatic high-grade internal carotid artery stenosis: long-term clinical and duplex follow-up.

The objective of this study was to evaluate the clinical and duplex outcome after carotid endarterectomy (CEA) in recently symptomatic patients aged 80 years or older. Information was assembled from a prospective data collection of all CEAs performed from January 1986 to December 1999. Included were all patients with recently symptomatic carotid artery stenosis who were aged 80 years or older at time of operation. Thirty-two patients, with a mean age of 82 years, were included. Outcome events were stroke, death, and restenosis (more than 50% diameter reduction) during routine duplex scan follow-up. Conventional surgical technique was used regarding anesthesia and selective shunting or patching. None of the operated-on patients suffered a stroke at any time during follow-up. One patient (3.1%) died in the early postoperative phase (<30 days). An additional 8 patients died during follow-up. None of these deaths were of cerebrovascular origin. Survival at 3 years was 73% (life table analysis). Routine duplex scan follow-up showed 2 patients with a diameter reduction of more than 50%, both 3 months after CEA. Restenosis rate on duplex scan was 7.4% after 1 year. The authors conclude that there seems to be no reason to deny the very elderly the benefits of CEA. Stroke-free survival and survival rates show that carotid surgery is a safe procedure in patients aged 80 and over who are in apparently good health. These findings are supported by a low incidence of restenosis on duplex scan follow-up, indicating a durable repair.

Coexistence of cardiac and aortic sources of embolization and high-grade stenosis and occlusion of the internal carotid artery

Background Patients who have had an endarterectomy for symptomatic high-grade internal carotid artery (ICA) stenosis (70 to 99) still have a 9 risk of having an ischemic stroke in the same surgical region 2 years later. Significant cardiac or aortic sources of embolization (CASOE) may coexist with high-grade stenosis and occlusion of the ICA. Methods : A retrospective-inpatient chart review of patients with a diseased ICA (high-grade stenosis or occlusion) that was confirmed by carotid duplex ultrasonography was performed. These charts contained the clinical reason for carotid ultrasonography, recent echocardiography, and when available, brain neuroimaging scans. Echocardiography was reviewed for the presence of a CASOE. Neuroimaging was reviewed for all types of infarctions. Brain neuroimaging was considered predictive of finding a CASOE by echocardiography when infarctions were present in vascular territories other than that supplied by the diseased ICA. Results : There were 46 patients that met the criteria of the study. From all the CASOEs present, aortic arch plaque greater than 4 mm (48) and left ventricular ejection fraction of less than 30 (44) were the sources most frequently found. Twenty-nine patients had ischemic hemispheric symptoms ipsilateral to the diseased ICA. A CASOE was present in 18 (62) of 29 patients who had ischemic hemispheric symptoms ipsilateral to the diseased ICA. Neuroimaging predicted that there would be a CASOE present by echocardiography ( P Conclusion : A CASOE may coexist with high-grade stenosis and occlusion of the ICA. A complete evaluation for both CASOEs and carotid embolism is necessary to determine the cause of the stroke symptoms.

B-mode Ultrasound Imaging in Symptomatic Internal Carotid Artery Stenosis: Correlation with Clinical and Operative Findings

B-mode ultrasound (duplex) imaging is a technique that enables the evaluation of plaque characteristics. The purpose of this study was to determine the accuracy and usefulness of duplex imaging by comparing a relationship between the preoperative clinical neurologic status, preoperative duplex findings, and operative findings in patients who had carotid endarterectomy (CEA) for symptomatic high-grade internal carotid artery (ICA) stenosis. Sixty patients with symptomatic ICA stenosis who underwent CEA from September 1995 to August 1998 were included in this study. Plaque morphology was categorized in terms of echogenicity by preoperative duplex imaging. A correlation between the frequency of preoperative ischemic stroke and duplex and operative findings was prospectively evaluated. Thirty-eight patients had recent and multiple cerebral ischemia, and 22 experienced a single episode more than 1 month before CEA. Recent and multiple events occurred in 24 (72.7%) of 33 patients with echolucent plaques, but only 6 (40.0%) of 15 with echogenic plaques (p&lt;0.05). Thirty-six (75%) of 48 patients with soft plaques by operative findings had recent and multiple events, but only two (16.7%) of 12 with calcified plaques experienced recent and multiple events (p&lt;0.01). Overall sensitivity, specificity, and accuracy of duplex imaging were 79.5%, 77.8%, and 79.2%, respectively. Duplex imaging is reliable in determining ICA plaque characteristics. Recent and multiple cerebral ischemia occurred more frequently in patients with echolucent plaques by preoperative duplex and soft plaques by operative findings. The presence of echolucent plaque may be used as a strong indication for CEA in patients who have asymptomatic high-grade ICA stenosis.