Carotid endarterectomy among Medicare beneficiaries: a statewide evaluation of appropriateness and outcome

Comparative Effectiveness of Carotid Endarterectomy vs Initial Medical Therapy in Patients With Asymptomatic Carotid Stenosis

Importance

Carotid endarterectomy (CEA) among asymptomatic patients involves a trade-off between a higher short-term perioperative risk in exchange for a lower long-term risk of stroke. The clinical benefit observed in randomized clinical trials (RCTs) may not extend to real-world practice.

Objective

To examine whether early intervention (CEA) was superior to initial medical therapy in real-world practice in preventing fatal and nonfatal strokes among patients with asymptomatic carotid stenosis.

Design, Setting, and Participants

This comparative effectiveness study was conducted from August 28, 2018, to March 2, 2020, using the Corporate Data Warehouse, Suicide Data Repository, and other databases of the US Department of Veterans Affairs. Data analyzed were those of veterans of the US Armed Forces aged 65 years or older who received carotid imaging between January 1, 2005, and December 31, 2009. Patients without a carotid imaging report, those with carotid stenosis of less than 50% or hemodynamically insignificant stenosis, and those with a history of stroke or transient ischemic attack in the 6 months before index imaging were excluded. A cohort of patients who received initial medical therapy and a cohort of similar patients who received CEA were constructed and followed up for 5 years. The target trial method was used to compute weighted Kaplan-Meier curves and estimate the risk of fatal and nonfatal strokes in each cohort in the pragmatic sample across 5 years of follow-up. This analysis was repeated after restricting the sample to patients who met RCT inclusion criteria. Cumulative incidence functions for fatal and nonfatal strokes were estimated, accounting for nonstroke deaths as competing risks in both the pragmatic and RCT-like samples.

Exposures

Receipt of CEA vs initial medical therapy.

Main Outcomes and Measures

Fatal and nonfatal strokes.

Results

Of the total 5221 patients, 2712 (51.9%; mean [SD] age, 73.6 [6.0] years; 2678 men [98.8%]) received CEA and 2509 (48.1%; mean [SD] age, 73.6 [6.0] years; 2479 men [98.8%]) received initial medical therapy within 1 year after the index carotid imaging. The observed rate of stroke or death (perioperative complications) within 30 days in the CEA cohort was 2.5% (95% CI, 2.0%-3.1%). The 5-year risk of fatal and nonfatal strokes was lower among patients randomized to CEA compared with patients randomized to initial medical therapy (5.6% vs 7.8%; risk difference, -2.3%; 95% CI, -4.0% to -0.3%). In an analysis that incorporated the competing risk of death, the risk difference between the 2 cohorts was lower and not statistically significant (risk difference, -0.8%; 95% CI, -2.1% to 0.5%). Among patients who met RCT inclusion criteria, the 5-year risk of fatal and nonfatal strokes was 5.5% (95% CI, 4.5%-6.5%) among patients randomized to CEA and was 7.6% (95% CI, 5.7%-9.5%) among those randomized to initial medical therapy (risk difference, -2.1%; 95% CI, -4.4% to -0.2%). Accounting for competing risks resulted in a risk difference of -0.9% (95% CI, -2.9% to 0.7%) that was not statistically significant.

Conclusions and Relevance

This study found that the absolute reduction in the risk of fatal and nonfatal strokes associated with early CEA was less than half the risk difference in trials from 20 years ago and was no longer statistically significant when the competing risk of nonstroke deaths was accounted for in the analysis. Given the nonnegligible perioperative 30-day risks and the improvements in stroke prevention, medical therapy may be an acceptable therapeutic strategy.

High Operator and Hospital Volume Are Associated With a Decreased Risk of Death and Stroke After Carotid Revascularization: A Systematic Review and Meta-analysis

OBJECTIVE

To examine the association between operator or hospital volume and procedural outcomes of carotid revascularization.

BACKGROUND

Operator and hospital volume have been proposed as determinants of outcome after carotid endarterectomy (CEA) or carotid artery stenting (CAS). The magnitude and clinical relevance of this relationship are debated.

METHODS

We systematically searched PubMed and EMBASE until August 21, 2017. The primary outcome was procedural (30 days, in-hospital, or perioperative) death or stroke. Obtained or estimated risk estimates were pooled with a generic inverse variance random-effects model.

RESULTS

We included 87 studies. A decreased risk of death or stroke following CEA was found for high compared to low operator volume with a pooled adjusted odds ratio (OR) of 0.50 (95% confidence interval [CI] 0.28-0.87; 3 cohorts), and a pooled unadjusted relative risk (RR) of 0.59 (95% CI 0.42-0.83; 9 cohorts); for high compared to low hospital volume with a pooled adjusted OR of 0.62 (95% CI 0.42-0.90; 5 cohorts), and a pooled unadjusted RR of 0.68 (95% CI 0.51-0.92; 9 cohorts). A decreased risk of death or stroke after CAS was found for high compared to low operator volume with an adjusted OR of 0.43 (95% CI 0.20-0.95; 1 cohort), and an unadjusted RR of 0.50 (95% CI 0.32-0.79; 1 cohort); for high compared to low hospital volume with an adjusted OR of 0.46 (95% CI 0.26-0.80; 1 cohort), and no significant decreased risk in a pooled unadjusted RR of 0.72 (95% CI 0.49-1.06; 2 cohorts).

CONCLUSIONS

We found a decreased risk of procedural death and stroke after CEA and CAS for high operator and high hospital volume, indicating that aiming for a high volume may help to reduce procedural complications.

REGISTRATION

This systematic review has been registered in the international prospective registry of systematic reviews (PROSPERO): CRD42017051491.

Carotid Artery Endarterectomy in the Octogenarian: A Community Hospital Experience

Between May 1995 and April 1998 three vascular surgeons performed 310 consecutive primary carotid endarterectomies (CEAs) in a 224-bed community hospital. Seventy-six CEAs were performed in octogenarians (Group 1) and 234 CEAs were performed in nonoctogenarians (Group 2). Demographic information, indication for surgery, and outcomes were compared. There were no strokes or deaths in Group 1; there was a single death and three strokes in Group 2. The overall rates of death, stroke, and combined stroke and death were 0.3%, 1%, and 1% respectively. No statistically significant difference existed in rates of morbidity and mortality in Groups 1 and 2. On follow-up (mean = 18 months), 94% of the patients were alive without stroke, 5% were dead, and 1% were alive with stroke. These data demonstrate that CEA can be performed safely in the octogenarian in the community hospital setting.

What Should We Do with Asymptomatic Carotid Stenosis?

The benefit of prophylactic carotid endarterectomy (CEA) for patients with asymptomatic severe carotid stenosis in the major randomised surgical studies was small, expensive and may now be absorbed by improvements in best practice medical intervention. Strategies to identify patients with high stroke risk are needed. If surgical intervention is to be considered the complication rates of individual surgeons should be available. Clinicians will differ in their interpretation of the same published data. Maintaining professional relationships with clinicians from different disciplines often involves compromise. As such, the management of a patient will, in part, depend on what kind of specialist the patient is referred to. The clinician's discussion with patients about this complex issue must be flexible to accommodate differing patient expectations. Ideally, patients prepared to undergo surgical procedures should be monitored in a trial setting or as part of an audited review process to increase our understanding of current practice outcomes.

Common Reasons That Asymptomatic Patients Who Are 65 Years and Older Receive Carotid Imaging

IMPORTANCE

National guidelines do not agree on the role of carotid screening in asymptomatic patients (ie, patients who have not had a stroke or transient ischemic attack). Recently, several physician organizations participating in the Choosing Wisely campaign have identified carotid imaging in selected asymptomatic populations as being of low value. However, the majority of patients who are evaluated for carotid stenosis and subsequently revascularized are asymptomatic.

OBJECTIVE

To better understand why asymptomatic patients who undergo revascularization receive initial carotid imaging.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of 4127 Veterans Health Administration patients 65 years and older undergoing carotid revascularization for asymptomatic carotid stenosis between 2005 and 2009.

MAIN OUTCOMES AND MEASURES

Indications for carotid ultrasounds were extracted using trained abstractors. Frequency of indications and appropriateness of initial carotid ultrasound imaging for patients within each rating category after the intervention were reported.

RESULTS

The mean (SD) age of this cohort of 4127 patients was 73.6 (5.9) years; 4014 (98.8%) were male. Overall, there were 5226 indications for 4063 carotid ultrasounds. The most common indications listed were carotid bruit (1578 [30.2% of indications]) and follow-up for carotid disease (stenosis/history of carotid disease) in patients who had previously documented carotid stenosis (1087 [20.8% of indications]). Multiple vascular risk factors were the next most common indication listed. Rates of appropriate, uncertain, and inappropriate imaging were 5.4% (227 indications), 83.4% (3387 indications), and 11.3% (458 indications), respectively. Among the most common inappropriate indications were dizziness/vertigo and syncope. Among the 4063 patients, 3373 (83.0%) received a carotid endarterectomy. Overall, 663 procedures were performed in patients 80 years and older.

CONCLUSIONS AND RELEVANCE

Carotid bruit and follow-up for carotid disease accounted for approximately half of all indications provided by physicians for carotid testing. Strong consideration should be given to improving the evidence base around carotid testing, especially around monitoring stenosis over long periods and evaluating carotid bruits. Targeting carotid ultrasound ordering with decision support tools may also be an important step in reducing use of low-value imaging.

Meta- analysis and meta-regression analysis of the associations between sex and the operative outcomes of carotid endarterectomy

Background

Subgroup analyses from randomized controlled trials (RCT) of carotid endarterectomy (CEA) for both symptomatic and asymptomatic carotid stenosis suggest less benefit in women compared to men, due partly to higher age-independent peri-operative risk. However, a meta-analysis of case series and databases focussing on CEA-related gender differences has never been investigated.

Methods

A systematic review of all available publications (including case series, databases and RCTs) reporting data on the association between sex and procedural risk of stroke and/or death following CEA from 1980 to 2015 was investigated. Pooled Peto odds ratios of the procedural risk of stroke and/or death were obtained by Mantel-Haenszel random-effects meta-analysis. The I² statistic was used as a measure of heterogeneity. Potential publication bias was assessed with the Egger test and represented graphically with Begg funnel plots of the natural log of the OR versus its standard error. Additional sensitivity analyses were undertaken to evaluate the potential effect of key assumptions and study-level factors on the overall results. Meta-regression models were formed to explore potential heterogeneity as a result of potential risk factors or confounders on outcomes. A tria sequential analysis (TSA) was performed with the aim to maintain an over- all 5 % risk of type I error, being the standard in most meta- analyses and systematic reviews.

Results

58 articles reported combined stroke and mortality rates within 30 days of treatment. In the unselected overall meta-analysis, the incidence of stroke and death in the male and female groups differed significantly (Peto OR, 1,162; 95 % CI, 1.067-1.266; P = .001), revealing a worse outcome for female patients. Moderate heterogeneity among the studies was identified (I² = 36 %), and the possibility of publication bias was low (P = .03). In sensitivity analyses the meta-analysis of case series with gender aspects as a secondary outcome showed a significantly increased risk for 30-day stroke and death in women compared to men (Peto OR, 1.390; 95 % CI, 1.148-1.684; P = .001), In contrast, meta-analysis of databases (Peto OR, 1.025; 95 % CI, 0.958-1.097; P = .474) and case series with gender related outcomes as a primary aim (Peto OR, 1.202; 95 % CI, 0.925-1.561; P = .168) demonstrated no increase in operative risk of stroke and death in women compared to men.

Conclusions

Metanalyses of case series and databases dealing with CEA reveal inconsistent results regarding gender differences related to CEA-procedure and should not be transferred into clinical practice.

[A role of carotid endarterectomy in prevention of cerebral ischemic damage]

Authors present a literature review on the prevalence, clinical presentations, diagnosis and outcome of surgical treatment of atherosclerotic stenosis of the internal carotid artery.

Carotid Endarterectomy: A Review

Background:

Since the validation of carotid endarterectomy (CEA) as an effective means of stroke prevention, there has been renewed interest in its best indications and methods, as well as in how it compares to carotid angioplasty and stenting (CAS). This review examines these topics, as well as the investigation of carotid stenosis and the role of auditing and reporting CEAresults.

Investigation:

Brain imaging with CTor MRI should be obtained in patients considered for CEA, in order to document infarction and rule out mass lesions. Carotid investigation begins with ultrasound and, if results agree with subsequent, good-quality MRAor CTangiography, treatment can be planned and catheter angiography avoided. An equally acceptable approach is to proceed directly from ultrasound to catheter angiography, which is still the gold-standard in carotid artery assessment.

Indications:

Appropriate patients for CEA are those symptomatic with transient ischemic attacks or nondisabling stroke due to 70-99% carotid stenosis; the maximum allowable stroke and death rate being 6%. Uncertain candidates for CEA are those with 50 - 69% symptomatic stenosis, and those with asymptomatic stenosis ≥ 60% but, if selected carefully on the basis of additional risk factors (related to both the carotid plaque and certain patient characteristics), some will benefit from surgery. Asymptomatic patients will only benefit if surgery can be provided with exceptionally low major complication rates (3% or less). Inappropriate patients are those with less than 50% symptomatic or 60% asymptomatic stenosis, and those with unstable medical or neurological conditions.

Techniques:

Carotid endarterectomy can be performed with either regional or general anaesthesia and, for the latter, there are a number of monitoring techniques available to assess cerebral perfusion during carotid cross-clamping. While monitoring cannot be considered mandatory and no single monitoring technique has emerged as being clearly superior, EEG is most commonly used. “Eversion” endarterectomy is a variation in surgical technique, and there is some evidence that more widely practiced patch closure may reduce the acute risk of operative stroke and the longer-term risk of recurrent stenosis.

Carotid angioplasty and stenting:

Experience with this endovascular and less invasive procedure grows, and its technology continues to evolve. Some experienced therapists have reported excellent results in case series and a number of randomized trials are now underway comparing CAS to CEA. However, at this time it is premature to incorporate CAS into routine practice replacing CEA.

Auditing:

It has been shown that auditing of CEA indications and results with regular feed-back to the operating surgeons can significantly improve the performance of this operation. Carotid endarterectomy auditing is recommended on both local and regional levels.

Unchanged safety outcomes in deep brain stimulation surgery for Parkinson disease despite a decentralization of care

OBJECT

Early work on deep brain stimulation (DBS) surgery, when procedures were mostly carried out in a small number of high-volume centers, demonstrated a relationship between surgical volume and procedural safety. However, over the past decade, DBS has become more widely available in the community rather than solely at academic medical centers. The authors examined the Nationwide Inpatient Sample (NIS) to study the safety of DBS surgery for Parkinson disease (PD) in association with this change in practice patterns.

METHODS

The NIS is a stratified sample of 20% of all patient discharges from nonfederal hospitals in the United States. The authors identified patients with a primary diagnosis of PD (332.0) and a primary procedure code for implantation/replacement of intracranial neurostimulator leads (02.93) who underwent surgery between 2002 and 2009. They analyzed outcomes using univariate and hierarchical, logistic regression analyses.

RESULTS

The total number of DBS cases remained stable from 2002 through 2009. Despite older and sicker patients undergoing DBS, procedural safety (rates of non-home discharges, complications) remained stable. Patients at low-volume hospitals were virtually indistinguishable from those at high-volume hospitals, except that patients at low-volume hospitals had slightly higher comorbidity scores (0.90 vs 0.75, p < 0.01). Complications, non-home discharges, length of hospital stay, and mortality rates did not significantly differ between low- and high-volume hospitals when accounting for hospital-related variables (caseload, teaching status, location).

CONCLUSIONS

Prior investigations have demonstrated a robust volume-outcome relationship for a variety of surgical procedures. However, the present study supports safety of DBS at smaller-volume centers. Prospective studies are required to determine whether low-volume centers and higher-volume centers have similar DBS efficacy, a critical factor in determining whether DBS is comparable between centers.

Stratifying risk: asymptomatic carotid disease

Stroke generates significant healthcare expenses and it is also a social and economic burden. The carotid artery atherosclerotic plaque instability is responsible for a third of all embolic strokes. The degree of stenosis has been deliberately used to justify carotid artery interventions in thousands of patients worldwide. However, the annual risk of stroke in asymptomatic carotid artery disease is low. Plaque morphology and its kinetics have gained ground to explain cerebrovascular and retinal embolic events. This review provides the readers with an insightful and critical analysis of the risk stratification of asymptomatic carotid artery disease in order to assist in selecting potential candidates for a carotid intervention.

Strategies for asymptomatic carotid artery stenosis

The treatment of asymptomatic carotid artery stenosis (ACAS) has continued to evolve for the past 3 decades. With rapidly advancing technology, the results of old trials have become obsolete. While there has been little change in the efficacy of carotid endarterectomy, there have been vast improvements in both medical management and carotid angioplasty with stenting. Finding the best therapy for a given patient can therefore be difficult. In this article, the authors review the current literature regarding treatment options for ACAS and the methods available for stratifying patients who would benefit from surgical versus medical treatment.

Current outcomes of simultaneous carotid endarterectomy and coronary artery bypass graft surgery in North America

OBJECTIVE

Management of patients with concomitant carotid and coronary artery disease has been controversial. Divergent strategies have been employed, including simultaneous carotid endarterectomy and coronary bypass (SCC) versus various staged procedures. Although no strict comparison group is available, this study defines current outcomes of SCC, compared qualitatively to two reference categories.

METHODS

Utilizing the STS database from 2003 to 2007, patients who had SCC were compared with patients with cerebrovascular disease who had coronary bypass (CABG) with prior carotid endarterectomy (CEA), and those with carotid Doppler stenosis >75% and no carotid intervention. Logistic regression analysis adjusted for differences in baseline characteristics and operative mortality (OM), and a composite of neurological complications (NC) was assessed.

RESULTS

Of 745,769 patients who underwent isolated CABG with/without CEA, 108,212 (14%) had cerebrovascular disease. Of this group, 5,732 (5%) underwent SCC. The SCC group had more males and lower preoperative risk factors. After statistical adjustment for all baseline differences, SCC had clinically and statistically higher OM and NC compared with any of the reference groups, with 20-40% higher event risk.

CONCLUSIONS

Although no quantitative control group exists for comparison, SCC as recently performed in North America has a high risk compared with any of the reference groups. Suboptimal results associated with the SCC strategy suggest a need for quality improvement and research on the optimal management of patients with simultaneous carotid and coronary disease.

Risk factors associated with major cerebrovascular complications after intracranial stenting

BACKGROUND

There are limited data on the relationship between patient and site characteristics and clinical outcomes after intracranial stenting.

METHODS

We performed a multivariable analysis that correlated patient and site characteristics with the occurrence of the primary endpoint (any stroke or death within 30 days of stenting or stroke in the territory of the stented artery beyond 30 days) in 160 patients enrolled in this stenting registry. All patients presented with an ischemic stroke, TIA, or other cerebral ischemic event (e.g., vertebrobasilar insufficiency) in the territory of a suspected 50-99% stenosis of a major intracranial artery while on antithrombotic therapy.

RESULTS

Cerebral angiography confirmed that 99% (158/160) of patients had a 50-99% stenosis. In multivariable analysis, the primary endpoint was associated with posterior circulation stenosis (vs anterior circulation) (hazard ratio [HR] 3.4, 95% confidence interval [CI] 1.2-9.3, p = 0.018), stenting at low enrollment sites (< 10 patients each) (vs high enrollment site) (HR 2.8, 95% CI 1.1-7.6, p = 0.038), < or = 10 days from qualifying event to stenting (vs > or = 10 days) (HR 2.7, 95% CI 1.0-7.8, p = 0.058), and stroke as a qualifying event (vs TIA/other) (HR 3.2, 95% CI 0.9-11.2, p = 0.064). There was no significant difference in the primary endpoint based on age, gender, race, or percent stenosis (50-69% vs 70-99%).

CONCLUSIONS

Major cerebrovascular complications after intracranial stenting may be associated with posterior circulation stenosis, low volume sites, stenting soon after a qualifying event, and stroke as the qualifying event. These factors will need to be monitored in future trials of intracranial stenting.

Multidetector-row computed tomography in evaluation of atherosclerotic carotid plaques complicated with intraplaque hemorrhage

Our aim was to determine the sensitivity and specificity of multidetector-row computed tomography (CT) in detecting atherosclerotic carotid plaques complicated with intraplaque hemorrhage. We examined carotid plaques from 31 patients operated for carotid artery stenosis. Results of preoperative multidetector-row CT analysis of carotid plaques were compared with results of histological analysis of the same plaque areas. Carotid endarterectomy was performed within 1 week of multidetector-row CT. American Heart Association classification of atherosclerotic plaques was applied for histological classification. Median tissue density of carotid plaques complicated with intraplaque hemorrhage was 22 Hounsfield units (HU). Median tissue density of noncalcified segments of uncomplicated plaques was 59 HU (p=0.0062). The highest tissue density observed for complicated plaques was 31 HU. Multidetector-row CT detected plaques complicated with hemorrhage with sensitivity of 100% and specificity of 64.7%, with tissue density of 31 HU as a threshold value. Multidetector-row CT showed a high level of sensitivity and a moderate level of specificity in detecting atherosclerotic carotid plaques complicated with hemorrhage.

Meta-Analysis and Systematic Review of the Relationship between Hospital Volume and Outcome Following Carotid Endarterectomy

OBJECTIVES

This study investigated the relationship between annual hospital volume and the outcomes in carotid endarterectomy and quantified critical volume threshold for this procedure.

DATA SOURCES

PubMed, EMBASE and the Cochrane library were searched for all articles on the volume-outcome relationship in CEA.

REVIEW METHODS

Articles were included if they presented data on post-operative mortality and/or stroke rates and annual hospital volume of CEA. The review conformed to the QUOROM statement. The data were meta-analysed and a pooled effect estimate of volume on the stroke and/or mortality rates from CEA quantified, along with the critical volume threshold.

RESULTS

Twenty-five articles, encompassing 936 436 CEA, were analysed. Significant relationships between mortality rate and stroke rate and annual volume were seen. Overall, the pooled effect estimate was odds ratio 0.78 [95% confidence interval 0.64-0.92], in favour of surgery at higher volume units, with a critical volume threshold of 79 CEA per annum.

CONCLUSIONS

Significantly lower mortality and stroke rates were achieved at hospitals providing a higher annual hospital volume of CEA. Hospitals wishing to provide CEA should adhere to minimum volume criteria.

Factors influencing the volume-outcome relationship in gastrectomies: a population-based study

BACKGROUND

A relationship between hospital procedural volume and patient outcomes has been observed in gastrectomies for primary gastric cancer, but modifiable factors influencing this relationship are not well elaborated.

METHODS

We performed a population-based study of 1864 patients undergoing gastrectomy for primary gastric cancers at 214 hospitals. Hospitals were stratified as high-, intermediate-, or low-volume centers. Multivariate models were constructed to evaluate the effect of institutional procedural volume and other hospital- and patient-specific factors on the risk of in-hospital mortality, adverse events, and failure to rescue, defined as mortality after an adverse event.

RESULTS

High-volume centers attained an in-hospital mortality rate of 1.0% and failure-to-rescue rate of .7%, both less than one-fifth of that seen at intermediate- and low-volume centers, although adverse event rates were similar across the three volume tiers. In multivariate modeling, treatment at a high-volume hospital decreased the odds of mortality (odds ratio [OR], .22; 95% confidence interval [95% CI], .05-.89), whereas treatment at an institution with a high ratio of licensed vocational nurses per bed increased the odds of mortality (OR, 1.96; 95% CI, 1.04-3.75). Being treated at a hospital with a greater than median number of critical care beds decreased odds of mortality (OR, .46; 95% CI, .25-.81) and failure to rescue (OR, .53; 95% CI, .29-.97).

CONCLUSIONS

Undergoing gastrectomy at a high-volume center is associated with lower in-hospital mortality. However, improving the rates of mortality after adverse events and reevaluating nurse staffing ratios may provide avenues by which lower-volume centers can improve mortality rates.

A systematic review of the impact of volume of surgery and specialization on patient outcome

BACKGROUND AND METHODS

Volume of surgery and specialization may affect patient outcome. Articles examining the effects of one or more of three variables (hospital volume of surgery, surgeon volume and specialization) on outcome (measured by length of hospital stay, mortality and complication rate) were analysed. Reviews, opinion articles and observational studies were excluded. The methodological quality of each study was assessed, a correlation between the variables analysed and the outcome accepted if it was significant.

RESULTS

The search identified 55,391 articles published between 1957 and 2002; 1075 were relevant to the study, of which 163 (9,904,850 patients) fulfilled the entry criteria. These 163 examined 42 different surgical procedures, spanning 13 surgical specialities. None were randomized and 40 investigated more than one variable. Hospital volume was reported in 127 studies; high-volume hospitals had significantly better outcomes in 74.2 per cent of studies, but this effect was limited in prospective studies (40 per cent). Surgeon volume was reported in 58 studies; high-volume surgeons had significantly better outcomes in 74 per cent of studies. Specialization was reported in 22 studies; specialist surgeons had significantly better outcomes than general surgeons in 91 per cent of studies. The benefit of high surgeon volume and specialization varied in magnitude between specialities.

CONCLUSION

High surgeon volume and specialization are associated with improved patient outcome, while high hospital volume is of limited benefit.

Provider volume and outcomes for abdominal aortic aneurysm repair, carotid endarterectomy, and lower extremity revascularization procedures

BACKGROUND

Intuitively, vascular procedures performed by high-volume vascular subspecialists working at high-volume institutions should be associated with improved patient outcome. Although a large number of studies assess the relationship between volume and outcome, a single contemporary compilation of such studies is lacking.

METHODS

A review of the English language literature was performed incorporating searches of the Medline, EMBASE, and Cochrane collaboration databases for abdominal aortic aneurysm repair (elective and emergent), carotid endarterectomy, and arterial lower limb procedures for any volume outcome relationship. Studies were included if they involved a patient cohort from 1980 onwards, were community or population based, and assessed health outcomes (mortality and morbidity) as a dependent variable and volume as an independent variable.

RESULTS

We identified 74 relevant studies, and 54 were included. All showed either an inverse relationship of variable magnitude between provider volume and mortality, or no volume-outcome effect. The reduction in the risk-adjusted mortality rate (RAMR) for high-volume providers was 3% to 11% for elective abdominal aortic aneurysm (AAA) repair, 2.5 to 5% for emergent AAA repair, 0.7% to 4.7% carotid endarterectomy, and 0.3% to 0.9% for lower limb arterial bypass procedures. Subspeciality training also conferred a considerable morbidity and mortality benefit for emergent AAA repair, carotid endarterectomy, and lower limb arterial procedures.

CONCLUSION

High-volume providers have significantly better outcomes for vascular procedures both in the elective and emergent setting. Subspeciality training also has a considerable impact. These data provide further evidence for the specialization of vascular services, whereby vascular procedures should generally be preformed by high-volume, speciality trained providers.

The CAPTURE registry: results of carotid stenting with embolic protection in the post approval setting

BACKGROUND

Pivotal study data examining carotid stenting with embolic protection as a less invasive alternative to endarterectomy for high surgical risk patients have been acquired under controlled conditions with highly selected physicians and hospitals. This report examines outcomes of carotid stenting post-approval after diffusion of this technology to a broader cross-section of physicians and hospitals.

METHODS

The Carotid Acculink/Accunet Post-Approval Trial to Uncover Unanticipated or Rare Events (CAPTURE) is a prospective, multi-center registry to assess two important aspects of the post-IDE experience: the safety of carotid stenting by physicians with varying levels of experience as a measure of the adequacy of physician training, and the identification of rare/unexpected device-related complications. The primary endpoint was a composite of death, any stroke, or myocardial infarction within 30 days post-procedure.

RESULTS

3,500 patients were enrolled by 353 physicians at 144 sites. The 30-day primary endpoint event rate was 6.3% (95% CI: 5.5-7.1%) and did not differ among the three operator experience levels (5.3%, 6.0%, and 7.4%; P = 0.31) from most to least experienced, respectively. There were no differences in outcomes among physician specialties when adjusted for case mix. There were no unanticipated device related adverse events.

CONCLUSIONS

The results of the CAPTURE study compare favorably to those achieved in the predicate pivotal investigations, and suggest that the post-approval transfer of this new therapy to the community practice setting via carotid stent training programs is effective in preparing physicians with varying experience levels and specialty training backgrounds.

Cervical carotid revascularization: the case for carotid angioplasty with stenting

Carotid artery angioplasty with or without stent placement has evolved as an alternative to carotid endarterectomy, particularly for those patients in whom carotid endarterectomy is associated with a higher risk of complications. This article summarizes the selection criteria for participation in and the results of several carotid intervention trials, reviews the relative indications and limitations for both surgical and endovascular revascularization approaches, and describes the technique for and results associated with carotid stenting. The discussion is presented from the vantage of neurosurgeons who are experienced in both revascularization approaches.

Defining the high-risk patient for carotid endarterectomy: An analysis of the prospective National Surgical Quality Improvement Program database

BACKGROUND

Carotid endarterectomy (CEA) is the gold standard for the treatment of carotid stenosis, but carotid angioplasty and stenting has been advocated in high-risk patients. The definition of such a population has been elusive, particularly because the data are largely retrospective. Our study examined results for CEA in the National Surgical Quality Improvement Program database (both Veterans Affairs and private sector).

METHODS

National Surgical Quality Improvement Program data were gathered prospectively for all patients undergoing primary isolated CEA during the interval 2000 to 2003 at 123 Veterans Affairs and 14 private sector academic medical centers. Study end points included the 30-day occurrence of any stroke, death, or cardiac event. A variety of clinical, demographic, and operative variables were assessed with multivariate models to identify risk factors associated with the composite (stroke, death, or cardiac event) end point. Adjudication of end points was by trained nurse reviewers (previously validated).

RESULTS

A total of 13,622 CEAs were performed during the study period; 95% were on male patients, and 91% of cases were conducted within the Veterans Affairs sector. The average age was 68.6 +/- 0.1 years, and 42.1% of the population had no prior neurologic event. The composite stroke, death, or cardiac event rate was 4.0%; the stroke/death rate was 3.4%. Multivariate correlates of the composite outcome were (odds ratio, P value) as follows: deciles of age (1.13, .018), insulin-requiring diabetes (1.73, <.001), oral agent-controlled diabetes (1.39, .003), decade of pack-years smoking (1.04, >.001), history of transient ischemic attack (1.41, >.001), history of stroke (1.51, >.001), creatinine >1.5 mg/dL (1.48, >.001), hypoalbuminemia (1.49, >.001), and fourth quartile of operative time (1.44, >.001). Cardiopulmonary comorbid features did not affect the composite outcome in this model. Regional anesthesia was used in 2437 (18%) cases, with a resultant relative risk reduction for stroke (17%), death (24%), cardiac event (33%), and the composite outcome (31%; odds ratio, 0.69; P = .008).

CONCLUSIONS

Carotid endarterectomy results across a spectrum of Veterans Affairs and private sector hospitals compare favorably to contemporary studies. These data will assist in selecting patients who are at an increased risk for adverse outcomes. Use of regional anesthetic significantly reduced perioperative complications in a risk-adjusted model, thus suggesting that it is the anesthetic of choice when CEA is performed in high-risk patients.

A Systematic Review of the Associations between Age and Sex and the Operative Risks of Carotid Endarterectomy

BACKGROUND

Randomized trials of carotid endarterectomy (CEA) for both symptomatic and asymptomatic carotid stenosis have demonstrated that benefit is decreased in women, due partly to a high operative risk, which is independent of age. However, it is uncertain whether these trial-based observations are generalisable to routine clinical practice.

METHODS

We performed a systematic review of all publications reporting data on the association between age and/or sex and procedural risk of stroke and/or death following CEA from 1980 to 2004.

RESULTS

62 eligible papers reported relevant data. Females had a higher rate of operative stroke and death (25 studies, OR = 1.31, 95% CI = 1.17-1.47, p < 0.001) than males, but no increase in operative mortality (15 studies, OR = 1.05, 95% CI = 0.81-0.86, p = 0.78). Compared with younger patients, operative mortality was increased at > or =75 years (20 studies, OR = 1.36, 95% CI = 1.07-1.68, p = 0.02), at age > or =80 years (15 studies, OR = 1.80, 95% CI = 1.26-2.45, p < 0.001) and in older patients overall (35 studies, OR = 1.50, 95% CI = 1.26-1.78, p < 0.001). In contrast, risk of non-fatal stroke did not increase with age and so the combined perioperative risk was only slightly increased at age > or =75 years (21 studies, OR = 1.18, 95% CI = 0.94-1.44, p = 0.06), at age > or =80 years (10 studies, OR = 1.14, 95% CI = 0.92-1.36, p = 0.34) and in older patients overall (36 studies, OR = 1.17, 95% CI = 1.04-1.31, p = 0.01).

CONCLUSIONS

The effects of age and sex on the operative risk of CEA in published case series are consistent with those observed in the trials. Operative risk of stroke is increased in women and operative mortality is increased in patients aged > or =75 years.

An audit tool for assessing the appropriateness of carotid endarterectomy

Background

To update appropriateness ratings for carotid endarterectomy using the best clinical evidence and to develop a tool to audit the procedure's use.

Methods

A nine-member expert panel drawn from all the Canadian Specialist societies that are involved in the care of patients with carotid artery disease, used the RAND Appropriateness Methodology to rate scenarios where carotid endarterectomy may be performed. A 9-point rating scale was used that permits the categorization of the use of carotid endarterectomy as appropriate, uncertain, or inappropriate. A descriptive analysis was undertaken of the final results of the panel meeting. A database and code were then developed to rate all carotid endarterectomies performed in a Western Canadian Health region from 1997 to 2001.

Results

All scenarios for severe symptomatic stenosis (70–99%) were determined to be appropriate. The ratings for moderate symptomatic stenosis (50–69%) ranged from appropriate to inappropriate. It was never considered appropriate to perform endarterectomy for mild stenosis (0–49%) or for chronic occlusions. Endarterectomy for asymptomatic carotid disease was thought to be of uncertain benefit at best. The majority of indications for the combination of endarterectomy either prior to, or at time of coronary artery bypass grafting were inappropriate. The audit tool classified 98.0% of all cases.

Conclusions

These expert panel ratings, based on the best evidence currently available, provide a comprehensive and updated guide to appropriate use of carotid endarterectomy. The resulting audit tool can be downloaded by readers from the Internet and immediately used for hospital audits of carotid endarterectomy appropriateness.

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

OBJECTIVES

The overall benefit of carotid endarterectomy (CEA) is dependent on the outcome from the procedure. However, many reports are from selected centres and not population-based. The aim of this study was to assess the 30-day complication rate for a whole country and also to determine independent risk factors for serious complications.

MATERIALS AND METHODS

One thousand five hundred and eighteen CEA were retrospectively reviewed, covering principally all the CEAs in Sweden, during a three year period. Indications for surgery were; minor stroke 34%, TIA 34%, amaurosis fugax 18%, asymptomatic 11% and others 3%. Data were collected from the Swedish Vascular Registry (Swedvasc). Combined cohort and case-control methodology was used.

RESULTS

Registered complications were; 43 permanent strokes, 32 transient strokes (<30 days), 18 TIA/amaurosis fugax and 22 deaths (seven fatal stokes). In the cohort study, the 30-day permanent stroke and death rate were 4.3% (65/1518). Significant risk factors in multivariate analyses were the indication for surgery (minor stroke vs. other indications) (p=0.02, RR=1.38), diabetes (p=0.02, RR=1.41), cardiac disease (p<0.01, RR 1.43) and operation at a university hospital (p=0.02, RR=1.39). In the case-control study comparing the 65 cases of permanent stroke and/or death with 130 matched controls the only significant risk factor was contralateral occlusion (p<0.01, OR=5.27). One patient (1/130) with a permanent stroke was wrongly reported as a local neurological complication (facial paresis).

CONCLUSION

This national audit demonstrated population-based data on complication rates after CEA well comparable with previous randomised trials. The validity of the Swedvasc data was confirmed. Combined cohort and case-control methodology was useful in analysing risk factors for serious perioperative complications.

Multistate improvement in process and outcomes of carotid endarterectomy

OBJECTIVES

The purpose of this study was to assess the effect of community-wide performance measurement and feedback on key processes and outcomes of carotid endarterectomy (CEA).

METHODS

Complete medical record (hospital chart) review for indications, care processes, and outcomes was performed on a random sample of Medicare patients undergoing CEA in 10 states (Arkansas, Georgia, Illinois, Indiana, Iowa, Kentucky, Michigan, Nebraska, Ohio, Oklahoma) during baseline (Jun 1, 1995 to May 31, 1996) and remeasurement (Jun 1, 1998 to May 31, 1999) periods. In addition to review of the index hospital stay, hospital admissions within 30 days of the procedure were reviewed and the Medicare enrollment database queried to identify out-of-hospital deaths, to determine 30-day outcome results. The baseline data by state were provided to the Medicare Quality Improvement Organizations (QIOs) in the respective states, and quality improvement initiatives were encouraged.

RESULTS

We reviewed 9945 primary CEA alone procedures, 236 CEA and coronary artery bypass grafting (CABG) procedures, and 380 repeat CEA operations during the baseline period (B), and 9745 primary CEA alone procedures, 233 CEA and CABG procedures, and 401 repeat CEA operations during the remeasurement period (R). There was a significant decrease in the combined event rate (30-day stroke or mortality) for CEA alone procedures between baseline and remeasurement (B, 5.6%; R, 5.0%). A decrease occurred in each of the indication strata; transient ischemic attack or stroke (B, 7.7%; R, 6.9%), nonspecific symptoms (B, 5.9%; R, 5.4%), and no symptoms (B, 4.1%; R, 3.8%). The combined event rate also decreased for CEA and CABG (B, 17.4%; R, 13.3%) and repeat CEA operations (B, 6.8%; R, 5.7%). The remeasurement period state-to-state variation in combined event rate for CEA alone ranged from 2.7% (Georgia) to 5.9% (Indiana) for all indications combined, from 4.4% (Georgia) to 10.9% (Michigan) in patients with recent transient ischemia or stroke, from 1.4% (Georgia) to 6.0% (Oklahoma) in patients with no symptoms, and from 3.7% (Georgia) to 7.9% (Indiana) in patients with nonspecific symptoms. There were significant increases in preoperative antiplatelet administration (62%-67%; P <.0001) and patching (29%-45%; P =.05) from baseline to remeasurement in the CEA alone subset. Preoperative antiplatelet administration and patching were associated with improved outcomes in the combined baseline and remeasurement data.

CONCLUSIONS

Community-wide quality improvement initiatives with performance measurement and confidential reporting of provider level data can lead to improvement in important care processes and outcomes. There is considerable variation between states in outcome and process, and thus continued room for improvement. Quality improvement projects that include standardized confidential outcome reporting should be encouraged. Preoperative antiplatelet therapy administration and patching rates should be considered as evidence-based performance measures.

Carotid Angioplasty and Stenting versus Carotid Endarterectomy for Treatment of Asymptomatic Carotid Stenosis: A Randomized Trial in a Community Hospital

OBJECTIVE

Carotid endarterectomy (CEA) is effective in reducing the risk of stroke in individuals with more than 60% carotid stenosis. Carotid angioplasty and stenting (CAS) has been proffered as effective and used in treating individuals with asymptomatic carotid stenosis despite the absence of proven clinical equivalency. This randomized trial was designed to explore the hypothesis that CAS is equivalent to CEA for treating asymptomatic carotid stenosis.

METHODS

A total of 85 individuals presenting with asymptomatic carotid stenosis of more than 80% were selected randomly for CAS or CEA and followed up for 48 months.

RESULTS

Stenosis decreased to an average of 5% after CAS. The patency of the reconstructed artery remained satisfactory regardless of the technique, as determined by carotid ultrasonography. No major complications such as cerebral ischemia or death occurred. Procedural complications associated with CAS (n = 5) were hypotension and/or bradycardia; those concomitant with CEA (n = 3) were cervical nerve injury or complications related to general anesthesia (n = 4). Both procedures were well tolerated in the context of pain and discomfort. Hospital stay was similar in the two groups (mean, 1.1 versus 1.2 d). The occurrence of complications associated with CAS or CEA prolonged hospitalization by 3 days (mean, 4.0 versus 4.5 d). Return to full activity was achieved within 1 week by more than 85% of patients; all returned to their usual lifestyle by 2 weeks. Although hospital charges were slightly higher for CAS, costs were similar.

CONCLUSION

CAS and CEA may be equally effective and safe in treating individuals with asymptomatic carotid stenosis.

Carotid endarterectomy utilization and mortality in 10 states

BACKGROUND

Studies that examined the rates of and mortality after carotid endarterectomy (CEA) mainly were confined to a limited geographical location or population. The primary purposes of this study are to examine the variation of risk-adjusted in-hospital mortality rates after CEA in 10 states, and utilization rates per capita of CEA.

METHODS

An analysis was made of hospital discharge data from 10 states extracted from the Agency for Health Research and Quality national database, Healthcare Cost and Utilization Project (HCUP).

RESULTS

The rates of CEA per capita were found to differ among the 10 states examined. No significant association was detected between geographic location and the adjusted risk of in-hospital mortality. Sex, age, type of admission, and several comorbidities were found to be significant risk factors.

CONCLUSIONS

Rates of CEA per capita differ among states. However, geographical location does not affect the likelihood of risk-adjusted mortality after the procedure.

Who doesn't receive carotid endarterectomy when appropriate?

OBJECTIVE

The purpose of this study was to identify clinical and nonclinical factors associated with failure to perform carotid endarterectomy (CEA) in patients with clinically appropriate indications. We analyzed data from a prospective cohort study performed at five Veterans Affairs medical centers. Patients were referred for carotid artery evaluation if they had at least 50% stenosis in one carotid artery, had no history of CEA, and were independently classified preoperatively as appropriate candidates for CEA, according to clinical criteria. The primary outcome was receipt of CEA within 6 months of evaluation. Data were collected by medical record review and interview regarding clinical status, and patient and physician perception of the risks and benefits of CEA.

RESULTS

Among clinically appropriate candidates for CEA, 66.8% (n = 233) did not undergo the operation. Compared with patients who did undergo CEA, a greater proportion of these patients had no symptoms (68.7% vs 45.7%; P <.001). A twofold greater proportion of patients who did not undergo CEA were in the highest quartile of reported aversion to surgery. Moreover, a fourfold greater proportion were perceived by their physicians to be at less than 5% risk for future stroke without the operation, and more than a twofold greater proportion were believed to experience less than 5% efficacy from the operation by their providers (P <.01). In multivariable analyses, four characteristics were significantly associated with whether an appropriate candidate did not receive CEA: asymptomatic disease, less than 70% stenosis, high expressed aversion to surgery score, and low (<5%) provider-perceived efficacy of the operation.

CONCLUSION

Among patients in the Veterans Affairs health care system who are clinically appropriate candidates for CEA, those who did not receive the operation were less likely to have symptomatic disease or high-grade carotid artery stenosis, but were more likely to report high aversion to surgery and to have a provider who believed CEA would not be efficacious.

Local versus general anaesthesia for carotid endarterectomy

BACKGROUND

Carotid endarterectomy reduces the risk of stroke in people with recently symptomatic, severe carotid artery stenosis. However, there are significant perioperative risks which may be lessened by performing the operation under local rather than general anaesthetic.

OBJECTIVES

The aim of this review was to assess the risks of endarterectomy under local compared with general anaesthetic.

SEARCH STRATEGY

We searched the Stroke Group trials register (April 2003), MEDLINE (1966 to April 2003), EMBASE (1980 to 2002), and Index to Scientific and Technical Proceedings (1980 to 1994). We handsearched 13 relevant journals up to 2002, and searched the reference lists of articles identified. We also advertised the review in Vascular News (a newspaper for European vascular specialists) in August 2001.

SELECTION CRITERIA

Randomised trials and non-randomised studies comparing carotid endarterectomy under local versus general anaesthetic.

DATA COLLECTION AND ANALYSIS

One reviewer selected studies for inclusion and another independently checked the decisions. Two reviewers assessed trial quality and independently extracted the data.

MAIN RESULTS

Seven randomised trials involving 554 operations, and 41 non-randomised studies involving 25622 operations were included. The methodological quality of the non-randomised trials was questionable. Eleven of the non-randomised studies were prospective and 29 reported on a consecutive series of patients. In nine non-randomised studies the number of arteries, as opposed to the number of patients, was unclear. Meta-analysis of the non-randomised studies showed that the use of local anaesthetic was associated with significant reductions in the odds of death (35 studies), stroke (31 studies), stroke or death (26 studies), myocardial infarction (22 studies), and pulmonary complications (7 studies), within 30 days of the operation. Meta-analysis of the randomised studies showed that the use of local anaesthetic was associated with a significant reduction in local haemorrhage (OR = 0.31, 95% CI = 0.12 to 0.79) within 30 days of the operation, but there was no evidence of a reduction in the odds of operative stroke. However, the trials were too small to allow reliable conclusions to be drawn, and in some studies intention-to-treat analyses were not possible because of exclusions.

REVIEWERS' CONCLUSIONS

There is insufficient evidence from randomised trials comparing carotid endarterectomy performed under local and general anaesthetic. Non-randomised studies suggest potential benefits with the use of local anaesthetic, but these studies may be biased. More randomised studies are needed.

Mortality rates after subarachnoid hemorrhage: variations according to hospital case volume in 18 states

Object. The goal of this study was to determine whether a hospital's volume of subarachnoid hemorrhage (SAH) cases affects mortality rates in patients with SAH. For certain serious illnesses and surgical procedures, outcome has been associated with hospital case volume. Subarachnoid hemorrhage, usually resulting from a ruptured cerebral aneurysm, yields a high mortality rate. There has been no multistate study of a diverse set of hospitals to determine whether in-hospital mortality rates are influenced by hospital volume of SAH cases.

Methods. The authors conducted an analysis of a retrospective, administrative database of 16,399 hospitalizations for SAH (9290 admitted through emergency departments). These hospitalizations were from acute-care hospitals in 18 states representing 58% of the US population. Both univariate and multivariate analyses were used to assess the case volume—mortality rate relationship. The authors used patient age, sex, Medicaid status, hospital region, data source year, hospital case volume quartile, and a comorbidity index in multivariate generalized estimating equations to model the relationship between hospital volume and mortality rates after SAH.

Patients with SAH who were treated in hospitals in which low volumes of patients with SAH are admitted through the emergency department had 1.4 times the odds of dying in the hospital (95% confidence interval 1.2–1.6) as patients admitted to high-volume hospitals after controlling for patient age, sex, Medicaid status, hospital region, database year, and comorbid conditions.

Conclusions. Patients with a diagnosis of SAH on their discharge records who initially presented through the emergency department of a hospital with a high volume of SAH cases had significantly lower mortality rates. Concentrating care for this disease in high-volume SAH treatment centers may improve overall survival.

Threshold volumes associated with higher survival in health care: a systematic review

BACKGROUND

To date, systematic reviews on the relationship between the volume of specific diagnoses and procedures and patient outcomes have several limitations, including the omission of the most recent publications.

OBJECTIVE

To investigate the relationship between hospital and physician volume and patient mortality rate for all diagnoses and interventions in health care.

RESEARCH DESIGN

Medline and the Cochrane Library were searched from January 1990 to December 2000 for all studies published in Dutch, English, French, German, and Italian. The following Boolean search statement was used: hospitals AND volume AND (outcome OR mortality OR quality). Studies were included in which patient enrollment ended within 10 years of the current study and that were adjusted for case-mix. For each diagnosis and intervention, the study most likely to provide an unbiased estimate of the effect of volume on mortality rate was identified using a specific algorithm (best study).

RESULTS

A total of 34 diagnoses and interventions with at least one qualifying study on the volume-outcome relationship were identified. The summary odds ratio/relative risk for the best studies on hospital and physician volume were 0.87 (95% confidence interval [CI], 0.85-0.89) and 0.87 (95% CI, 0.81-0.94), respectively. From the best studies on hospital volume, 48.5% (16 of 33) were published either in 1999 or 2000.

CONCLUSIONS

There is evidence for a volume-mortality relationship for hospitals and physicians. The use of appropriate methods for analyzing additional diagnoses and interventions as well as a continuous systematic evaluation of the evidence is recommended.

Overview of the principal results and secondary analyses from the European and North American randomised trials of endarterectomy for symptomatic carotid stenosis

OBJECTIVES

Review of the primary results and secondary analyses from the European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET).

DESIGN

Review of 48 ECST and NASCET papers.

RESULTS

The simple assumption that all patients with a symptomatic stenosis >70% benefit from CEA is untenable. Approximately 70-75% will not have a stroke if treated medically. The ECST and NASCET have identified subgroups that should have expedited investigation and surgery (male sex, age >75 years, 90-99% stenosis, irregular plaque, hemispheric symptoms, recurrent events for >6 months, contralateral occlusion, multiple co-morbidity). Accordingly development of local protocols for patient selection/exclusion should involve surgeons and physicians and take account of the local operative risk. The ECST and NASCET have also shown that the ubiquitous "string sign" is not associated with a high risk of stroke, and emergency CEA is unnecessary.

CONCLUSIONS

Surgeons must quote their own results and be aware that a high operative risk reduces long-term benefit. Accordingly, in those centres with a higher operative death/stroke rate, some "lower risk" patients should probably be considered for best medical therapy alone. It is hoped that pooling of the ECST and NASCET databases will enable more definitive guidelines to be developed regarding who benefits most from CEA.

Outcome of carotid endarterectomy in African Americans: is race a factor?

OBJECTIVE

African American patients have been underrepresented in large-scale trials of carotid endarterectomy (CEA). Thus the role of CEA in the treatment of extracranial carotid artery occlusive disease in black patients remains unclear. We undertook this study to determine the effect of black race on early and late outcome of CEA.

METHODS

A retrospective review was performed of records for patients who underwent CEA from 1990 to 1999. Data on demographics, operative indications, hospital course, and long-term follow-up were obtained for each patient. Patients were stratified by race for comparison of perioperative course and late outcome. Risk factors were compared using chi(2) methods, and life table analysis was performed with Kaplan-Meier survival plots.

RESULTS

One thousand forty-five CEA procedures were performed during the study period, 133 (13%) in black patients and 912 (87%) in white patients. Demographic risk factors were similar in both groups, except for hypertension (P =.003), diabetes (P <.001), and renal insufficiency (P =.03), which were more prevalent in blacks. Just over half of patients had symptoms at presentation, with equal racial distribution. The perioperative stroke and death rate was 3.3% (blacks, 5.3%; whites, 3.1%; P =.19). The 8-year actuarial ipsilateral stroke rate was 7% in patients without symptoms and 8% in patients with symptoms, with no racial variation. There was, however, a racial difference in the long-term "all strokes" rate (P =.002), regardless of vascular territory. This difference was largely due to the high late stroke rate in black patients with symptoms at presentation. A Cox proportional hazards analysis showed that only black race was a significant predictor of any stroke.

CONCLUSIONS

CEA can be accomplished with acceptable morbidity and mortality in black patients with an expectation of similar protection from ipsilateral ischemic stroke as in white patients. Black patients, however, have a higher incidence of all strokes at long-term follow-up due to the higher risk of stroke in patients with symptoms of carotid bifurcation disease.

Association of sex with perioperative mortality and morbidity after carotid endarterectomy for asymptomatic carotid stenosis

OBJECTIVE

To examine whether perioperative morbidity and mortality after carotid endarterectomy depend on the sex and the presence of symptoms on presentation.

DESIGN

Retrospective review of quality assurance database prospectively collected.

SETTING

A university teaching hospital.

PARTICIPANTS

One thousand two hundred eighty-seven patients who had 1,503 carotid endarterectomies from 1990 to 1999 from a quality assurance database.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The cases were divided into 4 groups by sex and symptoms on presentation: male-symptomatic (MS), male-asymptomatic (MA), female-symptomatic (FS), and female-asymptomatic (FA). The 4 groups were compared for preoperative demographic and comorbidity profiles, carotid plaque characteristics, and outcome. Outcome measures included in-hospital stroke, myocardial infarction (MI), congestive heart failure (CHF), and death. There were 496 cases in the MS group, 407 in the MA group, 315 in the FS group, and 285 in the FA group. Women were less likely to have a history of coronary artery disease, prior MI, or smoking, and their carotid plaques were less likely to be ulcerated or contain intraplaque hemorrhage. Even when controlling for the comorbidities and plaque characteristics, the incidence of each of the complications examined was low and not significantly different between the sexes in both the symptomatic and asymptomatic groups. The rate of stroke or death was 3.0% (MS) versus 1.9% (FS) (p = NS) and 1.2% (MA) versus 1.8% (FA) (p = NS).

CONCLUSION

There is no significant sex difference in perioperative cardiac or cerebrovascular complications. Women with symptomatic or asymptomatic carotid stenosis can have acceptably low complication rates from carotid endarterectomy and may benefit from the surgery as much as men.

Auditing carotid endarterectomy: a regional experience

BACKGROUND

Proof from randomized controlled trials that carotid endarterectomy (CEA) is efficacious in stroke prevention has resulted in a large resurgence of its use in recent years. We wished to determine if patients in our region were being selected and treated with complication rates consistent with the randomized trials.

METHODS

We have completed four audits of CEAs performed in our region since 1994, each followed by feed-back of results to the participating surgeons. Operations for > 70% symptomatic stenosis were considered appropriate, those for 50%-69% symptomatic and > 60% asymptomatic stenosis were considered uncertain and all others, including those in medically or neurologically unstable patients, were designated inappropriate. In part 4, the referral source and nature of the patients was also determined.

RESULTS

Part 1 (April 1994-September 1995) found that of 291 CEAs performed 33% were appropriate, 48% were uncertain and 18% were inappropriate, and 40% of patients who underwent CEA were asymptomatic. In part 2 (September 1996-September 1997) appropriate indications significantly improved to 49% of 184 CEAs (P=0.005), uncertain indications remained nearly the same at 47%, inappropriate indications fell to 4% (P=.00002), and asymptomatic patients remained at 40%. The results of part 3 (October 1997-October 1998) remained nearly the same as part 2 (249 CEAs, 47% appropriate, 51% uncertain, 2% inappropriate, 45% asymptomatic). Part 4 (October 1999-October 2000) results were significantly better than part 3, appropriate indications increasing from 47% to 58% of 222 CEAs (P=0.02), and an elimination of inappropriate operations (P=0.03). Stroke and death complications declined over the study period from an overall rate of 5.2% in part 1 to 2.3% in part 4. In part 4 the majority of patients (69%) were referred to surgeons directly from general practitioners, including 58 (73%) of the 80 asymptomatic patients who underwent CEA.

INTERPRETATION

Regular auditing and feedback of results and information to surgeons has resulted in significant and continued improvements in the surgical performance of CEA in our region. Since the majority of patients are referred directly to surgeons by general practitioners, it is important that this group of physicians be familiar with current CEA guidelines.

Variation in surgical and anaesthetic technique and associations with operative risk in the European carotid surgery trial: implications for trials of ancillary techniques

OBJECTIVES

several ancillary surgical techniques, such as shunting and patching, are used in association with carotid endarterectomy. However, the balance of risks and benefits of these techniques is uncertain because of the lack of large randomised controlled trials (RCTs). To assess the potential for further trials, we studied the variation in use of these techniques by surgeon and by country in the European Carotid Surgery Trial (ECST).

METHODS

use of each ancillary technique was assessed by surgeon and by country. For each technique, the relationships between the use of the technique and baseline patient characteristics, use of other techniques, and the 30-day operative risk of stroke and death were determined.

RESULTS

there was considerable variation between surgeons in the use of ancillary operative techniques both within (p<0.001 for shunting and patching), and between countries (p<0.001 for shunting and patching). Some surgeons used techniques selectively, and so the characteristics of patients differed depending on which techniques were used. Use of each technique was also significantly associated with the use of other techniques. Multiple regression analysis, taking into account all these factors, found no statistically significant associations between operative risk and the use of shunting, patching, intra-operative EEG monitoring, or type of anaesthetic. The only surgical technique significantly associated with an increased operative risk was not using intra-operative anticoagulation (hazard ratio=2.33, 95% CI=1.4-4.2). Other factors associated with an increased risk were an operation time of less than 1 h, or greater than 1.5 h, and the surgeons' subjective assessment that the operation was difficult.

CONCLUSIONS

in the ECST, operative risk was more closely related to patient characteristics, length of surgery, and the surgeons' perception of the difficulty of the operation, than to the use of particular ancillary operative techniques. The considerable variation between surgeons, and between countries, in the use of ancillary techniques is in keeping with the lack of convincing data from RCTs, and suggests that there should be sufficient uncertainty to make large pragmatic trials possible.

Volume standards for high-risk surgical procedures: potential benefits of the Leapfrog initiative

BACKGROUND

As part of a broader effort aimed at improving hospital safety, a large coalition of employers, the Leapfrog Group, will soon require hospitals caring for their employees to meet volume standards for 5 high-risk surgical procedures. We estimated the potential benefits of full nationwide implementation of these volume standards. METHODS. Using data from Nationwide Inpatient Sample and other sources, we first estimated the total number of each of the 5 procedures-coronary-artery bypass graft, abdominal aortic aneurysm repair, coronary angioplasty, esophagectomy, and carotid endarterectomy-performed each year in hospitals in US metropolitan areas. (Leapfrog exempts hospitals in rural areas to avoid access issues.) We then projected the effectiveness of volume standards (in terms of relative risks of mortality) for each procedure using data from a published structured literature review.

RESULTS

With full implementation nationwide, the Leapfrog volume standards would save 2581 lives. Of the procedures, volume standards would save the most lives with coronary-artery bypass graft (1486), followed by abdominal aortic-aneurysm repair (464), coronary angioplasty (345), esophagectomy (168), and carotid endarterectomy (118). In our estimates of the number of lives saved, we considered assumptions about how many patients would be affected and the effectiveness of volume standards (ie, strength of underlying volume-outcome relationships with each procedure).

CONCLUSIONS

If the Leapfrog volume standards are successfully implemented, employers and health-care purchasers could prevent many surgical deaths by requiring hospital volume standards for high-risk procedures.