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1 Platelet inhibitory therapy may protect patency in prosthetic arterial grafts. 2 The effect of the thromboxane synthetase inhibitor dazoxiben (UK 37248) on 113Indium-labelled platelet deposition on Dacron arterial grafts was examined in an artificial circulation containing human blood which mimics the haemodynamics of femoropopliteal bypass. The influence of this drug on thromboxane production and platelet reactivity was measured during the experiment. The study was controlled and performed in two parts to assess in vitro and ex vivo drug effect. 3 Both in vitro and ex vivo dazoxiben reduced plasma thromboxane by about 80% and in citrated ex vivo blood increased mean (+/- s.e. mean) platelet aggregation threshold to collagen from control values of 4.8 +/- 1.7 mg/ml to 10.6 +/- 3.3 mg/ml (P less than 0.01). Dazoxiben, however, had no effect on platelet deposition on the arterial grafts. 4 Selective thromboxane inhibition failed to exert an antithrombotic effect in this model. [ABSTRACT FROM AUTHOR]

Background: The Sepsis-3 guidelines diagnose sepsis based on organ dysfunction in patients with either proven or suspected infection. The objective of this study was to assess the incidence and outcomes of sepsis diagnosed using these guidelines in patients in a cardiac intensive care unit (CICU) after cardiac surgery., Methods: Daily sequential organ failure assessment (SOFA) scores were calculated for 2230 consecutive adult cardiac surgery patients between January 2013 and May 2015. Patients with an increase in SOFA score of ≥2 and suspected or proven infection were identified. The length of CICU stay, 30-day mortality and 2-yr survival were compared between groups. Multivariable linear regression, multivariable logistic regression, and Cox proportional hazards regression were used to adjust for possible confounders., Results: Sepsis with suspected or proven infection was diagnosed in 104 (4.7%) and 107 (4.8%) patients, respectively. After adjustment for confounding variables, sepsis with suspected infection was associated with an increased length of CICU stay of 134.1h (95% confidence interval (CI) 99.0-168.2, P<0.01) and increased 30-day mortality risk (odds ratio 3.7, 95% CI 1.1-10.2, P=0.02). Sepsis with proven infection was associated with an increased length of CICU stay of 266.1h (95% CI 231.6-300.7, P<0.01) and increased 30-day mortality risk (odds ratio 6.6, 95% CI 2.6-15.7, P<0.01)., Conclusions: Approximately half of sepsis diagnoses were based on proven infection and half on suspected infection. Patients diagnosed with sepsis using the Sepsis-3 guidelines have significantly worse outcomes after cardiac surgery. The Sepsis-3 guidelines are a potentially useful tool in the management of sepsis following cardiac surgery., (Copyright © 2017 British Journal of Anaesthesia. All rights reserved.)

Three-dimensional (3D) ultrasound is an evolving modality that may have numerous applications in the management of abdominal aortic aneurysms. Many vascular specialists will not be familiar with the different ways in which 3D vascular ultrasound data can be acquired nor how potential applications are being explored by researchers. Most of the current literature consists of small series and single-centre experience, although clinical themes such as measurement of abdominal aortic aneurysm volume and surveillance following endovascular repair are emerging. The aim of this topical review is to introduce clinicians to the current concepts of 3D ultrasound, review the current literature, and highlight avenues for further research in this new and exciting field of vascular imaging., (Copyright © 2016 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Abdominal aortic aneurysm (AAA) repair aims to prevent premature death from AAA rupture. Elective repair is currently recommended when AAA diameter reaches 5.5 cm (men) and 5.0 cm (women). Applying population-based indications may not be appropriate for individual patient decisions, as the optimal indication is likely to differ between patients based on age and comorbidities., Objective: To develop an Aneurysm Repair Decision Aid (ARDA) to indicate when elective AAA repair optimises survival for individual patients and to assess the cost-effectiveness and associated uncertainty of elective repair at the aneurysm diameter recommended by the ARDA compared with current practice., Data Sources: The UK Vascular Governance North West and National Vascular Database provided individual patient data to develop predictive models for perioperative mortality and survival. Data from published literature were used to model AAA growth and risk of rupture. The cost-effectiveness analysis used data from published literature and from local and national databases., Methods: A combination of systematic review methods and clinical registries were used to provide data to populate models and inform the structure of the ARDA. Discrete event simulation (DES) was used to model the patient journey from diagnosis to death and synthesised data were used to estimate patient outcomes and costs for elective repair at alternative aneurysm diameters. Eight patient clinical scenarios (vignettes) were used as exemplars. The DES structure was validated by clinical and statistical experts. The economic evaluation estimated costs, quality-adjusted life-years (QALYs) and incremental cost-effectiveness ratios (ICERs) from the NHS, social care provider and patient perspective over a lifetime horizon. Cost-effectiveness acceptability analyses and probabilistic sensitivity analyses explored uncertainty in the data and the value for money of ARDA-based decisions. The ARDA outcome measures include perioperative mortality risk, annual risk of rupture, 1-, 5- and 10-year survival, postoperative long-term survival, median life expectancy and predicted time to current threshold for aneurysm repair. The primary economic measure was the ICER using the QALY as the measure of health benefit., Results: The analysis demonstrated it is feasible to build and run a complex clinical decision aid using DES. The model results support current guidelines for most vignettes but suggest that earlier repair may be effective in younger, fitter patients and ongoing surveillance may be effective in elderly patients with comorbidities. The model adds information to support decisions for patients with aneurysms outside current indications. The economic evaluation suggests that using the ARDA compared with current guidelines could be cost-effective but there is a high level of uncertainty., Limitations: Lack of high-quality long-term data to populate all sections of the model meant that there is high uncertainty about the long-term clinical and economic consequences of repair. Modelling assumptions were necessary and the developed survival models require external validation., Conclusions: The ARDA provides detailed information on the potential consequences of AAA repair or a decision not to repair that may be helpful to vascular surgeons and their patients in reaching informed decisions. Further research is required to reduce uncertainty about key data, including reintervention following AAA repair, and assess the acceptability and feasibility of the ARDA for use in routine clinical practice., Funding: The National Institute for Health Research Health Technology Assessment programme.

Background: Cardiopulmonary exercise testing (CPET) is increasingly used in the preoperative assessment of patients undergoing major surgery. The objective of this study was to investigate whether CPET can identify patients at risk of reduced survival after abdominal aortic aneurysm (AAA) repair., Methods: Prospectively collected data from consecutive patients who underwent CPET before elective open or endovascular AAA repair  (EVAR) at two tertiary vascular centres between January 2007 and October 2012 were analysed. A symptom-limited maximal CPET was performed on each patient. Multivariable Cox proportional hazards regression modelling was used to identify risk factors associated with reduced survival., Results: The study included 506 patients with a mean age of 73.4 (range 44-90). The majority (82.6%) were men and most (64.6%) underwent EVAR. The in-hospital mortality was 2.6%. The median follow-up was 26 months. The 3-year survival for patients with zero or one sub-threshold CPET value ([Formula: see text] at AT<10.2 ml kg(-1) min(-1), peak [Formula: see text]<15 ml kg(-1) min(-1) or [Formula: see text] at AT>42) was 86.4% compared with 59.9% for patients with three sub-threshold CPET values. Risk factors independently associated with survival were female sex [hazard ratio (HR)=0.44, 95% confidence interval (CI) 0.22-0.85, P=0.015], diabetes (HR=1.95, 95% CI 1.04-3.69, P=0.039), preoperative statins (HR=0.58, 95% CI 0.38-0.90, P=0.016), haemoglobin g dl(-1) (HR=0.84, 95% CI 0.74-0.95, P=0.006), peak [Formula: see text]<15 ml kg(-1) min(-1) (HR=1.63, 95% CI 1.01-2.63, P=0.046), and [Formula: see text] at AT>42 (HR=1.68, 95% CI 1.00-2.80, P=0.049)., Conclusions: CPET variables are independent predictors of reduced survival after elective AAA repair and can identify a cohort of patients with reduced survival at 3 years post-procedure. CPET is a potentially useful adjunct for clinical decision-making in patients with AAA., (© The Author 2014. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: Iodinated contrast during endovascular aneurysm repair (EVAR) is used with caution in patients with chronic kidney disease. Contrast-enhanced ultrasound (CEUS) imaging using nonnephrotoxic sulphur hexafluoride microbubble contrast is a novel imaging modality that accurately identifies and characterizes endoleaks during EVAR follow-up. We report our initial experience of using three-dimensional (3D) CEUS imaging intraoperatively as completion imaging after endograft deployment. Our aim was to compare intraoperative 3D CEUS against uniplanar angiography in the detection of endoleak, stent deformity, and renal artery perfusion during EVAR., Methods: The study enrolled 20 patients undergoing elective conventional infrarenal EVAR, after which a completion angiogram was performed and the presence of endoleak, renal artery perfusion, or device deformity were recorded. With the patient still under anesthetic, a vascular scientist blinded to angiographic findings performed 3D CEUS and reported on the same parameters., Results: Three endoleaks, one type I and two type II, were detected on uniplanar angiography and 13 endoleaks, 11 type II and two type I, were found using 3D CEUS imaging. Of note, one of these type I endoleaks was not seen on angiography, and this patient underwent balloon moulding of the neck with resolution of the endoleak on repeat imaging. Of the 11 type II endoleaks seen with 3D CEUS imaging, the inflow vessel was identified in nine cases. No graft deformity or limb kinking was seen in any patient. Both renal arteries could be visualized in 10 patients, whereas the target renal artery was seen in 11 patients. In the remaining patients, the renal arteries could not be visualized, mainly due to intra-abdominal gas or patient body habitus., Conclusions: 3D CEUS imaging detected endoleaks not seen on uniplanar digital subtraction angiography, including a clinically important type I endoleak, and was also more sensitive than 2D CEUS imaging for the detection of the source of endoleak. This technology has the potential to supplement or replace digital subtraction angiography for completion imaging to reduce the use of x-ray contrast. Intraoperative 3D CEUS has been applied to allow safe EVAR with ultralow or no iodinated contrast usage in selected cases, without compromising completion imaging., (Copyright © 2014 Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.)

Objective/background: A number of contemporary risk prediction models for mortality following elective abdominal aortic aneurysm (AAA) repair have been developed. Before a model is used either in clinical practice or to risk-adjust surgical outcome data it is important that its performance is assessed in external validation studies., Methods: The British Aneurysm Repair (BAR) score, Medicare, and Vascular Governance North West (VGNW) models were validated using an independent prospectively collected sample of multicentre clinical audit data. Consecutive, data on 1,124 patients undergoing elective AAA repair at 17 hospitals in the north-west of England and Wales between April 2011 and March 2013 were analysed. The outcome measure was in-hospital mortality. Model calibration (observed to expected ratio with chi-square test, calibration plots, calibration intercept and slope) and discrimination (area under receiver operating characteristic curve [AUC]) were assessed in the overall cohort and procedural subgroups., Results: The mean age of the population was 74.4 years (SD 7.7); 193 (17.2%) patients were women and the majority of patients (759, 67.5%) underwent endovascular aneurysm repair. All three models demonstrated good calibration in the overall cohort and procedural subgroups. Overall discrimination was excellent for the BAR score (AUC 0.83, 95% confidence interval [CI] 0.76-0.89), and acceptable for the Medicare and VGNW models, with AUCs of 0.78 (95% CI 0.70-0.86) and 0.75 (95% CI 0.65-0.84) respectively. Only the BAR score demonstrated good discrimination in procedural subgroups., Conclusion: All three models demonstrated good calibration and discrimination for the prediction of in-hospital mortality following elective AAA repair and are potentially useful. The BAR score has a number of advantages, which include being developed on the most contemporaneous data, excellent overall discrimination, and good performance in procedural subgroups. Regular model validations and recalibration will be essential., (Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: CT angiography (CTA) for endovascular aneurysm repair (EVAR) surveillance involves irradiation and nephrotoxic X-ray contrast agents. Three-dimensional contrast enhanced ultrasound (3D CEUS) is a novel imaging technique that may be more sensitive to blood flow detection than CTA or 2D CEUS. 3D CEUS utilises positional information from magnetic field emitters to assemble all ultrasound reflections into a high-definition image. We compared 3D CEUS with CTA for the detection of endoleak and aneurysm expansion following EVAR., Methods: 3D CEUS (Curefab), 2D CEUS (Philips IU22), and CTA were compared in 30-paired images from 23 patients. Sensitivity, specificity, positive, and negative predictive value were calculated for 2D and 3D CEUS against CTA as the 'gold standard'. Pearson correlation was used to compare aneurysm sac diameter. Data were analysed using SPSS version 19.0., Results: 30 paired 3D CEUS and CTA images were analysed from 23 patients. Endoleaks were detected in 17 images with CTA, 18 on 2D CEUS, and 18 on 3D CEUS. The sensitivity, specificity, positive, and negative predictive values of 3D CEUS to detect endoleak were 100%, 92%, 94%, and 100%, respectively. There was excellent correlation (r=0.935; p≤.0001) between CTA and 3D CEUS for AAA sac diameter. Only 3D CEUS detected the inflow and outflow arteries in all 18 scans with endoleak. 2D CEUS detected the inflow in 16 (88.8%) and CTA on 12 (66.6%) of the images., Conclusion: 3D CEUS may be more sensitive to endoleak following EVAR than either 2D CEUS or CTA., (Copyright © 2014 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Introduction: Carotid endarterectomy (CEA) should be performed within two weeks of symptoms for patients with carotid stenosis >50%. Whether these standards are being achieved and causes of delay between symptoms and CEA were investigated., Design: An analysis of prospectively collected multi-centre data., Materials: Consecutive data for patients undergoing CEA between January-2006 and September-2010 were collected. Asymptomatic patients and those with no details on the timing of cerebral symptoms were excluded., Methods: 'Delay' from symptom to CEA was defined as more than two weeks and 'prolonged-delay' more than eight weeks. Univariable and multivariable analyses were used to identify factors associated with these delays., Results: Of 2147 patients with symptoms of cerebral ischaemia, 1522(70.9%) experienced 'delay' and 920(42.9%) experienced 'prolonged delay'. Patients with ischaemic heart disease were more likely to experience 'delay' (OR = 1.56; 95% CI 1.11-2.19, p = 0.011), whereas patients with stroke (OR = 0.77; 95%CI 0.63-0.94, p = 0.011) and those treated at hospitals with a stroke-prevention clinic (OR = 0.57; 95%CI 0.46-0.71, p < 0.001) were less likely to experience 'delay'. Patients treated after the publication of National Institute for Health and Clinical Excellence (NICE) guidelines were less likely to experience 'prolonged delay' (OR = 0.77; 95%CI 0.65-0.91, p = 0.003) but not 'delay'., Conclusion: Few patients achieved CEA within two weeks of symptoms. Introducing stroke-prevention clinics with one-stop carotid imaging appears important., (Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Objectives: Renal failure following abdominal aortic aneurysm (AAA) repair is a common and significant complication. The objective of this study was to identify risk factors for renal failure following open elective AAA repair., Design: A retrospective analysis of prospectively collected multi-centre data., Materials: Consecutive data on patients undergoing open elective AAA repair were collected between January 2000 and December 2010. Patients with pre-operative serum creatinine >200 μmol/L were excluded., Methods: Renal failure was reported by clinicians and included all patients requiring post-operative renal-replacement therapy. Univariate and multivariate analyses were used to identify renal failure risk factors. A simplified clinical risk score was developed., Results: Post-operative renal failure occurred in 140 (6.0%) of 2347 patients and was associated with age >75 (OR = 1.58, 95%CI 1.11-2.26), symptomatic AAA (OR = 1.77, 95%CI 1.24-2.52), supra/juxta renal AAA (OR = 2.17, 95%CI 1.32-3.57) pre-operative serum creatinine >150 (OR = 2.75, 95%CI 1.69-4.50), treated hypertension (OR = 1.87, 95%CI 1.28-2.74), and respiratory disease (OR = 2.08, 95%CI 1.45-2.97). Patients with post-operative renal failure had significantly higher 30-day mortality (35.0% vs. 4.3%, p < 0.001)., Conclusions: Renal failure following open elective AAA repair was associated with an increased risk of mortality. Risk factors for post-operative renal failure were identified and a simple clinical risk score developed to facilitate focussed care strategies for high-risk patients., (Copyright © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: Currently there is no universally accepted standard for ultrasound measurement of abdominal aortic aneurysm (AAA). The aim was to investigate the reliability and reproducibility of inner to inner (ITI) versus outer to outer (OTO) ultrasound measurement of AAA diameter., Methods: A prospective study design was used to collect 60 random images of aorta (1.4-7.1 cm). Inner and outer wall diameter measurements were then performed by 13 qualified AAA screening technicians and 11 vascular sonographers., Results: The mean (range) diameter for all 60 aortas by ITI was 3.91 cm (1.39-6.80) and by OTO was 4.18 cm (1.63-7.09), a significant mean difference of 0.27 cm (95% CI: 0.23-0.32 cm). The reproducibility coefficients for differences between technicians were 0.30 cm (95% CI: 0.24-0.36) for ITI and 0.42 cm (95% CI: 0.35-0.49) for OTO indicating significantly better repeatability using ITI. Finally, 15 images were measured twice in random order by all screeners and sonographers. For AAAs > 5 cm, repeatability was significantly better with ITI than OTO (0.14 vs. 0.21; p = 0.016)., Conclusion: There was the expected difference in AAA diameter between the two methods (0.27 cm). However, ITI wall method was measurably more reproducible., (Copyright © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Evidence suggests that cancer patients who develop venous thromboembolism (VTE) have a poorer outcome than those who do not. The aim of this prospective study was to assess the incidence of the development of VTE in breast cancer patients commencing chemotherapy and the relationship between development of thrombosis and cancer progression and death., Patients and Methods: One hundred and thirty-four breast cancer patients were recruited and followed up prior to chemotherapy and at 3, 6, 12 and 24 months. Duplex ultrasound imaging (DUI) was performed 1 month following commencement of chemotherapy or if patients became symptomatic., Results: Thirteen patients developed VTE. Six patients with advanced breast cancer and seven with early breast cancer developed VTE. Three patients died from VTE; all had advanced breast cancer. In patients with VTE, the 28-day mortality rate was 15%, but in patients with symptomatic VTE, the 28-day mortality was 22%. Development of VTE did not predict for progression by three and six months in advanced breast cancer patients. VTE demonstrated a trend for predicting progression by two years. Using Cox regression survival analysis, there was no survival advantage in those with or without VTE., Conclusion: Although the body of evidence supports a worse prognosis when VTE and cancer coexist as compared to either diagnosis alone, a larger prospective study is required to confirm this and clarify whether any premature death is primarily due to VTE or to more aggressive cancer.

Background: Varicose veins are common and increasingly are being treated by less invasive endoscopic methods such as foam sclerotherapy. Patent foramen ovale (PFO) is also common, present in approximately one-quarter of adults. PFO allows bubbles introduced by foam sclerotherapy to cross into the general circulation, potentially causing cerebral artery gas embolization with unevaluated consequences., Methods: Men and women aged 18 to 60 years with symptomatic varicose veins (CEAP C(3-5)) responded to an advertisement to recruit volunteers for a study on endovenous microfoam ablation (EMA). Participants' veins were screened by duplex ultrasound imaging, and those with isolated great saphenous vein (GSV) incompetence were tested for right-to-left (R-L) vascular shunt using transcranial Doppler (TCD) of the middle cerebral artery to detect the presence of bubble emboli after an injection of an agitated saline, blood, and air mixture as a contrast at rest and with the Valsalva maneuver., Results: Of 221 participants tested for R-L shunt, 85 (38.5%) were positive at rest (95% confidence interval [CI], 32.5-45.2) and 114 (51.8%) were positive after the Valsalva maneuver (95% CI, 45.4-58.5). A total 130 patients (58.8%) were positive for R-L shunt at rest or after Valsalva (95% CI, 52.5%-65.1%). This is significantly higher than the reported 26% prevalence of PFO in the general population (95% CI, 24.4-30.1)., Conclusions: The prevalence of R-L shunt in patients with GSV incompetence CEAP C(3-5) in this study was higher than expected in the general population. TCD does not differentiate between intracardiac shunts and intrapulmonary shunts, so this observation needs further investigation. This link between R-L shunt and varicose veins is novel and, whether etiologic or functional, may improve the understanding of both conditions. The findings have importance in the treatment of varicose veins with foam sclerotherapy and EMA., (Copyright 2010 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

Venous thromboembolism (VTE) following breast cancer chemotherapy is common. Chemotherapy-induced alterations in markers of haemostasis occur during chemotherapy. It is unclear how rapidly this occurs, whether this is upregulated in patients developing VTE and whether changes predict for VTE. Markers of haemostasis, functional clotting assays and vascular endothelial growth factor were measured before chemotherapy and at 24 h, 4 days, 8 days and 3 months following commencement of chemotherapy in early and advanced breast cancer patients and in age- and sex-matched controls. Duplex ultrasound imaging was performed after 1 month or if symptomatic. Of 123 patients, 9.8% developed VTE within 3 months. Activated partial thromboplastin time (APTT), prothrombin time (PT), D-dimer, fibrinogen, platelet count, VEGF and fibrinogen were increased in cancer. Fibrinogen, D-dimer, VEGF and tissue factor were increased, at baseline, in patients subsequently developing VTE. D-dimer of less than 500 ng ml(-1) has a negative predictive value of 97%. Activated partial thromboplastin time, PT and thrombin-antithrombin showed significantly different trends, as early as within 24 h, in response to chemotherapy in patients subsequently developing VTE. Markers of coagulation and procoagulants are increased, before chemotherapy, in patients who subsequently develop VTE. A group of patients at minimal risk of VTE can be identified, allowing targeted thrombopropylaxis to the higher risk group.

Five consecutive cases of prosthetic inter-vertebral disc displacement with severe vascular complications on revisional surgery are described. The objective of this case report is to warn spinal surgeons that major vascular complications are likely with anterior displacement of inter-vertebral discs. We have not been able to find a previous report on vascular complications associated with anterior displacement of prosthetic inter-vertebral discs. In all five patients the prosthetic disc had eroded into the bifurcation of the inferior vena cava and the left common iliac vein. In three cases the aortic bifurcation was also involved. The fibrosis was so severe that dissecting out the arteries and veins to provide access to the relevant disc proved impossible. Formal division of the left common iliac vein and artery with subsequent repair was our solution. Anterior inter-vertebral disc displacement was associated with severe vascular injury. Preventing anterior disc displacement is essential in disc design. In the event of anterior displacement, disc removal should be planned with a Vascular Surgeon.

The aim of this study was to examine our hypothesis that platelets of patients with breast cancer were functionally altered compared to healthy controls. The results have shown that the platelets from women with early breast cancer released significantly more vascular endothelial growth factor (VEGF) when stimulated with thrombin, tissue factor, clotting, or over a period of time. Similarly, release of thrombospondin (TSP) with thrombin and tissue factor was higher, but failed to reach a significant level. Thus, the observed differences in platelet response support our hypothesis, but warrant further work to determine the reason underlying the observed difference and potential clinical relevance of our findings.

Objective: To investigate changes in cognitive function following carotid endarterectomy (CEA)., Design: Prospective study with controls., Methods: CEA patients (n=159) were compared to a urology surgery control group (n=20). In CEA patients cerebrovascular reserve (CVR) was measured preoperatively. During surgery emboli and blood flow velocity in the middle cerebral artery were measured by transcranial Doppler (TCD) and cerebral oxygen saturation (CsO2) by near infrared spectroscopy. Cognitive function was measured preoperatively and at 5 days and 8 weeks postoperatively using a standardised computer battery of tests., Results: Only 8% of patients had normal CVR bilaterally. The median number of emboli during CEA was 12 (range 0-181). On carotid clamping, TCD velocity fell a median of 41% and cerebral oxygen saturation by 5%. Attention deteriorated compared to controls 5 days following CEA (p=0.003) and this deterioration was related to the rise in TCD velocity on declamping (r=-0.3, p=0.002). Median attention reaction times improved significantly by 8 weeks (p=0.001) especially in patients' with severely impaired CVR before surgery (p=0.02)., Conclusions: Attention improved at 2 months following CEA in patients with impaired CVR. CEA may offer more than reduced stroke risk to patients with impaired CVR.

Objectives: to investigate the relationship between clinical severity of venous disease, calf muscle pump dysfunction and range of ankle movement (ROAM)., Materials and Methods: ROAM was assessed by goniometry in the supine, nonweightbearing position. Calf muscle pump function was assessed by ambulatory venous pressure (AVP), calculating the pressure relief index (PRI). Venous disease was classified according to the CEAP classification (International Consensus Committee reporting standards on venous disease). Forty seven limbs in 38 adults were recruited and matched for age: 11 normal controls CEAP(0), 12 varicose veins CEAP(2), 12 chronic venous insufficiency CEAP(4,5) and 12 active ulceration CEAP(6)., Results: mean (S.E.M.) age was 60.7 (1.3) years. Mean (S.E.M.) PRI was 1959.6 (313.7) in CEAP(0), 905.3 (139.3) in CEAP(2), 596.5 (148.5) in CEAP(4,5) and 170.6 (69.0) in CEAP(6) (p < 0.001, ANOVA). Mean (S.E.M.) ROAM was 61.3 (2.0) degrees in CEAP(0), but significantly reduced to 49.7 (2.0) in CEAP(2), 42.1 (2.6) in CEAP(4,5) and 40.9 (2.7) in CEAP(6) (p < 0.004, ANOVA post hoc Tukey). PRI correlated with ROAM (p < 0.001, Pearson correlation coefficientr = 0.52)., Conclusions: limbs with venous hypertension have a reduced range of ankle movement related to the clinical severity of venous disease.

Increased low-density lipoprotein (LDL)-cholesterol is a risk factor for atherosclerosis--a disease in which damage to the endothelium is believed to be an important early step. Increased levels of the endothelial marker von Willebrand factor (vWF) in the plasma of patients with hypercholesterolaemia and atherosclerosis probably reflect this process. In this study we seek to link the established observation that oxidised LDL-cholesterol is cytotoxic to human umbilical vein endothelial cells (HUVECs) in vitro with the common finding of raised plasma vWF in patients with atherosclerosis by incubating HUVECs with physiological/pathological levels of native and oxidised LDL-cholesterol for up to 48 h. Microphotography revealed morphological changes in the HUVECs within 24 h, becoming severe at 48 h, which was mirrored by increased levels of vWF (ELISA) and the release of preloaded radioactive (111)indium tracer into culture supernatants. Our data support and extend the hypothesis that oxidised LDL is directly cytotoxic to HUVECs, and, in addition, provide an important link between in vitro studies and clinical studies where endothelial cell markers such as vWF are increased in the plasma of patients with hypercholesterolaemia and atherosclerosis.

Objectives: we investigated whether carotid sinus nerve infiltration with lignocaine reduced blood pressure lability during the first 24h following carotid endarterectomy (CEA)., Design: prospective randomised double-blind controlled trial., Materials: eighty patients undergoing CEA for significant symptomatic stenosis of the internal carotid artery., Methods: after initial dissection, 5 ml of 1% lignocaine or normal saline placebo according to randomisation was infiltrated around the carotid sinus nerve. Blood pressure was measured by intra-arterial cannula during surgery and for four hours afterwards every 15 min, then manually, hourly for 18 h., Results: patients having excision of the carotid sinus nerve were grouped separately for analysis: 29 patients had lignocaine, 33 placebo and 17 excision (one early death with incomplete data was excluded). Mean systolic, diastolic and pulse pressures did not differ significantly between the three groups before carotid sinus nerve infiltration. After infiltration, those patients who had carotid sinus nerve excision, had significantly higher systolic [mean (SD)=155 (16)mmHg] and diastolic [75 (9)mmHg] pressures than those receiving LA [systolic=136 (15)mmHg, diastolic=65 (10)mmHg] or placebo [systolic=136 (19)mmHg, diastolic=65 (9)mmHg], (p<0.005 ANOVA). Nerve excision also resulted in wider variability of blood pressure as defined by the mean of individual standard deviations (systolic=25 mmHg, diastolic=13 mmHg) compared to LA (systolic=19 mmHg, diastolic=12 mmHg) or placebo (systolic=18 mmHg, diastolic=10 mmHg) (p<0.05 ANOVA). Normotensive patients had significantly lower mean diastolic pressures (p<0.001 ANOVA) and variability (p<0.05) if they received lignocaine although this did not influence pulse pressure., Conclusions: lignocaine injection of the carotid sinus nerve has no benefit in those patients with existing treated hypertension and only marginal effects in normotensives. It is more important to preserve the carotid sinus nerve if possible.

We investigated whether near infrared spectroscopy could be used to monitor regional tissue oxygenation during uncompensated hemorrhage in man. A Somanetics INVOS 4100 oximeter was used to measure regional hemoglobin oxygen saturation in the cerebral cortex (CsO2, left frontal area) and from the left calf muscle (PsO2) in 40 volunteers donating 470 mL of the whole blood. A Critikon 2001 Cerebral Redox Instrument was used to monitor total (tHb), oxygenated (O2Hb), and deoxygenated (HHb) hemoglobin in the right calf muscle. The oxygenation index, [HbD] = [O2Hb] - [HHb] was derived. CsO2 decreased by a mean (95% CI) of 2 (1-3.3%) (P < 0.001), PsO2 decreased by a mean (95% CI) of 3.2 (1.7-4.6%) (P < 0.001), and HbD decreased by a median (95% CI) of 6.4 (2.65-10.16) delta microM/cm (P < 0.001) during blood collection. There was an inverse correlation between blood loss and CsO2 (R = -0.59, P < 0.001), PsO2 (R = -0.61, P < 0.001), and HbD (R = -0.5, P < 0.001). Regional tissue oxygenation decreases in proportion to uncompensated blood loss. Near infrared spectroscopy may potentially be developed into a transfusion trigger.

Blood and blood products are commonly over-used in hospital practice. We investigated whether the introduction of a red-cell transfusion trigger (haemoglobin <8 g dL(-1)) influenced transfusion practice in surgery. Coronary artery bypass grafts (CABGs, n=400), total hip replacements (n=107), colectomies (n=85) and transurethral prostatectomies (TURPs, n=158) were reviewed over two periods of six months, before and after the introduction of the policy by the local hospital transfusion committee. After introduction of the policy, the proportion of patients transfused fell from 57% to 45% with CABGs (P=0.02) and from 52% to 26% with hip replacements (P=0.006); for colectomies and TURPs there was no change. Hospital stay did not increase in any of the groups. In the second period, haemoglobin concentration on discharge was lower after total hip replacement, by a mean (95% CI) of 0.7 (0.3-1.2) g dL(-1) (P=0.002) and after colectomy, by a mean of 0.6 (0.1-1.1) g dL(-1) (P=0.03). Although other factors cannot be excluded, we suggest that the reductions in red-cell transfusion were in large part attributable to the new transfusion policy.

Objective: The objective of this study was to report current transfusion requirements and outcomes in patients undergoing elective aortic surgery with autologous transfusion., Methods: This was a retrospective review of transfusion practice in infrarenal aortic surgery in a tertiary vascular unit with a longstanding interest in autologous transfusion. One hundred and ten consecutive patients underwent infrarenal aortic surgery with a combination of acute normovolemic hemodilution (ANH) and intraoperative cell salvage (ICS). All patients underwent hemodilution to a target hemoglobin concentration of 11 g/dL and underwent ICS with a centrifugal device., Results: Median blood loss was 1140 mL (interquartile range [IQR], 683 to 1609 mL) in 78 aneurysm repairs and 775 mL (IQR, 400 to 1225 mL) in 32 aortobifemoral bypasses for occlusive disease (P =.02), resulting in a median salvaged red cell volume of 403 mL (IQR, 256 to 563 mL) for aneurysm repairs and 250 mL (IQR, 200 to 290 mL) in bypass surgery (P =.001). Thirty-six patients (33%) needed transfusion of stored blood, for a total of 115 units, with just four patients needing more than five units. The mortality rate was 8% (9/110). With multivariate analysis, low hemoglobin level (P =.006) and low platelet count (P =.023) were associated with stored blood transfusion., Conclusion: Blood loss is too small to justify ICS in surgery for occlusive disease; ANH alone may be a suitable strategy. With appropriate experience, the combination of ANH and ICS may render crossmatching unnecessary, even in aortic aneurysm surgery.

Purpose: The degree of ischemia during intermittent claudication is difficult to quantify. We evaluated calf muscle ischemia during exercise in patients with claudication with near infrared spectroscopy., Methods: A Critikon Cerebral Redox Model 2001 (Johnson & Johnson Medical, Newport, Gwent, United Kingdom) was used to measure calf muscle deoxygenated hemoglobin (HHb), oxygenated hemoglobin (O(2)Hb), and total hemoglobin levels and oxygenation index (HbD; HbD = O(2)Hb - HHb) in 16 patients with claudication and in 14 control subjects before, during, and after walking on a treadmill for 1 minute (submaximal exercise). These measures were repeated after a second maximal exercise in patients with claudication and after 7 minutes walking in control subjects. Near-infrared spectroscopy readings during maximal exercise were then compared with a model of total ischemia induced with tourniquet in 16 young control subjects., Results: Total hemoglobin level changed little during exercise in both patients with claudication and control subjects. HHb levels rose, and O(2)Hb level and HbD falls were more pronounced in patients with claudication than in control subjects after submaximal and maximal exercise. During maximal exercise, HbD fell markedly by a median (interquartile range) of 210.5 micromol/cm (108.2 to 337.0 micromol/cm) in patients with claudication compared with 66.0 micromol/cm (44.0 to 101.0 micromol/cm) in elderly control subjects and 41.0 micromol/cm (36.0 to 65.0 micromol/cm) in young control subjects (P <.001). This fall also was greater than the HbD fall induced with tourniquet ischemia at 90.8 micromol/cm (57.6 to 126.2 micromol/cm; P =.006)., Conclusion: Hemoglobin desaturation in exercising calf muscle is profound in patients with claudication, considerably greater even than that induced with three minutes of tourniquet occlusion. Further studies are necessary to investigate the relationship between the inflammatory response and near-infrared spectroscopy during exercise in patients with claudication.

Background and Purpose: Transcranial Doppler may be used to detect spontaneous cerebral emboli (SCE), but this information will only identify at-risk patients if these individuals are consistently identified over time. We investigated the consistency of SCE production in patients with symptomatic carotid disease., Methods: Transcranial Doppler signals from the ipsilateral middle cerebral artery in 25 patients with symptomatic carotid stenosis of >70% were recorded over 1 hour for blind analysis by a panel of trained observers. This was repeated at the same time of day, weekly, for 6 weeks., Results: The number of patients with SCE increased with each week of monitoring until 13 (52%) were positive. The range of the cumulative number of SCE was 1 to 6. Ten (40%) patients were positive for SCE during only 1 monitoring session, and 2 (8%) were positive for SCE during 2 sessions. SCE-positive patients tended to have more recent symptoms. The correlation coefficients between time elapsed since last cerebral symptom and SCE were weak and not significant., Conclusions: Most, if not all, patients with severe carotid disease will eventually produce SCE. However, the production of an SCE is random, and it is likely that many hours of monitoring are required to determine whether a patient with symptomatic carotid disease is SCE positive. SCE are unlikely to identify at-risk patients but may indicate periods of transiently increased risk in individual patients.

Objective: To evaluate the efficacy of acute normovolemic hemodilution (ANH) and intraoperative cell salvage (ICS) in blood-conservation strategies for infrarenal aortic surgery., Summary Background Data: Recent concerns over the risks of transfusion-related infection have resulted in sharp rises in the cost of blood preparations. Autologous transfusion may be a safe alternative to allogeneic transfusion, which has been associated with immune modulation and postoperative infection., Methods: This multicenter prospective randomized trial compared standard transfusion practice with autologous transfusion combining ANH with ICS in 145 patients undergoing elective aortic surgery. The primary outcome measures were the proportion of patients requiring allogeneic blood and the volume of allogeneic transfusion. The secondary outcome measures were the frequency of complications, including postoperative infection, and postoperative hospital stay., Results: The combination of ANH and ICS reduced the volume of allogeneic blood transfused from a median of two units to zero units. The proportion of patients transfused was 56% in allogeneic and 43% in autologous. There were no significant differences in complications or length of hospital stay., Conclusions: Both ANH and ICS were safe and reduced the allogeneic blood requirement in patients undergoing elective infrarenal aortic surgery.

Objectives: Cerebral microembolisation still occurs during cardiopulmonary bypass and may cause both stroke and postoperative cognitive impairment. We investigated the frequency of cerebral embolisation during coronary artery bypass surgery with modern cardiopulmonary bypass and related these to ascending aortic atherosclerosis., Methods: Transcranial Doppler monitoring for cerebral embolisation to both middle cerebral arteries was performed in 65 patients undergoing coronary artery surgery with non-pulsatile alpha-stat hypothermic bypass. Epicardial ultrasound imaging of ascending aortic atherosclerosis was performed in 14 patients., Results: Thirty patients (56.9%) had more than 200 emboli entering the middle cerebral artery territories during surgery; most at the start of bypass and during defibrillation. Readjustment of aortic clamps and aortic cannulation also caused a large number of emboli which were probably particulate. Aortic disease was mild (mean plaque thickness 1 mm, interquartile range 0.9-1.2 mm) and did not relate to the number of cerebral emboli produced by aortic manipulation., Conclusions: Cerebral embolisation remains common during coronary surgery despite advances in filter and bypass pump technology. Aortic manipulation and clamping was associated with emboli but epicardial ultrasound imaging was of little help in its prediction.

Objectives: To evaluate the influence of homologous blood transfusion on immune responses and post-operative morbidity in aortic surgery., Design: Analysis of the effects of homologous blood transfusion in 128 patients in a prospective randomised trial evaluating homologous and autologous blood transfusion in aortic surgery., Materials and Methods: Blood sampled before and at five times after surgery was assayed for C-reactive protein (CRP), neutrophil elastase, TNF-alpha and IL-6. Transfusions, morbidity and mortality were recorded; factors associated with poor outcome were identified by logistic regression., Results: homologous transfusion during surgery was required in 32 patients and precipitated an increase in neutrophil elastase (p=0.008) and TNF-alpha (p=0.015) but not IL-6 and CRP. Elastase peaked early in transfused patients at 41.27 (13.92-52.11) Deltang/ml by 2 h compared to a peak of 21.51 (10.64-31.13) Deltang/ml by 24 h in those who were not transfused. TNF-alpha peaked at 1.2 (0-4.33) Deltapg/ml by wound closure in transfused patients and at -0.1 (-2.05-2.52) Deltapg/ml by 2 h without transfusion. Intra-operative homologous transfusion was associated with increased mortality (p=0.01) and prolonged intensive care stay (p=0.03). Mortality increased with age (p=0.003) and was inversely related to the CRP peak (p=0.007). Prolonged surgery predicted post-operative complications (p=0.025)., Conclusion: Homologous transfusion increased the inflammatory response to aortic surgery and was associated with mortality.

Objectives: Cognitive deficits occur in up to 80% of patients after cardiac surgery. We investigated the influence of cerebral perfusion and embolization during cardiopulmonary bypass on cognitive function and recovery., Methods: Cerebrovascular reactivity was measured in 70 patients before coronary operations in which nonpulsatile bypass was used. Throughout the operations, middle cerebral artery flow velocity and embolization were recorded by transcranial Doppler and regional oxygen saturation was recorded by near-infrared spectroscopy. Cognitive function was measured by a computerized battery of tests before the operation and 1 week, 2 months, and 6 months after surgery. Elderly patients undergoing urologic surgery served as controls., Results: Cerebrovascular reactivity was impaired preoperatively in 49 patients. Median (interquartile range) regional cerebral oxygen saturation fell during bypass by 10% (6%-15%), indicating increased oxygen extraction, whereas mean middle cerebral flow velocity increased significantly by a median of 6 cm/s (both P <.0001, Wilcoxon), suggesting increased arterial tone. More than 200 emboli were detected in 40 patients, mainly on aortic clamping and release, when bypass was initiated, and during defibrillation. Cognitive function deteriorated more in patients having cardiopulmonary bypass than in control patients having urologic operations but recovered in most tests by 2 months. Measures of cerebral perfusion (poor cerebrovascular reactivity, low arterial pressures, and flow velocity in the middle cerebral artery) predicted poor attention at 1 week (r = 0.3, P <.01, Spearman). Emboli were associated with memory loss (r = 0.3, P <.02, Spearman)., Conclusions: Cognitive deficits were common after cardiopulmonary bypass. Occult cerebrovascular disease was more severe than expected and predisposed to attention difficulties, whereas emboli caused memory deficits. We believe this to be the first report of differing cognitive effects from emboli and hypoperfusion.

Purpose: In the presence of carotid occlusion, the external carotid artery (ECA) becomes an important source of cerebral blood flow, especially if the circle of Willis is incomplete. The contribution of the ECA to hemispheric blood flow in patients with severe ipsilateral carotid stenosis has never been previously investigated., Methods: One hundred eight patients were monitored during sequential cross-clamping of the external (ECA) and then ipsilateral internal carotid artery (ICA) during carotid endarterectomy using transcranial Doppler sonography (TCD) (Neuroguard CDS, Los Angeles, Calif), to measure middle cerebral artery blood flow velocity, and near-infrared spectroscopy, to measure regional cerebral oxygen saturation (CsO(2)) (Invos 3100A; Somanetics, Troy, Mich)., Results: On the ipsilateral ECA cross-clamp, the median fall in CsO(2) was 3% (interquartile range, 1%-4%; P <.0001). On addition of the ICA cross-clamp there was a further fall of 3% and a total fall of 6% (3%-9%; P <.0001). The median percentage fall in middle cerebral artery blood flow velocity on ECA clamping was 12% (4%-24%; P <.0001); on ICA clamping it was 48% (25%-74%; P <.0001). Falls in TCD on ECA clamping were greater with increasing severity of ipsilateral ICA stenosis. The correlation between CsO(2) and TCD on external clamping, although less strong than that on internal clamping, was statistically significant r = 0.32; P =.01; Spearman rank correlation)., Conclusions: The falls in TCD and CsO(2) were of a similar order of magnitude and must therefore reflect a fall in cerebral perfusion. The ipsilateral ECA contributes significantly to intracranial blood flow and oxygen saturation in severe carotid stenosis.

Objective: To review gradual snare occlusion for the management of complex or recurrent graft infection., Patients and Methods: Medical records of patients treated with gradual snare occlusion following graft infection were reviewed for indication for operation, type of bypass and graft material used. In addition, infecting organism, grade of infection (Szilágyi) and outcome were recorded., Results: Four femoropopliteal, two extra-anatomic (axillofemoral) and aortobifemoral bypasses were included in this study. All had chronic infection (Szilágyi grade III) with onset of 4 to 24 months and two of which were recurrent. The causative organisms were coagulase-negative staphylococci, Staphylococcus epidermidis and methicillin-resistant Staphylococcus aureus in three patients, with no organism isolated in the remaining cases. There was no loss of limb following gradual snare occlusion but there was only one death due to aortic stump rupture 2 weeks later., Conclusion: Gradual snare occlusion is an alternative for the management of chronic or recurrent graft infection., (Copyright 1999 Harcourt Publishers Ltd.)

Background: the Oxfordshire Community Stroke Project (OCSP) devised a simple clinical classification for acute stroke which predicted mortality, functional recovery and patterns of recurrent stroke. We aimed to determine whether this could predict the presence of carotid disease and be used to select which patients with acute stroke should be referred for carotid imaging with a view to subsequent carotid endarterectomy., Methods: we assessed patients with acute stroke admitted to seven hospitals over a 10-month period. Patients were classified according to the OCSP system and their carotid arteries investigated using portable continuous wave Doppler. Those with abnormal portable assessments had colour duplex Doppler imaging., Results: of 305 patients with proven or probable cerebral infarction, severe (70-99%) ipsilateral carotid stenosis was found in 16 (16%) of the 101 with partial anterior circulation infarct (PACI), four (4%) of the 100 with total anterior circulation infarct (TACI), none of the 80 with lacunar infarct (LACI) and one (4%) of the 24 with posterior circulation infarct (POCI). Complete ipsilateral carotid occlusion was found in 25 (25%) of the TACI group, 11 (11%) of the PACI group, three (4%) of the LACI group and none of the POCI group. Severe carotid stenosis or occlusion was more common in the ipsilateral than the contralateral carotid artery for the TACI and PACI groups (chi2 P< 0.05), but there was no difference between ipsilateral and contralateral carotid disease in the LACI and POCI groups. If the OCSP classification is used to detect patients with 70-99% carotid stenosis, then the sensitivity is 76% and specificity is 70%., Conclusion: these findings suggest that ipsilateral carotid disease is an important cause of stroke for those with anterior circulation infarcts but not for those with LACI or POCI. Subjects with PACI should be referred for early carotid imaging to identify those with severe disease who may be suitable for elective carotid surgery.

Purpose: The purpose of this study was to assess the outcome after the shortening and reimplantation of tortuous internal carotid arteries to prevent kinking after endarterectomy., Methods: Through a review of prospective records, we studied patients who underwent carotid endarterectomy (CEA) (n = 233) between 1993 and 1996 who had symptomatic stenosis of the internal carotid artery (ICA) of more than 70%. An elongated proximal ICA was excised, and the ICA was reimplanted into the bifurcation in 30 (13%) patients, with additional patch angioplasty in 5 patients. Of the remaining 203 patients, 50 (21%) had Dacron patch angioplasty, and the rest had conventional CEA with simple closure., Results: In the reimplanted group, one patient had a minor stroke with complete recovery on discharge. Three patients (10%) had neck hematomas requiring reexploration, but in none of these was the bleeding from the artery. At mean follow-up of 15 months, 93% of the arteries were widely patent. Significant stenosis secondary to neointimal hyperplasia was detected in only two patients, for a restenosis rate of 6.7%, which is in line with other published reports. In the control group, 8 (3.9%) patients had perioperative transient ischemic attacks, 5 (2.5%) had strokes, and 13 (6.4%) had hematomas requiring evacuation. At follow-up, 14 (6.9%) of the arteries had restenosed., Conclusion: In carotid surgery, reconstructive techniques must be tailored to operative findings. Excision of a tortuous elongated proximal ICA with reimplantation is not associated with additional mortality or morbidity rates over those of conventional CEA alone and has the advantage of removing disease at the bifurcation. This procedure was carried out in 13% of our patients and should be a procedure with which the vascular surgeon is familiar.

Our objective was to determine whether endothelial cell products von Willebrand factor and soluble E-selectin are related to serum lipids, lipoprotein (a), and vascular disease in patients with hyperlipidaemia. In order to achieve our aim, blood samples were obtained for four experiments from 1) 160 patients (49 with symptomatic vascular disease) with hypercholesterolaemia and an equal number of age and sex matched controls; 2) 31 patients who were studied serially before and after successful resolution of their hypercholesterolaemia; 3) 15 patients with hypertriglyceridaemia; and 4) 20 controls, half of whom consumed a lipid-rich breakfast. von Willebrand factor and soluble E-selectin were measured by enzyme linked immunosorbent assay (ELISA) using commercial reagents. In experiment (1) von Willebrand factor was increased in the patients with hypercholesterolaemia (P=0.0077) and was higher still in patients with vascular disease (P<0.0001). Soluble E-selectin was not influenced by hypercholesterolaemia or vascular disease. The correlation of von Willebrand factor with total and LDL cholesterol (both P<0.001) remained after both age and blood pressure were controlled. Experiment (2) showed that serial studies in patients over an average of 7 months a reduction in total cholesterol was associated with a reduction in von Willebrand factor (r=0.51, P=0.002). Experiment (3) demonstrated that von Willebrand factor was not increased in patients with hypertriglyceridaemia (median 8.9 mmol/L), and in experiment (4) a lipid-rich breakfast taken by fasted, healthy controls produced an increase in serum triglycerides (P<0.01) but did not influence von Willebrand factor over an 8 hour period. We conclude that von Willebrand factor, but not soluble E-selectin, is raised in hypercholesterolaemia and therefore may be a potential indicator of endothelial cell physiology in subjects with, or at risk of, atherosclerotic vascular disease.

Objective: To investigate whether heparin reversal after carotid endarterectomy reduces the incidence of haemorrhagic complications., Design: A randomised prospective trial., Methods: Sixty-four patients randomised to reversal of heparin or no reversal, of whom 31 received protamine titrated to the residual circulating heparin at closure of arteriotomy. Measurements included serial activated clotting times (ACTs), wound drainage, neck swelling using duplex Doppler imaging to measure the depth from skin to carotid bifurcation, and the recording of all complications., Results: Wound drainage volumes were significantly reduced by protamine reversal (68.5 ml compared to 35 ml, p < 0.001), but neck swelling was not (72 mm compared to 70 mm, p = 0.77). Two patients who were not reversed developed neck haematomas requiring evacuation. More importantly, two patients receiving protamine, thrombosed the operated internal carotid artery (ICA) postoperatively and died despite urgent thrombectomy. A further patient who was not randomised in this study but who received protamine also developed ICA thrombosis within the same 3 month period., Conclusions: Reversing heparin with protamine reduces postoperative wound drainage after carotid surgery but may predispose to ICA thrombosis and stroke. This is in keeping with a previous retrospective study published during our trial.

Introduction: Carotid endarterectomy reduces the risk of stroke in patients with a history of minor ischemic stroke or transient ischaemic attacks and severe carotid stenosis, but the timing of surgery following acute stroke is controversial. Urgent carotid surgery in acute stroke may reduce the risk of early stroke recurrence due to further emboli from the diseased carotid, or may improve neurological recovery by improving cerebral blood flow to the ischaemic penumbra., Methods: We identified from the literature patients undergoing carotid surgery in acute stroke using a Medline search and identifying references from these sources., Results: Over 2000 patients were identified from the literature who underwent acute carotid surgery. Heterogeneous groups of patients were recruited, with no control patients treated medically in the majority of the studies. Mortality and morbidity was highly variable and depended primarily on the initial severity of the neurological deficit, with lower mortality in patients with minor neurological deficits., Conclusions: The role of carotid surgery in acute stroke is uncertain. A multicentre randomised controlled trial is now required to assess the value of acute carotid surgery.