Halo sign on temporal artery ultrasound versus temporal artery biopsy for giant cell arteritis.

BACKGROUND: Giant cell arteritis (GCA) is a systemic, inflammatory vasculitis primarily affecting people over the age of 50 years. GCA is treated as a medical emergency due to the potential for sudden, irreversible visual loss. Temporal artery biopsy (TAB) is one of the five criteria of the American College of Rheumatology (ACR) 1990 classification, which is used to aid the diagnosis of GCA. TAB is an invasive test, and it can be slow to obtain a result due to delays in performing the procedure and the time taken for histopathologic assessment. Temporal artery ultrasonography (US) has been demonstrated to show findings in people with GCA such as the halo sign (a hypoechoic circumferential wall thickening due to oedema), stenosis or occlusion that can help to confirm a diagnosis more swiftly and less invasively, but requiring more subjective interpretation. This review will help to determine the role of these investigations in clinical practice. OBJECTIVES: To evaluate the sensitivity and specificity of the halo sign on temporal artery US, using the ACR 1990 classification as a reference standard, to investigate whether US could be used as triage for TAB. To compare the accuracy of US with TAB in the subset of paired studies that have obtained both tests on the same patients, to investigate whether it could replace TAB as one of the criteria in the ACR 1990 classification. SEARCH METHODS: We used standard Cochrane search methods for diagnostic accuracy. The date of the search was 13 September 2022. SELECTION CRITERIA: We included all participants with clinically suspected GCA who were investigated for the presence of the halo sign on temporal artery US, using the ACR 1990 criteria as a reference standard. We included studies with participants with a prior diagnosis of polymyalgia rheumatica. We excluded studies if participants had had two or more weeks of steroid treatment prior to the investigations. We also included any comparative test accuracy studies of the halo sign on temporal artery US versus TAB, with use of the 1990 ACR diagnostic criteria as a reference standard. Although we have chosen to use this classification for the purpose of the meta-analysis, we accept that it incorporates unavoidable incorporation bias, as TAB is itself one of the five criteria. This increases the specificity of TAB, making it difficult to compare with US. We excluded case-control studies, as they overestimate accuracy, as well as case series in which all participants had a prior diagnosis of GCA, as they can only address sensitivity and not specificity. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed the studies for inclusion in the review. They extracted data using a standardised data collection form and employed the QUADAS-2 tool to assess methodological quality. As not enough studies reported data at our prespecified halo threshold of 0.3 mm, we fitted hierarchical summary receiver operating characteristic (ROC) models to estimate US sensitivity and also to compare US with TAB. We graded the certainty of the evidence using the GRADE approach. MAIN RESULTS: Temporal artery ultrasound was investigated in 15 studies (617 participants with GCA out of 1479, 41.7%), with sample sizes ranging from 20 to 381 participants (median 69). There was wide variation in sensitivity with a median value of 0.78 (interquartile range (IQR) 0.45 to 0.83; range 0.03 to 1.00), while specificity was fair to good in most studies with a median value of 0.91 (IQR 0.78 to 1.00; range 0.40 to 1.00) and four studies with a specificity of 1.00. The hierarchical summary receiver operating characteristic (HSROC) estimate of sensitivity (95% confidence interval (CI)) at the high specificity of 0.95 was 0.51 (0.21 to 0.81), and 0.84 (0.58 to 0.95) at 0.80 specificity. We considered the evidence on sensitivity and specificity as of very low certainty due to risk of bias (-1), imprecision (-1), and inconsistency (-1). Only four studies reported data at a halo cut-off > 0.3 mm, finding the following sensitivities and specificities (95% CI): 0.80 (0.56 to 0.94) and 0.94 (0.81 to 0.99) in 55 participants; 0.10 (0.00 to 0.45) and 1.00 (0.84 to 1.00) in 31 participants; 0.73 (0.54 to 0.88) and 1.00 (0.93 to 1.00) in 82 participants; 0.83 (0.63 to 0.95) and 0.72 (0.64 to 0.79) in 182 participants. Data on a direct comparison of temporal artery US with biopsy were obtained from 11 studies (808 participants; 460 with GCA, 56.9%). The sensitivity of US ranged between 0.03 and 1.00 with a median of 0.75, while that of TAB ranged between 0.33 and 0.92 with a median of 0.73. The specificity was 1.00 in four studies for US and in seven for TAB. At high specificity (0.95), the sensitivity of US and TAB were 0.50 (95% CI 0.24 to 0.76) versus 0.80 (95% CI 0.57 to 0.93), respectively, and at low specificity (0.80) they were 0.73 (95% CI 0.49 to 0.88) versus 0.92 (95% CI 0.69 to 0.98). We considered the comparative evidence on the sensitivity of US versus TAB to be of very low certainty because specificity was overestimated for TAB since it is one of the criteria used in the reference standard (-1), together with downgrade due to risk of bias (-1), imprecision (-1), and inconsistency (-1) for both sensitivity and specificity. AUTHORS' CONCLUSIONS: There is limited published evidence on the accuracy of temporal artery US for detecting GCA. Ultrasound seems to be moderately sensitive when the specificity is good, but data were heterogeneous across studies and either did not use the same halo thickness threshold or did not report it. We can draw no conclusions from accuracy studies on whether US can replace TAB for diagnosing GCA given the very low certainty of the evidence. Future research could consider using the 2016 revision of the ACR criteria as a reference standard, which will limit incorporation bias of TAB into the reference standard.

Cost-effectiveness of Diagnostic Tools to Establish the Presence of Peripheral Arterial Disease in People With Diabetes.

OBJECTIVE: To evaluate the cost-effectiveness of point-of-care duplex ultrasound (PAD-scan) and other bedside tests for the diagnosis of peripheral arterial disease (PAD) in people with diabetes. BACKGROUND: PAD is a risk factor for cardiovascular disease, diabetic foot ulceration (DFU), and amputation in diabetic patients. Diagnosis enables optimization of therapies to manage these risks. PAD-scan can be performed by frontline staff and has been shown to be the most accurate bedside test. However, its cost-effectiveness has not been investigated. METHODS: A Markov model was constructed to estimate the health outcomes and costs over 5 years of different testing strategies applied to a cohort of diabetic patients. Bedside tests investigated were PAD-scan, ankle-brachial pressure index, toe-brachial pressure index, audible and visual Doppler, transcutaneous pressure of oxygen, and pulse palpation. Health outcomes were incidence of new DFU, major cardiovascular events, amputation, death, and DFU healing rates. Sensitivity analyses were performed. RESULTS: PAD-scan was the most cost-effective bedside test with an incremental cost-effectiveness ratio of £11,391/quality-adjusted life years. PADscan had the highest probability (78.7%) of having the greatest net benefit at a willingness to pay threshold of £20,000 per quality-adjusted life years. It reduced the number of amputations by 24% and the number of cardiovascular deaths by 10% over 5 years, compared to toe-brachial pressure index (next best alternative). PAD-scans superiority in incremental cost-effectiveness ratio occurred at a PAD prevalence threshold of 0.24. DISCUSSION: PAD-scan is a cost-effective test for the detection of PAD in patients with diabetes.

Study protocol for a multicentre comparative diagnostic accuracy study of tools to establish the presence and severity of peripheral arterial disease in people with diabetes mellitus: the DM PAD study.

INTRODUCTION: Peripheral arterial disease (PAD) is a key risk factor for cardiovascular disease, foot ulceration and lower limb amputation in people with diabetes. Early diagnosis of PAD can enable optimisation of therapies to manage these risks. Its diagnosis is fundamental, though challenging in the context of diabetes. Although a variety of diagnostic bedside tests are available, there is no agreement as to which is the most accurate in routine clinical practice.The aim of this study is to determine the diagnostic performance of a variety of tests (audible waveform assessment, visual waveform assessment, ankle brachial pressure index (ABPI), exercise ABPI and toe brachial pressure index (TBPI)) for the diagnosis of PAD in people with diabetes as determined by a reference test (CT angiography (CTA) or magnetic resonance angiography (MRA)). In selected centres, we also aim to evaluate the performance of a new point-of-care duplex ultrasound scan (PAD-scan). METHODS AND ANALYSIS: A prospective multicentre diagnostic accuracy study (ClinicalTrials.gov Identifier NCT05009602). We aim to recruit 730 people with diabetes from 18 centres across the UK, covering primary and secondary healthcare. Consenting participants will undergo the tests under investigation. Reference tests (CTA or MRA) will be performed within 6 weeks of the index tests. Imaging will be reported by blinded consultant radiologists at a core imaging lab, using a validated scoring system, which will also be used to categorise PAD severity. The presence of one or more arterial lesions of ≥50% stenosis, or tandem lesions with a combined value of ≥50%, will be used as the threshold for the diagnosis of PAD. The primary outcome measure of diagnostic performance will be test sensitivity. ETHICS AND DISSEMINATION: The study has received approval from the National Research Ethics Service (NRES) (REC reference 21/PR/1221). Results will be disseminated through research presentations and papers. TRIAL REGISTRATION NUMBER: NCT05009602.

Factors associated with infrainguinal bypass graft patency at 1-year; a retrospective analysis of a single centre experience.

INTRODUCTION: The aim of this study was to identify factors associated with primary graft patency 1 year following open lower limb revascularisation (LLR) at a tertiary referral vascular service. METHODS: A retrospective analysis of patients undergoing infra-inguinal bypass surgery between January 2016 and May 2017 at a tertiary vascular centre (St Mary's Hospital, London) was performed. Data regarding patient demographics, comorbidities, type of operation and post-operative anti-thrombotic strategy were collected. Quality of run-off score was assessed from pre-operative imaging. RESULTS: Seventy-seven cases were included in the analysis. Overall, the primary patency rate at 1-year was 63.6% (n = 49/77) and the secondary patency rate was 67.5% (n = 52/77). Independent variables with statistically significant inferior patency rates at 1-year were (1) bypasses with below knee targets (p = 0.0096), (2) chronic limb threatening ischaemia indication (p = 0.038), (3) previous ipsilateral revascularisation (p < 0.001) and (4) absence of hypertension history (p = 0.041). There was also a trend towards significance for American Society of Anesthesiologists (ASA) grade (p = 0.06). Independent variables with log-rank test p values of <0.1 were included in a Cox proportional hazards model. The only variable with a statistically significant impact on primary patency rates was previous open or endovascular ipsilateral revascularisation (HR 2.44 (1.04-5.7), p = 0.04). CONCLUSION: At 1-year follow-up, previous ipsilateral revascularisation was the most significant factor in affecting patency rates. Patients in this subgroup should therefore be deemed high-risk, which should be reflected in the informed consent and peri-operative management.

Diagnostic Accuracy of Point-of-care Tests Used to Detect Arterial Disease in Diabetes: TEsting for Arterial Disease in Diabetes (TrEAD) Study.

OBJECTIVE: We compared the diagnostic performance of a novel point-of-care duplex ultrasound test (podiatry ankle duplex scan; PAD-scan) against commonly used bedside tests for the detection of PAD in diabetes. BACKGROUND: PAD is a major risk factor for diabetic foot ulceration and amputation. Its diagnosis is fundamental though challenging. Although a variety of bedside tests are available, there is no agreement as to which is the most useful. PAD-scan may be advantageous over current tests as it allows for vessel visualization and more accurate arterial waveform assessment. However, its accuracy has not been previously evaluated. METHODS: From March to October 2019, we recruited 305 patients from 2 diabetic foot clinics. The diagnostic performance of ankle-brachial pressure index, toe-brachial pressure index, transcutaneous pressure of oxygen, pulse palpation, and ankle waveform assessment using PAD-scan and Doppler devices (audible and visual waveform assessment) were assessed. The reference test was a full lower limb duplex ultrasound. RESULTS: Based on the reference test, 202 (66.2%) patients had evidence of PAD. PAD-scan had a significantly higher sensitivity [95%, confidence interval (CI) 90%-97%) as compared to all other tests. Particularly low sensitivities were seen with pulse palpation (43%, CI 36%-50%) and transcutaneous pressure of oxygen (31%, CI 24%-38%). PAD-scan had a lower specificity (77%, CI 67%-84%) compared to toe-brachial pressure index (86%, CI 78%-93%; P < 0.001), but not statistically different when compared to all other tests. CONCLUSIONS: PAD-scan has superior diagnostic utility and is a valid first line investigation.

Applications of intraoperative Duplex ultrasound in vascular surgery: a systematic review.

OBJECTIVE: This review aims to summarise the contemporary uses of intraoperative completion Duplex ultrasound (IODUS) for the assessment of lower extremity bypass surgery (LEB) and carotid artery endarterectomy (CEA). METHODS: We performed a systematic literature search using the databases of MEDLINE. Eligible studies evaluated the use of IODUS during LEB or CEA. RESULTS: We found 22 eligible studies; 16 considered the use of IODUS in CEA and 6 in LEB. There was considerable heterogeneity between studies in terms of intervention, outcome measures and follow-up. In the assessment of CEA, there is conflicting evidence regarding the benefits of completion imaging. However, analysis from the largest study suggests a modest reduction in adjusted risk of stroke/mortality when using IODUS selectively (RR 0.74, CI 0.63-0.88, p = 0.001). Evidence also suggests that uncorrected residual flow abnormalities detected on IODUS are associated with higher rates of restenosis (range 2.1% to 20%). In the assessment of LEB, we found a paucity of evidence when considering the benefit of IODUS on patency rates or when considering its utility as compared to other imaging modalities. However, the available evidence suggests higher rates of thrombosis or secondary intervention in grafts with uncorrected residual flow abnormalities (up to 36% at 3 months). CONCLUSIONS: IODUS can be used to detect defects in both CEA and LEB procedures. However, there is a need for more robust prospective studies to determine the best scanning strategy, criteria for intervention and the impact on clinical outcomes.

Long-term incidence and outcomes of obesity-related peripheral vascular disease after bariatric surgery.

BACKGROUND AND AIMS: Patients with obesity are at high risk of suffering from arterial and venous peripheral vascular disease (PVD). Bariatric surgery is an effective strategy to achieve weight reduction for patients with obesity. The long-term impact of bariatric surgery on obesity-related morbidity is subject to increasing research interest. This study aimed to ascertain the impact of bariatric surgery on the long-term occurrence of PVD in patients with obesity. METHODS: The study population was extracted from the Clinical Practice Research Datalink, a nation-wide database containing primary and secondary care records of consenting patients. The intervention cohort was 2959 patients who had undergone bariatric surgery during follow-up; their controls were 2959 propensity-score-matched counterparts. The primary endpoint was development of any PVD: arterial or venous. Secondary endpoints were incident peripheral arterial disease alone, incident peripheral venous disease alone. RESULTS: Three hundred forty-six patients suffered a primary endpoint during follow-up. Bariatric surgery did not improve peripheral vascular disease rates as a whole, but it was associated with significantly lower event rates of arterial disease (HR = 0.560, 95%CI 0.327-0.959, p = 0.035) but higher event rates of venous disease (HR = 1.685, 95%CI 1.256-2.262, p < 0.001). CONCLUSIONS: Bariatric surgery was associated with significantly reduced long-term occurrence of arterial disease but increased occurrence of venous disease in patients with obesity.

A systematic review and meta-analysis of the diagnostic accuracy of point-of-care tests used to establish the presence of peripheral arterial disease in people with diabetes.

OBJECTIVE: No agreement has been reached regarding which bedside test is the most useful for the diagnosis of peripheral arterial disease (PAD) in patients with diabetes. The aim of the present systematic review and meta-analysis was to evaluate the performance of bedside tests for the detection of PAD in individuals with diabetes. METHODS: MEDLINE and EMBASE databases were systematically searched for studies providing data on the diagnostic performance of bedside tests used for the detection of PAD in those with diabetes. A meta-analysis was performed to obtain pooled estimates of sensitivity and specificity for the diagnosis of PAD. RESULTS: A total of 18 studies, reporting on a total of 3016 limbs of diabetic patients, were included in our qualitative review. Of these, 11 studies (1543 limbs) were included in the meta-analysis of diagnostic accuracy: ankle-brachial pressure index (9 studies and 1368 limbs; sensitivity, 63.5% [95% confidence interval (CI), 51.7%-73.9%]; specificity, 89.3% [95% CI, 81.1%-94.2%]); toe-brachial pressure index (3 studies and 221 limbs; sensitivity, 83.0% [95% CI, 59.1-94.3%]; specificity, 66.3% [95% CI, 41.3%-84.6%]); and tibial waveform assessment (4 studies and 397 limbs; sensitivity, 82.8% [95% CI, 73.3%-89.4%], specificity, 86.8% [95% CI, 75.5%-93.3%]). Overall, we found a high risk of bias across the studies, most frequently relating to patient selection and the lack of blinding. CONCLUSIONS: The toe-brachial pressure index, pulse oximetry, and tibial arterial waveform assessment demonstrated some promise, warranting further investigation.

The Effect of Lower Limb Revascularization on Flow, Perfusion, and Systemic Endothelial Function: A Systematic Review.

Peripheral arterial disease (PAD) is associated with reduced lower limb blood flow and tissue perfusion. The consequent reduction in vessel wall shear stress as well as ischemia-reperfusion injury has also been associated with systemic endothelial dysfunction and inflammation. We aimed to explore the impact of lower limb revascularization on (1) lower limb blood flow, (2) tissue perfusion, and (3) systemic endothelial function. We performed a systematic literature search using the MEDLINE, Embase, and Web of Science databases. Eligible studies measured changes in lower limb blood flow, perfusion, or systemic endothelial function following revascularization for the treatment of symptomatic PAD. We found 19 eligible studies, which were limited by considerable heterogeneity. Current evidence suggests that revascularization has a positive effect on flow, perfusion, and systemic endothelial dysfunction. Any changes may take a number of weeks to become apparent. There is a need for well-designed studies to explore the association between flow, perfusion, and endothelial dysfunction.

Study protocol for a comparative diagnostic accuracy study of bedside tests used to detect arterial disease in diabetes: TEsting for Arterial disease in Diabetes (TrEAD) study.

INTRODUCTION: In the UK, over 7000 amputations are performed each year because of diabetes. Up to 80% of these are preceded by a foot ulcer and could therefore be prevented with improvements in ulcer care. Peripheral arterial disease is an important risk factor for the development of diabetic foot ulceration. However, its diagnosis in diabetes is challenging due to the presence of neuropathy and arterial calcification. Commonly used bedside tests either have low sensitivities or little supporting evidence to justify their use. Duplex ultrasound (DUS) has good correlation to angiography findings but a full scan is difficult to learn and time consuming to perform. We have previously demonstrated that a focused DUS of the distal anterior and posterior tibial arteries at the ankle (podiatry ankle duplex scan (PAD-scan)) can be readily learnt by novices and performed rapidly and accurately. The primary aim of this study is to determine the diagnostic accuracy of the PAD-scan and other commonly used bedside tests in detecting arterial disease in diabetes. METHODS AND ANALYSIS: The study will include 305 patients presenting to diabetic foot clinics at two centres. Arterial assessment will be performed using the following index tests: the PAD-scan, pulse palpation, audible handheld Doppler, Ankle Brachial Pressure Index, Toe Brachial Pressure Index and transcutaneous pressure of oxygen. Patients will then undergo a full lower limb arterial DUS by a blinded vascular scientist as a reference test. ETHICS AND DISSEMINATION: Approval was gained from NRES Committee London (REC reference 17/LO/1447). Findings will be disseminated by various methods including international presentations and publication in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT04058626).

A novel team Familiarity Score for operating teams is a predictor of length of a procedure: A retrospective Bayesian analysis.

OBJECTIVE: The aim of our retrospective study was to assess whether a novel team Familiarity Score (FS) is associated with the length of procedure (LOP), postoperative length of stay (LOS), and complication rate after vascular procedures. METHODS: We retrospectively analyzed 326 vascular procedures performed at a tertiary care vascular surgery center between April 2012 and September 2014. Data collected included patients' age, American Society of Anesthesiologists grade, LOP, type and urgency of procedure, LOS, and complications. Familiarity Score (FS) was defined as the sum of the number of times that each possible pair of the team (vascular consultant, vascular registrar, scrub nurse, anesthetic consultant) within the team had worked together during the previous 6 months, divided by the number of possible combinations of pairs in the team. Bayesian statistics was used to analyze the data. RESULTS: FS was significantly associated with type and urgency of the procedure (Bayes factor [BF] >1000). Emergency procedures were performed by less familiar teams, and the least familiar teams were involved in the emergency aortic procedures-endovascular and open. FS was strongly associated with LOP (BF = 37) but not with LOS (BF = 4.0) and complication rate. CONCLUSIONS: FS in vascular teams was shown to be strongly associated with LOP, suggesting that more familiar teams might collaborate more efficiently.

A pilot study of preoperative heart rate variability predicting pain during local anesthetic varicose vein surgery.

OBJECTIVE: Local anesthetic endovenous procedures were shown to reduce recovery time, to decrease postoperative pain, and to more quickly return the patient to baseline activities. However, a substantial number of patients experience pain during these procedures. The autonomic nervous system modulates pain perception, and its influence on stress response can be noninvasively quantified using heart rate variability (HRV) indices. The aim of our study was to evaluate whether preoperative baseline HRV can predict intraoperative pain during local anesthetic varicose vein surgery. METHODS: Patients scheduled for radiofrequency ablation were included in the study. They had their electrocardiograms recorded from a single channel of a custom-made amplifier. Each patient preoperatively filled in forms Y-1 and Y-2 of Spielberger's State and Trait Anxiety Inventory, completed the Aberdeen Varicose Vein Questionnaire, and rated anxiety level on a numeric scale. Postoperatively, patients filled in the pain they felt during the procedure on the numeric pain intensity scale. MATLAB software (MathWorks, Natick, Mass) was used to extract R waves and to generate HRV signals, and a mathematical model was created to predict the pain score for each patient. RESULTS: In multivariable analysis, we looked into correlation between reported patient's pain score (rPPS) and Aberdeen Varicose Vein Questionnaire score, preoperative forms Y-1 and Y-2, preoperative anxiety level, and predicted patient's pain (pPPS) score. Multivariable analysis found association only between rPPS and pPPS. The pPPS was significantly correlated with rPPS (R = 0.807; P < .001) with accuracy of prediction of 65.2%, which was calculated from R2 on a linear regression model. CONCLUSIONS: This preliminary study shows that preoperative HRV can accurately predict patients' pain, allowing patients with higher predicted score to have the procedure under general anesthesia.

Management of peripheral arterial disease in diabetes: a national survey of podiatry practice in the United Kingdom.

BACKGROUND: We aimed to investigate podiatry practice in diagnosing peripheral arterial disease (PAD) in diabetes, decision making once PAD is suspected and limitations of referral pathways. METHODS: A survey, comprising 26 questions was distributed to podiatrists across the UK via mailing lists of collaborating organizations including the College of Podiatry (UK). Response rates were estimated based on NHS workforce data. Analysis of responses from the open-ended questions was performed using inductive content analysis. RESULTS: Data from 283 respondents were analyzed. Response rate for all NHS podiatrists across the UK was estimated to be 6%. For the detection of arterial disease only 18.8% (n = 49/260) of participants reported using a full combination of history, pulse palpation, Doppler and ABPI assessment. Self-reported confidence in detecting arterial disease was highest amongst podiatrists who felt they had received adequate training compared to podiatrists who felt they had not (median 85 (IQR 75-90) vs 67 (50-77), respectively; p < 0.001) as well as those who see > 20 diabetic patients per week compared to those who see < 20 (median 80 (IQR 70-90) vs 72 (60-82.8), respectively; p < 0.001). Over one third of respondents (35.8%, n = 93/260) were aware of missed cases of PAD in the past year and 17.5% (n = 38/217) believed that this resulted in an amputation in some cases.The survey highlighted a lack of clarity amongst podiatrists regarding referral guidelines. Additionally, 69% (n = 169/242) reported that their patients had to wait longer than 2-weeks for specialist vascular assessment and 67.6% (n = 54/80) reported similar waits for a Duplex Ultrasound scan. There was a statistically significant variation in DUS waiting time across the UK (X2 (10, N = 80) = 21.59, p = 0.017). Inability to make a direct referral to vascular services and long delays were reported as major limitations of the referral pathway. CONCLUSION: We have identified important targets for further investigation and quality improvement.

Self-assessment of surgical ward crisis management using video replay augmented with stress biofeedback.

BACKGROUND: We aimed to explore the feasibility and attitudes towards using video replay augmented with real time stress quantification for the self-assessment of clinical skills during simulated surgical ward crisis management. METHODS: Twenty two clinicians participated in 3 different simulated ward based scenarios of deteriorating post-operative patients. Continuous ECG recordings were made for all participants to monitor stress levels using heart rate variability (HRV) indices. Video recordings of simulated scenarios augmented with real time stress biofeedback were replayed to participants. They were then asked to self-assess their performance using an objective assessment tool. Participants attitudes were explored using a post study questionnaire. RESULTS: Using HRV stress indices, we demonstrated higher stress levels in novice participants. Self-assessment scores were significantly higher in more experienced participants. Overall, participants felt that video replay and augmented stress biofeedback were useful in self-assessment. CONCLUSION: Self-assessment using an objective self-assessment tool alongside video replay augmented with stress biofeedback is feasible in a simulated setting and well liked by participants.

Pain Prediction From ECG in Vascular Surgery.

Varicose vein surgeries are routine outpatient procedures, which are often performed under local anaesthesia. The use of local anaesthesia both minimises the risk to patients and is cost effective, however, a number of patients still experience pain during surgery. Surgical teams must therefore decide to administer either a general or local anaesthetic based on their subjective qualitative assessment of patient anxiety and sensitivity to pain, without any means to objectively validate their decision. To this end, we develop a 3-D polynomial surface fit, of physiological metrics and numerical pain ratings from patients, in order to model the link between the modulation of cardiovascular responses and pain in varicose vein surgeries. Spectral and structural complexity features found in heart rate variability signals, recorded immediately prior to 17 varicose vein surgeries, are used as pain metrics. The so obtained pain prediction model is validated through a leave-one-out validation, and achieved a Kappa coefficient of 0.72 (substantial agreement) and an area below a receiver operating characteristic curve of 0.97 (almost perfect accuracy). This proof-of-concept study conclusively demonstrates the feasibility of the accurate classification of pain sensitivity, and introduces a mathematical model to aid clinicians in the objective administration of the safest and most cost-effective anaesthetic to individual patients.

Bilateral Internal Carotid Artery Occlusion, External Carotid Artery Stenosis, and Vertebral Artery Kinking: May It Be Asymptomatic?

The clinical spectrum of internal carotid artery occlusion ranges from being a completely asymptomatic occlusion to a devastating stroke or death. The prevalence of asymptomatic internal carotid artery occlusion is unknown, particularly for bilateral occlusion. The distal branches of the external carotid artery anastomose with distal branches of the internal carotid artery provide important sources of collateral circulation to the brain. Stenosis of the external carotid artery with ipsilateral/bilateral internal occlusion may result in ischemic sequelae. Coiling or kinking of the vertebral artery is a rare morphological entity that is infrequently reported because it remains asymptomatic and has no clinical relevance. Currently, there is little evidence to support management strategies for this disease entity and no official recommendations for asymptomatic bilateral carotid artery occlusion. We present a case of a 62-year-old female with asymptomatic bilateral internal carotid artery occlusion, bilateral external carotid artery stenoses, and bilateral kinking of the vertebral artery at the V2 segment, who has been successfully managed conservatively for over 5 years. An individualized approach to management of patients with bilateral internal carotid artery occlusion, especially in combination with external carotid artery stenosis and elongation malformations of the vertebral artery is key to a successful strategy.

Sources of Delay in the Acute Limb Ischemia Patient Pathway.

BACKGROUND: Acute limb ischemia (ALI) continues to pose a significant challenge to clinicians and is associated with an unacceptably high rate of morbidity and mortality. Despite its time critical nature, little is known regarding the delays encountered during the patient pathway. The aim of this study was to identify sources of delay in the patient pathway at our institution. METHODS: Sixty-seven cases of ALI of the lower extremities from 66 patients, who had presented to our center between May 2003 and April 2014, were identified for retrospective analysis. Data were retrieved from the patient records, discharge summaries and hospital laboratory, emergency department and radiology databases. RESULTS: Median time from onset of symptom to arrival at our institution was 11.35 hr (interquartile range [IQR] 6.27-72). Median cumulative time taken from arrival to vascular team review was 40 min (22.5-120), to imaging being performed was 4.75 hr (2.42-17.25), and to intervention being performed was 10.2 hr (4-31). There were significantly longer delays to presentation in those transferred from inpatient beds as compared with those transferred from the emergency department of other hospitals (66 hr [10.3-98] vs. 8 hr [5.6-14.9], P = 0.007). In total, 84.6% of patients underwent preoperative arterial imaging. Time taken from arrival to diagnostic arterial imaging was significantly longer in patients presenting out-of-ours (15 hr [6.5-20.75]) as compared with patients presenting in-hours (3.5 hr [2-6.5], P = 0.014) or during the weekend (2 hr [2-3], P = 0.022). Time from presentation to intervention was significantly shorter in patients presenting over the weekend (3.9 hr [2.6-5.1]) as compared with those presenting in-hours (14.2 hr [6.2-29], P = 0.006) and out-of-hours (16 hr [10-33], P = 0.021). Out-of-hours, a significant portion of the delay, was attributable to imaging (median time to imaging 15 hr). CONCLUSIONS: This study demonstrates the systematic nature of delays in the patient pathway from onset of symptoms to treatment. Several factors including time to patient presentation and time to imaging and delays in timely transfer to an appropriate facility contribute to this. Strategies need to be deployed to reduce time to revascularization.

A systematic review and meta-analysis of the risk for development of varicose veins in women with a history of pregnancy.

OBJECTIVE: The association between pregnancy and the development of varicose veins is uncertain. We aimed to determine whether a history of pregnancy is associated with the development of varicose veins. METHODS: We performed a systematic literature search using the databases of PubMed, Embase, Robert Koch-Institut, and Cochrane Central and the references of included papers. Eligible studies were all epidemiologic observational studies in which the outcome "varicose veins" and pregnancy history were assessed. The quality of each study was evaluated on the basis of the Dutch Cochrane review checklist and by the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) statement. For our meta-analysis, a random effects model was applied to pool odds ratios and 95% confidence intervals across studies. RESULTS: We found nine eligible studies enrolling 17,109 women. Pregnancy was associated with a significant risk increase in developing varicose veins. The results of our meta-analysis suggest that the odds for women with a history of pregnancy in developing varicose veins significantly increases by 82% (odds ratio, 1.82; 95% CI, 1.43-2.33) compared with women with no history of pregnancy. As expected for epidemiologic observational studies, the heterogeneity was considerably high (I(2) = 81%). CONCLUSIONS: Our meta-analysis strongly supports the hypothesis that there is a significant and strong association between a history of pregnancy and varicose veins. However, qualitative and quantitative differences among studies were evident and were also reflected in a considerably high heterogeneity.

Transfemoral Valve-in-Valve Transcatheter Aortic Valve Implantation (TAVI) in a Patient With Previous Endovascular Aortic Repair (EVAR).

A 90-year-old man presented with increasing exertional breathlessness. He had previous implantation of a Perimount bioprosthetic aortic valve (Edwards Lifesciences) and coronary artery bypass graft surgery. Due to severe transvalvular bioprosthetic regurgitation with preserved left ventricular dimensions and ejection fraction, the heart team decided on valve-in- valve transcatheter aortic valve implantation via the transfemoral route in view of the patient's prohibitively high surgical and anesthetic risk. The patient had an uncomplicated recovery and was symptomatically much improved at 3-month follow-up.

Intensive Simulation Training in Lower Limb Arterial Duplex Scanning Leads to Skills Transfer in Real-World Scenario.

OBJECTIVES: To train novices to perform an abbreviated duplex lower limb ultrasound scan using simulation training and assess real-world skills transference. METHODS: Novices undertook 3 days of simulation training. Their progress was assessed using the Duplex Ultrasound Objective Structured Assessment of Technical Skills (DUOSATS) for simulation and Cumulative Imaging Score (CIS). A final assessment day was held to assess DUOSATS for simulation and real patient scanning, CIS, cumulative diagnostic accuracy, and sections A and B of the Society of Vascular Technology examination. MSc students in vascular ultrasound were also assessed for comparison. RESULTS: A total of 17 novices and 7 MSc students with 3-month training participated. Novices improved DUOSATS for simulation scores between days 1, 3, and 4: 18 (17-19) vs 27 (25-28) vs 30 (28-32), (median [interquartile range], p < 0.001). Novices improved in CIS between days 1 and 3: 10 (10-13) vs 21 (19-21), p < 0.001, with a decline on day 4: 15.3 (11.3-18.3), p < 0.001. On the final assessment day, there were no significant differences between novices and MSc students in: DUOSATS for simulation scores (30 [28-32] vs 31 [6-31.5], p = 0.85); DUOSATS for patient assessment (31 [28.7-33.7] vs 26.7 [24.5-35.7], p = 0.41); CIS (15.3 [11.3-18.7] vs 20.7 [12.3-22.2], p = 0.2), respectively. However, novices performed better in section B of the Society of Vascular Technology examination compared with MSc students (72.9% vs 54.3%, p < 0.001). Novices also demonstrated a higher diagnostic accuracy when compared with MSc students (65.7% of arterial segments correctly assessed vs 47.6%, respectively [p = 0.044]). CONCLUSIONS: Intensive simulation of 3-day training achieved real patient-based assessments that were comparable to MSc students who were 3 months into their traditional training program.