Variation in perioperative cerebral and hemodynamic monitoring during carotid endarterectomy.

BACKGROUND: Hemodynamic disturbances cause half of the perioperative strokes following carotid endarterectomy (CEA). Guidelines strongly recommend strict pre- and postoperative blood pressure (BP) monitoring in CEA patients, but do not provide firm practical recommendations. Although in the Netherlands 50 centres perform CEA, no national protocol on perioperative hemodynamic, and cerebral monitoring exists. To assess current monitoring policies of all Dutch CEA-centres, a national survey was conducted. METHODS: Between May and July 2017 all 50 Dutch CEA-centres were invited to complete a 42-question survey addressing perioperative hemodynamic and cerebral monitoring during CEA. Nonresponders received a reminder after 1 and 2 months. By November 2017 the survey was completed by all centres. RESULTS: Preoperative baseline BP was based on a single bilateral BP-measurement at the outpatient-clinic in the majority of centres (n = 28). In 43 centres (86%) pre-operative monitoring (transcranial Doppler (TCD, n = 6), electroencephalography (EEG, n = 11), or TCD + EEG (n = 26)) was performed as a baseline reference. Intraoperatively, large diversity for type of anaesthesia (general: 45 vs. local [LA]:5) and target systolic BP (>100 mm hg - 160 mm hg [n = 12], based on preoperative outpatient-clinic or admission BP [n = 18], other [n = 20]) was reported. Intraoperative cerebral monitoring included EEG + TCD (n = 28), EEG alone (n = 13), clinical neurological examination with LA (n = 5), near-infrared spectroscopy with stump pressure (n = 1), and none due to standard shunting (n = 3). Postoperatively, significant variation was reported in standard duration of admission at a recovery or high-care unit (range 3-48 hr, mean:12 hr), maximum accepted systolic BP (range >100 mm hg - 180 mm Hg [n = 32]), postoperative cerebral monitoring (standard TCD [n = 16], TCD on indication [n = 5] or none [n = 24]) and in timing of postoperative cerebral monitoring (range directly postoperative - 24 hr postoperative; median 3 hr). CONCLUSIONS: In Dutch centres performing CEA the perioperative hemodynamic and cerebral monitoring policies are widely diverse. Diverse policies may theoretically lead to over- or under treatment. The results of this national audit may serve as the baseline dataset for development of a standardized and detailed (inter)national protocol on perioperative hemodynamic and cerebral monitoring during CEA.

The diagnostic value of skin biopsies in Sneddon syndrome.

BACKGROUND: Sneddon syndrome (SS) is defined by widespread livedo reticularis (LR) and stroke. There is no single diagnostic test for SS and diagnosis can be solely based on clinical features. This cross-sectional case-control study aimed to determine the diagnostic value of skin biopsies in SS patients. MATERIALS AND METHODS: We studied skin biopsies from patients with a clinical diagnosis of SS or isolated LR. We also studied controls with vitiligo or normal skin. Biopsies were considered standardized if 3 biopsies were taken from the white centre of the livedo and reached until the dermis-subcutis border. Biopsies were scored for features of an occlusive microangiopathy without knowledge of the clinical features. Sensitivity and specificity of the biopsy findings were calculated with the clinical criteria as the reference standard. RESULTS: We included 34 SS patients, 14 isolated LR patients and 41 control patients. Biopsies of 17 patients with SS (50%), 4 with isolated LR (31%) and 10 control patients (24%) showed at least one artery in the deep dermis with a thickened vessel wall combined with recanalization or neovascularization (sensitivity 50% and specificity 69% with LR as reference). Standardized biopsies increased the sensitivity to 70%. In a post hoc analysis the combination of an occlusive microangiopathy and the presence of a livedo pattern in the superficial dermis increased the specificity to 92%. CONCLUSIONS: Standardized skin biopsies can support the clinical diagnosis of SS. An occlusive microangiopathy as the only positive criterion for the diagnosis of SS had insufficient specificity for a definite diagnosis.

Sneddon syndrome: a comprehensive clinical review of 53 patients.

BACKGROUND: The presence of livedo reticularis in patients with ischaemic stroke is associated with Sneddon syndrome (SS). Our objective was to present the clinical features of SS patients and to assess the role of antiphospholipid antibodies (APL). METHODS: Consecutive patients, diagnosed with SS between 1996 and 2017, were retrospectively reviewed for their demographic, neurological, dermatological, cardiac and extracerebral vascular features. Diagnosis of SS was made only if other causes of stroke were excluded. Patients with and without APL were included and compared for their clinical features. RESULTS: Fifty-three patients (79% female) were included, of whom 14 patients were APL-positive. Median age at diagnosis was 40 years. Approximately 60% of the patients had ≥ 3 cardiovascular risk factors. There were 129 previous vascular events (66 ischaemic strokes, 62 TIAs and 1 amaurosis fugax) during a median period of 2 years between the first event and diagnosis of SS. Skin biopsy was positive for SS in 29 patients (67%), mostly showing a thickened vessel wall with neovascularization in the deep dermis. After a median follow-up of 28 months, 4 patients, either on antiplatelet or oral anticoagulation therapy, had a recurrent stroke. There were few statistically significant differences between APL-negative and APL-positive patients, including the number of vascular events before diagnosis. CONCLUSIONS: SS predominantly affects young women with a relatively large number of cardiovascular risk factors. Clinical features of SS are comparable across different studies. We found no differences in the main clinical features between APL-positive and APL-negative patients.

Sex differences in intracranial and extracranial atherosclerosis in patients with acute ischemic stroke.

BACKGROUND AND AIM: To investigate sex differences with respect to presence and location of atherosclerosis in acute ischemic stroke patients. METHODS: Participants with acute ischemic stroke were included from the Dutch acute stroke trial, a large prospective multicenter cohort study performed between May 2009 and August 2013. All patients received computed tomography/computed tomography-angiography within 9 h of stroke onset. We assessed presence of atherosclerosis in the intra- and extracranial internal carotid and vertebrobasilar arteries. In addition, we determined the burden of intracranial atherosclerosis by quantifying internal carotid and vertebrobasilar artery calcifications, resulting in calcium volumes. Prevalence ratios between women and men were calculated with Poisson regression analysis and adjusted prevalence ratio for potential confounders (age, hypertension, hyperlipidemia, diabetes, smoking, and alcohol use). RESULTS: We included 1397 patients with a mean age of 67 years, of whom 600 (43%) were women. Presence of atherosclerosis in intracranial vessel segments was found as frequently in women as in men (71% versus 72%, adjusted prevalence ratio 0.95; 95% CI 0.89-1.01). In addition, intracranial calcification volume did not differ between women and men in both intracranial internal carotid (large burden 35% versus 33%, adjusted prevalence ratio 0.93; 95% CI 0.73-1.19) and vertebrobasilar arteries (large burden 26% versus 40%, adjusted prevalence ratio 0.69; 95% CI 0.41-1.12). Extracranial atherosclerosis was less common in women than in men (74% versus 81%, adjusted prevalence ratio 0.86; 95% CI 0.81-0.92). CONCLUSIONS: In patients with acute ischemic stroke the prevalence of intracranial atherosclerosis does not differ between women and men, while extracranial atherosclerosis is less often present in women compared with men.

The relation between healthy lifestyle changes and decrease in systemic inflammation in patients with stable cardiovascular disease.

BACKGROUND AND AIMS: Pharmacological lowering of inflammation has proven effective in reducing recurrent cardiovascular event rates. Aim of the current study is to evaluate lifestyle changes (smoking cessation, weight loss, physical activity level increase, alcohol moderation, and a summary lifestyle improvement score) in relation to change in plasma C-reactive protein (CRP) concentration in patients with established cardiovascular disease. METHODS: In total, 1794 patients from the UCC-SMART cohort with stable cardiovascular disease and CRP levels ≤10 mg/L, who returned for a follow-up study visit after median 9.9 years (IQR 5.4-10.8), were included. The relation between changes in smoking status, weight, physical activity, alcohol consumption, a summary lifestyle improvement score and change in plasma CRP concentration was evaluated with linear regression analyses. RESULTS: Smoking cessation was related to a 0.40 mg/L decline in CRP concentration (ß-coefficient -0.40; 95%CI -0.73,-0.07). Weight loss (per 1SD = 6.4 kg) and increase in physical activity (per 1 SD = 48 MET hours per week) were related to a decrease in CRP concentration (ß-coefficients -0.25; 95%CI -0.33,-0.16 and -0.09; 95%CI -0.17,-0.01 per SD). Change in alcohol consumption was not related to CRP difference. Every point higher in the summary lifestyle improvement score was related to a decrease in CRP concentration of 0.17 mg/L (ß-coefficient -0.17; 95%CI -0.26,-0.07). CONCLUSIONS: Smoking cessation, increase in physical activity, and weight loss are related to a decrease in CRP concentration in patients with stable cardiovascular disease. Patients with the highest summary lifestyle improvement score have the most decrease in CRP concentration. These results may indicate that healthy lifestyle changes contribute to lowering systemic inflammation, potentially leading to a lower cardiovascular risk in patients with established cardiovascular disease.

Thyroid-stimulating hormone levels in the normal range and incident type 2 diabetes mellitus.

AIM: To evaluate the relationship between thyroid-stimulating hormone (TSH) levels within the normal range and the risk of type 2 diabetes mellitus (T2DM) in a cohort of patients at high cardiovascular risk, and to perform a systematic review and meta-analysis of previous studies. METHODS: We included 5542 patients without T2DM from the prospective Secondary Manifestations of ARTerial disease study with TSH levels between 0.35 and 5.0 mIU/L without anti-thyroid medication or thyroid-hormone replacement therapy. Cox regression was used to investigate the relationship between baseline plasma TSH levels and incident T2DM. MEDLINE, EMBASE, and Cochrane were searched for prospective cohorts assessing TSH and incident T2DM. Hazard ratios (HR) from included prospective cohort studies were pooled using a random-effects model. RESULTS: In patients at high cardiovascular risk, higher plasma TSH levels in the normal range were not associated [HR 1.07 per mIU/L increase in TSH (95% confidence interval (95% CI) 0.95-1.22)] with an increased risk of T2DM, adjusted for age, sex, smoking, total and HDL cholesterol, and triglycerides. In the meta-analysis involving three prospective cohort studies, including the present study, including 29,791 participants with 1930 incident events, there was no relation between plasma TSH levels in the normal range and incident T2DM [pooled HR 1.06 (95% CI 0.99-1.14)]. CONCLUSION: There is no apparent relation between plasma TSH levels in the normal range and incident T2DM in patients at high cardiovascular risk.

[When is carotid endarterectomy actually indicated for stenosis?] / Wie moet er eigenlijk nog aan vernauwing in de A. carotis geopereerd worden?

Criteria for carotid endarterectomy are based on the results of clinical trials that were conducted more than two decades ago. In the meantime medical treatment has improved, and surgery can be performed more safely. As such, it is currently unknown which patients should be recommended to undergo carotid surgery. The aim of the currently running European Carotid Surgery Trial 2 is to find better answers to this dilemma.

Relation between adiposity and vascular events, malignancy and mortality in patients with stable cerebrovascular disease.

BACKGROUND: Abdominal adiposity is associated with various risk factors including hypertension, and is therefore particularly relevant in patients with stable cerebrovascular disease (CeVD). A U-shaped relation between body mass index (BMI, kg m-2) and cardiovascular events is often described. Whether this U-shape persists for abdominal adiposity, and consequently which reference values should guide clinical practice, is unclear. We described the relation between multiple adiposity measurements and risk of vascular events, vascular mortality, malignancy and all-cause mortality in patients with clinically stable CeVD. METHODS: During a median follow-up time of 6.8 years, 1767 patients were prospectively followed. Relations were assessed using multivariable adjusted Cox proportional hazards models. Adiposity was assessed with BMI, waist circumference (stratified by gender) and the contribution of visceral fat to total abdominal fat (VAT%) measured using ultrasound. Relations were nonlinear if the χ2-statistic of the nonlinear term was significant (P-value<0.05). Nadirs were reported for nonlinear and hazard ratios (HRs) for linear relations. RESULTS: The relations between BMI and outcomes were nonlinear with nadirs ranging between 27.1 (95% confidence interval (CI) 21.9-29.3) kg m2 for vascular mortality and 28.1 (95% CI, 19.0-38.2)) kg m-2 for malignancy. The relation between waist circumference and all-cause mortality was nonlinear with a nadir of 84.0 (95% CI, 18.7-134.8) cm for females and 94.8 (95% CI, 80.3-100.1) cm for males. No nonlinearity was detected for VAT%. A 1-s.d. (9.8%) increase in VAT% was related to both vascular (HR, 1.23, 95% CI 1.00-1.51) and all-cause mortality (HR, 1.22, 95% CI 1.05-1.42). CONCLUSIONS: In patients with CeVD, a BMI around 27-28 kg m-2 relates to the lowest risk of vascular events, vascular mortality, malignancy and all-cause mortality. However, increasing abdominal adiposity confers a higher risk of all-cause mortality. Thus, whereas traditional BMI cutoffs may be re-evaluated in this population, striving for low abdominal obesity should remain a goal.

[Calcified cerebral embolism as a cause of ischemic stroke]. / Een vrouw met linkszijdig krachtsverlies en sufheid.

A 60-year-old woman with a history of hypertension presented with acute onset of left-sided weakness and drowsiness. Non-contrast CT at baseline and follow-up showed a focal high density lesion in the right middle cerebral artery, consistent with a calcified embolus. CT angiography confirmed its location.

Management of extracranial carotid artery aneurysm.

INTRODUCTION: Aneurysms of the extracranial carotid artery (ECAA) are rare. Several treatments have been developed over the last 20 years, yet the preferred method to treat ECAA remains unknown. This paper is a review of all available literature on the risk of complications and long-term outcome after conservative or invasive treatment of patients with ECAA. METHODS: Reports on ECAA treatment until July 2014 were searched in PubMed and Embase using the key words aneurysm, carotid, extracranial, and therapy. RESULTS: A total of 281 articles were identified. Selected articles were case reports (n = 179) or case series (n = 102). Papers with fewer than 10 patients were excluded, resulting in the final selection of 39 articles covering a total of 1,239 patients. Treatment consisted of either conservative treatment in 11% of the cases or invasive treatment in 89% of the cases. Invasive treatment comprised surgery in 94%, endovascular approach in 5%, and a hybrid approach in 1% of the patients. The most common complication described after invasive therapy was cranial nerve damage, which occurred in 11.8% of patients after surgery. The 30 day mortality rate and stroke rate in conservatively treated patients was 4.67% and 6.67%, after surgery 1.91% and 5.16%. Information on confounders in the present study was incomplete. Therefore, adjustments to correct for confounding by indication could not be done. CONCLUSIONS: This review summarizes the largest available series in the literature on ECAA management. The number of ECAAs reported in current literature is scarce. The early and long-term outcome of invasive treatment in ECAA is favorable; however, cranial nerve damage after surgery occurs frequently. Unfortunately, due to limitations in reporting of results and confounding by indication in the available literature, it was not possible to determine the optimal treatment strategy. There is a need for a multicenter international registry to reveal the optimal treatment for ECAA.

Delay to carotid endarterectomy in patients with symptomatic carotid artery stenosis.

OBJECTIVE: In patients with recently symptomatic carotid artery stenosis, guidelines recommend carotid revascularization within 2 weeks of the index event. The "index event" may be defined as either the first or the most recent event. The delay between the index event and carotid endarterectomy (CEA) over a period of 6 years in a single centre was evaluated and the effect of defining the index event as either the first or the most recent event was assessed. DESIGN: Observational study. METHODS: 555 consecutive patients with symptomatic carotid stenosis ≥ 50% treated with CEA between 2007 and 2012 were assessed. In 2010, changes to the in-hospital process of care to reduce delays in referral and CEA were introduced. These changes included, for example, improving access to physicians, imaging, and operating rooms. The delay from symptoms to surgery was expressed in days. RESULTS: The median time between the first event and surgery was reduced from 53 days (interquartile range [IQR] 30-78) in 2007 to 21 days (IQR 12-45) in 2012, and between the most recent event and CEA from 45 days (IQR 28-67) to 17 days (IQR 9-28). Patients referred directly by their general practitioner more often underwent CEA within 2 weeks than patients referred by specialists from other hospitals. Compared to patients with transient ischaemic attack or ocular symptoms, patients with ischaemic stroke more often underwent CEA within 2 weeks. CONCLUSIONS: A small change in the process of care significantly reduced the delay from the index event to CEA, but in 2012 it still exceeded 14 days in the majority of patients. The definition of the "index event" has a large impact on the total duration of delay, and should therefore be uniform across studies.

Incompleteness of the circle of Willis is related to EEG-based shunting during carotid endarterectomy.

OBJECTIVES: The occurrence of cerebral ischemia during carotid endarterectomy (CEA) can be prevented by (selective) placement of an intraluminal shunt during cross-clamping. We set out to develop a rule to predict the likelihood for shunting during CEA based on preoperative assessment of collateral cerebral circulation and patient characteristics. METHODS: Patients who underwent CEA between 2004 and 2010 were included. Patients without preoperative magnetic resonance (MRA) or computed tomography angiography (CTA) were excluded. The primary endpoint was intraluminal shunt placement based on electroencephalography changes. Age, sex, cardiovascular risk factors peripheral artery disease, symptomatic status, degree of ipsilateral and contralateral carotid, status of the vertebral arteries, and morphology of the CoW were studied as potential predictors for shunt use. A prediction model was derived from a multivariable regression model using discrimination, calibration, and bootstrapping approaches and transformed into a clinical prediction model. RESULTS: A total of 431 patients were included, of which 65 patients (15%) received an intraluminal shunt. In the MRA group (n = 285) factors related to shunt use in multivariate analysis were ipsilateral carotid stenosis 90-99% (odds ratio [OR] 0.15, 95% CI 0.04-0.53), contralateral carotid occlusion (OR 4.29, 95% CI 1.68-10.95) and any not-visible anterior (OR 4.96, 95% CI 1.95-12.58) or ipsilateral posterior segment of the CoW (OR 5.08, 95% CI 2.10-12.32). In the CT group none of the factors were independently related to shunt use; therefore, only predictors describing morphology of CoW derived from MRA findings were included in our model. The c-statistic of this model was 0.79 (95% CI 0.72-0.86). Among patients with an estimated chance of needing a shunt of under 10% (49% of the population), the likelihood of shunting was 5%. In those in whom this chance was estimated higher than 30% (13% of the population) the likelihood was 51%. CONCLUSIONS: Among patients scheduled for CEA, assessment of cerebral arteries and of the configuration of the CoW based on MRA-derived images can help to identify patients with low and high likelihood of the need of shunt use during surgery.

Near-infrared spectroscopy to indicate selective shunt use during carotid endarterectomy.

OBJECTIVES: This study assessed the value of cerebral near-infrared spectroscopy (NIRS) and transcranial Doppler (TCD) in relation to electroencephalography (EEG) changes for the detection of cerebral hypoperfusion necessitating shunt placement during carotid endarterectomy (CEA). METHODS: This was a prospective cohort study. Patients with a sufficient TCD window undergoing CEA from February 2009 to June 2011 were included. All patients were continuously monitored with NIRS and EEG. An intraluminal shunt was placed, selectively determined by predefined EEG changes in alpha, beta, theta, or delta activity. Relative changes in regional cerebral oxygen saturation (rSO2) in the frontal lobe and mean blood flow velocity (Vmean) 30 seconds before carotid cross-clamping versus 2 minutes after carotid cross-clamping were related to shunt placement. Receiver operating characteristic curve analysis was performed to determine the optimal thresholds. Diagnostic values were reported as positive and negative predictive value (PPV and NPV). RESULTS: Of a cohort of 151 patients, 17(11%) showed EEG changes requiring shunt placement. The rSO2 and Vmean decreased more in the shunt group than in the non-shunt group (mean ± standard error of the mean) 21 ± 4% versus 7 ± 5% and 76 ± 6% versus 12 ± 3%, respectively (p < .005), Receiver operating characteristic curve analysis revealed a threshold of 16% decrease in rSO2 (PPV 76% and NPV 99%) and 48% decrease in Vmean (PPV 53% and NPV 99%) as the optimal cut-off value to detect cerebral ischemia during CEA under general anesthesia. CONCLUSIONS: Compared with EEG, we found moderate PPV but high NPV for NIRS and TCD to detect cerebral ischemia during CEA under general anesthesia, meaning that both techniques independently may be suitable to exclude patients for unnecessary shunt use and to direct the use of selective shunting. However, the optimal thresholds for NIRS remain to be determined.

Prediction of cerebral hyperperfusion after carotid endarterectomy with transcranial Doppler.

OBJECTIVES: To determine the diagnostic value for predicting cerebral hyperperfusion syndrome (CHS) by adding a transcranial Doppler (TCD) measurement in the early postoperative phase after carotid endarterectomy (CEA). DESIGN: Patients who underwent carotid endarterectomy between January 2004 and August 2010 and in whom both intra- and postoperative TCD monitoring were performed were included. METHODS: In 184 CEA patients the mean velocity (V(mean)) preoperatively (V1), pre-clamping (V2), post-declamping (V3) and postoperatively (V4) was measured using TCD. The intra-operative V(mean) increase ((V3 - V2)/V2) was compared to the postoperative increase ((V4 - V1)/V1) in relation to CHS. CHS was diagnosed if the patient developed neurological complaints in the presence of a preoperative V(mean) increase >100%. RESULTS: Sixteen patients (9%) had an intra-operative V(mean) increase >100% and 22 patients (12%) a postoperative V(mean) increase of >100%. In 10 patients (5%) CHS was diagnosed; two of those had an intra-operative V(mean) increase of >100% and nine postoperative V(mean) increase >100%. This results in a positive predictive value of 13% for the intra-operative and 41% for the postoperative measurement. CONCLUSIONS: Besides the commonly used intra-operative TCD monitoring additional TCD measurement in the early postoperative phase is useful to more accurately predict CHS after CEA.

Effectiveness of a hospital-based vascular screening programme (SMART) for risk factor management in patients with established vascular disease or type 2 diabetes: a parallel-group comparative study.

AIMS: Modification of vascular risk factors is effective in reducing mortality and morbidity in patients with symptomatic atherosclerosis; however, it is difficult to achieve and maintain. The aim of the Risk management in Utrecht and Leiden Evaluation (RULE) study was to assess risk factor status after referral in patients with established vascular disease or type 2 diabetes who took part in the multidisciplinary hospital-based vascular screening programme, Second Manifestations of ARTerial disease, compared with a group who did not participate in such a programme. METHODS AND RESULTS: Patients with type 2 diabetes, coronary artery disease, cerebrovascular disease or peripheral arterial disease referred by general practitioners to the medical specialist at the University Medical Center (UMC) Utrecht (a setting with a vascular screening programme of systematic screening of risk factors followed by treatment advice) and the Leiden UMC (a setting without such a screening programme), were enrolled in the study. Blood pressure, levels of lipids, glucose and creatinine, weight, waist circumference and smoking status were measured in patients 12-18 months after referral to the two hospitals. A total of 604 patients were treated in the setting with a vascular screening programme and 566 in the setting without such a programme; 70% of all patients were male, with a mean age of 61 +/- 10 years. Amongst screened patients, systolic blood pressure [2.5 mmHg, 95% confidence interval (CI) 0.3-4.6] and the level of LDL cholesterol (0.3 mmol L(-1), 95% CI 0.2-0.4) were lower compared with the group that received usual care, after a median of 16 months from referral. CONCLUSION: Systematic screening of risk factors, followed by evidence-based, tailored treatment advice contributed to slightly better risk factor reduction in patients with established vascular disease or type 2 diabetes. However, a large proportion of patients did not reach the treatment goals according to (inter)national guidelines. Systematic screening of vascular risk factors alone is not enough for adequate risk factor management in high-risk patients.

The value of near-infrared spectroscopy measured cerebral oximetry during carotid endarterectomy in perioperative stroke prevention. A review.

BACKGROUND: Transcranial Doppler (TCD) for identification of patients at risk for cerebral hyperperfusion syndrome (CHS) following carotid endarterectomy (CEA) cannot be performed in 10-15% of patients because of the absence of a temporal bone window. Near-infrared spectroscopy (NIRS) may be of additional value in these patients. We aimed to (1) compare the value of NIRS related to existing cerebral monitoring techniques in prediction of perioperative cerebral ischaemia and (2) compare the relation between NIRS and the occurrence of CHS. METHODS: A systematic literature search relating to NIRS and CEA was conducted in PubMed and EMBASE databases. Those included were: (1) prospective studies; (2) on NIRS for brain monitoring during CEA; (3) including comparison of NIRS to any other intra-operative cerebral monitoring systems; and (4) on either symptomatic or asymptomatic patients. RESULTS: We identified 16 studies, of which 14 focussed on the prediction of intra-operative cerebral ischaemia and shunt indication. Only two studies discussed the ability of NIRS in predicting CHS. NIRS values correlated well with TCD and electroencephalography (EEG) values indicating ischaemia. However, a threshold for postoperative cerebral ischaemia could not be determined. Neither could a threshold for selective shunting be determined since shunting criteria varied considerably across studies. The evidence suggesting that NIRS is useful in predicting CHS is modest. CONCLUSION: NIRS seems a promising monitoring technique in patients undergoing CEA. Yet the evidence to define clear cut-off points for the presence of perioperative cerebral ischaemia or identification of patients at high risk of CHS is limited. A large prospective cohort study addressing these issues is urgently needed.

Risk indicators for development of headache during dipyridamole treatment after cerebral ischaemia of arterial origin.

A considerable proportion of patients discontinue dipyridamole therapy because of headache. Risk indicators for the development of dipyridamole induced headache were identified by means of an exploratory analysis of data from the European/Australasian Stroke Prevention in Reversible Ischaemia Trial (ESPRIT) and the Second European Stroke Prevention Study (ESPS 2). In ESPRIT, dipyridamole induced headache was significantly associated with female sex, absence of hypertension and non-smoking (area under the receiver operator characteristic (ROC) curve 0.63 (95% CI 0.58 to 0.68)) and in ESPS 2 with female sex and absence of ischaemic lesions on imaging (area under the ROC curve 0.64 (95% CI 0.59 to 0.69)).

Carotid stenting versus carotid endarterectomy: evidence basis and cost implications.

OBJECTIVE: Carotid Angioplasty combined with Stenting (CAS) is increasingly performed because of its presumed benefits. A study was performed to identify key factors that determine the cost-effectiveness as compared to conventional carotid endarterectomy (CEA). METHODS: The incremental cost-effectiveness of CAS over CEA for different scenarios was estimated using a modeling approach. Treatment costs were based on actual costs of successful procedures whereas costs of complications were taken from the literature. Patient survival was modeled using the endarterectomy patients from the ECST trial. RESULTS: Procedural costs of CAS are higher than those of CEA, mainly as a result of the high material costs. Cost-effectiveness of CAS primarily depends on major stroke rates. One percent increase in the peri-operative major stroke rate causes a cost increase of 1051 euros and a loss of 0.06 quality adjusted life years. CONCLUSIONS: At present CAS is at best non-inferior to CEA in terms of clinical outcome. Cost savings due to shorter admission are offset by the high costs associated with catheter-based interventions. At present CAS should be restricted to controlled settings until clinical trials have shown a substantial clinical benefit.