Temporal Trends in the Risks of Stroke and Death due to Endarterectomy for Symptomatic Carotid Stenosis: An Updated Systematic Review

Circadian and Diurnal Regulation of Cerebral Blood Flow

Circadian and diurnal variation in cerebral blood flow directly contributes to the diurnal variation in the risk of stroke, either through factors that trigger stroke or due to impaired compensatory mechanisms. Cerebral blood flow results from the integration of systemic hemodynamics, including heart rate, cardiac output, and blood pressure, with cerebrovascular regulatory mechanisms, including cerebrovascular reactivity, autoregulation, and neurovascular coupling. We review the evidence for the circadian and diurnal variation in each of these mechanisms and their integration, from the detailed evidence for mechanisms underlying the nocturnal nadir and morning surge in blood pressure to identifying limited available evidence for circadian and diurnal variation in cerebrovascular compensatory mechanisms. We, thus, identify key systemic hemodynamic factors related to the diurnal variation in the risk of stroke but particularly identify the need for further research focused on cerebrovascular regulatory mechanisms.

Update in Carotid Disease

This review of the literature analyzes publications over the past five years on various problems associated with carotid endarterectomy: 1. Is the eversion or classical technique of surgery with plastic repair of the reconstruction area with a patch more effective? 2. Carotid endarterectomy or carotid angioplasty with stenting is more optimal? 3. When should brain revascularization be performed after the development of ischemic stroke? 4. Should a temporary shunt be used to protect the brain during carotid endarterectomy? 5. How to prevent and treat different types of intraoperative ischemic strokes? 6. What tactics of treatment of patients with combined lesions of the carotid and coronary arteries is more effective? 7. What are the causes and methods of elimination of restenosis of the internal carotid artery known? 8. Is carotid endarterectomy safe in old age?

Patch angioplasty versus primary closure for carotid endarterectomy

BACKGROUND

Carotid patch angioplasty may reduce the risk of acute occlusion or long-term restenosis of the carotid artery and subsequent ischaemic stroke in people undergoing carotid endarterectomy (CEA). This is an update of a Cochrane Review originally published in 1995 and updated in 2008.

OBJECTIVES

To assess the safety and efficacy of routine or selective carotid patch angioplasty with either a venous patch or a synthetic patch compared with primary closure in people undergoing CEA. We wished to test the primary hypothesis that carotid patch angioplasty results in a lower rate of severe arterial restenosis and therefore fewer recurrent strokes and stroke-related deaths, without a considerable increase in perioperative complications.

SEARCH METHODS

We searched the Cochrane Stroke Group trials register, CENTRAL, MEDLINE, Embase, two other databases, and two trial registries in September 2021.

SELECTION CRITERIA

Randomised controlled trials and quasi-randomised trials comparing carotid patch angioplasty with primary closure in people undergoing CEA.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and risk of bias; extracted data; and determined the certainty of evidence using the GRADE approach. Outcomes of interest included stroke, death, significant complications related to surgery, and artery restenosis or occlusion during the perioperative period (within 30 days of the operation) or during long-term follow-up.

MAIN RESULTS

We included 11 trials involving 2100 participants undergoing 2304 CEA operations. The quality of trials was generally poor. Follow-up varied from hospital discharge to five years. Compared with primary closure, carotid patch angioplasty may make little or no difference to reduction in risk of any stroke during the perioperative period (odds ratio (OR) 0.57, 95% confidence interval (CI) 0.31 to 1.03; P = 0.063; 8 studies, 1769 participants; very low-certainty evidence), but may lower the risk of any stroke during long-term follow-up (OR 0.49, 95% CI 0.27 to 0.90; P = 0.022; 7 studies, 1332 participants; very low-certainty evidence). In the included studies, carotid patch angioplasty resulted in a lower risk of ipsilateral stroke during the perioperative period (OR 0.31, 95% CI 0.15 to 0.63; P = 0.001; 7 studies, 1201 participants; very low-certainty evidence), and during long-term follow-up (OR 0.32, 95% CI 0.16 to 0.63; P = 0.001; 6 studies, 1141 participants; very low-certainty evidence). The intervention was associated with a reduction in the risk of any stroke or death during long-term follow-up (OR 0.59, 95% CI 0.42 to 0.84; P = 0.003; 6 studies, 1019 participants; very low-certainty evidence). In addition, the included studies suggest that carotid patch angioplasty may reduce the risk of perioperative arterial occlusion (OR 0.18, 95% CI 0.08 to 0.41; P < 0.0001; 7 studies, 1435 participants; low-certainty evidence), and may reduce the risk of restenosis during long-term follow-up (OR 0.24, 95% CI 0.17 to 0.34; P < 0.00001; 8 studies, 1719 participants; low-certainty evidence). The studies recorded very few arterial complications, including haemorrhage, infection, cranial nerve palsies and pseudo-aneurysm formation, with either patch or primary closure. We found no correlation between the use of patch angioplasty and the risk of either perioperative or long-term stroke-related death or all-cause death rates.

AUTHORS' CONCLUSIONS

Compared with primary closure, carotid patch angioplasty may reduce the risk of perioperative arterial occlusion and long-term restenosis of the operated artery. It would appear to reduce the risk of ipsilateral stroke during the perioperative and long-term period and reduce the risk of any stroke in the long-term when compared with primary closure. However, the evidence is uncertain due to the limited quality of included trials.

The 2nd European Carotid Surgery Trial (ECST-2): rationale and protocol for a randomised clinical trial comparing immediate revascularisation versus optimised medical therapy alone in patients with symptomatic and asymptomatic carotid stenosis at low to intermediate risk of stroke

Background

Carotid endarterectomy is currently recommended for patients with recently symptomatic carotid stenosis ≥50%, based on randomised trials conducted 30 years ago. Several factors such as carotid plaque ulceration, age and associated comorbidities might influence the risk-benefit ratio of carotid revascularisation. A model developed in previous trials that calculates the future risk of stroke based on these features can be used to stratify patients into low, intermediate or high risk. Since the original trials, medical treatment has improved significantly. Our hypothesis is that patients with carotid stenosis ≥50% associated with a low to intermediate risk of stroke will not benefit from additional carotid revascularisation when treated with optimised medical therapy. We also hypothesise that prediction of future risk of stroke in individual patients with carotid stenosis can be improved using the results of magnetic resonance imaging (MRI) of the carotid plaque.

Methods

Patients are randomised between immediate revascularisation plus OMT versus OMT alone. Suitable patients are those with asymptomatic or symptomatic carotid stenosis ≥50% with an estimated 5-year risk of stroke of <20%, as calculated using the Carotid Artery Risk score. MRI of the brain at baseline and during follow-up will be used as a blinded measure to assess the incidence of silent infarction and haemorrhage, while carotid plaque MRI at baseline will be used to investigate the hypotheses that plaque characteristics determine future stroke risk and help identify a subgroup of patients that will benefit from revascularisation. An initial analysis will be conducted after recruitment of 320 patients with baseline MRI and a minimum of 2 years of follow-up, to provide data to inform the design and sample size for a continuation or re-launch of the study. The primary outcome measure of this initial analysis is the combined 2-year rate of any clinically manifest stroke, new cerebral infarct on MRI, myocardial infarction or periprocedural death.

Discussion

ECST-2 will provide new data on the efficacy of modern optimal medical therapy alone versus added carotid revascularisation in patients with carotid stenosis at low to intermediate risk of future stroke selected by individualised risk assessment. We anticipate that the results of baseline brain and carotid plaque MRI will provide data to improve the prediction of the risk of stroke and the effect of treatment in patients with carotid stenosis.

Trial registration

ISRCTN registry ISRCTN97744893. Registered on 05 July 2012

Routine or selective carotid artery shunting for carotid endarterectomy (and different methods of monitoring in selective shunting)

BACKGROUND

Temporary interruption of cerebral blood flow during carotid endarterectomy can be avoided by using a shunt across the clamped section of the carotid artery. The shunt may improve the outcome. This is an update of a Cochrane review originally published in 1996 and previously updated in 2002, 2009, and 2014.

OBJECTIVES

To assess the effect of routine versus selective or no shunting, and to assess the best method for selective shunting on death, stroke, and other complications in people undergoing carotid endarterectomy under general anaesthesia.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched April 2021), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2021, Issue 4), MEDLINE (1966 to April 2021), Embase (1980 to April 2021), and the Science Citation Index Expanded (SCI-EXPANDED) (1980 to April 2021). We also searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform, and handsearched relevant journals, conference proceedings, and reference lists.

SELECTION CRITERIA

Randomised and quasi-randomised trials of routine shunting compared with no shunting or selective shunting, and trials that compared different shunting policies in people undergoing carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

Three independent review authors performed data extraction, selection, and analysis. A pooled Peto odds ratio (OR) and 95% confidence interval (CI) were computed for all outcomes of interest. Best and worse case scenarios were also calculated in case of unavailable data. Two authors independently assessed risk of bias, and quality of evidence using GRADE.

MAIN RESULTS

No new trials were found for this updated review. Thus, six trials involving 1270 participants are included in this latest review: three trials involving 686 participants compared routine shunting with no shunting, one trial involving 200 participants compared routine shunting with selective shunting, one trial involving 253 participants compared selective shunting with and without near-infrared refractory spectroscopy monitoring, and the other trial involving 131 participants compared shunting with a combination of electroencephalographic and carotid pressure measurement with shunting by carotid pressure measurement alone. Only three trials comparing routine shunting and no shunting were eligible for meta-analysis. Major findings of this comparison found that the routine shunting had less risk of stroke-related death within 30 days of surgery (best case) than no shunting (Peto odds ratio (OR) 0.13, 95% confidence interval (CI) 0.02 to 0.96, I² not applicable, P = 0.05, low-quality evidence), the routine shunting group had a lower stroke rate within 24 hours of surgery (Peto odds ratio (OR) 0.15, 95% CI 0.03 to 0.78, I² = not applicable, P = 0.02, low-quality evidence), and ipsilateral stroke within 30 days of surgery (best case) (Peto OR 0.41, 95% CI 0.18 to 0.97, I² = 52%, P = 0.04, low-quality evidence) than the no shunting group. No difference was found between the groups in terms of postoperative neurological deficit between selective shunting with and without near-infrared refractory spectroscopy monitoring. However, this analysis was inadequately powered to reliably detect the effect. There was no difference between the risk of ipsilateral stroke in participants selected for shunting with the combination of electroencephalographic and carotid pressure assessment compared with pressure assessment alone, although again the data were limited.

AUTHORS' CONCLUSIONS

This review concluded that the data available were too limited to either support or refute the use of routine or selective shunting in carotid endarterectomy when performed under general anaesthesia. Large-scale randomised trials of routine shunting versus selective shunting are required. No method of monitoring in selective shunting has been shown to produce better outcomes.

Development of a Whole-Task Simulator for Carotid Endarterectomy

BACKGROUND

Surgical education relies on operative exposure with live patients. Carotid endarterectomy (CEA) demands an experienced surgeon with a very low complication rate. The high-risk nature of this procedure and the decline in number of CEAs performed annually has created a gap in residency training.

OBJECTIVE

To develop a high-fidelity whole-task simulation for CEA that demonstrates content, construct, and face validity.

METHODS

Anatomically accurate models of the human neck were created using multilayered poly-vinyl alcohol hydrogels. Graded polymerization of the hydrogel was achieved by inducing crosslinks during freeze/thaw cycles, stiffening the simulated tissues to achieve realistic tactile properties. Venous bleeding was simulated using pressure bags and a ventricular assistive device created pulsatile flow in the carotid. Ten surgeons performed the simulation under operating room conditions, and metrics were compared among experience levels to determine construct validity. Participants completed surveys about realism and usefulness to evaluate face validity.

RESULTS

A significant difference was found in operative measures between attending and resident physicians. The mean operative time for the expert group was 63.6 min vs 138.8 for the resident group (P = .002). There was a difference in mean internal carotid artery clamp time of 43.4 vs 83.2 min (P = .04). There were only 2 hypoglossal nerve injuries, both in the resident group (P = .009).

CONCLUSION

The whole-task CEA simulator is a realistic, inexpensive model that offers comprehensive training and allows residents to master skills prior to operating on live patients. Overall, the model demonstrated face and construct validity among neurosurgery and vascular surgeons.

Secular Trends in Procedural Stroke or Death Risks of Stenting Versus Endarterectomy for Symptomatic Carotid Stenosis

BACKGROUND

Over the past decades, stroke risk associated with carotid disease has decreased, reflecting improvements in medical therapy and a more rigorous control of vascular risk factors. It is less clear whether the procedural risk of carotid revascularization has declined over time.

METHODS

We analyzed temporal changes in procedural risks among 4597 patients with symptomatic carotid stenosis treated with carotid artery stenting (n=2326) or carotid endarterectomy (n=2271) in 4 randomized trials between 2000 and 2008, using generalized linear mixed-effects models with a random intercept for each source trial. Models were additionally adjusted for age and other baseline characteristics predicting treatment risk. The primary outcome event was any procedural stroke or death, occurring during or within 30 days after revascularization.

RESULTS

The procedural stroke or death risk decreased significantly over time in all patients (unadjusted odds ratio per year, 0.91; 95% CI, 0.85-0.97; P=0.006). This effect was driven by a decrease in the carotid endarterectomy group (unadjusted odds ratio per year, 0.82; 95% CI, 0.73-0.92; P=0.003), whereas no significant decrease was found after carotid artery stenting (unadjusted odds ratio, 0.96; 95% CI, 0.88-1.04; P=0.33). Carotid endarterectomy patients had a lower procedural stroke or death risk compared with carotid artery stenting patients, and the difference significantly increased over time (interaction P=0.031). After adjustment for baseline characteristics, the results remained essentially the same.

CONCLUSIONS

The risk of stroke or death associated with carotid endarterectomy for symptomatic carotid stenosis decreased over an 8-year period, independent of clinical predictors of procedural risk. No corresponding reduction in procedural risk was seen in patients treated with stenting.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov; http://www.isrctn.com. Unique identifier: NCT00190398 (EVA-3S), NCT00004732 (CREST), ISRCTN57874028 (SPACE), and ISRCTN25337470 (ICSS).

Sensitivity of Administrative Coding in Identifying Inpatient Acute Strokes Complicating Procedures or Other Diseases in UK Hospitals

Background

Administrative hospital diagnostic coding data are increasingly used in “big data” research and to assess complication rates after surgery or acute medical conditions. Acute stroke is a common complication of several procedures/conditions, such as carotid interventions, but data are lacking on the sensitivity of administrative coding in identifying acute stroke during inpatient stay.

Methods and Results

Using all acute strokes ascertained in a population‐based cohort (2002–2017) as the reference, we determined the sensitivity of hospital administrative diagnostic codes (International Classification of Diseases, Tenth Revision; ICD‐10) for identifying acute strokes that occurred during hospital admission for other reasons, stratified by coding strategies, study periods, and stroke severity (National Institutes of Health Stroke Score</≥5). Of 3011 acute strokes, 198 (6.6%) occurred during hospital admissions for procedures/other diseases, including 122 (61.6%) major strokes. Using stroke‐specific codes (ICD‐10=I60–I61 and I63–I64) in the primary diagnostic position, 66 of the 198 cases were correctly identified (sensitivity for any stroke, 33.3%; 95% CI, 27.1–40.2; minor stroke, 30.3%; 95% CI, 21.0–41.5; major stroke, 35.2%; 95% CI, 27.2–44.2), with no improvement of sensitivity over time (P_trend=0.54). Sensitivity was lower during admissions for surgery/procedures than for other acute medical admissions (n/% 17/23.3% versus 49/39.2%; P=0.02). Sensitivity improved to 60.6% (53.6–67.2) for all and 61.6% (50.0–72.1) for surgery/procedures if other diagnostic positions were used, and to 65.2% (58.2–71.5) and 68.5% (56.9–78.1) respectively if combined with use of all possible nonspecific stroke‐related codes (ie, adding ICD‐10=I62 and I65–I68).

Conclusions

Low sensitivity of administrative coding in identifying acute strokes that occurred during admission does not support its use alone for audit of complication rates of procedures or hospitalization for other reasons.

An update of the Italian Stroke Organization–Stroke Prevention Awareness Diffusion Group guidelines on carotid endarterectomy and stenting: A personalized medicine approach

Although proof-based medicine has generated much valid evidence for the drawing up of guidelines and recommendations for best clinical practice in symptomatic and asymptomatic carotid stenosis, whether and when it is better to employ endarterectomy or stenting as the intervention of choice still remain matters of debate. Moreover, guidelines have been targeted up to now to the ‘representative’ patient, as resulting from the statistical analyses of the studies conducted on the safety and efficacy of both interventions as well as on medical therapy alone. The Italian Stroke Organization (ISO) and Stroke Prevention and Awareness Diffusion (SPREAD) group has thus decided to update its statements for an 8th edition. To this end, a multidisciplinary team of authors representing Italian scientific societies in the neurology, neuroradiology, vascular and endovascular surgery, interventional cardiology, and general medicine fields re-examined the literature available on stroke. Analyses and considerations on patient subgroups have allowed to model the risks/benefits of endarterectomy and stenting in the individual. Accordingly, the guideline's original methodology has been revised to follow the new SIGN (Scottish Intercollegiate Guideline Network) Grade-like approach, integrating it with new considerations on Precision, or Personalized Medicine. Therefore, this guideline offers recommendations on precision medicine for the single patient, and can be followed in addition to the more standard guidelines.

Risk Factors For Stroke, Myocardial Infarction, or Death Following Carotid Endarterectomy: Results From the International Carotid Stenting Study

OBJECTIVES

Carotid endarterectomy (CEA) is standard treatment for symptomatic carotid artery stenosis but carries a risk of stroke, myocardial infarction (MI), or death. This study investigated risk factors for these procedural complications occurring within 30 days of endarterectomy in the International Carotid Stenting Study (ICSS).

METHODS

Patients with recently symptomatic carotid stenosis >50% were randomly allocated to endarterectomy or stenting. Analysis is reported of patients in ICSS assigned to endarterectomy and limited to those in whom CEA was initiated. The occurrence of stroke, MI, or death within 30 days of the procedure was reported by investigators and adjudicated. Demographic and technical risk factors for these complications were analysed sequentially in a binomial regression analysis and subsequently in a multivariable model.

RESULTS

Eight-hundred and twenty-one patients were included in the analysis. The risk of stroke, MI, or death within 30 days of CEA was 4.0%. The risk was higher in female patients (risk ratio [RR] 1.98, 95% CI 1.02-3.87, p = .05) and with increasing baseline diastolic blood pressure (dBP) (RR 1.30 per +10 mmHg, 95% CI 1.02-1.66, p = .04). Mean baseline dBP, obtained at the time of randomization in the trial, was 78 mmHg (SD 13 mmHg). In a multivariable model, only dBP remained a significant predictor. The risk was not related to the type of surgical reconstruction, anaesthetic technique, or perioperative medication regimen. Patients undergoing CEA stayed a median of 4 days before discharge, and 21.2% of events occurred on or after the day of discharge.

CONCLUSIONS

Increasing diastolic blood pressure was the only independent risk factor for stroke, MI, or death following CEA. Cautious attention to blood pressure control following symptoms attributable to carotid stenosis could reduce the risks associated with subsequent CEA.

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.

An Update on Italian Stroke Organization Guidelines on Carotid Endarterectomy and Stenting

One hundred and fifty-three authors, 45 Italian scientific societies, and two Italian patients' associations participated in drafting the Italian Stroke Organization document, which has become the national guideline for the prevention and treatment of stroke in Italy. For the surgical therapy section of the Italian Stroke Organization document, the main trials on carotid endoarterectomy and stenting were critically reviewed in order to formulate recommendations for these procedures. Recommendations are presented here for the referral of patients to either carotid endarterectomy or stenting on the basis of whether carotid stenosis is symptomatic or asymptomatic.

Routine or selective carotid artery shunting for carotid endarterectomy (and different methods of monitoring in selective shunting)

BACKGROUND

Temporary interruption of cerebral blood flow during carotid endarterectomy can be avoided by using a shunt across the clamped section of the carotid artery. This may improve outcome. This is an update of a Cochrane review originally published in 1996 and previously updated in 2009.

OBJECTIVES

To assess the effect of routine versus selective or no shunting during carotid endarterectomy, and to assess the best method for selecting people for shunting.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (last searched August 2013), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2013, Issue 8), MEDLINE (1966 to August 2013), EMBASE (1980 to August 2013) and Index to Scientific and Technical Proceedings (1980 to August 2013). We handsearched journals and conference proceedings, checked reference lists, and contacted experts in the field.

SELECTION CRITERIA

Randomised and quasi-randomised trials of routine shunting compared with no shunting or selective shunting, and trials that compared different shunting policies in people undergoing carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

Three review authors independently performed the searches and applied the inclusion criteria. For this update, we identified two new relevant randomised controlled trials.

MAIN RESULTS

We included six trials involving 1270 participants in the review: three trials involving 686 participants compared routine shunting with no shunting, one trial involving 200 participants compared routine shunting with selective shunting, one trial involving 253 participants compared selective shunting with and without near-infrared refractory spectroscopy monitoring, and the other trial involving 131 participants compared shunting with a combination of electroencephalographic and carotid pressure measurement with shunting by carotid pressure measurement alone. In general, reporting of methodology in the included studies was poor. For most studies, the blinding of outcome assessors and the report of prespecified outcomes were unclear. For routine versus no shunting, there was no significant difference in the rate of all stroke, ipsilateral stroke or death up to 30 days after surgery, although data were limited. No significant difference was found between the groups in terms of postoperative neurological deficit between selective shunting with and without near-infrared refractory spectroscopy monitoring, However, this analysis was inadequately powered to reliably detect the effect. There was no significant difference between the risk of ipsilateral stroke in participants selected for shunting with the combination of electroencephalographic and carotid pressure assessment compared with pressure assessment alone, although again the data were limited.

AUTHORS' CONCLUSIONS

This review concluded that the data available were too limited to either support or refute the use of routine or selective shunting in carotid endarterectomy. Large scale randomised trials of routine shunting versus selective shunting are required. No method of monitoring in selective shunting has been shown to produce better outcomes.

Local versus general anaesthesia for carotid endarterectomy

BACKGROUND

Carotid endarterectomy may significantly reduce the risk of stroke in people with recently symptomatic, severe carotid artery stenosis. However, there are significant perioperative risks that may be reduced by performing the operation under local rather than general anaesthetic. This is an update of a Cochrane Review first published in 1996, and previously updated in 2004 and 2008.

OBJECTIVES

To determine whether carotid endarterectomy under local anaesthetic: (1) reduces the risk of perioperative stroke and death compared with general anaesthetic; (2) reduces the complication rate (other than stroke) following carotid endarterectomy; and (3) is acceptable to patients and surgeons.

SEARCH METHODS

We searched the Cochrane Stroke Group Trials Register (September 2013), MEDLINE (1966 to September 2013), EMBASE (1980 to September 2013) and Index to Scientific and Technical Proceedings (ISTP) (1980 to September 2013). We also handsearched relevant journals, and searched the reference lists of articles identified.

SELECTION CRITERIA

Randomised trials comparing the use of local anaesthetic to general anaesthetic for carotid endarterectomy were considered for inclusion.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trial quality and extracted data. We calculated a pooled Peto odds ratio (OR) and corresponding 95% confidence interval (CI) for the following outcomes that occurred within 30 days of surgery: stroke, death, stroke or death, myocardial infarction, local haemorrhage, cranial nerve injuries, and shunted arteries.

MAIN RESULTS

We included 14 randomised trials involving 4596 operations, of which 3526 were from the single largest trial (GALA). In general, reporting of methodology in the included studies was poor. All studies were unable to blind patients and surgical teams to randomised treatment allocation and for most studies the blinding of outcome assessors was unclear. There was no statistically significant difference in the incidence of stroke within 30 days of surgery between the local anaesthesia group and the general anaesthesia group. The incidence of strokes in the local anaesthesia group was 3.2% compared to 3.5% in the general anaesthesia group (Peto OR 0.92, 95% CI 0.67 to 1.28). There was no statistically significant difference in the proportion of patients who had a stroke or died within 30 days of surgery. In the local anaesthesia group 3.6% of patients had a stroke or died compared to 4.2% of patients in the general anaesthesia group (Peto OR 0.85, 95% CI 0.63 to 1.16). There was a non-significant trend towards lower operative mortality with local anaesthetic. In the local anaesthesia group 0.9% of patients died within 30 days of surgery compared to 1.5% of patients in the general anaesthesia group (Peto OR 0.62, 95% CI 0.36 to 1.07). However, neither the GALA trial or the pooled analysis were adequately powered to reliably detect an effect on mortality.

AUTHORS' CONCLUSIONS

The proportion of patients who had a stroke or died within 30 days of surgery did not differ significantly between the two types of anaesthetic techniques used during carotid endarterectomy. This systematic review provides evidence to suggest that patients and surgeons can choose either anaesthetic technique, depending on the clinical situation and their own preferences.

A Clinical Rule (Sex, Contralateral Occlusion, Age, and Restenosis) to Select Patients for Stenting Versus Carotid Endarterectomy

Background and Purpose—

Compared with carotid endarterectomy (CEA), carotid angioplasty and stenting (CAS) is associated with a higher risk of procedural stroke or death especially in patients with symptomatic stenosis. However, after the perioperative period, risk is similar with both treatments, suggesting that CAS could be an acceptable option in selected patients.

Methods—

We performed systematic reviews of observational studies of procedural risks of CEA or CAS and extracted data on 9 predefined risk factors (age, contralateral carotid occlusion, coronary artery disease, diabetes mellitus, sex, hypertension, peripheral artery disease, and type and side of stenosis). We calculated pooled relative risks of procedural stroke or death. Factors with differential effects on risk of CAS versus CEA were identified by interaction tests and used to derive a rule. The rule was tested using individual patient data from randomized trials of CAS versus CEA from the Carotid Stenting Trialists’ Collaboration (CSTC).

Results—

We identified 170 studies. The effects of sex, contralateral occlusion, age, and restenosis (SCAR) on the procedural risk of stroke or death differed. Patients with contralateral occlusion or restenosis and women <75 years were at relatively low risk for CAS (SCAR negative), with all others being high risk (SCAR positive). Among the 3049 patients in the CSTC validation, 694 (23%) patients were SCAR negative. The pooled RR of procedural stroke and death with CAS versus CEA was 0.93 (0.49–1.77; P =0.83) in SCAR-negative and 2.41 (1.68–3.45; P <0.0001) in SCAR-positive patients ( P [interaction]=0.05).

Conclusions—

The SCAR rule is potentially useful to identify patients in whom CAS has a similar risk of perioperative stroke or death to CEA.

Surgical dissection of the internal carotid artery under flow control by proximal vessel clamping reduces embolic infarcts during carotid endarterectomy

OBJECTIVE

To evaluate the efficacy of flow control of the internal carotid artery (ICA) by the clamping of the common carotid artery, external carotid artery, and superior thyroid artery during surgical ICA dissection to reduce ischemic complications after carotid endarterectomy (CEA).

METHODS

Sixty-seven patients (59 men; age, 70.5 ± 6.2 years) who underwent CEA by the same surgeon were retrospectively studied. Both conventional CEA (n = 29) and flow-control CEA (n = 38) were performed with the patient under general anesthesia and with the use of somatosensory-evoked potential and near-infrared spectroscopy monitoring as a guide for selective shunting. The number of new postoperative infarcts was assessed with preoperative and postoperative diffusion-weighted images (DWIs) obtained within 3 days of surgery. In addition to surgical technique, the effects of the following factors on new infarcts also were examined: age, side of ICA stenosis, high-grade stenosis, symptoms, and application of shunting.

RESULTS

New postoperative DWI lesions were observed in 7 of 67 patients (10.4%), and none of them was symptomatic. With respect to operative technique, the incidence rate of DWI spots was significantly lower in the flow-control group (2.6%) than in the conventional group (20.7%), odds ratio: 0.069; 95% confidence interval: 0.006-0.779; P = 0.031). On multiple logistic regression analysis, age, side of ICA stenosis, high-grade stenosis, symptoms, and the use of internal shunting did not have significant effects on new postoperative DWI lesions, whereas technique did have an effect.

CONCLUSION

The proximal flow-control technique for CEA helps avoid embolic complications during surgical ICA dissection.

Urgent Carotid Endarterectomy in Patients with Acute Neurological Symptoms: The Results of a Single Center Prospective Nonrandomized Study

BACKGROUND

To evaluate the feasibility and the safety of performing urgent (within 24 hours) carotid endarterectomy in patients with carotid stenosis presenting with repetitive transient ischemic attacks or progressing stroke.

METHODS

Thirty consecutive patients underwent urgent carotid endarterectomy for repetitive transient ischemic attacks (N = 12) or progressing stroke (N = 18) according to the following criteria: two or more transient ischemic attacks or a fluctuating neurological deficit over a period of less than 24 hours (progressing stroke), no impairment of consciousness, no cerebral infarct larger than 1.5 cm in diameter on computed tomography and a carotid artery stenosis of 70% or more on the appropriate side, diagnosed by echodoppler ultrasonography and/or arteriography. Patients with cerebral hemorrhage were excluded. All patients were examined pre- and postoperatively by the same neurologist and surgery was performed by the same vascular surgeon. All the patients underwent a cerebral CT scan within 5 days after surgery.

RESULTS

There were 19 men and 11 women. The mean age was 71 ± 7.6 years. The time delay of surgery after the onset of transient ischemic attacks or progressing stroke averaged 19.4 ± 11.5 hours. For patients suffering progressive stroke, one developed a fatal ischemic stroke 24 hours after surgery, five showed no improvement of their neurological status after surgery, but none worsened. Twelve patients experienced significant improvement of their neurological status with an European Stroke Scale of 77.9 ± 25.2 at admission and 95.8 ± 4.6 at discharge, and all but one of those patients had a Barthel's index value over 85/100 at discharge. The 12 patients with repetitive transient ischemic attacks had an uneventful postoperative outcome. The mean duration of follow-up was 3.4 ± 1.2 years. No patient developed another transient ischemic attack or ischemic stroke during the follow-up period.

CONCLUSIONS

The results of our series documented the feasibility and the safety of performing urgent (within 24 hours) carotid endarterectomy in patients presenting with repetitive transient ischemic attacks or progressing stroke. This procedure seems to us to be justified by the fact that waiting for surgery may lead to the development of a more profound deficit or another stroke in these neurologically unstable patients whose only chance for neurological recovery is in the early phase.

Longer time interval between carotid cross-clamping and shunting is associated with increased 30-day stroke and death rate

BACKGROUND

The benefit of carotid endarterectomy (CEA) in patients with a significant (>70%) (a)symptomatic stenosis has been proven thoroughly in major trials. It is unknown whether, after cross-clamping the carotid artery, the time interval between determination that a shunt is needed and the actual functioning of the shunt, defined as the need for shunt-to-shunt time (NST), influences 30-day morbidity and mortality rate after CEA.

METHODS

Experienced vascular surgeons performed 851 CEAs with a selective shunting protocol based on perioperative transcranial Doppler measurement and electroencephalographic findings, and data were analyzed retrospectively. The study included 156 shunted patients.

RESULTS

Longer NST was associated with an increase in the 30-day stroke/death rate. A binary logistic regression model was used to determine a 2-tailed P value of .004 and an odds ratio of 1.5/min increase of the NST. There was no influence on stroke-death rate of gender, age, symptomatic or asymptomatic stenosis, the use of a patch or not, or the number of periprocedural microembolic signals.

CONCLUSION

If CEA is performed with a selective shunting protocol, a longer NST increases the 30-day stroke/death rate. These results support a strong recommendation that shunt placement should be as quick as possible.

Intensive medical therapy for asymptomatic carotid artery stenosis

The majority of carotid revascularization procedures are done in patients without recent symptoms of cerebral ischemia (asymptomatic carotid stenosis). In previous studies from the past two decades, the stroke risk associated with asymptomatic carotid stenosis has been estimated to be 2-2.5% per year. Given the relatively benign nature of asymptomatic carotid stenosis, it has been proposed that confining revascularization to a limited, higher-risk subgroup is a sensible strategy. Evidence is accumulating that improved medical therapy has led to a lower risk of stroke in medically treated patients and that ultrasound methods can identify higher-risk patients. These developments are highlighted in this article.

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.

Will molecular optical imaging have clinically important roles in stroke management, and how?

Molecular imaging is a novel technology to visualize biological processes at the cellular and molecular levels, which is reshaping both biomedical research and clinical practice. By providing molecular information to supplement and augment conventional anatomy-based imaging, molecular imaging is expected to allow 1) the earlier detection of diseases, 2) precise evaluation of disease stages, and 3) both diagnostic and therapeutic monitoring of disease progression in a quantitative manner. In this brief review, we present our view on the prospects of molecular optical imaging in the field of stroke practice, focusing on the imaging vulnerability of atherosclerotic plaques, thrombolytic resistance, real-time cerebral perfusion, and penumbra.

Patch angioplasty versus primary closure for carotid endarterectomy

BACKGROUND

Carotid patch angioplasty (with either a venous or a synthetic patch) may reduce the risk of carotid artery restenosis and subsequent ischaemic stroke. This is an update of a Cochrane Review originally published in 1995 and previously updated in 2004.

OBJECTIVES

To assess the safety and efficacy of routine or selective carotid patch angioplasty compared to carotid endarterectomy with primary closure.

SEARCH STRATEGY

We searched the Cochrane Stroke Group Trials Register (last searched 5 May 2009), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2009), MEDLINE (1966 to November 2008), EMBASE (1980 to November 2008) and Index to Scientific and Technical Proceedings (1980 to November 2008). We handsearched journals and conference proceedings, checked reference lists, and contacted experts in the field.

SELECTION CRITERIA

Randomised and quasi-randomised trials comparing carotid patch angioplasty with primary closure in any patients undergoing carotid endarterectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility, trial quality and extracted data.

MAIN RESULTS

We included 10 trials involving 1967 patients undergoing 2157 operations. The quality of trials was generally poor. Follow up varied from hospital discharge to five years. Carotid patch angioplasty was associated with a reduction in the risk of ipsilateral stroke during the perioperative period (odds ratio (OR) 0.31, 95% confidence interval (CI) 0.15 to 0.63, P = 0.001) and long-term follow up (OR 0.32, 95%CI 0.16 to 0.63, P = 0.001). It was also associated with a reduced risk of perioperative arterial occlusion (OR 0.18, 95% CI 0.08 to 0.41, P < 0.0001), and decreased restenosis during long-term follow up in eight trials (OR 0.24, 95% CI 0.17 to 0.34, P < 0.00001). These results are more certain than those of the previous review since the number of operations and events have increased. However, the sample sizes are still relatively small, data were not available from all trials, and there was significant loss to follow up. Very few arterial complications, including haemorrhage, infection, cranial nerve palsies and pseudo-aneurysm formation were recorded with either patch or primary closure. No significant correlation was found between use of patch angioplasty and the risk of either perioperative or long-term all-cause death rates.

AUTHORS' CONCLUSIONS

Limited evidence suggests that carotid patch angioplasty may reduce the risk of perioperative arterial occlusion and restenosis. It would appear to reduce the risk of ipsilateral stroke and there is a non significant trend towards a reduction in perioperative any stroke rate and all-cause case fatality.