Risk Factors for Complications After Carotid Endarterectomy—A Population-based Study

Role of Intraoperative Neurophysiological Monitoring in Preventing Stroke After Cardiac Surgery

BACKGROUND

Perioperative stroke after cardiac surgical procedures carries significant morbidity. Dual intraoperative neurophysiological monitoring with electroencephalography (EEG) and somatosensory-evoked potentials detects cerebral hypoperfusion and predicts postoperative stroke in noncardiac procedures. We further evaluated preoperative risk factors and intraoperative neuromonitoring ability to predict postoperative stroke after cardiac operations.

METHODS

All patients who underwent cardiac operations with intraoperative neurophysiological monitoring from 2009 to 2020 at a single academic medical center were retrospectively analyzed. Patients with circulatory arrest were excluded. Risks factors analyzed were sex, age, tobacco use, hypertension, diabetes mellitus, dyslipidemia, atrial fibrillation, prior cerebrovascular accident, cerebrovascular disease, antiplatelet/anticoagulant use, abnormal somatosensory-evoked potentials and EEG baselines, and significant somatosensory-evoked potentials and EEG change as well as their permanence. Patients were divided into 2 groups by 30-day postoperative stroke occurrence. Univariate and multivariate logistical regressions were used for postoperative stroke significant predictors, and Kaplan-Meier curves estimated survival.

RESULTS

The study included 620 patients (67.6% men), mean age 65.1 ± 14.1 years, with stroke in 5.32%. In univariate analysis, diabetes (odds ratio [OR], 2.62) and permanence of EEG change (OR, 5.35) were each associated with increased postoperative stroke odds. In multivariate analysis, diabetes (OR, 2.64) and permanent EEG change (OR, 4.22) were independently significantly associated with postoperative stroke. Overall survival was significantly better for patients with no intraoperative neurophysiological monitoring changes (P < .005).

CONCLUSIONS

Permanent EEG change and diabetes were significant postoperative stroke predictors in cardiac operations. Furthermore, overall survival out to 10 years postoperatively was significantly higher in the group without intraoperative neurophysiological monitoring changes, emphasizing its important predictive role.

Configuration of vascular services: a multiple methods research programme

Background

Vascular services is changing rapidly, having emerged as a new specialty with its own training and specialised techniques. This has resulted in the need for reconfiguration of services to provide adequate specialist provision and accessible and equitable services.

Objectives

To identify the effects of service configuration on practice, resource use and outcomes. To model potential changes in configuration. To identify and/or develop electronic data collection tools for collecting patient-reported outcome measures and other clinical information. To evaluate patient preferences for aspects of services other than health-related quality of life.

Design

This was a multiple methods study comprising multiple systematic literature reviews; the development of a new outcome measure for users of vascular services (the electronic Personal Assessment Questionnaire – Vascular) based on the reviews, qualitative studies and psychometric evaluation; a trade-off exercise to measure process utilities; Hospital Episode Statistics analysis; and the development of individual disease models and a metamodel of service configuration.

Setting

Specialist vascular inpatient services in England.

Data sources

Modelling and Hospital Episode Statistics analysis for all vascular inpatients in England from 2006 to 2018. Qualitative studies and electronic Personal Assessment Questionnaire – Vascular evaluation with vascular patients from the Sheffield area. The trade-off studies were based on a societal sample from across England.

Interventions

The data analysis, preference studies and modelling explored the effect of different potential arrangements for service provision on the resource use, workload and outcomes for all interventions in the three main areas of inpatient vascular treatment: peripheral arterial disease, abdominal aortic aneurysm and carotid artery disease. The electronic Personal Assessment Questionnaire – Vascular was evaluated as a potential tool for clinical data collection and outcome monitoring.

Main outcome measures

Systematic reviews assessed quality and psychometric properties of published outcome measures for vascular disease and the relationship between volume and outcome in vascular services. The electronic Personal Assessment Questionnaire – Vascular development considered face and construct validity, test–retest reliability and responsiveness. Models were validated using case studies from previous reconfigurations and comparisons with Hospital Episode Statistics data. Preference studies resulted in estimates of process utilities for aneurysm treatment and for travelling distances to access services.

Results

Systematic reviews provided evidence of an association between increasing volume of activity and improved outcomes for peripheral arterial disease, abdominal aortic aneurysm and carotid artery disease. Reviews of existing patient-reported outcome measures did not identify suitable condition-specific tools for incorporation in the electronic Personal Assessment Questionnaire – Vascular. Reviews of qualitative evidence, primary qualitative studies and a Delphi exercise identified the issues to be incorporated into the electronic Personal Assessment Questionnaire – Vascular, resulting in a questionnaire with one generic and three disease-specific domains. After initial item reduction, the final version has 55 items in eight scales and has acceptable psychometric properties. The preference studies showed strong preference for endovascular abdominal aortic aneurysm treatment (willingness to trade up to 0.135 quality-adjusted life-years) and for local services (up to 0.631 quality-adjusted life-years). A simulation model with a web-based interface was developed, incorporating disease-specific models for abdominal aortic aneurysm, peripheral arterial disease and carotid artery disease. This predicts the effects of specified reconfigurations on workload, resource use, outcomes and cost-effectiveness. Initial exploration suggested that further reconfiguration of services in England to accomplish high-volume centres would result in improved outcomes, within the bounds of cost-effectiveness usually considered acceptable in the NHS.

Limitations

The major source of evidence to populate the models was Hospital Episode Statistics data, which have limitations owing to the complexity of the data, deficiencies in the coding systems and variations in coding practice. The studies were not able to address all of the potential barriers to change where vascular services are not compliant with current NHS recommendations.

Conclusions

There is evidence of potential for improvement in the clinical effectiveness and cost-effectiveness of vascular services through further centralisation of sites where major vascular procedures are undertaken. Preferences for local services are strong, and this may be addressed through more integrated services, with a range of services being provided more locally. The use of a web-based tool for the collection of clinical data and patient-reported outcome measures is feasible and can provide outcome data for clinical use and service evaluation.

Future work

Further evaluation of the economic models in real-world situations where local vascular service reconfiguration is under consideration and of the barriers to change where vascular services do not meet NHS recommendations for service configuration is needed. Further work on the electronic Personal Assessment Questionnaire – Vascular is required to assess its acceptability and usefulness in clinical practice and to develop appropriate report formats for clinical use and service evaluation. Further studies to assess the implications of including non-health-related preferences for care processes, and location of services, in calculations of cost-effectiveness are required.

Study registration

This study is registered as PROSPERO CRD42016042570, CRD42016042573, CRD42016042574, CRD42016042576, CRD42016042575, CRD42014014850, CRD42015023877 and CRD42015024820.

Funding

This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 5. See the NIHR Journals Library website for further project information.

The SAPPHIRE criteria, history of myocardial infarction and diabetes predict adverse outcomes following carotid endarterectomy similar to stenting

AIMS

Identifying factors associated with worse outcome following carotid endarterectomy (CEA) is important to improve prevention of major adverse cardiovascular and cerebrovascular events (MACCE), yet rarely used for registries. We intended to identify predictors of MACCE following CEA as recently analysed for stenting.

METHODS AND RESULTS

Patients undergoing CEA at 2 centers over 13 years were entered into a database. Baseline clinical characteristics, procedural factors and a panel of clinical and lesion-related high-risk features (SHR) and exclusion criteria (SE), empirically compiled for stratification in the SAPPHIRE trial, were differentially analysed using Cox regressions. The analysis included 748 operations; 262 (35%) asymptomatic, 208 (28%) with previous strokes, and 278 (37%) with transient ischemic attacks (TIA). The overall 30-day MACCE rate was 6.7%, 5.0% in asymptomatic and 7.6% in symptomatic patients. Previous MI (HR 2.045, p = 0.022), diabetes (HR 2.111, p = 0.011) and symptomatic patients (HR 2.045, p = 0.044) were independently associated with MACCE. SE patients (n = 81) had a MACCE rate of 13.6%; the MACCE rate of the remainder dropped to 5.8% (4.7% in asymptomatic and 6.5% in symptomatic patients). Hazard ratio for SHR patients was 2.069 (CI 1.087-3.941) and 2.389 for SE (CI 1.223-4.666), each compared to all patients with lower risk and adjusted for symptomatic status. Among SHR and SE criteria NYHA 3-4, contralateral occlusions and intraluminal thrombus were significant determinants and MI < 4 weeks before CEA showed a strong trend (p = 0.05).

CONCLUSION

Patients identified by SHR and SE criteria, prior MI and diabetes warrant increased attention to prevent MACCE following CEA.

The Dutch Audit of Carotid Interventions: Transparency in Quality of Carotid Endarterectomy in Symptomatic Patients in the Netherlands

BACKGROUND

The Dutch Audit for Carotid Interventions (DACI) registers all patients undergoing interventions for carotid artery stenosis in the Netherlands. This study describes the design of the DACI and results of patients with a symptomatic stenosis undergoing carotid endarterectomy (CEA). It aimed to evaluate variation between hospitals in process of care and (adjusted) outcomes, as well as predictors of major stroke/death after CEA.

METHODS

All patients with a symptomatic stenosis, who underwent CEA and were registered in the DACI between 2014 and 2016 were included in this cohort. Descriptive analyses of patient characteristics, process of care, and outcomes were performed. Casemix adjusted hospital procedural outcomes as (30 day/in hospital) mortality, stroke/death, and major stroke/death, were compared with the national mean. A multivariable logistic regression model (backward elimination at p > 0.10) was used to identify predictors of major stroke/death.

RESULTS

A total of 6459 patients, registered by 52 hospitals, were included. The majority (4,832, 75%) were treated <2 weeks after their first hospital consultation, varying from 40% to 93% between hospitals. Mortality, stroke/death, and major stroke/death were, respectively, 1.1%, 3.6%, and 1.8%. Adjusted major stroke/death rates for hospital comparison varied between 0 and 6.5%. Nine hospitals performed significantly better, none performed significantly worse. Predictors of major stroke/death were sex, age, pulmonary disease, presenting neurological symptoms, and peri-operative shunt.

CONCLUSION

CEA in The Netherlands is associated with an overall low mortality and (major) stroke/death rate. Whereas the indicator time to intervention varied between hospitals, mortality and (major) stroke/death were not significantly distinctive enough to identify worse practices and therefore were unsuitable for hospital comparison in the Dutch setting. Additionally, predictors of major stroke/death at population level could be identified.

Systematic review of carotid artery procedures and the volume-outcome relationship in Europe

BACKGROUND

Hospitals that conduct more procedures on the carotid arteries may achieve better outcomes. In the context of ongoing reconfiguration of UK vascular services, this systematic review was conducted to evaluate the relationship between the volume of carotid procedures and outcomes, including mortality and stroke.

METHODS

Searches of electronic databases identified studies that reported the effect of hospital or clinician volume on outcomes. Reference and citation searches were also performed. Inclusion was restricted to European populations on the basis that the model of healthcare delivery is similar across Europe, but differs from that in the USA and elsewhere. Analyses of hospital and clinician volume, and carotid endarterectomy (CEA) and carotid artery stenting (CAS) were conducted separately.

RESULTS

Eleven eligible studies were identified (233 411 participants), five from the UK, two from Sweden, one each from Germany, Finland and Italy, and a combined German, Austrian and Swiss population. All studies were observational. Two large studies (179 736 patients) suggested an inverse relationship between hospital volume and mortality (number needed to treat (NNT) as low as 165), and combined mortality and stroke (NNT as low as 93), following CEA. The evidence was less clear for CAS; multiple analyses in three studies did not identify convincing evidence of an association. Limited data are available on the relationship between clinician volume and outcome in CAS; in CEA, an inverse relationship was identified by two of three small studies.

CONCLUSION

The evidence from the largest and highest-quality studies included in this review support the centralization of CEA.

Impact of Surgeon Experience During Carotid Endarterectomy Operation and Effects on Perioperative Outcomes

Objective

We evaluated the effect of surgeon experience on complication and mortality rates of carotid endarterectomy operation.

Methods

Fifty-nine consecutive patients who underwent carotid endarterectomy between January 2013 and February 2016 were divided into two groups. Patients who had been operated by surgeons performing carotid endarterectomy for more than 10 years were allocated to group 1 (experienced surgeons; n=34). Group 2 (younger surgeons; n=25) consisted of patients operated by surgeons independently performing carotid endarterectomy for less than 2 years. Both groups were compared in respect of operative results and postoperative complications.

Results

No intergroup difference was found for laterality of the lesion or concomitant coronary artery disease. In group 1, signs of local nerve damage (n=2; 5.9%) were detected, whereas in group 2 no evidence of local nerve damage was observed. Surgeons in group 1 used local and general anesthesia in 3 (8.8%) and 31 (91.2%) patients, respectively, while surgeons in group 2 preferred to use local and general anesthesia in 1 (4%) and 24 (96%) patients, respectively. Postoperative stroke was observed in group 1 (n=2; 5.9%) and group 2 (n=2; 5.8%).

Conclusion

Younger surgeons perform carotid endarterectomy with similar techniques and have similar results compared to experienced surgeons. Younger surgeons rarely prefer using shunt during carotid endarterectomy. The experience and the skills gained by these surgeons during their training, under the supervision of experienced surgeons, will enable them to perform successful carotid endarterectomy operations independently after completion of their training period.

Type-2 diabetes and carotid stenosis: a proposal for a screening strategy in asymptomatic patients

The objective of this prospective observational study was to establish the prevalence of carotid atherosclerosis in an asymptomatic diabetic population and to determine predictive factors for a screening optimization. A total of 300 consecutive type-2 diabetic subjects (166 males, 134 females) underwent a physical examination and duplex carotid scanning. Patients with a recent cerebrovascular event (±6 weeks) or previous carotid surgery were excluded. The prevalence of carotid stenosis ≥60% or occlusion was 4.7%; the prevalence of carotid atherosclerosis was 68.3%. Risk factors for stenosis ≤60% or occlusion were the presence of diabetic retinopathy (OR: 3.62; 95% CI: 1.12-11.73), ankle-brachial index (ABI) <0.85 (OR: 3.94; 95% CI: 1.21-12.84) and a personal history of neurological disorders (OR: 4.54; 95% CI: 1.16-17.81). Being female was a protective factor (OR: 0.09; 95% CI: 0.01-0.78). The two factors in the analysis limited to the male population were an ABI < 0.85 (OR: 3.66; 95% CI: 1.04-12.84) and a personal history of coronary heart disease (OR: 3.34; 95% CI: 1.01-11.01). If male diabetics without either of these two factors are excluded, the negative predictive value for carotid stenosis is 96.6%. In conclusion, the prevalence of atherosclerotic carotid disease in diabetic patients is high. In these patients, the probability of finding >60% stenosis is highest among men with a history of coronary heart disease or an ABI <0.85.

Pre-operative methods to predict need for shunting during carotid endarterectomy

OBJECTIVES

To establish whether pre-operative investigations are able to predict cerebral tolerance to carotid cross clamping during carotid endarterectomy (CEA).

METHODS

A search of the MEDLINE database from 1950 to 2015 was made in combination with manual cross-referencing using the search strategy: ("carotid" [all fields] AND "endarterectomy" [all fields]) AND "preoperative" [all fields]) AND "clamping" [all fields]) AND ("MRA" [all fields] OR "MRI" [all fields] OR "CT" [all fields] OR "CTA" [all fields] OR "EEG" [all fields] OR "Doppler" [all fields] OR "angiography" [all fields]). A total of 20 studies were identified as eligible for inclusion.

RESULTS

3D Time of Flight MRA and acetazolomide stress SPECT imaging have been reported to have a negative predictive value of 96% and 94% respectively for the need for intraoperative shunting during carotid endarterectomy.

CONCLUSIONS

There is some evidence to suggest that pre-operative imaging investigations can reliably identify which patients undergoing CEA will not require carotid shunting for neurological protection. However, this evidence is limited and there is a need for more rigorous studies to be conducted.

Predictors of 30-day postoperative stroke or death after carotid endarterectomy using the 2012 carotid endarterectomy-targeted American College of Surgeons National Surgical Quality Improvement Program database

OBJECTIVE

This study used a recently released procedure-targeted multicenter data source to determine independent predictors of postoperative stroke or death in patients undergoing carotid endarterectomy (CEA) for carotid artery stenosis.

METHODS

The 2012 CEA-targeted American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database was used for this study. Patient, disease, and procedure characteristics of patients undergoing CEA were assessed. Multivariate logistic regression analysis was used to determine independent risk factors for 30-day postoperative stroke/death or other major complications.

RESULTS

The analysis included 3845 patients undergoing CEA (58.1% with asymptomatic and 41.9% with symptomatic carotid disease). The overall 30-day postoperative stroke/death rate was 3.0% (1.9% in asymptomatic patients, 4.6% in symptomatic patients). The variables that maintained an independent association with postoperative stroke/death after adjustment for other known patient-related and procedure-related factors were age ≥80 years, active smoking, contralateral internal carotid artery stenosis of 80% to 99%, emergency procedure status, preoperative stroke, presence of one or more ACS NSQIP-defined high-risk characteristics (including any or all of New York Heart Association class III/IV congestive heart failure, left ventricular ejection fraction <30%, recent unstable angina, or recent myocardial infarction), and operative time ≥150 minutes.

CONCLUSIONS

After adjustment for a comprehensive array of patient-related and procedure-related variables of particular import to patients with carotid artery stenosis, we have identified several factors that are independently associated with early stroke or death after CEA. These factors are generally related to the comorbid condition of CEA patients and to specific characteristics of their carotid disease, and not to technical features of the CEA procedure. Knowledge of these factors will assist surgeons in selecting appropriate patients for this procedure.

Impact of diabetes mellitus on characteristics of carotid plaques and outcomes after carotid endarterectomy

BACKGROUND

Published results for carotid endarterectomy (CEA) in symptomatic and asymptomatic severe carotid stenosis with diabetes mellitus (DM) are contradictory. To evaluate perioperative and long-term results of CEA in patients with DM, we retrospectively analyzed data of patients with or without DM who underwent CEA in our institute.

METHODS

Between January 2005 and December 2010, 281 consecutive CEAs were performed in 268 patients under general anesthesia. All patients were subject to cardiac work-ups before surgery, and coronary revascularization was performed prior to CEA if patients were diagnosed with significant coronary artery stenosis. Lesion characteristics were assessed by a duplex ultrasound scan, computed tomography angiography (CTA), and plaque imaging on magnetic resonance imaging (MRI) before surgery, and patients were followed-up by a duplex ultrasound scan at three, six, and 12 months, then yearly, after surgery.

RESULTS

Of 281 cases, 136 had DM (48 %). Diabetic patients more frequently had a history of coronary artery disease than non-diabetic patients (48.5 % vs. 36.6 %, P = 0.042). Coronary intervention prior to CEA was more frequently performed in diabetic patients than in non-diabetic patients (22.1 % vs. 11.0 %, P = 0.013). The incidence of perioperative (30 day) stroke (P = 1.000), death (P = 1.000), and cardiac complications (P = 0.484) did not differ among groups. Follow-up was available in 77.2 % of patients, with a median duration of 50 months (interquartile range, 32.1-67.2 months). The incidence of ipsilateral stroke (P = 0.720), death (P = 0.351), and severe restenosis (peak systolic velocity > 230 cm/sec) (P = 0.905) were not different between groups.

CONCLUSIONS

DM does not increase the risk of perioperative complications and does not influence long-term outcomes after CEA if preexisting vascular risk factors and cardiac diseases are appropriately evaluated and treated before surgery.

A risk factor-based predictive model of outcomes in carotid endarterectomy: the National Surgical Quality Improvement Program 2005-2010

BACKGROUND AND PURPOSE

Accurate knowledge of individualized risks and benefits is crucial to the surgical management of patients undergoing carotid endarterectomy (CEA). Although large randomized trials have determined specific cutoffs for the degree of stenosis, precise delineation of patient-level risks remains a topic of debate, especially in real world practice. We attempted to create a risk factor-based predictive model of outcomes in CEA.

METHODS

We performed a retrospective cohort study involving patients who underwent CEAs from 2005 to 2010 and were registered in the American College of Surgeons National Quality Improvement Project database.

RESULTS

Of the 35 698 patients, 20 015 were asymptomatic (56.1%) and 15 683 were symptomatic (43.9%). These patients demonstrated a 1.64% risk of stroke, 0.69% risk of myocardial infarction, and 0.75% risk of death within 30 days after CEA. Multivariate analysis demonstrated that increasing age, male sex, history of chronic obstructive pulmonary disease, myocardial infarction, angina, congestive heart failure, peripheral vascular disease, previous stroke or transient ischemic attack, and dialysis were independent risk factors associated with an increased risk of the combined outcome of postoperative stroke, myocardial infarction, or death. A validated model for outcome prediction based on individual patient characteristics was developed. There was a steep effect of age on the risk of myocardial infarction and death.

CONCLUSIONS

This national study confirms that that risks of CEA vary dramatically based on patient-level characteristics. Because of limited discrimination, it cannot be used for individual patient risk assessment. However, it can be used as a baseline for improvement and development of more accurate predictive models based on other databases or prospective studies.

Very urgent carotid endarterectomy confers increased procedural risk

BACKGROUND AND PURPOSE

Current Swedish guidelines recommend that carotid endarterectomy should be performed within 14 days of a qualifying neurological event, but it is not clear if very urgent surgery after an event is associated with increased perioperative risk. The aim of this study was to determine how the time between the event and carotid endarterectomy affects the procedural risk of mortality and stroke.

METHODS

We prospectively analyzed data on all patients who underwent carotid endarterectomies for symptomatic carotid stenosis between May 12, 2008, and May 31, 2011, with records in the Swedish Vascular Registry (Swedvasc). Patients were divided according to time between the qualifying event and surgery (0-2 days, 3-7 days, 8-14 days, 15-180 days). Stroke rate and mortality at 30 days postsurgery were determined.

RESULTS

We analyzed data for 2596 patients and found that the combined mortality and stroke rate for patients treated 0 to 2 days after qualifying event was 11.5% (17 of 148) versus 3.6% (29 of 804), 4.0% (27 of 677), and 5.4% (52 of 967) for the groups treated at 3 to 7 days, 8 to 14 days, and 15 to 180 days, respectively. In a multivariate analysis, time was an independent risk factor for perioperative complications: patients treated at 0 to 2 days had a relative OR of 4.24 (CI, 2.07-8.70; P<0.001) compared with the reference 3- to 7-day group.

CONCLUSIONS

In this study of patients treated for symptomatic carotid disease, it was safe to perform surgery as early as Day 3 after a qualifying neurological event in contrast to patients treated within 0 to 2 days, which has a significantly increased perioperative risk.

Characterization of resident surgeon participation during carotid endarterectomy and impact on perioperative outcomes

INTRODUCTION

The impact of resident surgeon participation during vascular procedures on postoperative outcomes is incompletely understood. We characterized resident physician participation during carotid endarterectomy (CEA) procedures within the 2005-2009 American College of Surgeons National Surgical Quality Improvement Participant Use Datafile and evaluated associations with procedural characteristics and perioperative adverse events.

METHODS

CEAs were identified using primary current procedural terminology codes; those performed simultaneously with other major procedures or unknown resident participation status were excluded. Group-wise comparisons based on resident participation status were performed using χ(2) or Fisher's exact test for categorical variables and t tests or nonparametric methods for continuous variables. Associations with perioperative adverse events (major = stroke, death, myocardial infarction, or cardiac arrest; minor = peripheral nerve injury, bleeding requiring transfusion, surgical site infection, or wound disruption) were assessed using multivariable logistic regression models adjusting for other known risk factors.

RESULTS

A total of 25,280 CEA procedures were analyzed, of which residents participated in 13,705 (54.2%), while residents were absent in 11,575 (45.8%). Among CEAs with resident physician participation, resident level was categorized as junior (postgraduate year [PGY] 1-2) in 21.9%, senior (PGY 3-5) in 52.7%, and fellow (PGY ≥6) in 25.3%. Major adverse event rates with and without resident participation were 1.9% versus 2.1%, and minor adverse event rates with and without resident participation were 0.9% versus 1.0%, respectively. In multivariable models, resident physician participation was not associated with perioperative risk for major adverse events (odds ratio [OR], 0.90; 95% confidence interval [CI], 0.75-1.08) or minor adverse events (OR, 0.93; 95% CI, 0.72-1.21).

CONCLUSIONS

Resident surgeon participation during CEA is not associated with risk of adverse perioperative events.

Cardiovascular risk assessment of the diabetic patient undergoing major noncardiac surgery

Noncardiac surgery is associated with an increased risk for cardiovascular morbidity and mortality. It is important to stratify the risk of these patients for perioperative cardiac events. Diabetes, a presently rapidly expanding disease, is a major risk factor for cardiovascular morbidity and mortality. Importantly, silent ischemia is more common in diabetic patients than in the general population. When preoperative risk assessment identifies an increased risk, further cardiac testing is warranted. The most commonly used stress tests for detecting cardiac ischemia is treadmill or bicycle ergometry. However, patients undergoing noncardiac surgery frequently have limited exercise capacity due to co-morbidities. Pharmacologic testing, such as dobutamine stress echocardiography and dipyridamole myocardial perfusion scintigraphy can be performed in patients with limited exercise capacity. Non-invasive stress testing should be considered, especially in diabetic patients, to detect asymptomatic coronary artery disease. Furthermore, when an increased cardiac risk is assessed, two strategies could be used to reduce the incidence of perioperative cardiac events: 1) prophylactic coronary revascularization from which the value is still controversial, and 2) pharmacological treatment (with beta-blockers, statins and aspirin), associated with improved post-operative outcome.

Risk factors for perioperative death and stroke after carotid endarterectomy: results of the new york carotid artery surgery study

BACKGROUND AND PURPOSE

The benefit of carotid endarterectomy is heavily influenced by the risk of perioperative death or stroke. This study developed a multivariable model predicting the risk of death or stroke within 30 days of carotid endarterectomy.

METHODS

The New York Carotid Artery Surgery (NYCAS) Study is a population-based cohort of 9308 carotid endarterectomies performed on Medicare patients from January 1998 through June 1999 in New York State. Detailed clinical data were abstracted from medical charts to assess sociodemographic, neurological, and comorbidity risk factors. Deaths and strokes within 30 days of surgery were confirmed by physician overreading. Multivariable logistic regression was used to identify independent patient risk factors.

RESULTS

The 30-day rate of death or stroke was 2.71% among asymptomatic patients with no history of stroke/transient ischemic attack (TIA), 4.06% among asymptomatic ones with a distant history of stroke/TIA, 5.62% among those operated on for carotid TIA, 7.89% of those with stroke, and 13.33% in those with crescendo TIA/stroke-in-evolution. Significant multivariable predictors of death or stroke included: age >/=80 years (OR, 1.30; 95% CI, 1.03 to 1.64), nonwhite (OR, 1.83; 1.23 to 2.72), admission from the emergency department (OR, 1.95; 1.50 to 2.54), asymptomatic but distant history of stroke/TIA (OR, 1.40; 1.02 to 1.94), TIA as an indication for surgery (OR, 1.81; 1.39 to 2.36), stroke as the indication (OR, 2.40; 1.74 to 3.31), crescendo TIA/stroke-in-evolution (OR, 3.61; 1.15 to 11.28), contralateral carotid stenosis >/=50% (OR, 1.44; 1.15 to 1.79), severe disability (OR, 2.94; 1.91 to 4.50), coronary artery disease (OR, 1.51; 1.20 to 1.91), and diabetes on insulin (OR, 1.55; 1.10 to 2.18). Presence of a deep carotid ulcer was of borderline significance (OR, 2.08; 0.93 to 4.68).

CONCLUSIONS

Several sociodemographic, neurological, and comorbidity risk factors predicted perioperative death or stroke after carotid endarterectomy. This information may help inform decisions about appropriate patient selection, assessments about the impact of different surgical processes of care on outcomes, and facilitate comparisons of risk-adjusted outcomes among providers.

External validation of the Swedvasc registry: a first-time individual cross-matching with the unique personal identity number

OBJECTIVE

To study external validity of the Swedvasc registry concerning numbers of procedures and mortality.

MATERIALS AND METHODS

Vascular registry data for carotid, infrainguinal bypass and aortic aneurysm (AAA) procedures were compared to the Swedish Hospital Discharge Register (SHDR) data, and the National Population Registry (for mortality) by matching every individual patient using the unique personal identity numbers (PINs). The time-period studied was 2000-2004 (5 years) for carotid and infrainguinal procedures. A separate analysis was performed for AAA-surgery in 2006.

RESULTS

The external validity for carotid, infrainguinal bypass and AAA repair was 93.4%, 93.0% and 93.1%, respectively. The 30-day mortality was 0.86% after carotid and 2.9% after infrainguinal bypass procedures. Mortality was 2.6% after planned and 25.9% after unplanned AAA repair. Although there was a general trend towards inferior outcomes after procedures not registered in the Swedvasc, those procedures were so few that in none of the analyses did the inclusion of non-registered procedures affect general outcomes significantly. Combining data from both registries, the incidence for carotid, infrainguinal bypass and AAA procedures was 7.8, 15.2 and 13.6 per 100,000 person-years, respectively. In the hospital-specific analysis for 2006 it was shown that the non-registered procedures for AAA were localized to one non-compliant county hospital, and small district hospitals not performing elective AAA-surgery but only rare emergency operations.

CONCLUSION

The external and internal validity of the Swedvasc registry allows to confidently assess volumes of, and mortality after, vascular surgery in Sweden.

Diabetes and asymptomatic carotid stenosis: does diabetic disease influence the outcome of carotid endarterectomy? A 10-year single center experience

BACKGROUND

Few studies have focused directly on carotid endarterectomy (CEA) in symptomatic and asymptomatic diabetic patients, reporting controversial outcome. We compared perioperative (30-day) and late outcomes in diabetic versus nondiabetic patients undergoing CEA for severe asymptomatic carotid disease.

METHODS

Over 10 years, data were prospectively collected for diabetic and nondiabetic patients undergoing CEA for asymptomatic severe carotid disease. All procedures were eversion CEA. All patients underwent concomitant neurologic follow-up and a duplex ultrasound scan at 1, 6, and 12 months, then yearly, after operation.

RESULTS

Of 391 CEAs performed on 374 patients, 112 (28.7%) were in diabetic patients. There were no perioperative deaths or strokes in either diabetic patients or nondiabetic patients. A significantly higher incidence of cardiac complications occurred in diabetic patients (P < .01). A complete follow-up (mean, 6.1 years) was obtained for 348 patients. No recurrent stenoses or late occlusions were diagnosed in diabetic or nondiabetic patients. At 10 years, the risk of death was up to 4.6 times higher in diabetic patients, with a significant prevalence of cardiac-related deaths (P < .01).

CONCLUSIONS

CEA can be performed with no perioperative stroke risk or mortality, for asymptomatic disease in both diabetic and nondiabetic patients. The absence of fatal strokes associated with a significantly higher risk of cardiac-related death in the long-term points to the need to improve prevention strategies for postoperative cardiac risk in diabetic patients.

Popliteal Artery Aneurysm with Acute Ischemia in 229 Patients. Outcome after Thrombolytic and Surgical Therapy

OBJECTIVES

The aim of this study was to assess the national management and outcome of popliteal artery aneurysm (PAA).

METHODS

In the Swedish National Registry 717 primary operations for PAA on 571 patients were registered prospectively between 1987 and 2002. 235 legs [corrected] presented with acute ischemia.

RESULTS

Median age was 70 for men and 75 for women. Immediate surgery was performed in 135 legs, including intraoperative thrombolysis in 32 cases (Immediate Surgery Group, ISG). Pre-operative thrombolysis was performed in 100 legs, followed by acute (<or=24 hours, 41 legs) or elective (59 legs) surgery (Delayed Surgery Group, DSG). DSG had smaller PAA (27 versus 37 mm, p<0.0001) and were younger (67 versus 72 years, p<0.001). Run-off was worse in DSG than in ISG (p<0.001) and improved in 87% after thrombolysis. Amputation-rate was 27% in the ISG and 7% in the DSG, P<0.0001. The ISG required fasciotomy in 30% compared to 11% of the DSG, p=0.0001.

CONCLUSION

Patients in the ISG and DSG differed in their pre-operative characteristics and were selected to the treatment modalities in a complex manner. Preoperative thrombolysis improves run-off.

The value of urgent carotid surgery for crescendo transient ischemic attacks

OBJECTIVE

This study audited operative risk in patients undergoing urgent carotid surgery for crescendo transient ischemic attacks (TIAs).

METHODS

Interrogation of the vascular unit database (January 1992 to July 2004) identified 42 patients operated on urgently for crescendo TIAs, which were defined as>or=3 TIAs within the preceding 7 days. Stroke, death, and any major cardiac events were analyzed.

RESULTS

Thirty-nine patients underwent conventional endarterectomy, and three underwent interposition vein bypass. Crescendo TIA patients had sustained a median of five TIAs (range, 3 to 20) in the 7 days before surgery. Three patients died or had a stroke after surgery, for a combined stroke/death rate of 7%. This compares with 2.4% in 1000 patients undergoing elective carotid endarterectomy in this unit during the same time period. The combined stroke/death/major cardiac event rate was 14% (n=6).

CONCLUSIONS

The combined risk of neurologic and cardiac complications after urgent carotid surgery for crescendo TIA is higher than that expected after elective cases but is still acceptable considering the natural history of patients with unstable neurologic symptoms.

Nationwide study of the outcome of popliteal artery aneurysms treated surgically

Background

The aim was to study the epidemiology and outcomes of popliteal artery aneurysm (PA) treated surgically.

Methods

Among 110 000 procedures registered prospectively in the Swedish Vascular Registry (Swedvasc), there were 717 primary operations for PA among 571 patients. Patient records were reviewed and data validated against other registries.

Results

The median age of the patients was 71 years; 5·8 per cent were women. Among 264 legs treated urgently, 235 had acute ischemia and 24 had rupture. Of patients with unilateral PA, 28·1 per cent had an aortic aneurysm, 8·4 per cent an iliac aneurysm and 9·4 per cent a femoral aneurysm. Extra-popliteal aneurysms were more common when the PAs were bilateral (P = 0·004). The rate of limb loss within 1 year of operation was 8·8 per cent; 12·0 per cent for symptomatic and 1·8 per cent for asymptomatic limbs (P &lt; 0·001). Risk factors for amputation were symptomatic disease, poor run-off, urgent treatment, age over 70 years, prosthetic graft and no preoperative thrombolysis when the ischaemia was acute. Amputation rates decreased over time (P = 0·003). Crude survival was 91·4 per cent at 1 year and 70·0 per cent at 5 years.

Conclusion

Multiple aneurysm disease was common when PAs were bilateral. Preoperative thrombolysis of acute thrombosis and the use of vein grafts for bypass improved outcome.

Impact of diabetes mellitus on outcome of patients undergoing carotid artery stenting: Insights from a single center registry

OBJECTIVE

To evaluate the impact of diabetic status on outcome of patients undergoing carotid artery stenting (CAS).

BACKGROUND

Diabetes has been demonstrated to be a strong predictor of adverse outcome in patients undergoing coronary revascularization. Its significance in predicting outcome of patients undergoing carotid interventions has not been ascertained.

METHODS

We evaluated the short-term outcomes of 833 patients who underwent CAS at our institution. The primary outcome of this analysis was 30 day incidence of stroke, myocardial infarction, and death.

RESULTS

Diabetes was present in 311 patients. Baseline characteristics were comparable between diabetics and nondiabetics except for the diabetics having a lower left ventricular ejection fraction, lower hemoglobin, and a higher body mass index at baseline. Further, they were more likely to have congestive heart failure and coronary artery disease. There was no difference in the incidence of stroke (1.9% versus 2.7%,), myocardial infarction (MI) (2.6% versus 1.9%), death (3.9% versus 2.5%), or the composite of death stroke or MI (6.8% versus 5.9%) at 30 days between diabetics and nondiabetics. Similar results were seen when the analysis was restricted to patients treated with an emboli protection device. Diabetes was not a risk factor for adverse outcome after CAS after multivariate adjustment.

CONCLUSION

Diabetics undergoing CAS are more likely to have associated co-morbidities. However despite this handicap, their short term outcome after CAS is similar to that of nondiabetics.

Hyperglycemia independently increases the risk of perioperative stroke, myocardial infarction, and death after carotid endarterectomy

OBJECTIVE

Clinical and experimental evidence suggests that hyperglycemia lowers the neuronal ischemic threshold, potentiates stroke volume in focal ischemia, and is associated with morbidity and mortality in the surgical critical care setting. It remains unknown whether hyperglycemia during carotid endarterectomy (CEA) predisposes patients to perioperative stroke and operative related morbidity and mortality.

METHODS

The clinical and radiological records of all patients undergoing CEA and operative day glucose measurement from 1994 to 2004 at an academic institution were reviewed and 30-day outcomes were assessed. The independent association of operative day glucose before CEA and perioperative morbidity and mortality were assessed via multivariate logistic regression analysis.

RESULTS

One thousand two hundred and one patients with a mean age of 72 +/- 10 years (748 men, 453 women) underwent CEA (676 asymptomatic, 525 symptomatic). Overall, stroke occurred in 46 (3.8%) patients, transient ischemic attack occurred in 19 (1.6%), myocardial infarction occurred in 19 (1.6%), and death occurred in 17 (1.4%). Increasing operative day glucose was independently associated with perioperative stroke or transient ischemic attack (Odds ratio [OR], 1.005; 95% confidence interval [CI], 1.00-1.01; P = 0.03), myocardial infarction (OR, 1.01; 95% CI, 1.004-1.016; P = 0.017), and death (OR, 1.007; 95% CI, 1.00-1.015; P = 0.04). Patients with operative day glucose greater than 200 mg/dl were 2.8-fold, 4.3-fold, and 3.3-fold more likely to experience perioperative stroke or transient ischemic attack (OR, 2.78; 95% CI, 1.37-5.67; P = 0.005), myocardial infarction (OR, 4.29; 95% CI, 1.28-14.4; P = 0.018), or death (OR, 3.29; 95% CI, 1.07-10.1; P = 0.037), respectively. Median and interquartile range length of hospitalization was greater for patients with operative day glucose greater than 200 mg/dl (4 d [interquartile range, 2-15 d] versus 3 d [interquartile range, 2-7 d]; P < 0.05).

CONCLUSION

Independent of previous cardiac disease, diabetes, or other comorbidities, hyperglycemia at the time of CEA was associated with an increased risk of perioperative stroke or transient ischemic attack, myocardial infarction, and death. Strict glucose control should be attempted before surgery to minimize the risk of morbidity and mortality after CEA.

Outcomes of carotid endarterectomy for asymptomatic stenosis in Sweden are improving: Results from a population-based registry

OBJECTIVE

In large randomized trials, carotid endarterectomy (CEA) for asymptomatic stenosis has shown a net benefit compared with best medical treatment. To justify an increased number of procedures for this indication, the perioperative risk of stroke or death must not exceed that of the trials. The aim of this study was to evaluate the outcome in routine clinical practice in Sweden in a population-based study.

METHODS

The Swedish Vascular Registry (Swedvasc) covers all centers performing CEA. Data on all registered CEAs during 1994 to 2003 were analyzed both for the whole time period and for two 5-year periods to study alterations over time. Four validation procedures of the registry were performed. Medical records were reviewed for both a random sample and a target sample (a total of 12% of the CEAs for asymptomatic stenosis). Swedvasc data were cross-matched with the In-Patient-Registry (used for reimbursement) and the Population-registry (death).

RESULTS

A total of 6182 CEAs were registered, 671 being for asymptomatic stenosis. In the validation process, no missed registration of major stroke or death was found. Patients with asymptomatic stenosis had, when the whole time-period was analyzed, a perioperative combined stroke or death rate of 2.1%. Outcome improved over time; the combined stroke or death rate decreased from 3.3% (11/330) from 1994 to 1998 to 0.9% (3/341) from 1999 to 2003 (P = .026). During the second time period, no patient with a perioperative major stroke or death was reported.

CONCLUSIONS

This extensively validated national audit of CEA for patients with asymptomatic carotid artery stenosis showed results well comparable with those of the randomized trials. The results improved over time.

Does the Type, Number or Combinations of Traditional Cardiovascular Risk Factors Affect Early Outcome After Carotid Endarterectomy?

PURPOSE

The present study was undertaken in order to assess the 30-day complication rate of carotid endarterectomy (CEA) in relation to the patients' cardiovascular risk factors.

METHODS

Cardiovascular risk factors, operative details, morbidity and mortality of 1002 carotid endarterectomies in 852 patients were prospectively recorded in a database. The indications for surgery were asymptomatic >or=75% or symptomatic >or=50% internal carotid stenosis when other causes of stroke were excluded. Exclusion criteria were intervention for post-CEA restenosis, post-irradiation lesions, kinking of the internal carotid artery, external carotid artery stenosis, endovascular and simultaneous cardiac procedures.

RESULTS

The 30-day combined minor and major stroke and death rate was 2.7% (27/1002). Significant risk factors in logistic regression model were diabetes (stroke and death rate=5.7%, p=0.002, OR=3.31), the simultaneous presence of three cardiovascular risk factors (stroke and death rate=5.3%, p=0.012, OR=3.11) and the combination diabetes, hypertension and hyperlipidemia (stroke and death rate=9.4%, p=0.001, OR=4.22).

CONCLUSIONS

Traditional cardiovascular risk factors significantly affect the 30-day stroke and death rate after carotid endarterectomy.

Predictors of neurocognitive decline after carotid endarterectomy

OBJECTIVE

Although the incidence of stroke after carotid endarterectomy (CEA) is low (1-3%), approximately 25% of patients experience subtle declines in postoperative neuropsychometric function. No studies have investigated the risk factors for this neurocognitive change. We sought to identify predictors of postoperative neurocognitive dysfunction.

METHODS

We enrolled 186 CEA patients, with both symptomatic and asymptomatic stenosis, to undergo a battery of neuropsychometric tests preoperatively and on postoperative Days 1 and 30. Neurocognitive dysfunction was defined as a two standard deviation decline in performance compared with a similarly aged control group of lumbar laminectomy patients. Univariate logistic regression was performed for age, sex, obesity, smoking, symptomatology, diabetes mellitus, hypertension, hypercholesterolemia, use of statin medication, previous myocardial infarction, previous CEA, operative side, duration of surgery, duration of carotid cross-clamp, and weight-adjusted doses of midazolam and fentanyl. Variables achieving univariate P < 0.10 were included in a multivariate analysis. Data is presented as (odds ratio, 95% confidence interval, P-value).

RESULTS

Eighteen and 9% of CEA patients were injured on postoperative Days 1 and 30, respectively. Advanced age predicted neurocognitive dysfunction on Days 1 and 30 (1.93 per decade, 1.15-3.25, 0.01; and 2.57 per decade, 1.01-6.51, 0.049, respectively). Additionally, diabetes independently predicted injury on Day 30 (4.26, 1.15-15.79, 0.03).

CONCLUSIONS

Advanced age and diabetes predispose to neurocognitive dysfunction after CEA. These results are consistent with risk factors for neurocognitive dysfunction after coronary bypass and major stroke after CEA, supporting an underlying ischemic pathophysiology. Further work is necessary to determine the role these neurocognitive deficits may play in appropriately selecting patients for CEA.

American Society of Anesthesiology and Rankin as Predictive Parameters for the Outcome of Carotid Endarterectomy Within 28 Days After an Ischemic Stroke

OBJECTIVE

Recent studies suggest that carotid endarterectomy (CEA) is more effective when performed closer to an ischemic event than after an arbitrary 4- to 6-week delay. Factors need to be identified to evaluate potential perioperative complications after early CEA.

METHODS

We investigated the influence of several clinical and morphological variables on the perioperative combined stroke and mortality rate and their influence on the modified Rankin-scale (mRS). In order to increase the statistical power, we combined data from three clinical studies (one multicenter and two single center trials) concerning the CEA after a waiting period of no more than 28 days. A perioperative stroke was defined as an important of at least 1 score in the mRS. Statistical analysis included univariate and multivariate analysis.

RESULTS

A total of 226 patients (167 male), aged between 30 and 87 years (median 65.05 years) underwent CEA following an ischemic stroke within a period of no more than 28 days (median 12 days). The majority (>90%) showed severe stenosis of the internal carotid artery (>/=70%), 149 patients (66%) were ranked Rankin </=2, 91 (42%) ASA </=2. The perioperative stroke and mortality rate was 8.4%; 10 patients (4.4%) suffered a nondisabling stroke and 8 patients (3.5%) a disabling second ischemic event. One patient died due to a myocardial infarction. The degree of stenosis, use of a shunt, timing of surgery, or demographic data did not significantly influence the perioperative outcome. Only the preoperative ASA classification could be shown to be a significant predictor (ASA >2, P = .0245) for a deterioration of the postoperative neurological status of at least 1 Rankin grade. There was also a trend concerning the Rankin scale at admission (Rankin >2, P = .0658). The logistic regression analysis showed that patients with an ASA classification >2 and a preoperative Rankin >2 that were treated within 12 days after the initial ischemic event had the greatest risk for a perioperative deterioration of their neurological symptoms (odds ratio: 4.4, 1.48-13.0; P = .01).

CONCLUSION

The ASA classification and the neurological status measured by the Rankin scale are predictive variables for the clinical perioperative outcome in patients treated within 28 days after an ischemic stroke. Patients ranked ASA </=2 and/or Rankin </=2 can safely undergo the CEA within a shorter waiting period. In contrast, patients with a more severe neurological deficit and a higher number of comorbidities are at a greater risk if treated too close to the ischemic event.

The safety of carotid endarterectomy in diabetic patients: clinical predictors of adverse outcome

OBJECTIVES

Patients with diabetes mellitus have been shown to have an increased incidence of complications after elective major vascular surgery. The objective of this study was to evaluate a large series of diabetic patients undergoing carotid endarterectomy (CEA) to determine if outcome differed from nondiabetic patients and to examine predisposing factors of poor outcome among diabetic patients.

METHODS

A retrospective review of a prospectively compiled database was performed. From 1992 through 2000, 2151 CEAs were performed at our institution. Of these, 507 were in diabetic patients (23.6%), and the remaining 1644 procedures were in nondiabetic patients (76.4%).

RESULTS

Diabetic patients were significantly more likely than nondiabetic patients to have hypertension (70.8% vs 64.5%, P = .01) and cardiac disease (54.6% vs 49.1%, P = .03). They were more likely than nondiabetic patients to be symptomatic before surgery (52.5% vs 47.1%, P = .04) and to have sustained a preoperative stroke (21.3% vs 17.7%, P = .07). No differences were noted in other recorded demographic factors or in intraoperative factors between diabetic and nondiabetic patients. Despite these differences, diabetic patients had similar perioperative outcomes compared with nondiabetic patients, including perioperative myocardial infarction (0.6% vs 0.4%, P = NS), perioperative death (0.8% vs 0.5%, P = NS), and perioperative neurologic events such as transient ischemic attack and stroke (3.2% vs 2.4%, P = NS). Among diabetic patients alone, cigarette smoking, general anesthesia, the use of a shunt, and the lack of clamp tolerance while under regional anesthesia predicted adverse perioperative neurologic outcome, and contralateral occlusion was associated with increased perioperative mortality.

CONCLUSIONS

Despite an increased prevalence of cardiac disease and preoperative neurologic symptoms among diabetic patients undergoing CEA, the rates of perioperative cardiac morbidity, mortality, and stroke were equal to nondiabetic patients. In contrast to nondiabetic patients, current cigarette smoking appeared to predict increased adverse neurologic outcomes among diabetic patients, and the presence of contralateral occlusion among diabetic patients appeared to predispose them towards increased perioperative mortality. The use of a general anesthetic appeared to increased perioperative neurologic risk among diabetic patients; however, this may be related to surgeon bias in the selection of anesthetic technique. Although diabetic patients may have an increase in complications after other major vascular surgical procedures, the presence of diabetes mellitus does not appear to significantly increase risk.

Review of prevalence and outcome of vascular disease in patients with diabetes mellitus

OBJECTIVES

Review the literature to determine the prevalence and outcome in patients with diabetes that undergo surgery to correct carotid artery stenosis, lower extremity arterial disease, and abdominal aortic aneurysm (AAA).

DESIGN AND MATERIALS

Studies were obtained from searches over the past 15 years on the National Library of Medicine's online search engine.

RESULTS

The review demonstrated an equivalent prevalence of carotid artery stenosis requiring surgery in patients with diabetes, it favored no increase risk of post-CEA stroke, and it was split on perioperative morbidity and mortality risk. There was an increase prevalence of lower extremity arterial disease requiring surgery in patients with diabetes, it favored equivalent patency and limb salvage rates, and it was split on the morbidity and mortality risk. The review demonstrated a decrease in AAA prevalence among patients with diabetes, it found an increase in the morbidity risk, and equivalent mortality risk.

CONCLUSIONS

Stroke, graft patency, and limb salvage rates in patients with diabetes after surgery are similar to patients without diabetes; however, their risk of complications is increased after surgery and the mortality risk may be higher after CEA.

Clinical and operative predictors of outcomes of carotid endarterectomy

OBJECTIVE

The net benefit for patients undergoing carotid endarterectomy is critically dependent on the risk of perioperative stroke and death. Information about risk factors can aid appropriate selection of patients and inform efforts to reduce complication rates. This study identifies the clinical, radiographic, surgical, and anesthesia variables that are independent predictors of deaths and stroke following carotid endarterectomy.

METHODS

A retrospective cohort study of patients undergoing carotid endarterectomy in 1997 and 1998 by 64 surgeons in 6 hospitals was performed (N = 1972). Detailed information on clinical, radiographic, surgical, anesthesia, and medical management variables and deaths or strokes within 30 days of surgery were abstracted from inpatient and outpatient records. Multivariate logistic regression models identified independent clinical characteristics and operative techniques associated with risk-adjusted rates of combined death and nonfatal stroke as well as all strokes.

RESULTS

Death or stroke occurred in 2.28% of patients without carotid symptoms, 2.93% of those with carotid transient ischemic attacks, and 7.11% of those with strokes (P < .0001). Three clinical factors increased the risk-adjusted odds of complications: stroke as the indication for surgery (odds ratio [OR], 2.84; 95% confidence interval [CI] = 1.55-5.20), presence of active coronary artery disease (OR, 3.58; 95% CI = 1.53-8.36), and contralateral carotid stenosis > or =50% (OR, 2.32; 95% CI = 1.33-4.02). Two surgical techniques reduced the risk-adjusted odds of death or stroke: use of local anesthesia (OR, 0.30; 95% CI = 0.16-0.58) and patch closure (OR, 0.43; 95% CI = 0.24-0.76).

CONCLUSIONS

Information about these risk factors may help physicians weigh the risks and benefits of carotid endarterectomy in individual patients. Two operative techniques (use of local anesthesia and patch closure) may lower the risk of death or stroke.