Carotid Endarterectomy For Asymptomatic Carotid Stenosis Research Articles

Carotid endarterectomy in the asymptomatic elderly: a systematic review of literature.

Asymptomatic carotid stenosis (ACS) carries a 4.7% risk of ipsilateral stroke if left untreated. Carotid endarterectomy (CEA) is a surgical intervention that has demonstrated efficacy in reducing stroke risk among symptomatic elderly. However, literature on its efficacy in preventing stroke in patients with ACS remains limited. Our systematic review summarizes evidence on the safety and efficacy of CEA in the asymptomatic elderly.PubMed and Scopus were searched to identify articles that described outcomes after CEA for ACS in patients aged ≥ 65 years old. Articles that did not report outcomes specific to the asymptomatic elderly were excluded. Outcomes of interest were technical success, stroke, death, myocardial infarction and post-operative complications. The Newcastle Ottawa Scale (NOS) was used to perform a qualitative assessment for risk of bias and studies with NOS ≥ 6 were considered high quality. This systematic review was performed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement.After a title and abstract screen, followed by a full-text review, 7 studies reporting outcomes in 76,404 patients were included. Five studies were retrospective and two were prospective. Among studies that reported criteria for intervention in ACS patients, 2 studies performed CEA for 70% stenosis and one performed CEA for 60% stenosis. One study reported outcomes for all ranges of stenosis (mild: 0-50%, moderate: 50-79% and severe: 80-99%). Clinical outcomes varied among included studies, with rates of death stroke and myocardial infarction ranging from 0.39 to 6.1%, 0.5-1.2% and 0.9-3%, respectively.The decision to perform CEA in patients with ACS is made after outweighing risks and benefits of surgery based on various factors like age, comorbidities and frailty. At present, evidence is largely limited to retrospective studies that utilized nationwide databases. Prospective studies and randomized controlled trials could help characterize the risk of CEA in this cohort.

Carotid Artery Stenting for Asymptomatic Carotid Stenosis: What We Need to Know for Treatment Decision.

A clinical decision on the treatment of asymptomatic carotid stenosis is challenging, unlike symptomatic carotid stenosis. Carotid artery stenting (CAS) has been recommended as an alternative to carotid endarterectomy (CEA) based on the finding that the efficacy and safety of CAS were comparable to CEA in randomized trials. However, in some countries, CAS is often performed more frequently than CEA for asymptomatic carotid stenosis. Moreover, it has been recently reported that CAS is not superior to the best medical treatment in asymptomatic carotid stenosis. Due to these recent changes, the role of CAS in asymptomatic carotid stenosis should be revisited. When determining the treatment for asymptomatic carotid stenosis, one should consider several clinical factors including stenosis degree, patient life expectancy, stroke risk by medical treatment, availability of a vascular surgeon, high risk for CEA or CAS, and insurance coverage. This review aimed to present and pragmatically organize the information that is necessary for a clinical decision on CAS in asymptomatic carotid stenosis. In conclusion, although the traditional benefit of CAS is being revisited recently, it seems too early to conclude that CAS is no longer beneficial under intense and systemic medical treatment. Instead, a treatment strategy with CAS should evolve to select eligible or medically high-risk patients more precisely.

Association between Race and Perioperative Outcomes after Carotid Endarterectomy for Asymptomatic Carotid Artery Stenosis in NSQIP.

Previous studies have documented that Black patients have worse outcomes after lower extremity revascularization procedures compared with White patients. However, the association of race on carotid endarterectomy (CEA) outcomes is not well described. The aim of this study was to compare perioperative outcomes of CEA for Black vs White patients with asymptomatic carotid artery stenosis. All patients who underwent CEA for asymptomatic carotid stenosis in the ACS-NSQIP targeted vascular database (2011-2019) were included. Perioperative (30-day) outcomes were compared for Black vs White patients using multivariable logistic regression adjusting for age/sex, comorbidities, and disease characteristics. Of 16,764 asymptomatic CEA patients, 95.2% (N = 15,960) were White and 4.8% (N = 804) were Black. Black patients were slightly younger (mean age 71.4 ± 0.1 vs 69.9 ± 0.3 years, P < 0.001) and more frequently had high-grade carotid artery stenosis compared to White patients (79.5% vs 74.0%, p = 0.001). Comorbidities including hypertension, diabetes, kidney disease, congestive heart failure, and coronary artery disease were all more prevalent among Black patients (p ≤ 0.01). Crude perioperative stroke (2.4% vs 1.3%, p = 0.007) and stroke/death (2.6% vs 1.4%, p = 0.003) were higher for Black patients, but myocardial infarction (1.7% vs 1.5%, p = 0.67) and death (0.4% vs 0.2%, p = 0.12) were similar. After adjusting for baseline differences between groups, the risk of perioperative stroke (odds ratio 1.66, 95% CI 1.01 to 2.73) and stroke/death (odds ratio 1.75, 95% CI 1.10 to 2.81) remained significantly higher for Black patients compared with White patients. Black patients undergoing CEA for asymptomatic carotid artery stenosis had more severe stenosis, more comorbidities, and worse perioperative outcomes compared to White patients. Overall, our data suggest substantial differences in the treatment and outcomes of asymptomatic carotid artery stenosis based on race.

Changes in Cognition and Hemodynamics 1 Year after Carotid Endarterectomy for Asymptomatic Stenosis.

The impact of a change in hemodynamics on cognitive skills in patients with asymptomatic carotid stenosis (ACS) after carotid endarterectomy (CEA) remains unclear. The aim of this study was to evaluate the results of CEA for ACS at 1 year by assessing the changes in anterior, middle, and posterior cerebral artery blood flow in tandem with changes in cognitive efficiency. Flow volume in cerebral arteries using quantitative magnetic resonance angiography was measured in a group of 14 males and 5 females before and at 1 year after CEA for ACS. Cognitive efficiency was assessed by Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The values of flow volume were processed using simple ratio (SR) and were used for covariance analyses with changes in cognitive skills after CEA. A significant improvement in cognitive efficiency indexes of immediate memory and visuospatial perception at 1 year after CEA for ACS was observed. Simultaneously, a significant deterioration of speech index was noted. During the analysis of association between flow and cognition, the highest correlation could be seen between the middle cerebral artery (MCA) flow and the visuospatial perception. A change in posterior cerebral artery (PCA) flow was associated with an increase in immediate memory index and anterior cerebral artery (ACA) flow change with the speech index. Convergence of data supporting the association between revascularization and cognitive improvement were added in a small, single-center cohort of ACS patients undergoing CEA. No significant differences in cognition were seen between preoperative findings and at 1 year after CEA. Visuospatial perception improvement was linked to flow change in MCA, immediate memory improvement to flow change in PCA, and speech index change to flow change in ACA. Methodical limitations of this small study preclude formulating larger generalizations. Hemodynamic factors in CEA should be assessed in a larger-scale study.

Predictors and Consequences of Silent Brain Infarction in Patients with Asymptomatic Carotid Stenosis

AimSilent brain infarction (SBI) is associated with an increased risk of stroke in patients with asymptomatic carotid stenosis (ACS), and is therefore one of the criteria for performing carotid endarterectomy (CEA). Despite an extensive literature, this issue is still a matter of debate. Aim of the present work was to evaluate incidence and predictors of SBI in patients undergoing CEA for ACS, and to investigate its possible impact on CEA outcome. MethodsAll patients submitted to CEA in a single academic center from 2005 to 2019 were prospectively inserted into a specific database. The presence of SBI was evaluated by preoperative computed tomography (CT), considering exclusively infarctions in the carotid territories from an athero-embolic source. Preoperative characteristics were investigated as possible risk factor for SBI at the uni- and multivariate analysis. The impact of SBI on stroke occurrence after CEA was also evaluated. ResultsIn the designated period, over a total of 1288 ACS considered and submitted to CEA, 105 (8.2%) were associated with SBI. Male sex, hypertension, dyslipidaemia, smoking, contralateral carotid occlusion and severity of carotid stenosis were associated with SBI at the univariate analysis; preoperative statin therapy showed to be a protective factor. At the multivariate analysis, contralateral carotid occlusion and severity of stenosis were independently associated with SBI (OR: 3.16, 95%CI 1.62–6.18, P=.001; OR: 1.04, 95%CI 1.01–1.07, P=.004, respectively), with statin therapy confirmed as a protective factor (OR: 0.60, 95%CI: 0.40–0.92, P=.002). Overall post-CEA stroke rate was 0.9%, with a higher post-operative risk independently predicted by the presence of SBI (OR:4.23, 95%CI: 1.40–12.73, P=.01). ConclusionSBI is present in 8% of patients with ACS, and is significantly associated with contralateral carotid occlusion and severity of the carotid stenosis. Statin therapy reduces the occurrence of this phenomenon. The presence of SBI should be carefully considered in indication to CEA since it significantly increases the surgical risk

Carotid Endarterectomy With Shunt for Preoperative or Intraoperative Indication Is Associated With Increased Rate of Stroke

Carotid endarterectomy (CEA) is performed frequently both with and without the use of shunting, and previous studies have shown similar 1% to 2% rates of stroke with both techniques in asymptomatic patients. The rate of stroke when shunting is performed for a preoperative or intraoperative indication remains understudied. We aimed to evaluate the rate of stroke by shunt indication and to compare this cohort with routine shunt and no shunt cohorts in a large national registry. The Vascular Quality Initiative CEA registry was used to identify patients undergoing CEA for asymptomatic carotid stenosis from 2013 to 2019. Exclusion criteria included symptomatic patients (defined as ipsilateral transient ischemic attack or stroke within 6 months of operation), concomitant coronary intervention, proximal or distal endovascular intervention, and urgent or emergent procedures. Categorical variables were analyzed using χ2 test, and continuous variables were analyzed using analysis of variance. Multivariable logistic regression was used to evaluate demographic and perioperative predictors of stroke. There were 69,903 CEAs identified, which consisted of 33,459 without shunt, 31,711 routine shunts, 1369 shunts for preoperative indication, and 3364 shunts for intraoperative indication patients. The cohort with shunt for preoperative indication was more likely to be male, to be transferred from an outside hospital, and to have contralateral internal carotid artery (ICA) occlusion. In addition, the cohorts with shunt for indication had slightly increased procedure length, rates of re-exploration at time of initial operation, and protamine use (Table I). The rate of stroke was increased in shunt for preoperative and intraoperative indication cohorts (no shunt, 0.8%; routine shunt, 0.9%; preoperative indication, 1.8%; intraoperative indication, 1.3%; P < .01). On multivariable analysis, both shunt for preoperative indication and shunt for intraoperative indication are associated with stroke. Other perioperative and demographic variables associated with stroke include hypertension, any prior neurologic event, contralateral ICA occlusion, completion angiography, postoperative hemodynamic instability requiring intravenous medications, and re-exploration at the time of initial operation (Table II). The proportion of shunt for preoperative indication varies by region (East, 1.4%; North, 2.2%; South, 1.5%; West, 4.3%; P < .01). Regional variation is present in preoperative indication for shunt as the proportion of patients with contralateral ICA occlusion or >60% contralateral ICA stenosis varied widely (East, 55.3%; North, 62.9%; South, 52.2%; West, 47.6%; P < .01). CEA with shunt for preoperative or intraoperative indication is associated with increased rates of stroke, even in asymptomatic patients, suggesting a high-risk cohort that is poorly defined by registry data. Identifying this cohort may alter the risk-benefit ratio of the operation and inform clinical decision-making.Table IDemographic characteristics, preoperative workup, and intraoperative variablesDemographic characteristicsNo shunt (n = 33459)Routine shunt (n = 31711)Shunt: Preop indication (n = 1369)Shunt: Intraop indication (n = 3364)PAge, years (SD)70.7 (8.7)71.0 (8.8)70.4 (9.1)71.1 (8.9)<.01Sex (male)20263 (60.6)18715 (59.0)876 (64.0)1918 (57.0)<.01Comorbidities HTN29950 (89.5)28615 (90.2)1236 (90.3)3079 (91.5)<.01 CAD9092 (27.2)9061 (28.6)404 (29.5)926 (27.6)<.01 CHF3659 (10.9)3637 (11.5)157 (11.5)391 (11.6).15 Diabetes11988 (35.8)11881 (37.5)508 (37.1)1280 (38.0)<.01 Current Smoker7976 (23.8)8043 (25.4)330 (24.1)885 (26.3)<.01 ESRD352 (1.1)366 (1.2)16 (1.2)49 (1.5).16 ASA Class ≥45539 (16.6)6026 (19.0)274 (20.0)605 (18.0)<.01 Lived at Home33178 (99.2)31343 (99.1)1346 (98.4)3313 (98.5)<.01 Transfer OSH383 (1.1)341 (1.1)35 (2.6)46 (1.4)<.01Neurologic History Ipsi Neuro Event >6 months1891 (5.7)1803 (5.7)147 (10.8)214 (6.4)<.01 Ipsi Stroke >6 months1110 (3.3)1075 (3.4)103 (7.5)138 (4.1)<.01 Contra CEA5213 (15.6)5169 (16.3)156 (11.4)528 (15.7)<.01 Contra ICA Occlusion937 (2.8)1620 (5.2)370 (27.4)336 (10.3)<.01 Ipsi Stenosis ≥70%30362 (92.1)28306 (91.3)1232 (91.4)2932 (90.2)<.01 Contra Stenosis ≥70%6116 (18.6)5888 (19.0)314 (23.3)624 (19.2)<.01 Anatomic High Risk1433 (4.3)1232 (3.9)53 (3.9)147 (4.4).06Operative Factors Procedure Length (SD)114 (44)112 (42)122 (44)121 (43)<.01 Protamine23494 (70.2)21643 (68.3)985 (72.0)2581 (76.8)<.01 Patch27831 (83.3)30607 (96.5)1289 (94.2)3165 (94.1)<.01 Re-explore at Initial Operation459 (1.4)390 (1.2)19 (1.4)72 (2.1)<.01ASA, American Society of Anesthesiologists; CAD, coronary artery disease; CHF, congestive heart failure; Contra, contralateral; ESRD, end stage renal disease requiring dialysis; HTN, hypertension; ICA, internal carotid artery; Ipsi, ipsilateral; Neuro, neurologic event >6 months from procedure; OSH, outside hospital; SD, standard deviation. Open table in a new tab Table IIMultivariable logistic regression: strokeStrokeOdds ratio (OR)95% Confidence intervalPP2Y12 Inhibitor0.640.53-0.77<.01Male Gender0.810.69-0.96.02Shunt for Intraop Indication1.431.02-2.01.04Shunt for Preop Indication1.611.05-2.53.03Completion Angiogram1.691.22-2.35<.01Hypertension1.701.20-2.40<.01Contralateral ICA Occlusion1.781.34-2.38<.01Any Prior Neurologic Event1.931.63-2.29<.01Postop IV Medication for Hemodynamic Instability3.432.91-4.05<.01Re-explore at Initial Operation9.5411.31-17.08<.01 Open table in a new tab

Defining the threshold surgeon volume associated with improved patient outcomes for carotid endarterectomy

ObjectiveThe outcomes for common vascular operations, such as carotid endarterectomy (CEA), are associated with surgeon volume. However, the number of operations associated with an improved stroke or death rate for CEA is not known. The objective of the current study was to define the annual surgeon volume of CEAs that is associated with a lower risk of stroke or death rate. MethodsThe Nationwide Inpatient Sample was analyzed to identify patients undergoing CEA between 2003 and 2009. Annual surgeon volume was correlated with a composite end point of in-hospital stroke or death. Mixed linear regression analyses were conducted to determine if annual surgeon volume of CEAs is independent predictor of the composite outcome. Receiver operating characteristic curves were constructed from the regression models and used to calculate the Youden Index, which defined the optimal cutoff point of annual surgeon volume of CEAs in predicting in-hospital stroke and death. This cutoff point was further assessed using Chi square analyses to determine whether incremental increases in the annual volume of CEAs were associated with a lower in-hospital stroke or death rate. ResultsA total of 104,918 CEA cases with surgeon identifiers were included in the analysis. The crude in-hospital stroke or death rate for CEA was 1.26 %. As expected, the stroke or death rate after CEA was higher for symptomatic patients, compared to asymptomatic patients (6.46 % vs 0.72%; P < .0001). For symptomatic patients, the relationship between surgeon volume and the composite end point was not significant (P = .435). In contrast, there was a strong relationship between surgeon volume and outcomes for asymptomatic patients undergoing CEA with a stroke/death rate of 1.66%, 0.91%, and 0.65% for low-, moderate-, and high-volume surgeons (P < .0001). Multivariate analysis identified age, African-American race, Charlson Comorbidity Index, and surgeon volume as independent predictors of stroke/death after CEA for asymptomatic carotid stenosis. For asymptomatic patients, the optimal cutoff number of CEAs to predict stroke/death rate was 19.4 CEAs per year (sensitivity = 74.9%, specificity = 72.6%, Youden index = 0.475). Analyses of outcomes at different cutoff points of surgeon volume revealed that the rate of crude complications and the adjusted probability of stroke or death was higher with case numbers less than 20 CEAs per year and lower with case numbers of 20 CEA or higher per year. Cutoff points above 20 cases were year did not yield a stroke/death rate that was significantly lower than the stroke/death rate at 20 CEAs per year, which confirmed the cutoff point of 20 CEAs per year. Only 16% of surgeons in the database achieved the threshold of 20 CEAs per year. ConclusionsHigher surgeon volume is associated with improved outcomes for CEAs performed in patients with asymptomatic carotid disease, but not for symptomatic carotid disease. For asymptomatic carotid disease, the probability of stroke or death was no longer reduced significantly at cutoff points of 20 or more CEAs per year. There are a number of other variables that may impact the clinical outcomes for CEA, so it is premature at this time to restrict privileges based on surgeon volume criteria.

Results of Carotid Endarteriectomy under Locoregional Anesthesia in acute Ischemic Stroke with Watershed zone Infarction Population

Introduction: Cerebral border zone infarctions (Watershed infarctions) on the early postoperative outcomes of patient undergoing carotid endarterectomy (CEA) were associated, in several studies, with a higher neurological complication rate. The current hypothesis is that hemodynamic phenomenon is involved. CEA performed under locoregional anesthesia enable to instantly reveal any hemodynamic phenomenon. The aim of this study was to compare the outcomes of carotid endarteriectomy carried out under locoregional anesthesia after watershed infarction ( WI ) with territorial infarction (TI) . Methods: This prospective study is based on patients admitted, between September 2014 and December 2017, with symptomatic carotid stenosis that underwent ipsilateral CEA after a WI or a TI within the first 30 days of their stroke. Using topographic pattern of the stroke on magnetic resonance imaging, the studied patients were sorted into two groups. The sorting was managed by two neuro vascular physicians. In case of discrepancies, the final diagnosis was made by a university neuroradiologist professor. All surgeries were carried out under locoregional anesthesia. Results: A total of 222 patients underwent CEA for a symptomatic carotid stenosis during this study. 98 patients were included, 65 in the WI group and 33 in the TI groupe. The discrepancy rate was 4%. The surgery and the clamping time was similar in the two groups. There was no significant difference in ipsilateral carotid stenosis in both groups. The median time between the stroke and the surgery was 11 days ( range : 2-30 days). Postoperative mortality was 2% : 1 in the WI group (1,5%) and 1 in the TI group (3%). There was not significant difference in both groups (p=0,27). One patient had an immediate postoperative stroke in the WI group. There were 4 shunts ( 6%) in the WI group and 2 (6%) in the TI group. There was however a significant difference between the two groups regarding the controlateral stenosis > 50% and the presence of incomplete circle of Willis: there were 10 (15%) controlateral stenosis > 50% in the WI groupe and 11 in the TI group ( 33% p=0,04). There were an incomplete circle of Willis for 4 patients in the WI groupe (6%) and 12 in the TI group (36%; p < 0,0001). Conclusion: Watershed zone infarction does not increase the occurrence of clamping intolerance and does not increase the 30-day mortality and postoperative cerebral stroke after carotid endarterectomy under locoregional anesthesia. Disclosure: Nothing to disclose

The Value of a Carotid Duplex Surveillance Program for Stroke Prevention

Although duplex ultrasonography (DU) can readily identify progression of carotid stenosis, controversy regarding the natural history of asymptomatic carotid stenosis as well as the need and appropriate interval for carotid DU surveillance still exists. Furthermore, consensus has not yet been made in the surgical literature regarding the usefulness, cost-effectiveness, or timing of DU surveillance after carotid endarterectomy (CEA). The purpose of this study was to determine how often DU surveillance for asymptomatic carotid disease or postintervention stenosis resulted in any change in the patient's clinical management, how many strokes were prevented by DU surveillance, and the cost of such a DU surveillance program per stroke prevented. We reviewed a 9-year vascular surgical database to identify all patients enrolled in a carotid DU surveillance program for asymptomatic carotid stenosis or following CEA between January 1, 2000, and December 31, 2008. The number of duplex scans and CEAs performed in those patients through March 2010 was also determined. The results of the Asymptomatic Carotid Atherosclerosis Study were then used to estimate the number of strokes prevented by CEA in the study population. Reimbursement data were assessed to calculate the average cost of each DU and the cost of the DU surveillance program for each stroke prevented. During the study period, there were 11,531 carotid duplex scans performed on 3,003 patients (mean: 3.84 scans per patient) who had been enrolled in the DU surveillance program. CEA for asymptomatic carotid stenosis was performed on 225 (7.5%) patients. The DU surveillance program prevented approximately 13 strokes (871 carotid duplex scans per stroke prevented). The mean cost of each duplex scan was $332 ± 170. The total cost of the DU surveillance program was approximately $3,830,000 or $290,000 per stroke prevented. Although a carotid DU surveillance program generates substantial revenue for a vascular surgery practice, it is costly and inefficient. A reappraisal of the "value" of carotid DU surveillance in stroke prevention is warranted. Consideration should be given to eliminating routine surveillance of postendarterectomy carotids in the absence of contralateral disease and limiting the number of DU surveillance studies for asymptomatic carotid disease.

Contemporary Results of Carotid Endarterectomy for Asymptomatic Carotid Stenosis

The validity of carotid endarterectomy (CEA) for asymptomatic carotid stenosis has been questioned recently due to the increasing effectiveness of medical management. In this study, we evaluated how contemporary outcomes of CEA for asymptomatic carotid stenosis compare with published stroke rates for best medical management. We identified all patients who underwent CEA for asymptomatic carotid stenosis from the 2005, 2006, and 2007 National Surgical Quality Improvement Program (NSQIP) database. Pre- and postoperative variables, including 30-day stroke, death, and myocardial infarction, were analyzed. Of 10 423 carotid endarterectomies identified, 5009 were for asymptomatic carotid stenosis. The stroke, death, and myocardial infarction rates of this group were 0.96%, 0.56%, and 0.22%, respectively. If the 0.96% perioperative stroke rate from our contemporary NSQIP analysis is combined with the 5-year stroke risk after CEA of 3.8% from the Asymptomatic Carotid Surgery Trial, the average annual stroke rate is 1%, comparable to the stroke rate of 0.8% for best medical management from the Second Manifestations of Arterial Disease Study trial. These contemporary results show that stroke rates with CEA and best medical management for asymptomatic stenosis are similar. Despite limitations, our results emphasize the importance of continuing randomized prospective trials comparing CEA and best medical management for asymptomatic carotid stenosis.

Carotid endarterectomy for asymptomatic carotid stenosis

Carotid endarterectomy (CEA) is of proven benefit in recently-symptomatic patients with severe carotid stenosis. Its role in asymptomatic stenosis is still debated. The Asymptomatic Carotid Surgery Trial (ACST) more than doubled the number of patients randomised to CEA trials. This revised review incorporates the recently published ACST results. Our objective was to determine the effects of CEA for patients with asymptomatic carotid stenosis. We searched the Cochrane Stroke Group Trials Register (searched May 2004), MEDLINE (1966 to May 2004), EMBASE (1980 to June 2004), Current Contents (1995 to January 1997), and reference lists of relevant articles. We contacted researchers in the field to identify additional published and unpublished studies. All completed randomised trials comparing CEA to medical treatment in patients with asymptomatic carotid stenosis. Two reviewers extracted data and assessed trial quality. Attempts were made to contact investigators to obtain missing information. Three trials with a total of 5223 patients were included. In these trials, the overall net excess of operation-related perioperative stroke or death was 2.9%. For the primary outcome of perioperative stroke or death or any subsequent stroke, patients undergoing CEA fared better than those treated medically (relative risk (RR) 0.69, 95% confidence interval (CI) 0.57 to 0.83). Similarly, for the outcome of perioperative stroke or death or subsequent ipsilateral stroke, there was benefit for the surgical group (RR 0.71, 95% CI 0.55 to 0.90). For the outcome of any stroke or death, there was a non-significant trend towards fewer events in the surgical group (RR 0.92, 95% CI 0.83 to 1.02). Subgroup analyses were performed for the outcome of perioperative stroke or death or subsequent carotid stroke. CEA appeared more beneficial in men than in women and more beneficial in younger patients than in older patients although the data for age effect were inconclusive. There was no statistically significant difference between the treatment effect estimates in patients with different grades of stenosis but the data were insufficient. Despite about a 3% perioperative stroke or death rate, CEA for asymptomatic carotid stenosis reduces the risk of ipsilateral stroke, and any stroke, by approximately 30% over three years. However, the absolute risk reduction is small (approximately 1% per annum over the first few years of follow up in the two largest and most recent trials) but it could be higher with longer follow up.

Carotid Artery Angioplasty and Stent Placement: Quality Improvement Guidelines to Ensure Stroke Risk Reduction

CERVICAL carotid atherosclerotic stenosis has been correctly surmised to be a potentially preventable cause of stroke for a half-century. For most of this time, neither the absolute risk of the condition nor the specific contributing factors were known. Not surprisingly, therefore, medical therapy was poorly understood and offered a limited armamentarium. Prior dogma maintained that medical therapy alone neither significantly affected the progression of atherosclerosis nor caused its regression. Today an extensive body of literature confirms that cervical carotid artery atherosclerosis is common, relatively easy to evaluate, a major health threat, and surgically correctable. The appropriateness of carotid endarterectomy (CEA) has been evaluated by at least seven randomized trials, and further study is warranted and ongoing. While great strides have been made in the last decade in understanding cervical carotid atherosclerotic stenosis, there are still many important unknowns concerning the clinicopathologic condition, its various manifestations, precipitating biochemical and pathophysiologic events, specific patient risk characteristics, optimal medical therapy, as well as indications for, and best methods of, surgical and interventional therapies. Perhaps one of the best examples of the evolutionary nature of knowledge in this field is the relatively new concept that the principal culpability for clinical neurologic events is not the “degree-of-stenosis” per se, but rather the pathology of the plaque and the ischemia produced by atherothrombotic emboli. This belief is universally accepted in the cardiovascular community but seems to be under-appreciated in the neuroscience community. The ultimate confirmation of this concept is the 10-fold or greater difference in risk for someone with an 80% “nonembologenic” (ie, “asymptomatic”) carotid stenosis as compared to an 80% “embologenic” (symptomatic) stenosis. For the former there is about 1% to 2% per year stroke risk from the lesion itself as compared to the latter, which has about 10% to 20% risk of stroke in the first year (1,2). Further, recent studies of newer pharmacologic agents including antiplatelet agents (such as clopidogrel) and plaque-stabilizing agents (such as HMGCoA-reductase inhibitors [“statins”] and angiotensin converting enzyme [“ACE”] inhibitors) do indeed demonstrate that the natural history of atherosclerotic plaques can be positively influenced in a way that changes the risk/benefit ratio of all therapies for not only coronary atherosclerosis but also for carotid atherosclerosis (3,4). However, none of these new medical therapies have been systematically compared to CEA or carotid artery stent placement (CAS) in controlled clinical trials aimed at evaluating the best method to reduce stroke and stroke-related morbidity and mortality. In March 2000, the American Society of Interventional and Therapeutic Neuroradiology (ASITN), the specialty organization then composed primarily of neuroradiologists and neurosurgeons most involved with cervico-cerebral angiography and cervical and intracranial endovascular intervention, published a review and analysis of the current literature on carotid atherosclerosis and its treatment (5). Since that time, continued progress has been made in further understanding the nature of carotid atherosclerosis, improving surgical techniques, advancing the pharmaceutical armamentarium, and refining a potential endovascular therapy: carotid artery angioplasty and stent placement. Three medical societies that include training in cervico-cerebral angiography as part of their ACGME defined residency programs, the ASITN, the American Society of Neuroradiology (ASNR), and the Society of Interventional Radiology (SIR), recognize the importance of carotid atherosclerosis and its appropriate management. In this issue of the Journal of Vascular and This article also appears in J Vasc Interv Radiol 2003; 14:1095–1097. From the Miami Cardiac and Vascular Institute, Miami, FL (J.J.C., G.J.B.), Department of Radiology, Reading Hospital and Medical Center, Reading PA (D.S.), and Mid-South Imaging and Therapeutics, Memphis, TN (J.D.B.). Received July 3, 2003; accepted August 6. Address correspondence to J.J.C., MCVI, 8900 Kendall Dr, Miami, FL 33176. E-mail budmancon@aol.com

Perioperative Stroke Prevention

The definitions of commonly used terms are given in Table 1 (1–8). Stroke has been simply defined as any form of cerebral infarction (2), which includes those attributable to hemorrhage. The latter group is more likely to occur as a complication of specific surgical procedures (e.g., carotid endarterectomy) or the use of anticoagulants and is otherwise rare in the perioperative period (3). Hence, much of the information in this review pertains to ischemic cerebral events.

Attitudes of Canadian and U.S. Neurologists Regarding Carotid Endarterectomy for Asymptomatic Stenosis

The American Heart Association carotid endarterectomy (CE) guidelines endorse CE for asymptomatic carotid stenosis if the procedure can be performed with low morbidity. However, the Canadian Stroke Consortium has published a consensus against CE for asymptomatic stenosis. The views of practicing neurologists in the two countries on this subject are unclear. A survey was undertaken of 270 neurologists from either Florida or Indiana and 180 neurologists from either Ontario or Quebec. The survey was returned by 36% of neurologists. Both Florida (65%) and Indiana neurologists (35%) were significantly more likely than Canadian neurologists (11%) to sometimes/often refer patients for surgery(p<0.001). Neurologists from Florida relied more on noninvasive methods of carotid stenosis assessment (36%) than Canadian neurologists (12%, p=0.003), who preferred angiography. Neurologists from Florida more often cited medicolegal concerns as a reason for referring patients for surgery (27%), compared to Canadian neurologists (3%, p=0.0001). Practices pertaining to carotid stenosis evaluation and management differ both regionally and by country. Canadian neurologists refer fewer asymptomatic patients for CE and rely more on angiography as a preoperative diagnostic tool. The potential of medicolegal liability is a greater force in clinical decision-making for certain U.S. neurologists, compared to their Canadian counterparts. These differences may partly explain the variations in CE utilization in the two countries.

Carotid endarterectomy for asymptomatic carotid stenosis.

Whilst carotid endarterectomy (CEA) is of proven benefit in recently symptomatic patients with severe carotid stenosis, the role of carotid endarterectomy in preventing stroke in patients with asymptomatic carotid stenosis remains uncertain. The objective of this review therefore was to determine the effects of CEA for patients with asymptomatic carotid stenosis. We searched the Cochrane Stroke Group Trials Register (June 1998), Medline (1966-Mar 1998), Current Contents (1995-Jan 1997), and reference lists of relevant articles. We contacted researchers in the field to identify additional published and unpublished studies. All completed randomised trials comparing CEA to medical treatment in patients with asymptomatic carotid stenosis. Two reviewers extracted data and assessed trial quality. Attempts were made to contact investigators to obtain missing information. Six trials were identified, but two were excluded on methodological grounds. Four trials with 2203 patients were included. In two trials aspirin was only given to patients in the medical group, and in two all patients received aspirin. The net excess "perioperative stroke or death" rate in the surgical group was 2.7% with relative risk 6.52 (95% confidence interval 2.66-15.96). The rates of "perioperative stroke or death or subsequent ipsilateral stroke" were 6.8% in the medical group vs 4.9% in the surgical group with RR 0.73 (0.52-1.02) favouring surgery. The rates of "any stroke or perioperative death" were 10.4% (medical) vs 8.1% (surgical) with RR 0.79 (0.60-1.02). The rates of "any stroke or death" were 23.2% (medical) vs 20.2% (surgical) with RR 0.89 (0.76-1.04). There were too few patients in CEA vs aspirin trials to determine whether aspirin had any confounding effect on outcome. An additional analysis including data from a fifth small unpublished trial altered slightly the risk ratios in favour of surgery and narrowed confidence intervals sufficiently to achieve statistical significance for each outcome. However, inclusion of these data had no appreciable effect on relative or absolute risk reduction. There is some evidence favouring CEA for asymptomatic carotid stenosis, but the effect is at best barely significant, and extremely small in terms of absolute risk reduction.

Cerebral tomographic findings in patients undergoing carotid endarterectomy for asymptomatic carotid stenosis: short-term and long-term implications

Purpose: Preoperative cerebral imaging has been considered not to be cost-effective in carotid endarterectomy (CEA) for asymptomatic carotid stenosis. Yet, silent brain infarction (SBI) has been associated with the embolization potential of a severe carotid stenosis. Thus the presence of SBI may represent an additional indication for CEA in asymptomatic patients. We examined the predictive value of preoperatively detected silent cerebral lesions on early and late outcomes in patients undergoing CEA for asymptomatic carotid stenosis. Methods: Preoperative cerebral tomographic (CT) scans performed on 301 asymptomatic patients undergoing 346 CEAs from 1986 to 1995 were reviewed by a single neuroradiologist blinded to patients' records. Mean follow-up was 67.3 months (range, 24-130 months). The degree of internal carotid lumen reduction was measured bilaterally in all patients (602 carotid arteries); carotid stenosis of 60% or more was found in 399 carotid arteries. Results: Of the 103 (34%) CT scans positive for cerebral lesions, 58% were lacunar. No significant association was observed between the side of the cerebral lesion on CT scan and the severity of the corresponding carotid stenosis; 38 silent lesions were detected in the 203 hemispheres ipsilateral to carotid stenoses that were less than 60% versus 95 SBIs in the 399 hemispheres ipsilateral to carotid stenoses that were 60% or more (19% vs 24%; P = .2). There were no significant differences in the perioperative stroke/death rate in patients with or without cerebral CT lesions (2% vs 1%; odds ratio, 1.94; P = .6). Mortality rate during follow-up was 22% in patients with preoperative SBI and 15% in patients without SBI ( P = .1). However, actuarial survival at 10 years was shorter ( P = .02) in patients with SBI. Late stroke occurred in 11% of patients with preoperative SBI and in 3% of patients without preoperative SBI ( P = .006). Cox regression analysis showed that both preoperative lacunar and nonlacunar infarctions were independent predictors of late stroke (hazard ratio, 3.6; P = .04; and hazard ratio, 7.1; P = .001; respectively). Conclusion: In our experience, preoperative SBI did not occur more frequently in the hemisphere ipsilateral to asymptomatic severe carotid stenosis. Although our study lacks a medically treated control group, our data show that SBI is predictive of poor neurologic outcome in asymptomatic patients undergoing CEA. We conclude that CT before CEA, selectively applied, provides information on long-term neurologic prognosis and that a less aggressive attitude towards CEA in asymptomatic patients with SBI may be justified. (J Vasc Surg 1999;29:995-1005.)