Degree Of Contralateral Stenosis Research Articles

Impact of intraoperative neurologic deficits in carotid endarterectomy under regional anesthesia

Objective Patients undergoing carotid endarterectomy (CEA) may experiment neurologic deficits during the carotid cross-clamping due to secondary cerebral hypoperfusion. An associated risk of postoperative stroke incidence is also well established. This work aimed to assess the postoperative adverse events related to neurologic deficits in the awake test after clamping and to determine its predictive factors. Methods. From January 2012 to January 2018, 79 patients from a referral hospital that underwent CEA with regional anesthesia for carotid stenosis and manifested neurologic deficits were gathered. Consecutively selected controls (n = 85) were submitted to the same procedure without developing neurological changes. Postoperative complications such as stroke, myocardial infarction, all-cause death, and Clavien–Dindo classification were assessed 30 days after the procedure. Univariate and binary logistic regressions were performed for data assessment. Results. Patients with clamping associated neurologic deficits were significantly more obese than the control group (aOR = 9.30; 95% CI: 2.57–33.69; p = .01). Lower degree of ipsilateral stenosis and higher degree of contralateral stenosis were independently related to clamping intolerance (aOR = 0.70; 95% CI: 0.49–0.99; p = .047 and aOR = 1.30; 95% CI: 1.06–1.50; p = .009, respectively). Neurologic deficits were a main 30-day stroke predictor (aOR = 4.30; 95% CI: 1.10–16.71; p = .035). Conclusions. Neurologic deficits during carotid clamping are a predictor of perioperative stroke. Body mass index > 30 kg/m2, a lower degree of ipsilateral stenosis, and a higher degree of contralateral stenosis are independent predictors of neurologic deficits and, therefore, might play a role in the prevention of procedure-related stroke.

Can risk modelling improve treatment decisions in asymptomatic carotid stenosis?

BackgroundCarotid endarterectomy (CEA) is routinely performed for asymptomatic carotid stenosis, yet its average net benefit is small. Risk stratification may identify high risk patients that would clearly benefit from treatment.MethodsRetrospective cohort study using data from the Asymptomatic Carotid Atherosclerosis Study (ACAS). Risk factors for poor outcomes were included in backward and forward selection procedures to develop baseline risk models estimating the risk of non-perioperative ipsilateral stroke/TIA. Baseline risk was estimated for all ACAS participants and externally validated using data from the Atherosclerosis Risk in Communities (ARIC) study. Baseline risk was then included in a treatment risk model that explored the interaction of baseline risk and treatment status (CEA vs. medical management) on the patient-centered outcome of any stroke or death, including peri-operative events.ResultsThree baseline risk factors (BMI, creatinine and degree of contralateral stenosis) were selected into our baseline risk model (c-statistic 0.59 [95% CI 0.54–0.65]). The model stratified absolute risk between the lowest and highest risk quintiles (5.1% vs. 12.5%). External validation in ARIC found similar predictiveness (c-statistic 0.58 [0.49–0.67]), but poor calibration across the risk spectrum. In the treatment risk model, CEA was superior to medical management across the spectrum of baseline risk and the magnitude of the treatment effect varied widely between the lowest and highest absolute risk quintiles (3.2% vs. 10.7%).ConclusionEven modestly predictive risk stratification tools have the potential to meaningfully influence clinical decision making in asymptomatic carotid disease. However, our ACAS model requires target population recalibration prior to clinical application.

Characterization of perioperative contralateral stroke after carotid endarterectomy

ObjectiveContralateral stroke is an infrequent cause of perioperative stroke after carotid endarterectomy (CEA). Whereas the risks of ipsilateral stroke complicating CEA have been discriminated, factors that lead to contralateral stroke are poorly defined. The purpose of this study was to identify the risk of perioperative (30-day) contralateral stroke after CEA as well as predisposing preoperative and operative factors. Its specific effect on long-term survival was interrogated. MethodsThe Vascular Study Group of New England (VSGNE) was queried from April 1, 2003, to February 29, 2016, for all CEAs. Duplicated patients and those without complete data were excluded. Patients sustaining contralateral stroke after CEA in the 30-day postoperative period were identified. Demographic, preoperative, and operative factors were analyzed to identify discriminators between those with and those without contralateral stroke. Logistic regression modeling was performed to identify factors independently associated with contralateral stroke. The effect of contralateral stroke on 5-year survival was compared with patients with ipsilateral stroke and no stroke using the Kaplan-Meier method. Log-rank testing compared survival curves. ResultsThere were 10,837 CEAs performed during the study. Average age was 70.4 ± 9.3 years; 6605 (61%) patients were male, and 40% (n = 4324) were performed for symptoms. Most were current or former smokers (n = 8619 [80%]). Coronary artery disease and congestive heart failure were identified in 31% and 8.6%, respectively. Overall, there were 190 strokes within 30 days of CEA (1.8%); 131 were ipsilateral (1.3%), and 59 (0.5%) patients were identified as having contralateral perioperative stroke. Thirteen patients sustained bilateral stroke (0.1%). Significant univariate associations included urgency (P = .0001), ipsilateral stenosis severity (P = .004), length of operation (P = .0001), CEA with coronary artery bypass graft (P = .0001), CEA with other arterial surgery (P = .01), and CEA with proximal endovascular procedure (P = .03). Contralateral occlusion (P = .06) and degree of contralateral carotid stenosis (P = .14) did not correlate. After logistic regression analysis of significant univariate anatomic and operative factors, length of procedure (odds ratio [OR], 1.08/15 minutes; 95% confidence interval [CI], 1.01-1.15; P = .02), urgency of operation (OR, 2.5; 95% CI, 1.3-4.6; P = .006), and concomitant proximal endovascular intervention (OR, 8.7; 95% CI, 4.5-31.2; P = .001) remained predictors of contralateral stroke after CEA. Occurrence of both ipsilateral (P < .001) and contralateral (P = .023) stroke significantly reduced 5-year survival compared with those without stroke. There was no difference in the negative survival effect based on laterality of stroke (P = .24). ConclusionsContralateral stroke after CEA is rare, affecting 0.5% of patients. Traditional risk reduction medical therapy does not affect occurrence. Degree of contralateral stenosis, including contralateral occlusion, does not predict perioperative contralateral stroke. Urgency of operation, length of operation, and performance of concomitant, ipsilateral endovascular intervention predict contralateral stroke risk with CEA. Contralateral stroke affects long-term survival similar to ipsilateral stroke after CEA.

Characterization of Perioperative Contralateral Stroke After Carotid Endarterectomy

Contralateral stroke is an infrequent cause of perioperative stroke after carotid endarterectomy (CEA). Whereas the risks of ipsilateral stroke complicating CEA have been discriminated, factors that lead to contralateral stroke are poorly defined. The goal of this study was to identify the risk of perioperative (30-day) contralateral stroke after CEA as well as predisposing preoperative and operative factors. The Vascular Study Group of New England was queried from April 1, 2003, to February 29, 2016, for all CEAs. Duplicated patients and those without complete data were excluded. Those patients sustaining contralateral stroke in the postoperative period were identified. Demographic, preoperative, and operative factors were analyzed to identify discriminators between those with and without contralateral stroke. Logistic regression modeling was performed to identify factors independently associated with contralateral stroke. There were 10,837 CEAs performed during the study. Average age was 70.4 ± 9.3 years, and 6605 patients (61%) were male; 40% (n = 4324) were performed for symptoms. Most were current or former smokers (n = 8619 [80%]); 8% (n = 831) had serum creatinine concentration ≥1.8 mg/dL, and dialysis dependence was present in 162 (2%). Coronary artery disease and congestive heart failure were identified in 31% and 8.6%, respectively; 59 patients (0.5%) were identified having contralateral perioperative stroke. Preoperative, operative, and postoperative significant univariate factors along with notable factors not affecting perioperative contralateral stroke are presented in Table. After logistic regression analysis of significant factors, with and without contralateral occlusion represented, length of procedure (odds ratio [OR], 1.01/minute; 95% confidence interval [CI], 1.008-1.009; P = .02), urgency of operation (OR, 2.5; 95% CI, 1.3-4.6; P = .006), and concomitant proximal endovascular procedure (OR, 8.7; 95% CI, 4.5-31.2; P = .001) remain predictors of contralateral stroke after CEA. Contralateral stroke after CEA is rare, affecting 0.5% of patients. Traditional risk reduction medical therapy does not affect occurrence. Degree of contralateral stenosis, including contralateral occlusion, does not predict perioperative contralateral stroke. Urgency of operation, length of operation, and performance of a concomitant, ipsilateral endovascular procedure predict risk of contralateral stroke with CEA.TableUnivariate discriminants of perioperative contralateral stroke after carotid endarterectomy (CEA)FactorP valuePreoperative Urgency of operation.0001 Degree of ipsilateral (operated) carotid stenosis.004 Stress test performance.02 Preoperative facility need.03 Beta blocker use.04 Contralateral occlusion.06 Degree of contralateral carotid stenosis.14 Symptomatic.23 Aspirin use.26 Clopidogrel use.43 Dual antiplatelet therapy.46 ACE inhibitor/ARB.57 Statin use.62Operative CEA with coronary bypass (P = .001).0001 Length of operation.0001 CEA with other open arterial component (P = .01).01 Ipsilateral proximal endovascular procedure (P = .02).02 Shunt.19 Dextran.45 Protamine.85 Type of CEA (eversion/longitudinal).91Postoperative Dysrhythmia (P = .0001).0001 Return to OR (P = .0001).0001 Reperfusion syndrome (P = .006).006ACE, Angiotensin-converting enzyme; ARB, angiotensin receptor blocker; OR, operating room. Open table in a new tab

Characteristics that define high risk in carotid endarterectomy from the Vascular Study Group of New England

The Stenting with Angioplasty and Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial compared carotid endarterectomy (CEA) to carotid artery stenting (CAS) among high-risk patients using a model of risk that has not been validated by previous publications. The objective of our study was to determine the accuracy of this high-risk model and to determine the true risk factors that result in patients being at high risk for CEA. Prospectively collected data for 3098 CEAs between 2003 and 2011 at 20 Vascular Surgery Group of New England (VSGNE) centers were used. SAPPHIRE general inclusion criteria and primary outcomes were assessed. Factors that were associated with the primary outcome by analysis of variance (P < .10) and not linearly dependent, as determined by a Pearson correlation analysis, were further assessed for an independent association by multivariate logistic regression. A risk index model was developed for these significant predictors to accurately define high-risk CEA. The average patient age was 69.9 ± 9.5 years, 60% were male, and 45.7% were asymptomatic. The 1-year composite outcome event rate, defined as postoperative myocardial infarction and stroke or death, was 14.2%. Multivariate analysis (P < .05) found the following independently significant risk factors: age in years (95% confidence interval [CI], 1.0-1.1; P < .001), preadmission living in a nursing home (95% CI, 1.2-6.6; P = .020), congestive heart failure (95% CI, 1.4-2.8; P < .001), diabetes mellitus (DM; 95% CI, 1.1-1.3; P < .001), chronic obstructive pulmonary disease (95% CI, 1.2-1.5; P < .001), any previous cerebrovascular disease (95% CI, 1.1-1.9; P = .003), and contralateral internal carotid artery stenosis (95% CI, 1.0-1.2; P = .001). Three of the SAPPHIRE high-risk criteria-abnormal stress test, recurrent stenosis after CEA, and previous radiotherapy to the neck-were not independently associated with an adverse outcome. Independently significant risk factors not included in the SAPPHIRE criteria are inclusion of ages <80 years, preadmission living in a nursing home, DM, contralateral carotid stenosis, and any previous cerebrovascular accident. The risk index predictors are age in years (40-49: 0 points; 50-59: 2 points; 60-69: 4 points; 70-79: 6 points; 80-89: 8 points), living in a nursing home (4 points), any cardiovascular disease (2 points), congestive heart failure (5 points), chronic obstructive pulmonary disease (3 points), DM (2 points), degree of contralateral stenosis (<50%: 0 points; 50%-69%: 1 point; 70%-near occlusion: 2 points; occlusion: 3 points). High-risk CEA is defined as >13 points, representing adverse outcome rate of 22.5%. SAPPHIRE and other previously reported high-risk CAS inclusion criteria do not include all of the factors found to be independently associated with outcomes. Further studies are required to determine whether CAS is inferior to CEA in high-risk patients using a validated model of risk. In addition, this preoperative assessment includes novel criteria that can be used to stratify risks.

RR6. High-Risk Carotid Endarterectomy (CEA) Beyond the SAPPHIRE Trial and Development of a Risk Index to Define Patients At Risk for Adverse Outcomes After CEA, From the Vascular Study Group of New England (VSGNE)

Recently we defined several independent high-risk criteria that were inclusive and exclusive of the SAPPHIRE (Stenting with Angioplasty and Protection in Patients at High Risk for Endarterectomy) trial. The objective of this study was to create a risk index that may predict patients at high risk for carotid endarterectomy (CEA). Data on 3,098 CEAs between 2003 and 2011 at 20 Vascular Study Group of New England (VSGNE) centers were used for this study. SAPPHIRE general inclusion criteria and primary outcomes of death, stroke, or myocardial infarction were used, as were other previously reported high-risk criteria. Factors that were associated with the primary outcome by analysis of variance (P < .10) and not linearly dependent, as determined by a Pearson's correlation analysis, were further assessed for an independent association by multivariate logistic regression. A risk index model was developed for these significant predictors using an integer score as a reliable formula. Multivariate analysis (P < .05) found the following independently significant risk factors (95% confidence interval): age in years (1.0-1.1; P < .001), preadmission nursing home (1.2-6.6; P = .020), congestive heart failure (CHF; 1.4-2.8; P < .001), diabetes (1.1-1.3; P < .001), chronic obstructive pulmonary disease (COPD; 1.2-1.5; P < .001), any previous cerebrovascular disease (CVD; 1.1-1.9; P = .003), and contralateral internal carotid artery stenosis (1.0-1.2; P = .001). The predictors are age in years (40-49: 0 points; 50-59: 2 points; 60-69: 4 points; 70-79: 6 points; 80-89: 8 points), living in a nursing home (4 points), any CVD (2 points), CHF (5 points), COPD (3 points), diabetes (2 points), degree of contralateral stenosis (<50%: 0 points; 50-69%: 1 point; 70-near occlusion: 2 points; occlusion: 3 points). Lowest-risk CEA was defined as 0 points with an estimated risk of 2.7%, highest-risk CEA was defined as >13 points, representing adverse outcome rate of 22.5%. The SAPPHIRE high-risk CEA definition is not accurate. We propose a new, evidence-based definition of high-risk CEA. The CEA risk index model may assist clinicians in appropriate patient selection. Future studies should aim at validation of this risk index model.

Abstract 3088: A Systematic Study of Cerebral Hyperperfusion Syndrome after Carotid Endarterectomy

Background: Cerebral hyperperfusion syndrome (CHS) is a well documented complication of carotid endarterecomy (CEA), yet prior research has been limited to small case series and retrospective analyses, or studies using radiographic rather than clinical definitions. Methods: A prospective, independent monitoring system was implemented to monitor CEA outcomes at a major academic medical center. Independent, trained monitors from the neurology department examined all patients undergoing CEA both preoperatively and postoperatively at 24 hours and 30 days. Data were collected on patient demographics, medical history, and procedural and anatomical variables. Clinical variables were analyzed to identify risk factors for CHS, which was defined as cases with postoperative development of a severe headache, new neurological deficits without infarction, seizure or intracerebral hemorrhage. Results: Between 2008 and 2010, 832 CEA were monitored and CHS occurred in 14 (1.7%), including seizures in 5 (0.6%) subjects and intracerebral hemorrhage in 4 (0.5%). Univariate analysis identified a history of dyslipidemia, degree of ipsilateral stenosis and urgent CEA (performed during hospitalization for a symptomatic ipsilateral stroke, TIA or amaurosis fugax) as potential risks for CHS (all p&lt;0.2), whereas age, sex, race, hypertension, diabetes, smoking, degree of contralateral stenosis, operative time, presence of intraoperative EEG slowing, history of prior CEA or carotid stent and time from prior carotid interventions were not significant. Multivariable analysis confirmed the risk association between urgent CEA and CHS (p=0.015) but not dyslipidemia (p=0.084) or degree of ipsilateral stenosis (p=0.118). Surgical indications in urgent CEA patients who developed CHS were amaurosis fugax (1), TIA (3) and stroke (5). Conclusions: Independent, prospective monitoring of a large cohort of CEA cases identified a brief time interval between ischemic symptoms and endarterectomy as the clearest risk factor for CHS, with dyslipidemia and a high degree of ipsilateral carotid stenosis as possible contributory risks. Occurrence of CHS in patients undergoing urgent CEA does not appear to be limited to those with large strokes.

Improvement of exhausted cerebral vasoreactivity in carotid occlusion: benefit of statins?

In internal carotid artery occlusion (ICAO), a spontaneous increase of cerebral vasoreactivity (CVR) may occur over time. Statins are known to increase CVR. We analyzed the influence of statin treatment and other cofactors on CVR improvement in patients with ICAO. Sixty-six patients with ICAO were reexamined after 15 ± 6 months. CVR in both middle cerebral arteries was assessed by transcranial Doppler and inhalation of 7% CO(2). Pre-defined cut-off values were used to define exhausted CVR. Cofactors analyzed were: age, sex, hypertension, diabetes, statin treatment, degree of contralateral stenosis, quality of intracranial collateral flow, duration of ICAO. Mean CVR did not differ between the two studies. Twenty patients had exhausted CVR at baseline, 11 of them improved above the cut-off at follow-up (55%). Factors significantly associated with this improvement were good collateral pattern at baseline (p = 0.0065) and statin treatment (p = 0.0179). Odds ratios for improving CVR were 36.0 [95% CI 2.7-476.3] for good collateral flow and 20.0 [95% CI 1.7-238.6] for statin treatment. In conclusion, exhausted CVR frequently improves during the course of ICAO. Good collateral function and statin treatment are significantly associated with improving CVR.

Effects of Pretreatment with a Xanthine Oxidase Inhibitor on Free Radical Levels during Carotid Endarterectomy

Objective: Free radicals contribute to the tissue damage caused by ischaemia–reperfusion. The aim of the present study was to investigate whether preoperative antioxidant therapy (allopurinol) affects free radical levels in cerebral venous blood in connection with surgery for carotid artery stenosis.Materials and methods: Twenty-five patients were randomised into the study. Thirteen were controls and 12 were pretreated with allopurinol the day before surgery. Before, during and after surgery, blood samples were drawn from the ipsilateral jugular vein. Radical levels were measured using the spin trap technique ex vivo using OXANOH as the spin trap. Multivariate statistics were used with Principal Component Analysis and Partial Least Square regression analysis.Results: Radical levels increased with diabetes, high leukocyte count, high creatinine and a high degree of contralateral stenosis. Radical levels decreased with high age, blood pressure, collateral circulation as well as operation for left-side carotid artery stenosis. After pretreatment with allopurinol, several of the relationships noted in the control group were eliminated, i.e. leukocyte count, side of operation, Betapred pretreatment and collateral circulation.Conclusions: Radical levels can be determined in connection with surgery for carotid artery stenosis using an ex vivo spin trap method. With preoperative antioxidant therapy the relationships between enhanced radical levels and clinical data, as seen in control subjects, disappeared. This might indicate a beneficial effect of preoperative pretreatment with antioxidants.

Severely impaired cerebrovascular reactivity predicts stroke and TIA risk in patients with carotid artery stenosis and occlusion.

Cross-sectional studies suggest that impaired cerebral haemodynamics is associated with symptomatic status in patients with carotid stenosis and occlusion, but there is relatively little prospective data confirming this association. Transcranial Doppler ultrasonography was used to determine the reactivity of the middle cerebral artery to 8% carbon dioxide in air in 107 patients with either carotid occlusion (n = 48) or asymptomatic carotid stenosis (n = 59). Subjects were followed prospectively until stroke, transient ischaemic attack (TIA), death or study end. Mean duration of follow-up was 635 days. No patients dropped out due to operation before an end-point was reached, or were lost to follow-up. There were 11 ipsilateral ischaemic events during follow-up (six strokes, five TIAs). Exhausted ipsilateral middle cerebral artery reactivity (>20% increase in ipsilateral middle cerebral flow velocity in response to 8% carbon dioxide) predicted ipsilateral stroke and TIA risk in the whole group (P: < 0.00001) and in the carotid occlusion (P: = 0.019) and carotid stenosis (P: = 0.015) groups alone. It also predicted the risk of ipsilateral stroke alone in all three groups. Cox regression was performed, controlling for age, gender, hypertension, diabetes, smoking, ipsilateral CT infarct, degree of contralateral stenosis and the presence of ipsilateral stenosis versus occlusion. Exhausted reactivity remained an independent predictor of ipsilateral stroke and TIA (odds ratio 14.4, 95% confidence interval 2.63-78.74, P: = 0.0021). In contrast, the pulsatility index of the middle cerebral artery was a poor predictor of the risk of stroke. Reactivity to 6% carbon dioxide also predicted the risk of stroke and TIA, but slightly less effectively than reactivity to 8% carbon dioxide. Severely reduced cerebrovascular reactivity predicts the risk of ipsilateral stroke and TIA in patients with carotid occlusion, and to a lesser extent in asymptomatic carotid stenosis. Particularly in the former group, a study is required to determine whether revascularization reduces the risk of stroke in patients with exhausted reactivity.

Serum Cholesterol Level Is Associated with the Severity of Carotid Stenosis in Symptomatic Patients: Results from NASCET

The aim of the study was to determine if total serum cholesterol (and its fractions) is related to the severity of angiographically defined extracranial carotid stenosis in patients with prior stroke or transient ischemic attack (TIA). We analyzed the data from 1,614 patients who underwent conventional cerebral arteriography and had serum cholesterol levels measured at entry to the North American Symptomatic Carotid Endarterectomy Trial (NASCET). Patients were classified into one of three ordered categories, according to their linear measurement of severity of extracranial carotid stenosis: mild (<30%), moderate (30–69%), and severe (70–99%). Using ordinal regression analysis, the level of total cholesterol was observed to be significantly related to the severity of carotid stenosis (adjusted OR = 1.17/2 mmol/1; 95% CI: 1.01–1.37). The only other variable that remained statistically significant after adjusting for all other potential confounders was the degree of contralateral stenosis. Our study demonstrates a relationship between the severity of angiographically defined carotid stenosis and total serum cholesterol level in symptomatic patients in whom their presenting stroke or TIA was related to their carotid stenosis. Noting that reductions in total serum cholesterol levels decrease the risk of future coronary events in cardiac patients, further study is required to determine if an analogous response occurs in patients with stroke or TIA. Nevertheless, it seems prudent at the present time to have patients with hypercholesterolemia receive appropriate medical attention for their condition.

Asymptomatic contralateral carotid artery stenosis: a five-year follow-up study following carotid endarterectomy.

Exactly 5 years after carotid endarterectomy for transient ischemic attacks (TIAs), the neurologic status of each of 67 patients whose angiograms demonstrated a contralateral carotid artery, two of which were fatal. One of these patients suffered antecedent TIAs. Two of the 50 patients (4%) without contralateral carotid stenosis experienced symptoms referable to the contralateral carotid; one of the 50 (2%) suffered a CVA without antecedent TIAs; and one of the 50 (2%) experienced a single TIA. Patients with a demonstrable contralateral carotid stenosis were at greater risk of developing contralateral symptoms than those without a stenosis [14 of the 67 versus two of the 50 (P < 0.01)]. There was no correlation between the incidence of new symptoms and the degree of contralateral stenosis. The 3% (two of the 67) incidence of stroke without antecedent TIAs on follow-up in those patients with a contralateral carotid stenosis suggests the following guideline: patients with contralateral carotid stenosis suggests the following guideline: patients with contralateral carotid artery stenosis can be advised to undergo staged carotid endarterectomies if the surgeon's stroke and morbidity rate is less than 3%.