Closing the Loop: A 21-year Audit of Strategies for Preventing Stroke and Death Following Carotid Endarterectomy

Stroke risk management in carotid atherosclerotic disease: a clinical consensus statement of the ESC Council on Stroke and the ESC Working Group on Aorta and Peripheral Vascular Diseases

Carotid atherosclerotic disease continues to be an important cause of stroke, often disabling or fatal. Such strokes could be largely prevented through optimal medical therapy and carotid revascularization. Advancements in discovery research and imaging along with evidence from recent pharmacology and interventional clinical trials and registries and the progress in acute stroke management have markedly expanded the knowledge base for clinical decisions in carotid stenosis. Nevertheless, there is variability in carotid-related stroke prevention and management strategies across medical specialities. Optimal patient care can be achieved by (i) establishing a unified knowledge foundation and (ii) fostering multi-specialty collaborative guidelines. The emergent Neuro-Vascular Team concept, mirroring the multi-disciplinary Heart Team, embraces diverse specializations, tailors personalized, stratified medicine approaches to individual patient needs, and integrates innovative imaging and risk-assessment biomarkers. Proposed approach integrates collaboration of multiple specialists central to carotid artery stenosis management such as neurology, stroke medicine, cardiology, angiology, ophthalmology, vascular surgery, endovascular interventions, neuroradiology, and neurosurgery. Moreover, patient education regarding current treatment options, their risks and advantages, is pivotal, promoting patient's active role in clinical care decisions. This enables optimization of interventions ranging from lifestyle modification, carotid revascularization by stenting or endarterectomy, as well as pharmacological management including statins, novel lipid-lowering and antithrombotic strategies, and targeting inflammation and vascular dysfunction. This consensus document provides a harmonized multi-specialty approach to multi-morbidity prevention in carotid stenosis patients, based on comprehensive knowledge review, pinpointing research gaps in an evidence-based medicine approach. It aims to be a foundational tool for inter-disciplinary collaboration and prioritized patient-centric decision-making.

Application of artificial intelligence in carotid endarterectomy and carotid artery stenting: A systematic review

ObjectivesCarotid stenosis plays a significant role in stroke burden. Surgical intervention in the form of carotid endarterectomy or carotid artery stenting is an important stroke risk reduction strategy. Careful patient selection with identification of high-risk individuals is crucial to operative planning given perioperative risks including stroke, myocardial infarction, and death. Machine learning (ML) is a subset of artificial intelligence (AI) consisting of mathematical algorithms that can learn from datasets to perform particular tasks. These algorithms offer a tool for prediction of patient outcomes by analysis of preoperative data leading to improved patient selection. This systematic review aims to assess the use of artificial intelligence in risk stratification for carotid endarterectomy and carotid artery stenting.MethodsPubMed, Web of Knowledge, EMBASE, and the Cochrane Library were systematically searched to identify any articles utilising artificial intelligence in predicting surgical outcomes in carotid endarterectomy or carotid artery stenting. After duplicate removal, all studies underwent independent title and abstract screening followed by quality assessment using the PROBAST tool. Data extraction was then carried out for synthesis and comparison of study outcomes including accuracy, area under receiver operator curve (AUC), sensitivity, and specificity.ResultsAfter duplicate processing, a total of 100 articles underwent title and abstract screening resulting in 11 clinical studies published between 2008 and 2023 that fit eligibility criteria. Surgical outcomes assessed included haemodynamic instability, shunt requirement, hyperperfusion syndrome, stroke, myocardial infarction, and death. Artificial intelligence models were able to accurately predict major adverse cardiovascular events (AUC 0.84), postoperative haemodynamic instability (AUC 0.86), shunt requirement (AUC 0.87), and postoperative hyperperfusion syndrome (AUC 0.95). However, many studies had a high risk of bias due to lack of external validation.ConclusionThis systematic review highlights the potential application of machine learning in prediction of surgical outcomes in carotid artery intervention. However, use of these tools in a clinical setting requires further robust study with use of external validation and larger patient datasets.

Assessment of atherosclerotic plaque morphology using contrast-enhanced ultrasound and its impact on primary cardiovascular events following simultaneous carotid endarterectomy and coronary artery bypass grafting

OBJECTIVE

The incidence of stroke after on-pump cardiac surgery during the perioperative period can affect up to 2% of patients, and is frequently linked to carotid artery disease. Notably, in patients with significant unilateral carotid artery stenosis of 80%-99%, the risk of stroke reaches 4%. Among individuals undergoing coronary artery bypass grafting (CABG), 3% to 10% exhibit significant carotid artery stenosis. To mitigate the risk of stroke and mortality, patients can undergo either simultaneous or staged carotid endarterectomy and CABG. The aim of this study was to assess whether early postoperative complications, including stroke, following simultaneous CABG/CAE procedures, correlate with morphological attributes of carotid plaque, assessed via contrast-enhanced ultrasound.

METHODS

A single centre retrospective analysis was performed including 62 patients who underwent simultaneous CABG/CEA between 2019 and 2022. Our study excluded patients who underwent staged carotid endarterectomy and CABG procedures, off-pump CABG, or those necessitating urgent CABG. Our analysis focused on patients meeting elective CABG criteria, diagnosed with symptomatic triple-vessel or left main trunk coronary artery disease (CAD), alongside asymptomatic carotid stenosis (a. carotis internae) exceeding 70% or symptomatic ipsilateral carotid stenosis surpassing 50%. The extent of contralateral carotid artery stenosis was not taken into account. Prior to the CEA/CABG procedure, each patient underwent contrast-enhanced ultrasound to assess atherosclerotic lesions, which were classified using Nakamura et al.'s classification. Among the patients, 37.1% exhibited no neovascularisation within the atherosclerotic plaque, 56.5% showed insignificant neovascularisation, and 6.5% displayed notable neovascularization within the plaque. Our study aimed to establish a connection between the degree of plaque vascularisation identified through contrast-enhanced ultrasound and subsequent postoperative complications.

RESULTS

Upon evaluating postoperative complications occurring within 30 days after the surgery and the plaque morphology identified through contrast-enhanced ultrasound, a statistically significant correlation was observed between a higher grade of plaque vascularisation and the occurrence of ischaemic stroke (r = 0.329, p = .008). Monte Carlo calculations of the Chi-square test indicated a significant association between a higher grade of plaque vascularisation and the presence of peripheral artery disease (χ2 = 15.175, lls = 2, p = .003).

CONCLUSION

Within 30 days of surgery, a significant correlation exists between the occurrence of ischaemic stroke following carotid endarterectomy subsequent to CABG and the presence of a higher grade plaque vascularisation as identified by contrast-enhanced ultrasound.

Locoregional Versus General Anesthesia in Prolonged Carotid Endarterectomy: A Propensity Score-Matched Study from the American College of Surgeons National Surgical Quality Improvement Program Database from 2011 to 2022

BACKGROUND

Carotid endarterectomy (CEA) is an effective treatment for carotid stenosis. Previous studies yielded conflicting findings regarding postoperative outcomes after CEA when comparing those under general and locoregional anesthesia. However, these findings may be influenced by an inherent selection bias, as general anesthesia is frequently selected for more complex CEA. To counteract this selection bias, this study compared the 30-day outcomes of locoregional and general anesthesia in patients who underwent prolonged CEA.

METHODS

Adult patients undergoing CEA were identified in American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP)-targeted database from 2011 to 2022. Only cases with prolonged operative times (over third quartile) were selected. Patients who had symptomatic and asymptomatic carotid stenosis were examined separately. A 1:3 propensity score matching was used to address preoperative differences between patients under locoregional and general anesthesia to assess 30-day postoperative outcomes. Moreover, factors associated with prolonged CEA were identified by multivariable logistic regression.

RESULTS

Among symptomatic patients who underwent prolonged CEA, 246 and 4,286 were under locoregional and general anesthesia, respectively. In asymptomatic patients, 388 had locoregional anesthesia and 5,137 had general anesthesia. After propensity score matching, patients under locoregional and general anesthesia had comparable 30-day mortality (symptomatic: 1.63% vs. 0.81%, P = 0.28; asymptomatic: 0.77% vs. 0.52%, P = 0.70) and stroke (symptomatic: 4.88% vs. 4.34%, P = 0.72; asymptomatic: 1.29% vs. 1.46%, P = 1.00). All other 30-day outcomes were comparable between groups, except for symptomatic patients under locoregional had shorter operation time (P < 0.01) and asymptomatic patients under locoregional had lower cranial nerve injury (2.06% vs. 4.90%, P = 0.02). High-risk anatomical factors, male sex, younger age, and certain comorbidities were associated with prolonged operative times.

CONCLUSIONS

Patients under both types of anesthesia had mostly comparable 30-day postoperative outcomes, including mortality and stroke, for both symptomatic and asymptomatic patients. Therefore, locoregional and general anesthesia appear to be equally effective in CEA cases characterized by anticipated complexity and, consequently, prolonged operative times.

Brazilian Angiology and Vascular Surgery Society Guidelines for the treatment of extracranial cerebrovascular disease

Extracranial cerebrovascular disease has been the subject of intense research throughout the world, and is of paramount importance for vascular surgeons. This guideline, written by the Brazilian Society of Angiology and Vascular Surgery (SBACV), supersedes the 2015 guideline. Non-atherosclerotic carotid artery diseases were not included in this document. The purpose of this guideline is to bring together the most robust evidence in this area in order to help specialists in the treatment decision-making process. The AGREE II methodology and the European Society of Cardiology system were used for recommendations and levels of evidence. The recommendations were graded from I to III, and levels of evidence were classified as A, B, or C. This guideline is divided into 11 chapters dealing with the various aspects of extracranial cerebrovascular disease: diagnosis, treatments and complications, based on up-to-date knowledge and the recommendations proposed by SBACV.

Redefining postoperative hypertension management in carotid surgery: a comprehensive analysis of blood pressure homeostasis and hyperperfusion syndrome in unilateral vs. bilateral carotid surgeries and implications for clinical practice

Background

This study evaluates the implications of blood pressure homeostasis in bilateral vs. unilateral carotid surgeries, focusing on the incidence of postoperative hypertension, hyperperfusion syndrome, and stroke as primary outcomes. It further delves into the secondary outcomes encompassing major adverse cardiovascular events and all-cause mortality.

Methods

Spanning two decades (2002-2023), this comprehensive retrospective research encompasses 15,369 carotid referrals, out of which 1,230 underwent carotid interventions. A subset of 690 patients received open carotid procedures, with a 10-year follow-up, comprising 599 unilateral and 91 bilateral surgeries. The Society for Vascular Surgery Carotid Reporting Standards underpin our methodological approach for data collection. Both univariate and multivariate analyses were utilized to identify factors associated with postoperative hypertension using the Statistical Package for the Social Sciences (SPSS) Version 22 (SPSS®, IBM® Corp., Armonk, N.Y., USA).

Results

A marked acute elevation in blood pressure was observed in patients undergoing both unilateral and bilateral carotid surgeries (p < 0.001). Smoking (OR: 1.183, p = 0.007), hyperfibrinogenemia (OR: 0.834, p = 0.004), emergency admission (OR: 1.192, p = 0.005), severe ipsilateral carotid stenosis (OR: 1.501, p = 0.022), and prior ipsilateral interventions (OR: 1.722, p = 0.003) emerged as significant factors that correlates with postoperative hypertension in unilateral surgeries. Conversely, in bilateral procedures, gender, emergency admissions (p = 0.012), and plaque morphology (p = 0.035) significantly influenced postoperative hypertension. Notably, 2.2% of bilateral surgery patients developed hyperperfusion syndrome, culminating in hemorrhagic stroke within 30 days. Intriguingly, postoperative stage II hypertension was identified as an independent predictor of neurological deficits post-secondary procedure in bilateral CEA cases (p = 0.004), attributable to hyperperfusion syndrome. However, it did not independently predict myocardial infarction or mortality outcomes. The overall 30-day stroke rate stood at 0.90%. Lowest incidence of post operative hypertension or any complications were observed in eversion carotid endartrertomy.

Conclusion

The study identifies postoperative hypertension as a crucial independent predictor of perioperative stroke following bilateral carotid surgery. Moreover, the study elucidates the significant impact of bilateral CEA on the development of post-operative hyperperfusion syndrome or stroke, as compared to unilateral CEA. Currently almost 90% of our carotid practice is eversion carotid endartrerectomy.

Association of Impedance Aggregometry-Measured Platelet Aggregation With Thromboembolic Events in Patients Who Undergo Carotid Endarterectomy: A Pilot Study

OBJECTIVES

The aim of the current study was to assess the relationship among thrombin receptor activator peptide 6 (TRAP test), adenosine-5'-diphosphate (ADP test), arachidonic acid (ASPI test), and stroke/transient ischemic attack (TIA), using the multiple electrode aggregometry (Multiplate) in patients undergoing carotid thromboendarterectomy (CEA).

DESIGN

A retrospective study.

SETTING

Vascular surgery operating rooms of a university hospital.

PARTICIPANTS

One hundred thirty-one out of 474 patients undergoing CEA between November 2020 and October 2022.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A preoperative blood sample of all enrolled patients was analyzed using the Multiplate analyzer. Receiver operating characteristics curves, were generated to test the ability of TRAP, ADP, and ASPI in discriminating perioperative thromboembolic stroke/TIA. A logistic LASSO regression model was used to identify factors independently associated with stroke/TIA. Eight patients experienced a perioperative stroke/TIA. Although all the platelet functional assays showed excellent predictive performance, an ADP value exceeding 72 U showed the highest specificity (87%) and sensitivity (68%) in discriminating patients who had a perioperative thromboembolic stroke/TIA, with a negative predictive value of 99% and a positive predictive value of 15%. After LASSO regression, an ADP >72 U and the need for a shunt during CEA were the only 2 variables independently associated with perioperative stroke/TIA.

CONCLUSION

Because the ADP test was independently associated with perioperative stroke/TIA, the assessment of platelet reactivity using Multiplate may offer potential utility in monitoring patients undergoing CEA.

Frequency of inter-specialty consensus decisions and adherence to advice following discussion at a weekly neurovascular multidisciplinary meeting

BACKGROUND/AIMS

Data are limited on the frequency of 'consensus decisions' between sub-specialists attending a neurovascular multidisciplinary meeting (MDM) regarding management of patients with extracranial carotid/vertebral stenoses and post-MDM 'adherence' to such advice.

METHODS

This prospective audit/quality improvement project collated prospectively-recorded data from a weekly Neurovascular/Stroke Centre MDM documenting the proportion of extracranial carotid/vertebral stenosis patients in whom 'consensus management decisions' were reached by neurologists, vascular surgeons, stroke physicians-geriatricians and neuroradiologists. Adherence to MDM advice was analysed in asymptomatic carotid stenosis (ACS), symptomatic carotid stenosis (SCS), 'indeterminate symptomatic status stenosis' (ISS) and vertebral artery stenosis (VAS) patients, including intervals between index event to MDM + / - intervention.

RESULTS

One hundred fifteen patients were discussed: 108 with carotid stenosis and 7 with VAS. Consensus regarding management was noted in 96.5% (111/115): 100% with ACS and VAS, 96.2% with SCS and 92.9% with ISS. Adherence to MDM management advice was 96.4% (107/111): 100% in ACS, ISS and VAS patients; 92% (46/50) in SCS patients. The median interval from index symptoms to revascularisation in 50-99% SCS patients was 12.5 days (IQR: 9-18.3 days; N = 26), with a median interval from MDM to revascularisation of 5.5 days (IQR: 1-7 days). Thirty patients underwent revascularisation. Two out of twenty-nine patients (6.9%) with either SCS or ISS had a peri-procedural ipsilateral ischaemic stroke, with no further strokes/deaths during 3-months follow-up.

CONCLUSIONS

The high frequency of inter-specialty consensus regarding management and adherence to proposed treatment supports a collaborative/multidisciplinary model of care in patients with extracranial arterial stenoses. Service development should aim to shorten times between MDM discussion-intervention and optimise prevention of stroke/death.

Diagnosis and management of acute conditions of the extracranial carotid artery

Symptomatic carotid stenosis and carotid dissection are acute conditions of extracranial cerebrovascular vessels determining transient ischemic attack or stroke. Medical, surgical, or endovascular management are different options to treat these pathologies. This narrative review focused on the management, from symptoms to treatment, of the acute conditions of extracranial cerebrovascular vessels, including post-carotid revascularization stroke. Symptomatic carotid stenosis (> 50% according to North American Symptomatic Carotid Endarterectomy Trial criteria) with transient ischemic attack or stroke benefits from carotid revascularization-primarily with carotid endarterectomy associated with medical therapy-within 2 weeks from symptom onset to reduce the risk of stroke recurrence. Different from acute extracranial carotid dissection, medical management with antiplatelet or anticoagulant therapy can prevent new neurologic ischemic events, considering stenting only in case of symptom recurrence. Stroke after carotid revascularization can be associated with the following etiologies: carotid manipulation, plaque fragmentation, or clamping ischemia. Medical or surgical management is therefore influenced by the cause and timing of the neurologic events after carotid revascularization. Acute conditions of the extracranial cerebrovascular vessels include a heterogeneous group of pathologies and correct management can reduce symptom recurrence substantially.

Anesthetic management of carotid endarterectomy: an update from Italian guidelines

BACKGROUND AND AIMS

In order to systematically review the latest evidence on anesthesia, intraoperative neurologic monitoring, postoperative heparin reversal, and postoperative blood pressure management for carotid endarterectomy. The present review is based on a single chapter of the Italian Health Institute Guidelines for diagnosis and treatment of extracranial carotid stenosis and stroke prevention.

METHODS AND RESULTS

A systematic article review focused on the previously cited topics published between January 2016 and October 2020 has been performed; we looked for both primary and secondary studies in the extensive archive of Medline/PubMed and Cochrane library databases. We selected 14 systematic reviews and meta-analyses, 13 randomized controlled trials, 8 observational studies, and 1 narrative review. Based on this analysis, syntheses of the available evidence were shared and recommendations were indicated complying with the GRADE-SIGN version methodology.

CONCLUSIONS

From this up-to-date analysis, it has emerged that any type of anesthesia and neurological monitoring method is related to a better outcome after carotid endarterectomy. In addition, insufficient evidence was found to justify reversal or no-reversal of heparin at the end of surgery. Furthermore, despite a low evidence level, a suggestion for blood pressure monitoring in the postoperative period was formulated.

ASNM and ASN joint guidelines for transcranial Doppler ultrasonic monitoring: An update

Today, it seems prudent to reconsider how ultrasound technology can be used for providing intraoperative neurophysiologic monitoring that will result in better patient outcomes and decreased length and cost of hospitalization. An extensive and rapidly growing literature suggests that the essential hemodynamic information provided by transcranial Doppler (TCD) ultrasonography neuromonitoring (TCDNM) would provide effective monitoring modality for improving outcomes after different types of vascular, neurosurgical, orthopedic, cardiovascular, and cardiothoracic surgeries and some endovascular interventional or diagnostic procedures, like cardiac catheterization or cerebral angiography. Understanding, avoiding, and preventing peri- or postoperative complications, including neurological deficits following abovementioned surgeries, endovascular intervention, or diagnostic procedures, represents an area of great public and economic benefit for society, especially considering the aging population. The American Society of Neurophysiologic Monitoring and American Society of Neuroimaging Guidelines Committees formed a joint task force and developed updated guidelines to assist in the use of TCDNM in the surgical and intensive care settings. Specifically, these guidelines define (1) the objectives of TCD monitoring; (2) the responsibilities and behaviors of the neurosonographer during monitoring; (3) instrumentation and acquisition parameters; (4) safety considerations; (5) contemporary rationale for TCDNM; (6) TCDNM perspectives; and (7) major recommendations.

Independent role of circle of Willis for peri-procedural evaluation of carotid endarterectomy in patients with severe carotid stenosis

OBJECTIVES

In patients with severe carotid stenosis (CS), collateral circulation via circle of Willis (CoW) is considered a compensatory response to maintain blood flow. The aim of this study was to evaluate the impact of CoW in patients with severe CS throughout carotid endarterectomy (CEA).

METHODS

A database of patients (n = 124) undergoing CEA was sampled from 2013 to 2020. Severe CS was defined as 90-99% caliber stenosis and collateral circulation was identified by CoW opening. Baseline characteristics, Age-related white matter change (ARWMC) score, immediate neurologic events (INEs) and manifestations were recorded and compared. Correlation and regression analysis for CoW were further investigated.

RESULTS

All patients enrolled were divided into two groups regarding to the visualized CoW opening and complete CoW was noticed in 57 patients. The prevalence of complete CoW was higher among asymptomatic patients (n = 39, 68.4%), while higher percentage of TIA or previous stroke were noticed in incomplete CoW (n = 45, 67.2%). Patients with incomplete CoW had a significantly higher median ARWMC score and remarkable cerebral perfusion deficit (P < 0.05*). Totally, 4 INEs (6.0%) were noted in patients with incomplete CoW after CEA. Cerebral hyperperfusion syndrome (CHS) was noticed in 10 patients and early-phase of postoperative hypertension (EPOH) in 15 ones with incomplete CoW versus patients with complete CoW (14.9% and 22.4% vs 3.5% and 7.0%, P < 0.05). Correlation analysis showed strong relationship between CoW opening and peri-operative factors like pre-operative symptoms, ARWMC, CHS and EPOH (P < 0.05*). Overall, CoW opening was an independent predictor of both CHS and EPOH (95% CI, 0.021-0.715 and 0.060-0.949, P < 0.05*) with logistic regression.

CONCLUSIONS

Sufficient collateral circulation via CoW may promote ipsilateral cerebral perfusion and mitigate WMC in patients with severe CS. In addition, collaterals may improve the predictive power of the risk scale for post-procedural complications after CEA.

Postoperative blood pressure management in patients treated in the ICU after noncardiac surgery

PURPOSE OF REVIEW

Blood pressure management is a cornerstone of hemodynamic management in patients treated in the ICU after noncardiac surgery. Postoperative blood pressure management is challenging, because blood pressure alterations after surgery can be profound and have numerous causes.

RECENT FINDINGS

Postoperative blood pressure alterations are common in patients treated in ICUs after noncardiac surgery. There is increasing evidence that hypotension during the initial days after noncardiac surgery is associated with postoperative adverse outcomes including myocardial infarction and death, acute myocardial injury, acute kidney injury, major adverse cardiac or cerebrovascular events, and delirium. Thus, postoperative hypotension could be a modifiable risk factor for postoperative adverse outcomes. However, robust evidence for a causal relationship between postoperative blood pressure and postoperative adverse outcomes is still lacking.

SUMMARY

Future research on postoperative blood pressure management in patients treated in the ICU after noncardiac surgery needs to assess whether the prevention or treatment of postoperative blood pressure alterations - especially postoperative hypotension - reduces the incidence of postoperative adverse outcomes.

Overview and Diagnostic Accuracy of Near Infrared Spectroscopy in Carotid Endarterectomy: A Systematic Review and Meta-analysis

OBJECTIVE

Carotid endarterectomy is recommended for the prevention of ischaemic stroke due to carotid stenosis. However, the risk of stroke after carotid endarterectomy has been estimated at 2% - 5%. Monitoring intra-operative cerebral oxygenation with near infrared spectroscopy (NIRS) has been assessed as a strategy to reduce intra- and post-operative complications. The aim was to summarise the diagnostic accuracy of NIRS to detect intra-operative ischaemic events, the values associated with ischaemic events, and the relative contribution of external carotid contamination to the NIRS signal in adults undergoing carotid endarterectomy.

DATA SOURCES

EMBASE, MEDLINE, Cochrane Centre Register of Controlled Trials, and reference lists through May 2019 were searched.

REVIEW METHODS

Non-randomised and randomised studies assessing NIRS as an intra-operative monitoring tool in carotid endarterectomy were included. Studies using NIRS as the reference were excluded. Risk of bias was assessed using the Newcastle Ottawa Scale, RoB-2, and QUADAS-2.

RESULTS

Seventy-six studies were included (n = 8 480), under local (n = 1 864) or general (n = 6 582) anaesthesia. Seven studies were eligible for meta-analysis (n = 524). As a tool for identifying intra-operative ischaemia, specificity increased with more stringent NIRS thresholds, while there was unpredictable variation in sensitivity across studies. A Δ20% threshold under local anaesthesia resulted in pooled estimates for sensitivity and specificity of 70.5% (95% confidence interval, CI, 54.1 - 82.9) and 92.4% (95% CI 85.5 - 96.1) compared with awake neurological monitoring. These studies had low or unclear risk of bias. NIRS signal consistently dropped across clamping and recovered to pre-clamp values upon de-clamp in most studies, and larger decreases were observed in patients with ischaemic events. The contribution of extracranial signal to change in signal across clamp varied from 3% to 50%.

CONCLUSION

NIRS has low sensitivity and high specificity to identify intra-operative ischaemia compared with awake monitoring. Extracranial signal contribution was highly variable. Ultimately, data from high quality studies are desperately needed to determine the utility of NIRS.

Intraoperative completion studies in carotid endarterectomy: systematic review and meta-analysis of techniques and outcomes

BACKGROUND

Declining perioperative stroke and death rates over the past 3 decades have been paralleled by an increasing use of intraoperative completion studies (ICS) following carotid endarterectomy (CEA). Techniques applied include angiography, intraoperative duplex ultrasound (IDUS), flowmetry, and angioscopy. This systematic review and meta-analysis is aiming on providing an overview of techniques and corresponding outcomes.

METHODS

A PubMed based systematic literature review comprising the years 1980 through 2020 was performed using predefined keywords to identify articles on different ICS techniques. Pooled analyses and meta-analyses estimating risk ratios (RR) and 95% confidence intervals (CI) were performed to compare outcomes of different ICS modes to nonapplication of any ICS. I2 values were assessed to quantify study heterogeneities.

RESULTS

Identification of 34 studies including patients undergoing CEA with angiography (n=53,218), IDUS (n=20,030), flowmetry (n=16,812), and angioscopy (n=2,291). Corresponding rates of perioperative stroke were 1.5%, 1.8%, 3.6%, and 1.5%, perioperative stroke or death occurred in 1.7%, 1.9%, 2.2%, and 2.0%. Intraoperative surgical revision rates were 6.2%, 5.9%, and 7.9% after CEA with angiography, IDUS, and angioscopy, respectively. Compared to nonapplication of any ICS, the pooled analysis revealed angiography to be significantly associated with lower rates of stroke (RR 0.47; 95% CI, 0.36-0.62; P<0.0001) and stroke or death (RR 0.76; 95% CI, 0.70-0.83; P<0.0001). IDUS was significantly associated with lower rates of stroke (RR 0.56; 95% CI, 0.43-0.73; P<0.0001) and stroke or death (RR 0.83; 95% CI, 0.74-0.93; P=0.0018), whereas angioscopy showed a significant association with a lower stroke rate (RR 0.48; 95% CI, 0.033-0.68; P=0.0001), but no effect on the combined stroke or death rate. Angioscopy was associated with a higher intraoperative revision rate compared to angiography (RR 1.29; 95% CI, 1.07-1.54; P=0.006). The meta-analyses confirmed lower perioperative stroke or death rates for angiography (RR 0.83; 95% CI, 0.76-0.91) and IDUS (RR 0.86; 95% CI, 0.76-0.98) compared to non-application of any ICS, whereas flowmetry showed no significant association.

CONCLUSIONS

This study represents the first systematic literature review and meta-analysis on usage of ICSs in CEA. Data strongly indicate a significant beneficial effect of angiography, IDUS, and angioscopy on perioperative CEA outcomes. Any carotid surgeon should consider implementation of ICSs in his routine armamentarium.

Procedural Stroke after Carotid Revascularization - Critical Analysis of the Literature and Standards of Reporting

OBJECTIVE

Mechanisms of procedural stroke after carotid endarterectomy (CEA) or stenting (CAS) are surprisingly underresearched. However, understanding the underlying mechanism could: (1) assist in balancing the choice for revascularization versus conservative therapy; (2) assist in choosing either open or endo techniques; and (3) assist in taking appropriate periprocedural measures to further reduce procedural stroke rate. The purpose of this study was to overview mechanisms of procedural stroke after carotid revascularization and establish reporting standards to facilitate more granular investigation and individual patient data meta-analysis in the future.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) statement.

RESULTS

The limited evidence in literature was heterogeneous and of low quality and hence no formal data meta-analysis could be performed. Procedural stroke was classified as haemorrhagic or ischemic; the latter was subclassified as haemodynamic, embolic (carotid- or cardio-embolic) or carotid occlusion-derived, using a combination of clinical inference and imaging data. Most events occurred in the first 24h after the procedure and were related to hypoperfusion (pooled incidence 10.2% (95% c.i. 3.0-17.5) versus 13.9% (95% c.i. 0.0-60.9) post-CEA vs CAS events, respectively) or atheroembolism (28.9% (95% c.i. 10.9-47.0) versus 34.3 (95% c.i. 0.0-91.5)) After the first 24 hours, haemorrhagic stroke (11.6 (95% c.i. 5.7-17.4) versus 9.0 (95% c.i. 1.3-16.7)) or thrombotic occlusion (18.4 (95% c.i. 0.9-35.8) versus 14.8 (95% c.i. 0.0-30.5)) became more likely.

CONCLUSIONS

Although procedural stroke incidence and aetiology may have changed over the last decades due to technical improvements and improvement in perioperative monitoring and quality control, the lack of literature data limits further statements. To simplify and enhance future reporting, procedural stroke analysis and classification should be documented pre-emptively in research settings. We propose a standardized form enclosing reporting standards for procedural stroke with a systematic approach to inference of the most likely aetiology, for prospective use in registries and RCTs on carotid revascularization.

Safe carotid endarterectomy: "one fits all strategy"

INTRODUCTION

Carotid artery stenosis of 50% or more in the extracranial internal carotid artery is responsible for 10-15% of all strokes. Interventional treatment options include carotid endarterectomy and carotid artery stenting, where endarterectomy is proven to be superior.

AIM

In this study, we report the carotid endarterectomy results of patients we operated on using the strategy we termed the "one fits all strategy".

MATERIAL AND METHODS

Seventy-six patients undergoing carotid endarterectomy between July 2016 and April 2020 were retrospectively studied. Conventional endarterectomy under general anesthesia with primary closure of the arteriotomy was performed in all patients. We used a near infrared spectroscopy oximeter to measure regional cerebral oxygenation continuously throughout the surgery.

RESULTS

The mean age of the patients was 70.96 8.15 years. There were 52 male and 24 female patients. The mean follow-up time was 20.6 ±13.6 months. Coronary artery disease was detected in 52 (73.6%) patients. Coronary artery bypass operation was indicated in 19 patients in whom a staged approach was performed in 13 and a reverse staged approach in 1. There were two perioperative strokes one of which recovered fully spontaneously and the other partially with physiotherapy. Eight cases were revised due to hematoma formation.

CONCLUSIONS

Carotid endarterectomy continues to prove its safety in carotid artery stenosis patients. Continuous cerebral oxygenation monitoring is indispensable for carotid surgery. Despite discrepancies in surgical techniques, we believe that "one fits all strategy: general anesthesia, conventional endarterectomy without patch plasty, never shunter and always NIRS monitorization" may be used safely in patients undergoing carotid endarterectomy.

A Machine Learning Approach for Predicting Early Phase Postoperative Hypertension in Patients Undergoing Carotid Endarterectomy

BACKGROUND

This study aimed to establish and validate a machine learning-based model for the prediction of early phase postoperative hypertension (EPOH) requiring the administration of intravenous vasodilators after carotid endarterectomy (CEA).

METHODS

Perioperative data from consecutive CEA procedures performed from January 2013 to August 2019 were retrospectively collected. EPOH was defined in post-CEA patients as hypertension involving a systolic blood pressure above 160 mm Hg and requiring the administration of any intravenous vasodilator medications in the first 24 hr after a return to the vascular ward. Gradient boosted regression trees were used to construct the predictive model, and the featured importance scores were generated by using each feature's contribution to each tree in the model. To evaluate the model performance, the area under the receiver operating characteristic curve was used as the main metric. Four-fold stratified cross-validation was performed on the data set, and the average performance of the 4 folds was reported as the final model performance.

RESULTS

A total of 406 CEA operations were performed under general anesthesia. Fifty-three patients (13.1%) met the definition of EPOH. There was no significant difference in the percentage of postoperative stroke/death between patients with and without EPOH during the hospital stay. Patients with EPOH exhibited a higher incidence of postoperative cerebral hyperperfusion syndrome (7.5% vs. 0, P < 0.001), as well as a higher incidence of cerebral hemorrhage (3.8% vs. 0, P < 0.001). The gradient boosted regression trees prediction model achieved an average AUC of 0.77 (95% CI 0.62 to 0.92). When the sensitivity was fixed near 0.90, the model achieved an average specificity of 0.52 (95% CI 0.28 to 0.75).

CONCLUSIONS

We have built the first-ever machine learning-based prediction model for EPOH after CEA. The validation result from our single-center database was very promising. This novel prediction model has the potential to help vascular surgeons identify high-risk patients and reduce related complications more efficiently.

[Diagnostic and Therapeutic Management of Carotid Artery Disease]

Diagnostic and Therapeutic Management of Carotid Artery Disease Abstract. A quarter of all ischemic strokes is caused by atherosclerotic obliterations of the extra- and intracranial brain-supplying vessels. The prevalence of atherosclerotic extracranial carotid stenosis rises up to 6-15 % from the age of 65. The risk of stroke in symptomatic carotid stenosis, i.e. after stroke or transient ischemic attack (TIA), is very high at 25 % within 14 days. Conservative therapy is the cornerstone of treatment by controlling the risk factors, treatment with platelet aggregation inhibitors and antihypertensive and lipid-lowering medication. Carotid endarterectomy (CEA) is the first line treatment for symptomatic patients with a >50 % and asymptomatic patients with a >60 % carotid stenosis. In order to ensure the best possible treatment of patients with asymptomatic and symptomatic carotid stenosis, interdisciplinary cooperation in diagnostics, therapy and aftercare in a neuromedical centre of maximum care is necessary.

[Intraoperative completion diagnostics in open vascular surgery]

Intraoperative imaging diagnostics during open vascular surgical procedures aim to enhance diagnostic certainty during the operation, ensure quality control documentation and reduce avoidable complications; however, the evidence for the various diagnostic imaging procedures with respect to improvement of perioperative outcome is not confirmed for carotid endarterectomy or for infrainguinal bypass surgery. Nevertheless, an intraoperative diagnostic control is principally recommended. The advantage of intraoperative imaging is confirmed and essential for the surgical reconstruction of bypass occlusions and acute thromboembolic occlusions.

Near-infrared spectroscopy as a predictor of cerebral ischaemia during carotid endarterectomy in awake patients

Objectives

The aim of our study was to evaluate the near-infrared spectroscopy monitoring system to detect cerebral ischaemia, find indications for selective shunting during carotid endarterectomy and compare it with an internal carotid artery stump pressure monitoring technique in patients operated under local anaesthesia.

Methods

During January 2015 and November 2018, 131 patients undergoing carotid endarterectomy under local anaesthesia were prospectively included in the study. Near-infrared spectroscopy as intraoperative monitoring was applied and compared with stump pressure.

Results

Carotid endarterectomy was performed successfully in 106 patients operated under local anaesthesia. Meanwhile, 25 patients developed neurological changes (motor or consciousness impairment, weakness of extremities, cognitive decline) during clamping, and all of them received a shunt. ΔrSO2, stump pressure and rSO2 (–11 ± 8%, 31 ± 6mmHg, 58 ± 11) values were smaller in the group of shunted subjects versus non-shunted group subjects (–2 ± 5%, 61 ± 17 mmHg, 64 ± 8) after 1 min of internal carotid artery clamping ( p < 0.05). Statistical analysis showed a sensitivity of 90% (95% CI: 0.85–0.95) and a specificity of 70% (95% CI: 0.62–0.78) for a ≥10% drop in ΔrSO2 to predict ischaemia symptoms during carotid clamping. Using stump pressure with a cut-off value of ≤40 mmHg for predicting symptoms, the sensitivity was 82% and specificity 54%.

Conclusions

Near-infrared spectroscopy is a suitable non-invasive cerebral oxygenation monitoring method during carotid endarterectomy. A 10% decrease of ΔrSO2 had a good correlation with clinical cerebral ischaemia signs and matched well with the stump pressure cut-off value of ≤40 mmHg. There is a possibility of near-infrared spectroscopy to replace stump pressure in cerebral oxygenation monitoring during carotid endarterectomy. However, we need larger prospective multicentre studies to identify the optimal threshold for shunt requirement.

Clinical outcomes of postcarotid endarterectomy hypertension

OBJECTIVE

The objective of this study was to determine the clinical relevance of postcarotid endarterectomy hypertension (PEH) by investigating the effect of PEH on hospital length of stay (LOS) and by investigating short-term and long-term complications of PEH. In addition, risk factors for PEH were determined.

METHODS

A single-center retrospective cohort study was performed. Demographic, preoperative, intraoperative, and postoperative outcomes of 192 patients undergoing carotid endarterectomy were evaluated. Outcomes were compared between patients with PEH and patients without PEH. PEH was defined as an acute systolic blood pressure (SBP) rise >170 mm Hg or persistent SBP >150 mm Hg on the ward and leading to the consultation of an internist. The overall survival and event-free survival were compared using a Kaplan-Meier analysis and a Cox regression analysis. A multivariate logistic regression analysis was performed to determine risk factors for PEH.

RESULTS

PEH developed in 44 of 192 patients (25%). Preoperative hypertension (SBP >150 mm Hg) was determined to be a risk factor for PEH (odds ratio, 3.3; 95% confidence interval [CI], 1.6-6.9). Hospital LOS was prolonged in patients with PEH compared with patients without PEH (median LOS of 5 days vs 3 days, respectively; P < .001). No difference in the occurrence of ischemic neurologic events or rebleeding during hospitalization was observed (P = .58 and P = .72, respectively). Cardiovascular and ischemic neurologic events during follow-up did not occur more often in patients with PEH than in patients without PEH (P = .46). There was no difference in mortality between the PEH and non-PEH groups (hazard ratio, 1.6; 95% CI, 0.6-4.3). The same applies to the event-free survival (hazard ratio, 0.77; 95% CI, 0.4-1.7). Combined event-free survival for stroke and myocardial infarction was 92% (95% CI, 87%-97%) at 2 years for patients without PEH and 86% (95% CI, 74%-98%) at 2 years for patients with PEH (P = .25). Event-free survival for mortality was 90% (95% CI, 85%-96%) at 2 years for patients without PEH and 94% (95% CI, 86%-100%) at 2 years for patients with PEH (P = .36).

CONCLUSIONS

Patients with PEH had a significant increase in hospital LOS. However, adverse short-term and long-term events did not occur more often in patients with PEH. High preoperative SBP was identified as a risk factor for PEH; no other demographic and clinical variables were associated with PEH.

Technical improvements in carotid revascularization based on the mechanism of procedural stroke

The benefit of carotid revascularization in patients with severe carotid artery stenosis is hampered by the risk of stroke due to the intervention itself. The risk of periprocedural strokes is higher for carotid artery stenting (CAS) as compared to carotid endarterectomy (CEA). Over the past years, the pathophysiological mechanism responsible for periprocedural stroke seems to unfold step by step. Initially, all procedural strokes were thought to be the result of technical errors during surgical repair: cerebral ischemia due to clamping time of the carotid artery, cerebral embolization of atherosclerotic debris due to manipulation of the atheroma or thrombosis of the artery. Following improvements in surgical techniques, technical skills, new intraoperative monitoring technologies such as angioscopy, and the results of the first large clinical randomized controlled trials (RCT) it was believed that most periprocedural strokes were of thromboembolic nature, while a large part of these caused by technical error. Nowadays, analyses of underlying pathophysiological mechanisms of procedural stroke make a clinically relevant distinction between intra-procedural and postprocedural strokes. Intra-procedural stroke is defined as hypoperfusion due to clamping (CEA) or dilatation (CAS) and embolization from the carotid plaque (both CEA and CAS). Postprocedural stroke can be caused by thrombo-embolisation but seems to have a primarily hemodynamic origin. Besides thrombotic occlusion of the carotid artery, cerebral hyperperfusion syndrome (CHS) due to extensively increased cerebral revascularization is the most reported pathophysiological mechanism of postprocedural stroke. Multiple technical improvements have attempted to lower the risk of periprocedural stroke. The introduction of antiplatelet therapy (APT) has significantly reduced the risk of thromboembolic events in patients with carotid stenosis. Over the years, recommendations regarding APT changed. While for a long time APT was discontinued prior to surgery because of a fear of increased bleeding risk, nowadays continuation of APT during carotid intervention (aspirin monotherapy or even dual APT including clopidogrel) is found to be safe and effective. In CAS patients, dual APT up to three months' postprocedural is considered best. Stent design and cerebral protection devices (CPD) for CAS procedure are continuously under development. Trials have suggested a benefit of closed-cell stent design over open-cell stent design in order to reduce procedural stroke, while the benefit of CPD during stenting is still a matter of debate. Although CPD reduce the risk of procedural stroke, a higher number of new ischemic brain lesions detected on diffusion weighted imaging was found in patients treated with CPD. In patients undergoing CEA under general anesthesia, adequate use of cerebral monitoring (EEG and transcranial Doppler [TCD]) has reduced the number of intraoperative stroke by detecting embolization and thereby guiding the surgeon to adjust his technique or to selectively shunt the carotid artery. In addition, TCD is able to adequately identify and exclude patients at risk for CHS. For CAS, the additional value of periprocedural cerebral monitoring to prevent strokes needs urgent attention. In conclusion, this review provides an overview of the pathophysiological mechanism of stroke following carotid revascularization (both CAS and CEA) and of the technical improvements that have contributed to reducing this stroke risk.

A systematic review of patch angioplasty versus primary closure for carotid endarterectomy

BACKGROUND

Guidelines recommend routine patching after carotid endarterectomy (CEA) on the basis of a lower restenosis rate and presumed lower procedural stroke rate than with primary repair. Underlying evidence is based on studies performed decades ago with perioperative care that significantly differed from current standards. Recent studies raise doubt about routine patching and have suggested that a more selective approach to patch closure (PAC) might be noninferior for procedural safety and long-term stroke prevention. The objective was to review the literature on the procedural safety and perioperative stroke prevention of PAC compared with primary closure (PRC) after CEA.

METHODS

MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases were searched from January 1966 to September 2017. Two authors independently performed the search, study selection, assessment of methodologic quality, and data extraction. Articles were eligible if they compared PAC and PRC after CEA, were published in English, included human studies, and had a full text available. Methodologic quality for nonrandomized studies was assessed using the Methodological Index for Non-Randomized Studies score; randomized controlled trials were assessed using Grading of Recommendations Assessment, Development, and Evaluation. Nonrandomized studies with a score ≤15 were excluded. The primary outcome measure was 30-day stroke risk. Secondary outcome measures were long-term restenosis (>50%) and postoperative bleeding.

RESULTS

Twenty-nine articles met the inclusion criteria, 9 randomized studies and 20 nonrandomized studies, for a total of 12,696 patients and 13,219 CEAs. Overall 30-day stroke risk was higher in the PRC group (odds ratio [OR], 1.9; 95% confidence interval [CI], 1.2-2.9). After exclusion of nonrandomized studies, this difference was not statistically significant anymore (OR, 1.8; 95% CI, 0.8-3.9). The restenosis rate was higher after PRC (OR, 2.2; 95% CI, 1.4-3.4). There were no differences in bleeding complications. Methodologic quality of the nonrandomized studies was moderate, and seven were excluded. Quality of the evidence according to Grading of Recommendations Assessment, Development, and Evaluation was moderate for restenosis, 30-day stroke, and bleeding.

CONCLUSIONS

In this systematic review, on the basis of moderate-quality evidence, perioperative stroke rate was lower after PAC compared with PRC. The rate of restenosis was higher after PRC, although the clinical significance of this finding in terms of long-term stroke prevention remained unclear.

Registry report on prediction by Pocock cardiovascular score of cerebral microemboli acutely following carotid endarterectomy

Background

Cerebral microemboli may lead to ischaemic neurological complications after carotid endarterectomy (CEA). The association between classical cardiovascular risk factors and acute cerebral microemboli following carotid surgery has not been studied. The aim of this study was to explore whether an established cardiovascular risk score (Pocock score) predicts the presence of cerebral microemboli acutely after CEA.

Subjects and methods

Pocock scores were assessed for the 670 patients from the Carotid Surgery Registry (age 71±1 (SEM) years, 474 (71%) male, 652 (97%) Caucasian) managed from January 2002 to December 2012 in the Regional Vascular Centre at University Hospitals Coventry and Warwickshire NHS Trust, which serves a population of 950 000. CEA was undertaken in 474 (71%) patients for symptomatic carotid stenosis and in 196 (25%) asymptomatic patients during the same period. 74% of patients were hypertensive, 71% were smokers and 49% had hypercholesterolaemia.

Results

A high Pocock score (≥2.3%) was significantly associated with evidence of cerebral microemboli acutely following CEA (P=0.039, Mann-Whitney (MW) test). A Pocock score (≥2.3%) did not predict patients who required additional antiplatelet therapy (microemboli signal (MES) rate >50 hour^-1: P=0.164, MW test). Receiver operating characteristic analysis also showed that the Pocock score predicts acute postoperative microemboli (area under the curve (AUC) 0.546, 95% CI 0.502 to 0.590, P=0.039) but not a high rate of postoperative microemboli (MES >50 hour⁻¹: AUC 0.546, 95% CI 0.482 to 0.610, P=0.164). A Pocock score ≥2.3% showed a sensitivity of 74% for the presence of acute postoperative cerebral microemboli. A Pocock score ≥2.3% also showed a sensitivity of 77% and a negative predictive value of 90% for patients who developed a high microembolic rate >50 hour⁻¹ after carotid surgery.

Conclusion

These findings demonstrate that the Pocock score could be used as a clinical tool to identify patients at high risk of developing acute postoperative microemboli.

Patch Angioplasty or Primary Closure Following Carotid Endarterectomy for Symptomatic Carotid Artery Stenosis

Objectives  Guidelines recommend routine patching to prevent restenosis following carotid endarterectomy, mainly based on studies performed many years ago with different perioperative care and medical treatment compared with current standards. Aim of the present study was to compare primary closure (PRC) versus patch closure (PAC) in a contemporary cohort of patients. Methods  Consecutive patients treated by carotid endarterectomy for symptomatic stenosis between January 2006 and April 2016 were retrospectively analyzed. Primary outcome was restenosis at 6 weeks and 1 year and occurrence of ipsilateral stroke. Secondary outcomes were mortality, complications, and reintervention rates. Results  Five hundred carotid artery endarterectomies were performed. Fifty-nine patients were excluded because eversion endarterectomy was performed or because they were asymptomatic. PRC was performed in 349 and PAC in 92 patients. Restenosis at 6 weeks was 6.0% in the PAC group versus 3.0% in the PRC group ( p  = 0.200). Restenosis at 1 year was 31.6 versus 14.1%, respectively ( p  = 0.104). No difference was found for stroke (3.4 vs 1.1%, p  = 0.319), death (1.1 vs 0.0%, p  = 0.584), or other complications (1.1 vs 0.0%, p  = 0.584), respectively. Conclusions  It remains unclear whether routine patching should be recommended for all patients. A strategy of selective patching compared with routine patching, based on internal carotid artery diameter and other patient characteristics, deserves further investigation.

Post-carotid Endarterectomy Hypertension. Part 2: Association with Peri-operative Clinical, Anaesthetic, and Transcranial Doppler Derived Parameters

OBJECTIVE/BACKGROUND

The first paper in this series observed that pre-operative baroreceptor dysfunction and poorly controlled hypertension were independently predictive for identifying patients who went on to require treatment for post-endarterectomy hypertension (PEH). The second paper examines the influence of intra-operative patient, transcranial Doppler (TCD) ultrasound, and anaesthetic variables on the incidence of PEH.

METHODS

In total, 106 patients underwent carotid endarterectomy (CEA) under general anaesthesia. Systolic blood pressure (SBP) changes, anaesthetic and vasoactive agents, analgesia, and post-operative pain scores, as well as TCD derived changes in middle cerebral artery (MCA) velocity during surgery were recorded. Patients who met pre-existing unit criteria for treating PEH after CEA (SBP > 170 mmHg without symptoms or SBP > 160 mmHg with headache/seizure/neurological deficit) were treated according to an established and validated protocol.

RESULTS

In total, 40/106 patients (38%) required treatment for PEH following CEA (26 in theatre recovery [25%], 27 back on the vascular surgery ward [25%]), whereas seven (7%) had SBP surges > 200 mmHg on the ward. Patients requiring treatment for PEH had significantly higher pre-induction SBP (174 ± 21 mmHg vs. 153 ± 21 mmHg; p < .001), the greatest decreases in SBP after induction of anaesthesia (median decrease 100 ± 32 mmHg vs. 83 ± 24 mmHg; p = .01) and were significantly more likely to experience moderate/severe pain scores post-operatively (p = .003). Logistic regression analysis of the pre- and intra-operative data revealed that higher pre-induction mean SBP and lower pre-operative (impaired) BRS were the only independent predictors of PEH.

CONCLUSION

This analysis of intra-operative variables has demonstrated that patients with poorly controlled and/or labile hypertension at induction of general anaesthesia were those at greatest risk of requiring treatment for PEH in the post-operative period after CEA. No other variables, including use of vasopressors, treatment of hypotension, anaesthetic agents, or changes in MCA velocity after clamp release and restoration of flow were able to predict who might go on to require treatment for PEH. Identification of at-risk individuals and aggressive blood pressure control in the post-operative period remains the mainstay of treatment.

Cost-Effectiveness of Two Decision Strategies for Shunt Use During Carotid Endarterectomy

Background

Arterial shunting during carotid endarterectomy (CEA) is essential in some patients because of insufficient cerebral perfusion during cross-clamping. However, the optimal diagnostic modality identifying these patients is still debated. None of the currently used modalities has been proved superior to another. The aim of this study was to assess the cost-effectiveness of two modalities, stump pressure measurement (SPM) versus electroencephalography (EEG) combined with transcranial Doppler (TCD) during CEA.

Methods

Two retrospective cohorts of consecutive patients undergoing CEA with different intraoperative neuromonitoring strategies (SPM vs. EEG/TCD) were analyzed. Clinical data were collected from patient hospital records. Primary clinical outcome was in-hospital stroke or death. Total admission costs were calculated based on volumes of healthcare resources. Analyses of effects and costs were adjusted for clinical differences between patients by means of a propensity score, and cost-effectiveness was estimated.

Results

A total of 503 (239 SPM; 264 EEG/TCD) patients were included, of whom 19 sustained a stroke or died during admission (3.3 vs. 4.2%, respectively, adjusted risk difference 1.3% (95% CI −2.3–4.8%)). Median total costs were €4946 (IQR 4424–6173) in the SPM group versus €7447 (IQR 6890–8675) in the EEG/TCD group. Costs for neurophysiologic assessments were the main determinant for the difference.

Conclusions

Given the evidence provided by this small retrospective study, SPM would be the favored strategy for intraoperative neuromonitoring if cost-effectiveness was taken into account when deciding which strategy to adopt.

Post-Carotid Endarterectomy Hypertension. Part 1: Association with Pre-operative Clinical, Imaging, and Physiological Parameters

OBJECTIVE/BACKGROUND

Post-endarterectomy hypertension (PEH) is a well recognised, but poorly understood, phenomenon after carotid endarterectomy (CEA) that is associated with post-operative intracranial haemorrhage, hyperperfusion syndrome, and cardiac complications. The aim of the current study was to identify pre-operative clinical, imaging, and physiological parameters associated with PEH.

METHODS

In total, 106 CEA patients undergoing CEA under general anaesthesia underwent pre-operative evaluation of 24 hour ambulatory arterial blood pressure (BP), baroreceptor sensitivity, cerebral autoregulation, and transcranial Doppler measurement of cerebral blood flow velocity (CBFv) and pulsatility index. Patients who met pre-existing criteria for treating PEH after CEA (systolic BP [SBP] > 170 mmHg without symptoms or SBP > 160 mmHg with headache/seizure/neurological deficit) were treated according to a previously established protocol.

RESULTS

In total, 40/106 patients (38%) required treatment for PEH at some stage following CEA (26 in theatre recovery [25%], 27 while on the vascular surgical ward [25%]), while seven (7%) had SBP surges > 200 mmHg back on the ward. Patients requiring treatment for PEH had a significantly higher pre-operative SBP (144 ± 11 mmHg vs. 135 ± 13 mmHg; p < .001) and evidence of pre-existing impairment of baroreceptor sensitivity (3.4 ± 1.7 ms/mmHg vs. 5.3 ± 2.8 ms/mmHg; p = .02). However, PEH was not associated with any other pre-operative clinical features, CBFv, or impaired cerebral haemodynamics. Paradoxically, autoregulation was better preserved in patients with PEH. All four cases of hyperperfusion associated symptoms were preceded by PEH. Length of hospital stay was significantly increased in patients with PEH (p < .001).

CONCLUSION

In this study, where all patients underwent CEA under general anaesthesia, PEH was associated with poorly controlled pre-operative BP and impaired baroreceptor sensitivity, but not with other peripheral or central haemodynamic parameters, including impaired cerebral autoregulation.

Diagnostic and Interventional Optical Angioscopy in Ex Vivo Carotid Arteries

BACKGROUND: Angioscopy – or endovascular endoscopy – is a catheter-based technique employing a flexible fiberoptic angioscope to directly visualize arterial lumen. Poor resolution and excessive stiffness of pre-existent angioscopes limited their use clinically. Recent advances resulted in novel fused optical fiber bundle angioscopes with improved flexibility and imaging resolution. Use of these devices in endovascular neurosurgery is still largely unexplored.

OBJECTIVE: To evaluate image quality and feasibility of optical angioscopes for diagnostic and interventional neuro-angioscopy in carotid arteries of human cadavers.

METHODS: A 5-F optical angioscope was used in human cadaveric carotid arteries to inspect integrity of arterial walls, identify atherosclerotic plaques and associated lesions prone to thrombogenicity, place intravascular occlusion coils, and deploy endovascular stents with real-time visualization.

RESULTS: Angioscopy provided key information about endoluminal anatomy such as presence and characteristics of atherosclerotic plaques and thrombogenic lesions not detected by conventional diagnostic methods. Direct real-time visualization of vascular lumen during endovascular interventions provided information on spatial distribution of coils, coil loop herniation, and apposition of stent cells against carotid artery wall complementary to angiography.

CONCLUSIONS: Fused optical fiber bundle angioscopes provide good-quality endoluminal images in human carotid arteries. Their use can feasibly assist in navigation of extracranial carotid arteries to inspect integrity of the arterial wall and identify atherosclerotic plaques and associated lesions vulnerable to thrombogenicity, allow placement of intravascular occlusion coils, and assess apposition of stents to vessel wall. Further in Vivo validation needs to be conducted along with additional research to improve image quality, flexibility, and size of angioscopes.

Time is brain: an update

The '6-month' threshold for treating symptomatic patients is obsolete. There is compelling evidence that the highest-risk period for stroke (after suffering a transient ischemic attack) is the first 2 weeks, especially the first few days, and that carotid endarterectomy (CEA) confers maximal benefit when performed early. Despite well-documented anxieties, there is increasing evidence that CEA can be performed safely within the first 7 days after onset of symptoms, although risks may be higher when performed within 48 h. The role for carotid artery stenting in the hyperacute period remains uncertain. Centers performing carotid artery stenting within 14 days of symptom onset with risks equivalent to CEA should be encouraged to continue and help others to achieve similar outcomes. For the majority, however, CEA will probably remain the safer option. 'Best medical therapy' and risk factor modification should be started as soon as a transient ischemic attack is suspected, while the early introduction of dual antiplatelet therapy may reduce recurrent events prior to CEA, without increasing perioperative bleeding complications.

Interventions for Extracranial Carotid Artery Stenosis: An Update

OPINION STATEMENT

Clinical trials demonstrate that stroke risk after the periprocedural period is similar for carotid angioplasty and stenting (CAS) and carotid endarterectomy (CEA), making CAS an acceptable alternative to CEA. However, there tends to be a higher procedural risk of stroke for CAS than for CEA and a potentially higher rate of myocardial infarction in patients undergoing CEA as compared to CAS. Furthermore, lower rates of complications with revascularization and of post-revascularization stroke have been attributed to advances in medical management, improved surgical technique, and new devices. We discuss identifying patients who may have higher complication rates and recent clinical studies and medical advances directed at reducing stroke risk in patients with extracranial carotid stenosis.

Dual antiplatelet therapy reduces stroke but increases bleeding at the time of carotid endarterectomy

OBJECTIVE

Controversy persists regarding the perioperative management of clopidogrel among patients undergoing carotid endarterectomy (CEA). This study examined the effect of preoperative dual antiplatelet therapy (aspirin and clopidogrel) on in-hospital CEA outcomes.

METHODS

Patients undergoing CEA in the Vascular Quality Initiative were analyzed (2003-2014). Patients on clopidogrel and aspirin (dual therapy) were compared with patients taking aspirin alone preoperatively. Study outcomes included reoperation for bleeding and thrombotic complications defined as transient ischemic attack (TIA), stroke, or myocardial infarction. Secondary outcomes were in-hospital death and composite stroke/death. Univariate and multivariable analyses assessed differences in demographics and operative factors. Propensity score-matched cohorts were derived to control for subgroup heterogeneity.

RESULTS

Of 28,683 CEAs, 21,624 patients (75%) were on aspirin and 7059 (25%) were on dual therapy. Patients on dual therapy were more likely to have multiple comorbidities, including coronary artery disease (P < .001), congestive heart failure (P < .001), and diabetes (P < .001). Patients on dual therapy were also more likely to have a drain placed (P < .001) and receive protamine during CEA (P < .001). Multivariable analysis showed that dual therapy was independently associated with increased reoperation for bleeding (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.20-2.42; P = .003) but was protective against TIA or stroke (OR, 0.61; 95% CI, 0.43-0.87; P = .007), stroke (OR, 0.63; 95% CI, 0.41-0.97; P = .03), and stroke/death (OR, 0.66; 95% CI, 0.44-0.98; P = .04). Propensity score matching yielded two groups of 4548 patients and showed that patients on dual therapy were more likely to require reoperation for bleeding (1.3% vs 0.7%; P = .004) but less likely to suffer TIA or stroke (0.9% vs 1.6%; P = .002), stroke (0.6% vs 1.0%; P = .04), or stroke/death (0.7% vs 1.2%; P = .03). Within the propensity score-matched groups, patients on dual therapy had increased rates of reoperation for bleeding regardless of carotid symptom status. However, asymptomatic patients on dual therapy demonstrated reduced rates of TIA or stroke (0.6% vs 1.5%; P < .001), stroke (0.4% vs 0.9%; P = .01), and composite stroke/death (0.5% vs 1.0%; P = .02). Among propensity score-matched patients with symptomatic carotid disease, these differences were not statistically significant.

CONCLUSIONS

Preoperative dual antiplatelet therapy was associated with a 40% risk reduction for neurologic events but also incurred a significant increased risk of reoperation for bleeding after CEA. Given its observed overall neurologic protective effect, continued dual antiplatelet therapy throughout the perioperative period is justified. Initiating dual therapy in all patients undergoing CEA may lead to decreased neurologic complication rates.

Intraoperative management of carotid endarterectomy

First reports on surgical treatment of cerebrovascular atherosclerosis date to the early 1950s. With advancements in surgical technique, carotid endarterectomy (CEA) has become the treatment of choice for patients with both symptomatic and asymptomatic severe carotid stenosis. Given the benefits that surgery offers beyond medical management, the number of CEA procedures continues to increase. The intraoperative management of patients undergoing CEA is challenging because of the combination of patient and surgical factors. This article explores and reviews the literature on anesthetic management and considerations of patients undergoing CEA.

Regional anaesthesia for carotid endarterectomy

Summary Regional anaesthesia is a popular choice for patients undergoing carotid endarterectomy (CEA). Neurological function is easily assessed during carotid cross-clamping; haemodynamic control is predictable; and hospital stay is consistently shorter compared with general anaesthesia (GA). Despite these purported benefits, mortality and stroke rates associated with CEA remain around 5% for both regional anaesthesia and GA. Regional anaesthetic techniques for CEA have improved with improved methods of location of peripheral nerves including nerve stimulators and ultrasound together with a modification in the classification of cervical plexus blocks. There have also been improvements in local anaesthetic, sedative, and arterial pressure-controlling drugs in patients undergoing CEA, together with advances in the management of patients who develop neurological deficit after carotid cross-clamping. In the UK, published national guidelines now require the time between the patient's presenting neurological event and definitive treatment to 1 week or less. This has implications for the ability of vascular centres to provide specialized vascular anaesthetists familiar with regional anaesthetic techniques for CEA. Providing effective regional anaesthesia for CEA is an important component in the armamentarium of techniques for the vascular anaesthetist in 2014.