A systematic comparison of the risks of stroke and death due to carotid endarterectomy for symptomatic and asymptomatic stenosis

Complication-Specific In-Hospital Costs After Carotid Endarterectomy vs Carotid Artery Stenting

Purpose: To quantify and compare the incremental cost associated with in-hospital stroke, death, and myocardial infarction (MI) after carotid endarterectomy (CEA) vs carotid artery stenting (CAS). Methods: A retrospective analysis was performed of 100,185 patients (mean age 70.7±9.5 years; 58.3% men) who underwent CEA (n=86,035) or CAS (n=14,150) between 2009 and 2015 and were entered into the Premier Healthcare Database. Multivariate logistic models and generalized linear models were used to analyze binary outcomes and hospitalization costs, respectively. Outcomes are presented as the adjusted odds ratio (aOR) and 95% confidence interval (CI). Results: CAS was associated with 1.6 times higher adjusted odds of stroke [aOR 1.55 (95% CI 1.36 to 1.77), p<0.001] and with 2.6 times higher odds of death [aOR 2.60 (95% CI 2.14 to 3.17), p<0.001] compared with CEA. There was no significant difference in MI risk between the 2 procedures. The adjusted incremental cost of death and MI were similar between the 2 procedures. However, the adjusted incremental cost of stroke was significantly higher in CEA compared with CAS by an estimated $2000. When stratified with respect to symptomatic status, the increased adjusted incremental cost of stroke in CEA was mainly seen in asymptomatic patients ($5284 vs $2932, p<0.01). Conclusion: The incremental cost of in-hospital stroke is relatively higher in CEA compared to CAS. However, CEA remains a more cost-effective carotid intervention due to lower complication rates and baseline costs compared with CAS. Long-term cost-effectiveness studies are needed before definite conclusions are made.

Radiographic and symptomatic brain ischemia in CEA and CAS: A systematic review and meta-analysis

OBJECTIVE

In a systematic review, we compared ratio of new periprocedural radiographic brain ischemia (RBI) to the number of strokes and TIAs among patients undergoing carotid endarterectomy (CEA) and carotid artery stenting (CAS).

METHODS

We searched 5 databases for entries related to brain ischemia in CEA or CAS from inception through September 2015. We included articles with CEA or CAS and systematic performance of preprocedural and postprocedural brain MRI and reporting of RBI and stroke incidence. We calculated a symptomatic risk ratio of number of strokes and TIAs to RBI. Random effects models were used.

RESULTS

Fifty-nine studies (5,431 participants) met the inclusion criteria. There were 22 cohorts in CEA, 34 in CAS with distal protection, 8 in CAS with proximal protection, 9 in CAS without protection, and 9 in CAS with unspecified devices. Overall, 30.7% (95% confidence interval [CI] 26.6%-34.7%) had RBI, while 3.2% (95% CI 2.6%-3.8%) had clinical strokes or TIAs, with a stroke and TIA to RBI weighted ratio of 0.18 (95% CI 0.15-0.22). CEA had lower incidence of RBI compared to CAS (13.0% vs 37.4%) and also lower number of strokes and TIAs (1.8% vs 4.1%). The stroke and TIA to RBI ratio did not differ across 5 different types of carotid interventions (p = 0.58).

CONCLUSIONS

One in 5 persons with periprocedural radiographic brain ischemia during CEA and CAS had strokes and TIAs. The stable ratio of stroke and TIA to radiographic ischemia suggests that MRI ischemia could serve as a surrogate measure of periprocedural risk.

[Cerebral vasoreactivity: Concordance of breath holding test and acetazolamide injection in current practice: 20 cases of asymptomatic carotid artery stenosis]

INTRODUCTION

Cerebral vasoreactivity (CVR) is the ability of the brain's vascular system to keep cerebral blood inflow stable. Impaired CVR is a risk marker of stroke in patients with asymptomatic carotid stenosis. The gold standard to assess CVR with transcranial ultrasound is acetazolamide (ACTZ) injection. The breath holding test (BHT) might be easier to perform. CVR proved to be efficient in laboratory conditions but not in routine practice.

OBJECTIVES

To study the validity of BHT versus ACTZ in routine practice in a vascular exploration unit in patients with asymptomatic carotid stenosis.

METHODS

Study of concordance of BHT and ACTZ, to assess CVR in patients consecutively explored on the same day.

RESULTS

Eighteen patients with 20 carotid stenosis were included. The temporal window was missing in 20% of cases. Only 11 out of the 20 procedures were analyzed. Concordance was low between BHT and ACTZ to assess CVR (k=0.3714).

CONCLUSION

BHT cannot replace ACTZ injection. It might be a first-step test so that ACTZ injection might be avoided if CVR is normal. Our present results must be confirmed by further study enrolling many more patients.

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.

Temporal trends in safety of carotid endarterectomy in asymptomatic patients: systematic review

OBJECTIVE

To systematically review temporal changes in perioperative safety of carotid endarterectomy (CEA) in asymptomatic individuals in trial and registry studies.

METHODS

The MEDLINE and EMBASE databases were searched using the terms "carotid" and "endarterectomy" and "asymptomatic" from 1947 to August 23, 2014. Articles dealing with 50%-99% stenosis in asymptomatic individuals were included and low-volume studies were excluded. The primary endpoint was 30-day stroke or death and the secondary endpoint was 30-day all-cause mortality. Statistical analysis was performed using random-effects meta-regression for registry data and for trial data graphical interpretation alone was used.

RESULTS

Six trials (n = 4,431 procedures) and 47 community registries (n = 204,622 procedures) reported data between 1983 and 2013. Registry data showed a significant decrease in postoperative stroke or death incidence over the period 1991-2010, equivalent to a 6% average proportional annual reduction (95% credible interval [CrI] 4%-7%; p < 0.001). Considering postoperative all-cause mortality, registry data showed a significant 5% average proportional annual reduction (95% CrI 3%-9%; p < 0.001). Trial data showed a similar visual trend.

CONCLUSIONS

CEA is safer than ever before and high-volume registry results closely mirror the results of trials. New benchmarks for CEA are a stroke or death risk of 1.2% and a mortality risk of 0.4%. This information will prove useful for quality improvement programs, for health care funders, and for those re-examining the long-term benefits of asymptomatic revascularization in future trials.

Temporal Changes in Periprocedural Events in the Carotid Revascularization Endarterectomy Versus Stenting Trial

BACKGROUND AND PURPOSE

Post-hoc, we hypothesized that over the recruitment period of the Carotid Revascularization Endarterectomy Versus Stenting Trial (CREST), increasing experience and improved patient selection with carotid stenting, and to a lesser extent, carotid endarterectomy would contribute to lower periprocedural event rates.

METHODS

Three study periods with approximately the same number of patients were defined to span recruitment. Composite and individual rates of periprocedural stroke, myocardial infarction, and death rate were calculated separately by treatment assignment (carotid stenting/carotid endarterectomy). Temporal changes in unadjusted event rates, and rates after adjustment for temporal changes in patient characteristics, were assessed.

RESULTS

For patients randomized to carotid stenting, there was no significant temporal change in the unadjusted composite rates that declined from 6.2% in the first period, to 4.9% in the second, and 4.6% in the third (P=0.28). Adjustment for patient characteristics attenuated the rates to 6.0%, 5.9%, and 5.6% (P=0.85). For carotid endarterectomy-randomized patients, both the composite and the combined stroke and death outcome decreased between periods 1 and 2 and then increased in period 3.

CONCLUSIONS

The hypothesized temporal reduction of stroke+death events for carotid stenting-treated patients was not observed. Further adjustment for changes in patient characteristics between periods, including the addition of asymptomatic patients and a >50% decrease in proportion of octogenarians enrolled, resulted in practically identical rates.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004732.

Surgical Outcomes for Cervical Carotid Artery Stenosis: Treatment Strategy for Bilateral Cervical Carotid Artery Stenosis

BACKGROUND

Carotid endarterectomy (CEA) and carotid stenting (CAS) are beneficial procedures for patients with high-grade cervical carotid stenosis. However, it is sometimes difficult to manage patients with bilateral carotid stenosis. To decide the treatment strategy, one of the most important questions is whether contralateral stenosis increases the risk of patients undergoing CEA.

METHODS

This retrospective study included 201 patients with carotid stenosis who underwent a total of 219 consecutive procedures (CEA 189/CAS 30). We retrospectively analyzed outcomes in patients with carotid stenosis who were treated with either CEA or CAS and evaluated whether or not contralateral lesions increases the risk of patients undergoing CEA or CAS. Furthermore, we retrospectively verified our treatment strategy for bilateral carotid stenosis.

RESULTS

The incidences of perioperative complications were 5.3% in the CEA patients and 6.7% in the CAS patients, respectively. There was no significant difference between these 2 groups. The existences of contralateral occlusion and/or contralateral stenosis were not associated with perioperative complications in both the groups. There were 32 patients with bilateral severe carotid stenosis (>50%). Of those, 13 patients underwent bilateral revascularizations; CEA followed by CEA in 8, CEA followed by CAS in 3, CAS followed by CEA + coronary artery bpass grafting in 1, and CAS followed by CAS in 1.

CONCLUSIONS

Our date showed that the existence of contralateral carotid lesion was not associated with perioperative complications, and most of our cases with bilateral carotid stenosis initially underwent CEA.

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.

Treatment strategy for bilateral carotid stenosis: 2 cases of carotid endarterectomy for the symptomatic side followed by carotid stenting

Since the introduction of carotid stenting (CAS), a combined treatment for bilateral lesions using carotid endarterectomy (CEA) and CAS has been developed. However, there has been only 1 report about CEA then CAS. Herein we describe 2 patients with bilateral severe carotid stenosis who were treated by CEA for the symptomatic side and CAS for the contralateral asymptomatic side. A 71-year-old man underwent CEA for the symptomatic side. Although the patient suffered hyperperfusion syndrome after CEA, he recovered fully after 3 weeks of rehabilitation. Two months later, CAS was performed for the asymptomatic side, and he was discharged with no deficit. A 67-year-old man underwent CEA for the symptomatic side. The patient developed no postoperative neurologic deficits except for hoarseness. Four weeks later, CAS was performed for the contralateral asymptomatic side. After the procedure, however, severe hypotension occurred, and treatment by continuous injection of catecholamine was necessary to maintain systematic blood pressure. The patient was ultimately discharged with no deficit. The combined therapy of CAS for the asymptomatic side and then CEA for the symptomatic side has been recommended by several authors. However, one of the problems of this strategy is the higher incidence of postprocedural hemodynamic complications, and hypotension after CAS may be dangerous for the symptomatic hemisphere. We suggest a combined therapy using CEA for the symptomatic side and then CAS for the asymptomatic side can be 1 beneficial treatment option for patients with bilateral carotid stenosis without coronary artery disease.

Impact of perioperative acute ischemic stroke on the outcomes of noncardiac and nonvascular surgery: a single centre prospective study

BACKGROUND

Although ischemic stroke is a well-known complication of cardiovascular surgery it has not been extensively studied in patients undergoing noncardiac surgery. The aim of this study was to assess the predictors and outcomes of perioperative acute ischemic stroke (PAIS) in patients undergoing noncardiothoracic, nonvascular surgery (NCS).

METHODS

We prospectively evaluated patients undergoing NCS and enrolled patients older than 18 years who underwent an elective, non-daytime, open surgical procedure. Electrocardiography and cardiac biomarkers were obtained 1 day before surgery, and on postoperative days 1, 3 and 7.

RESULTS

Of the 1340 patients undergoing NCS, 31 (2.3%) experienced PAIS. Only age (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.01-3.2, p < 0.001) and preoperative history of stroke (OR 3.6, 95% CI 1.2-4.8, p < 0.001) were independent predictors of PAIS according to multivariate analysis. Patients with PAIS had more cardiovascular (51.6% v. 10.6%, p < 0.001) and noncardiovascular complications (67.7% v. 28.3%, p < 0.001). In-hospital mortality was 19.3% for the PAIS group and 1% for those without PAIS (p < 0.001).

CONCLUSION

Age and preoperative history of stroke were strong risk factors for PAIS in patients undergoing NCS. Patients with PAIS carry an elevated risk of perioperative morbidity and mortality.

Prediction of high-risk plaque development and plaque progression with the carotid atherosclerosis score

OBJECTIVES

The goal of this prospective study was to evaluate the carotid atherosclerosis score (CAS) for predicting the development of high-risk plaque features and plaque burden progression.

BACKGROUND

Previous studies have shown that carotid intraplaque hemorrhage (IPH) and a disrupted luminal surface (DLS), as identified by using magnetic resonance imaging, are associated with greater risk for cerebrovascular events. On the basis of data from a large cross-sectional study, a scoring system was developed to determine which plaque features are associated with the presence of IPH and DLS. However, the predictive value of CAS has not been previously tested in a prospective, longitudinal study.

METHODS

A total of 120 asymptomatic subjects with 50% to 79% carotid stenosis underwent carotid magnetic resonance imaging scans at baseline and 3 years thereafter. Presence of IPH and DLS, wall volume, maximum wall thickness, and maximum percent lipid-rich necrotic core area were measured at both time-points. Baseline CAS values were calculated on the basis of previously published criteria.

RESULTS

Of the 73 subjects without IPH or DLS at baseline, 9 (12%) developed 1 or both of these features during follow-up. There was a significant increasing trend between CAS and the development of new DLS (p < 0.001) and with plaque burden progression (p = 0.03) but not with the development of new IPH (p = 0.3). Percent carotid stenosis was not significantly associated with new DLS (p = 0.2), new IPH (p = 0.1), or plaque progression (p = 0.6).

CONCLUSIONS

CAS was found to have a significant increasing relationship with incident DLS and plaque progression in this prospective study. CAS can potentially provide improved risk stratification beyond luminal stenosis.

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.

Interaction of cerebrovascular disease and contralateral carotid occlusion in prediction of shunt insertion during carotid endarterectomy

INTRODUCTION

To assess the possible role and the interaction of cerebrovascular disease and vascular stenosis on the necessity of shunt insertion during carotid endarterectomy (CEA).

MATERIAL AND METHODS

Eighty consecutive patients undergoing CEA under regional anaesthesia were prospectively enrolled. Patients were divided into two groups depending on whether they were shunted or not. The measured end-points were co-morbidities degree of contralateral and carotid stenosis and other intra- and postoperative outstanding parameters. ANOVA, Student's t and χ(2) tests were used (p<0.05). Variables differing significantly between groups and potential confounders were used in backward stepwise logistic regression to estimate the relative risk (RR, 95% CI) of shunt. In addition Wald's test (p<0.05) with and without adjustments for potential confounders was used with various different multivariate analysis models.

RESULTS

Contralateral stenosis and cerebral vascular accidents (CVA) were more frequently observed in shunted patients. The RR for patients with contralateral stenosis ≥ 50% was 1.3 (95% CI 1.0-1.5) and for patients with previous CVA was 1.2 (95% CI 1.0-1.4). For contralateral stenosis and CVA together the RR increased to 7.7 (95% CI 1.0-14.4). A model based on contralateral stenosis and CVA was found to be statistically significant (p=0.003) for shunt (RR=1.1, 95% CI 1.0-2.1). Relative excess risk due to interaction of both factors was 6.2.

CONCLUSIONS

The findings suggest that patients with contralateral stenosis ≥ 50% and previous CVA have a higher risk of requiring shunt use during CEA than patients with these risk factors separately.

Systematic review of methods used in meta-analyses where a primary outcome is an adverse or unintended event

BACKGROUND

Adverse consequences of medical interventions are a source of concern, but clinical trials may lack power to detect elevated rates of such events, while observational studies have inherent limitations. Meta-analysis allows the combination of individual studies, which can increase power and provide stronger evidence relating to adverse events. However, meta-analysis of adverse events has associated methodological challenges. The aim of this study was to systematically identify and review the methodology used in meta-analyses where a primary outcome is an adverse or unintended event, following a therapeutic intervention.

METHODS

Using a collection of reviews identified previously, 166 references including a meta-analysis were selected for review. At least one of the primary outcomes in each review was an adverse or unintended event. The nature of the intervention, source of funding, number of individual meta-analyses performed, number of primary studies included in the review, and use of meta-analytic methods were all recorded. Specific areas of interest relating to the methods used included the choice of outcome metric, methods of dealing with sparse events, heterogeneity, publication bias and use of individual patient data.

RESULTS

The 166 included reviews were published between 1994 and 2006. Interventions included drugs and surgery among other interventions. Many of the references being reviewed included multiple meta-analyses with 44.6% (74/166) including more than ten. Randomised trials only were included in 42.2% of meta-analyses (70/166), observational studies only in 33.7% (56/166) and a mix of observational studies and trials in 15.7% (26/166). Sparse data, in the form of zero events in one or both arms where the outcome was a count of events, was found in 64 reviews of two-arm studies, of which 41 (64.1%) had zero events in both arms.

CONCLUSIONS

Meta-analyses of adverse events data are common and useful in terms of increasing the power to detect an association with an intervention, especially when the events are infrequent. However, with regard to existing meta-analyses, a wide variety of different methods have been employed, often with no evident rationale for using a particular approach. More specifically, the approach to dealing with zero events varies, and guidelines on this issue would be desirable.

Improvement in executive function after unilateral carotid artery stenting for severe asymptomatic stenosis

Object

Executive functions are crucial for organizing and integrating cognitive processes. While some studies have assessed the effect of carotid artery stenting (CAS) on cognitive functioning, results have been conflicting. The object of this study was to assess the effect of CAS on cognitive status, with special interest on executive functions, among patients with severe asymptomatic internal carotid artery (ICA) stenosis.

Methods

The authors prospectively assessed the neuropsychological status of 20 patients with unilateral asymptomatic extracranial ICA stenosis of 60% or more by using a comprehensive assessment battery focused on executive functions before and after CAS. Individual raw scores on neuropsychological tests were converted into z scores by normalizing for age, sex, and years of education. The authors compared baseline and 3-month postoperative neuropsychological scores by using Wilcoxon signed-rank tests.

Results

The mean preoperative cognitive performance was within normal ranges on all variables. All patients underwent a successful CAS procedure. Executive function scores improved after CAS, relative to baseline performance as follows: set shifting (Trail-Making Test Part B: −0.75 ± 1.43 vs −1.2 ± 1.48, p = 0.003) and processing speed (digit symbol coding: −0.66 ± 0.85 vs −0.97 ± 0.82, p = 0.035; and symbol search: −0.24 ± 1.32 vs −0.56 ± 0.77, p = 0.049). The benefit of CAS for working memory was marginally significant (digit span backward: −0.41 ± 0.61 vs −0.58 ± 0.76, p = 0.052). Both verbal (immediate Rey Auditory Verbal Learning Test: 0.35 ± 1.04 vs −0.22 ± 0.82, p = 0.011) and visual (delayed Rey-Osterrieth Complex Figure: 0.27 ± 1.26 vs −0.22 ± 1.01, p = 0.024) memory improved after CAS.

Conclusions

The authors found a beneficial effect on executive function and memory 3 months after CAS among their prospective cohort of consecutive patients with unilateral and asymptomatic ICA stenosis of 60% or more.

Early carotid endarterectomy following thrombolysis in the hyperacute treatment of stroke

Background

Thrombolysis with intravenous recombinant tissue plasminogen activator improves the probability of complete neurological recovery if given promptly following the onset of acute ischaemic stroke. Carotid endarterectomy (CEA) can reduce the risk of further embolic stroke in selected patients and is most effective within 14 days of the incident event. The safety of surgery so soon after thrombolysis is unknown. The aim of this study was to report the immediate outcomes of this management strategy early in the unit experience and to encourage pooling of data, recognizing that this will be an uncommon procedure even in busy stoke units with an active lysis programme.

Methods

Data were extracted from two prospectively collected databases, and included patient demographics, type of stroke, type and timing of surgical procedure, and immediate outcome. On presentation with a stroke, all patients underwent urgent computed tomography (CT) of the brain. Those eligible received thrombolysis according to the unit protocol. They underwent CT angiography 24 h after thrombolysis and patients with a severe carotid stenosis had surgery.

Results

Ten of a cohort of 450 patients who had received lysis underwent CEA. Seven of these were women and eight of the procedures were carried out under local anaesthetic. Surgery was performed a median of 8 (range 2–23) days after the index event; there were no major complications.

Conclusion

Few patients with acute stroke are eligible, but CEA performed soon after thrombolytic therapy for stroke appears to be safe.

Consent issues in neurology

The requirement that doctors obtain valid consent from patients before providing medical treatment has long been ingrained in both legal doctrine and medical ethics. We summarize the foundations of the informed consent doctrine and discuss the recent evolution in thinking about consent and medical decision making. We show how consent has evolved from physicians merely providing patients information to shared decision making between patients and physicians. We then address three specific examples of situations common in neurological practice that pose challenges in obtaining valid consent: the administration of intravenous tPA following ischemic stroke, consideration of carotid endarterectomy for carotid artery stenosis, and implementation of do-not-resuscitate orders.

Geometric and compositional appearance of atheroma in an angiographically normal carotid artery in patients with atherosclerosis

BACKGROUND AND PURPOSE

Arterial remodeling may enable atherosclerotic disease without luminal stenosis. We sought to assess the prevalence and characteristics of atherosclerosis in angiographically normal carotid arteries.

MATERIALS AND METHODS

Forty-six arteries with 0% stenosis by MRA were evaluated with multicontrast carotid MR imaging at 3T. For each artery, the percentage wall volume (wall volume/[lumen volume + wall volume] x 100%) and the presence versus absence of an LRNC, calcification, IPH, and fibrous cap rupture were recorded. In addition, the relative size of each plaque component (eg, percentage LRNC = LRNC volume/wall volume x 100%), when present, was calculated.

RESULTS

The mean of percentage wall volume in arteries with 0% stenosis was 43.0 +/- 6.9% with a range from 31.6% to 60.1%. An LRNC was present in 67.4% (31/46) of arteries, calcification was present in 65.2% (30/46), IPH was present in 8.7% (4/46), and fibrous cap rupture was present in 4.3% (2/46). In arteries with an LRNC (n = 31), the average percentage LRNC volume was 8.8 +/- 7.3% with a range from 1.0% to 31.5%. For calcification (n = 30), the mean percentage calcification volume was 3.8 +/- 4.2% with a range of 0.1%-17.4%. The mean percentage IPH volume (n = 4) was 2.7 +/- 1.7% with a range of 0.5%-4.1%.

CONCLUSIONS

These findings indicate that stenosis by MRA may underestimate the presence of carotid atherosclerosis, and they demonstrate the need for improved methods for accurately identifying carotid atherosclerotic plaque severity.

Carotid artery stenting in high-risk patients: midterm mortality analysis

Carotid artery interventions are predicated on early and late survival to prevent ischemic strokes. The technical feasibility of carotid artery stenting (CAS) has been established. Short-term results have been conflicting. Despite this, many practices have adopted CAS as an alterative to carotid endarterectomy in high-risk patients. Long-term protective benefits, however, are less established in high-risk patients. Midterm results following CAS in our high-risk protocol were analyzed to determine specific and all-cause mortality rates (beyond 30 days). We retrospectively evaluated a prospective carotid artery stent registry from October 2003 to February 2006. Demographics, high-risk indication, presence of carotid symptoms, prior history of cancer, periprocedural success, complications, as well as follow-up including readmission rate as well as specific etiology of death were recorded. Fifty patients with critical carotid stenosis (mean stenosis 90%) underwent CAS. This cohort met high-risk criteria due to physiologic reasons in 26 patients and anatomic factors in 22 cases. Two patients met both criteria. Indications were symptomatic disease in 14 (30%) and asymptomatic in 36 cases. The overall 30-day stroke, myocardial infarction, and death rate was 2%. No minor or major strokes were recorded within 30 days postprocedure. Overall average follow-up was 11-28 months. Stroke-free survival was 94% for all patients. Overall 1-year survival was 75% for all patients, significantly higher for the asymptomatic group (88%) (p < 0.01). Late mortality after 30 days was 11 cases (22%) at an average of 9 months post-CAS, ranging 3-13 months. No late mortality was due to ischemic stroke. Specific etiologies of mortality included end-stage cardiac disease (n = 1), recurrent or metastatic cancer (n = 2), acute cardiac event (n = 1), infectious complications (n = 3), and other (n = 3). Only symptomatic indication was predictive of late mortality. Clinicians may continue to cautiously offer CAS to asymptomatic high-risk patients given their anticipated longevity. Symptomatic patients, despite poor midterm survival, do achieve freedom from neurologic death following CAS.

Current status of carotid endarterectomy and stenting for symptomatic carotid stenosis

There is still considerable uncertainty about the place of carotid stenting in patients with recently symptomatic carotid bifurcation stenosis. Most reviews of carotid endarterectomy versus carotid stenting concentrate on technical aspects and advances in stenting, but the techniques involved in both carotid endarterectomy and stenting are evolving. In addition to reviewing the results of the various randomised controlled trials of carotid endarterectomy versus stenting for symptomatic carotid stenosis, this review considers recent advances and current best practice for endarterectomy. Ongoing randomized trials will determine whether or not the procedural risk of stroke and death is definitely lower with endarterectomy than with stenting, but the key issue that remains to be determined reliably is how the procedural risks of stenting vary with patient characteristics - perhaps the most important question being not whether endarterectomy is better than stenting or vice versa, but for whom is one technique likely to be better than the other.

Carotid angioplasty and stenting versus redo endarterectomy for recurrent stenosis

BACKGROUND

Carotid angioplasty and stent (CAS) is an alternative to redo carotid endarterectomy (RCEA) for recurrent carotid stenosis (RCS). The purpose of this study was to evaluate the outcomes of CAS in the treatment of RCS.

METHODS

In an 8-year period, all patients presenting for treatment of RCS were followed-up prospectively. Logistic regression analysis was performed to identify variables associated with unfavorable outcomes.

RESULTS

There were 45 CAS and 46 RCEA procedures performed in 75 patients. One patient in each group suffered a stroke. There were no deaths. The hospital length of stay was significantly shorter for CAS. Secondary recurrence was higher after RCEA (14% vs 6.1%) and failure to take beta-blockers was an independent predictor for multiple recurrences.

CONCLUSIONS

CAS is a safe and effective method to treat patients with RCS and may become the procedure of choice for this disease.

Risk Estimates of Stroke After Coronary Artery Bypass Graft and Carotid Endarterectomy

Neurologic complications of cardiovascular surgeries are well documented in the literature. Neurologic deficits may be mild and reversible or may be associated with permanent neurologic deficit. The incidence and severity of such complications vary according to the type of surgical procedure and usually correlate with patients' preoperative general medical condition, duration of surgeries, and intraoperative complications.

Methodological shortcomings predicted lower harm estimates in one of two sets of studies of clinical interventions

OBJECTIVES

High quality harms data are necessary to appropriately assess the balance between benefits and harms of interventions. Little is known, however, about whether perceived methodological shortcomings are associated with lower estimates of harms.

STUDY DESIGN AND SETTING

Studies reporting harms associated with carotid endarterectomy (CEA) and rofecoxib were identified using published systematic reviews. A standardized abstraction form, including eight predefined criteria for assessing the quality of harms reporting, was used to extract data. Univariate and multivariate analyses were performed to empirically evaluate the association between quality criteria and estimates of harms.

RESULTS

In 111 studies of CEA, meeting five of the eight-quality criteria was associated with significantly higher adverse event rates. A quality-rating instrument with four criteria predicted adverse events (5.7% in studies rated "adequate," compared to 3.9% in studies rated "inadequate" [P=0.0003]). In multivariate analyses, the quality-rating assignment remained significant when controlling for other clinical and study-related variables. Different quality criteria, however, predicted estimates of risk for myocardial infarction in 16 trials of rofecoxib.

CONCLUSION

The presence of methodological shortcomings can predict lower estimates of serious harms. Clinicians and researchers should consider methodological shortcomings when evaluating estimates of harms associated with clinical interventions.

Assessment of short-term outcomes for protected carotid angioplasty with stents using recent evidence

BACKGROUND

Carotid artery stenosis is an important risk factor and etiology of stroke. Carotid endarterectomy (CEA) is the gold standard for the treatment of carotid artery stenosis; however, there are potential benefits to adopting the use of carotid artery stenting (CAS) with protection devices. A number of large protected CAS (PCAS) trials are underway, but final results are still several years away. In the interim, numerous PCAS studies have recently been published, and the aim of this study was to combine the published results and examine the outcomes and safety of PCAS.

METHODS

Electronic, manual, and bibliographic searches of PubMed and PreMedline were conducted. Proportion differences were calculated for the periprocedural (30-day) outcomes of any stroke and any stroke or death.

RESULTS

More than 400 articles were identified. Only 26 studies met the inclusion criteria, resulting in the inclusion of 2,992 patients treated with PCAS. Within this patient group, the pooled perioperative PCAS rate of any type of stroke was 2.4% +/- 0.3% (95% confidence interval [CI]). The 30-day minor stroke rate was 1.1% +/- 0.2% (95% CI), and the 30-day major stroke rate was 0.6% +/- 0.2% (95% CI). The 30-day mortality rate was 0.9% +/- 0.4% (95% CI).

CONCLUSION

This study demonstrates relatively low rates of reported perioperative adverse events in PCAS. Selective use of PCAS to treat carotid artery stenosis in those at highest risk for surgical complications is appropriate until the randomized trials of CEA vs PCAS provide concurrent short- and long-term outcome data.

Synthesizing medical evidence: systematic reviews and metaanalyses

Systematic reviews and metaanalyses have become increasingly popular ways of summarizing, and sometimes extending, existing medical knowledge. In this review the authors summarize current methods of performing meta-analyses, including the following: formulating a research question; performing a structured literature search and a search for trials not published in the formal medical literature; summarizing and, where appropriate, combining results from several trials; and reporting and presenting results. Topics such as cumulative and Bayesian metaanalysis and metaregression are also addressed. References to textbooks, articles, and Internet resources are also provided. The goal is to assist readers who wish to perform their own metaanalysis or to interpret critically a published example.

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.

A New Model for Determining the Influence of Age and Sex on Functional Recovery following Hypoxic-Ischemic Brain Damage

Stroke is a disorder affecting the lives of all age groups, and particularly those at the opposite ends of the age spectrum. It is generally believed that the immature brain is more resistant to damage resulting from a hypoxic/ischemic injury, and that it is also more 'plastic' in terms of its ability to recover. Evidence from our laboratory, and a host of others, has indicated, however, that the developing brain may in fact be more sensitive to injury resulting from hypoxia-ischemia. The question remains, however, whether the immature brain has a greater capacity for recovery. In order to determine the relative capability for functional recovery between age groups, a stroke model of comparable injury is required. This paper describes a new rodent model of ischemic injury allowing for comparisons of behavioral recovery spanning the spectrum of ages between newborn and the elderly. Endothelin-1, a potent vasoconstrictor, was stereotactically injected into the brains of 10-, 63-, and 180-day-old Wistar rats, immediately adjacent to the middle cerebral artery. Regionally, the cortex, caudate, and thalamus were most significantly affected, with sparing of the hippocampus. Pathologic assessment indicated a similar degree of injury across age groups affecting the territorial distribution of the middle cerebral artery, with a predominance of damage in the anterior sections of the cortex and caudate (p < 0.05), compared to the posterior sections including the cortex and thalamus. There were no regional differences in the extent of damage between age groups. Interestingly, however, there were significant differences between males and females regarding the overall extent of brain damage (p < 0.05), with males showing greater damage than females. In addition, there were significant regional differences in the extent of damage between males and females, particularly regarding cortical damage (p < 0.05), both anteriorly and posteriorly, and the caudate anteriorly (p < 0.05). Our findings provide an important new model for comparison of brain damage among the entire spectrum of ages affected by stroke. Importantly, this will allow for further investigations regarding both functional recovery and gender difference comparisons. This may have important ramifications for the development of therapeutic interventions that are age and gender specific.

Symptomatic patients have similar outcomes compared with asymptomatic patients after carotid artery stenting with emboli protection

In a single-center cohort of 174 consecutive patients, we sought to evaluate whether the use of emboli protection devices (EPDs) results in equivalent rates of adverse events in symptomatic and asymptomatic patients after carotid artery stenting (CAS) with EPDs. Death or stroke occurred in 3.3% in the symptomatic group and in 3.5% of the asymptomatic group at 30 days (p = NS). At 6 months, there was also no significant difference in the rate of stroke or death between the groups. Unlike surgical revascularization, symptomatic patients did not have a greater risk for stroke and death compared with asymptomatic patients after CAS with EPDs.

Treating individuals 2. Subgroup analysis in randomised controlled trials: importance, indications, and interpretation

Large pragmatic trials provide the most reliable data about the effects of treatments, but should be designed, analysed, and reported to enable the most effective use of treatments in routine practice. Subgroup analyses are important if there are potentially large differences between groups in the risk of a poor outcome with or without treatment, if there is potential heterogeneity of treatment effect in relation to pathophysiology, if there are practical questions about when to treat, or if there are doubts about benefit in specific groups, such as elderly people, which are leading to potentially inappropriate undertreatment. Analyses must be predefined, carefully justified, and limited to a few clinically important questions, and post-hoc observations should be treated with scepticism irrespective of their statistical significance. If important subgroup effects are anticipated, trials should either be powered to detect them reliably or pooled analyses of several trials should be undertaken. Formal rules for the planning, analysis, and reporting of subgroup analyses are proposed.

Cerebral protection during carotid endarterectomy

BACKGROUND

Perioperative stroke rates with carotid endarterectomy are 3.4% for asymptomatic and 5.2% for symptomatic patients. Several methods are used to limit perioperative stroke.

METHODS

A retrospective chart review of consecutive carotid endarterectomies from January 1, 2000 to February, 28, 2003, was performed. Data were collected on patient demographics, operative procedure, intraoperative monitoring, and outcome. Comparative analysis of intraoperative monitoring and outcome was performed.

RESULTS

Two hundred twenty-nine patients underwent 251 carotid endarterectomies. In 196 procedures decision to shunt was based on intraoperative monitoring, 129 by electroencephalogram (EEG), and 67 by stump pressures. Sixteen neurologic events occurred perioperatively, one transient ischemic attack and 15 strokes. The EEG group had 12 strokes, with a 38% event rate in procedures with EEG changes without shunting. The stump pressure group had one stroke. Stroke rate for intraoperative EEG monitoring was elevated (P = 0.02).

CONCLUSIONS

Intraoperative EEG based decision to shunt may not be as effective as other methods for prevention of perioperative neurologic events. When EEG changes occur, shunting is necessary.

Comparison of short-term clinical postoperative outcomes in patients who underwent carotid endarterectomy: Intensive care unit versus the ward high-dependency unit

The objective of this research was to examine the routine postoperative management of patients who have undergone carotid endarterectomy and compare the intensive care unit (ICU) with the ward high-dependency unit (HDU) in terms of the number, type, severity, or management of postoperative clinical events within a 48-hour time frame. Two of the vascular surgeons routinely admitted patients to the ICU, and 1 vascular surgeon routinely admitted patients to the ward HDU. This research determines whether there was a difference in outcomes between the 2 groups with the intention of changing the practice of the 2 vascular surgeons who routinely admitted their patients to the ICU. This was a nonexperimental, descriptive, prospective study of all patients who underwent carotid endarterectomy during an 18-month period between August 1999 and January 2000. A total of 104 patients were recruited to the study. There were 84 patients in the ICU cohort; 59 were male and 25 were female, with a mean age of 72 years. There were 20 patients in the ward HDU cohort; 12 were male and 8 were female, with a mean age of 66 years. Major complications occurred in 3 patients. One patient from the ICU group was returned to the operating room for evacuation of a hematoma, and 2 patients from the ward HDU group were transferred to the ICU for an inotropic infusion. During the first 24 hours, hypertension developed in 37 patients in the ICU cohort, 12 of whom did not require intervention. Hypertension requiring intervention developed in 3 patients in the ward group. Chi-square cross-tabulation revealed a chi 2 value of 1.4 and a P value of.01, which is a significant difference in the number of hypertensive events in the ICU versus the ward HDU. Hypotension occurred in 41 patients in the ICU group and in 9 patients in the ward cohort. The same chi 2 test was used to reveal a chi 2 value of 0.026 and a P value of.87, which are nonsignificant results. There was no difference in the number of hypotensive events in the ICU versus the ward HDU. There were no reported incidents of tachycardia. Bradycardia was reported in 64 patients in the ICU group and in 12 patients in the HDU group. There was no significant difference in the number of patients with bradycardia in either group of patients. Chi-square analysis revealed a chi 2 value of 1.4 and a P value of.23 during the first 24 hours postoperatively. We believe that careful selection of patients to the ward HDU is safe and cost-effective.