BACKGROUND:Clinical practice guidelines endorse arteriovenous fistulae (AVF) as the preferred form of vascular access. Despite recent advancements, concerns persist regarding variable AVF patency rates. This umbrella review aimed to evaluate and synthesize evidence on interventions and strategies associated with improved 12-month patency rates in AVF. METHODS:Systematic review and meta-analyses of randomized control trials (RCTs) providing data regarding primary patency (PP) and target-lesion primary patency (TLPP) of AVF (not grafts) were included. Covidence was used for screening and data extraction, while the AMSTAR-2 rating assessed the methodological quality. Credibility assessment followed Papatheodorou's criteria. Medline, EMBASE, CENTRAL and CINAHL were searched using a bespoke search strategy from inception to December 2024. RESULTS:Twenty-two reviews that included 136 RCTs involving 13,522 patients were included in the final review. Highly suggestive evidence supports functional end-to-side anastomosis (effect estimate (EE) 1.7) for improving PP. Drug-coated balloon angioplasty (DCB) showed varied results across nine reviews, with effect estimates ranging from 0.49 to 2.47. For TLPP, one review reported significant improvement (EE 2.47, 95% CI 1.53-3.99). Suggestive evidence favours flow-based access monitoring (RR 0.51-0.66), antithrombotic medication (EE 0.53), antiplatelet therapy (EE 0.54), far infrared therapy (EE 1.24-1.27) and pre-emptive correction of 'at-risk' AVF (EE 0.5) for prolonging PP. Button hole cannulation and side-to-side anastomosis showed mixed or non-significant results. Heterogeneity varied widely across reviews, ranging from 0% to 81%, and AMSTAR-2 ratings ranged from moderate to high. CONCLUSION:This umbrella review synthesizes evidence on interventions for AVF patency, revealing varying levels of support for different strategies and highlighting areas requiring further investigation.

Objective: This study aimed to explore the long term outcomes of patients with intermittent claudication (IC) who completed supervised exercise therapy (SET) vs. those who declined or prematurely discontinued SET, focusing on the incidence of chronic limb threatening ischaemia (CLTI), revascularisation, major adverse limb events (MALE), and major adverse cardiovascular events (MACE). Methods: A retrospective registry analysis of consecutive patients with IC who were referred for SET between March 2015 and August 2016 and followed up for a minimum of five years. Serial univariable analysis and logistic regression were performed to identify the statistically significant clinical variables that were independent predictors of each outcome measure. The resulting statistically significant variables were used to guide 1:1 propensity score matching (PSM) using the nearest neighbour method with a calliper of 0.2. Cox proportional hazards regression was used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between SET and the outcomes of interest. Results: Two hundred and sixty-six patients were referred to SET between March 2015 and August 2016. Of these, 64 patients completed SET and 202 patients did not. After PSM, 49 patients were analysed in each cohort. The Cox proportional hazards analysis revealed a significant association between completion of SET and revascularisation requirement (HR 0.46 95% CI 0.25 - 0.84; p = .011), completion of SET and progression to CLTI (HR 0.091, 95% CI 0.04 - 0.24; p < .001), completion of SET and MACE (HR 0.52; 95% CI 0.28 - 0.99; p = .05) and completion of SET and MALE (HR 0.28, 95% CI 0.13 - 0.65; p = .003). The Harrell's C index for all of these models was greater than 0.75, indicating good predictive accuracy. Conclusion: Completion of SET is associated with better outcomes in patients who completed SET compared with patients who declined or discontinued SET with respect to clinically important cardiovascular outcomes over seven years.

BACKGROUND:The reduction in distal arterial flow following arteriovenous fistula (AVF) creation can cause a perfusion deficit known as haemodialysis access induced distal ischemia (HAIDI). Various techniques have been advocated to treat this difficult problem with varying success. We present the long-term outcomes following a novel banding technique.METHODS:46 patients in this cohort from 2008 to 2021 underwent a novel banding procedure using a Dacron™ patch shaped with one slit-end and saw-tooth edges (resulting in a 'Christmas-tree' pattern) to provide a ratchet mechanism to progressively constrict the fistula outflow. Real-time finger perfusion pressure monitoring allowed an accurate reduction in AVF flow whilst increasing distal arterial perfusion pressure. Baseline characteristic were recorded and Kaplan-Meier survival curves were obtained to calculate the post-intervention primary, assisted primary and secondary patency.RESULTS:29 patients presented with rest pain and 11 presented with tissue loss due to distal ischemia. The post-intervention primary access patency was 100%, 98%, 78% and 61% at 30, 60 and 180 days and 1 year respectively. Complete resolution of symptoms was achieved in 74% (n = 34) of patients and a partial response needing no further intervention was achieved in 11% (n = 5) of patients. A Youden index calculation suggested that digital pressures of 41 mm Hg or lower in an open AVF were highly sensitive for symptomatic hand ischemia whereas pressures greater than 65 mm Hg ruled out distal ischemia.CONCLUSION:'Christmas-tree' banding with on table finger systolic pressures is not only an efficacious and durable method for treating HAIDI but also preserves fistula patency.

ImportanceIntermittent lower limb claudication limits function and quality of life. Supervised exercise programs are not readily available, and a noninvasive alternative is needed.ObjectiveTo assess extracorporeal corporeal shockwave therapy in improving quality of life in patients with claudication.Design, Setting, and ParticipantsIn this double-blind, placebo-controlled randomized clinical trial, patients in the outpatient setting at a single tertiary center for vascular surgery were randomized in a 1:1 ratio to extracorporeal shockwave therapy or placebo therapy with no shockwaves delivered. Recruitment was between June 2015 and January 2020, with 12-week follow-up ending in March 2020. A convenience sample of patients with claudication and conservative treatment requirements who refused or were unable to participate in supervised exercise were eligible. Patients receiving anticoagulation therapy or with an active cancer were excluded. Of 522 patients screened, 389 were eligible, 138 were enrolled, and 110 completed follow-up and were included in the primary analysis. Statistical analysis was completed by May 2021.InterventionIn the intervention group, patients received 100 impulses of 0.1mJ/mm/cm2 in an area of the gastrocnemius muscle 3 times weekly for 3 weeks. The steps for treatment were replicated for the control group without delivering the treatment.Main Outcomes and MeasuresThe primary outcome was the Physical Functioning domain of the 36-item Short-Form Quality of Life Questionnaire at 12-week follow-up. Secondary outcomes included walking distances, ankle brachial pressure index, and other quality-of-life measures.ResultsOf 138 patients recruited and randomized, 92 (67%) were male, and the mean (SD) age of the study population was 67 (9.6) years. The intervention group had a significantly higher physical function score at 12 weeks (estimated median difference 3.8; 95% CI, 0.0-7.7; P = .03). However, this significance did not remain when adjusting for covariates. At 12 weeks, the intervention group had significantly longer pain-free and maximum walking distances (pain-free estimated median difference, 34.1, 95% CI, 11.4-56.8; P = .004; maximum estimated median difference, 51.4; 95% CI, 10.7-86.5; P = .01).Conclusions and RelevanceTo our knowledge, this is the first double-blind, placebo-controlled, randomized clinical trial to consider extracorporeal shockwave therapy for the management of intermittent claudication. It demonstrated efficacy for walking distances, may have a positive effect on quality of life, and may provide a safe, noninvasive alternative therapy for patients with intermittent claudication.Trial RegistrationClinicalTrials.gov Identifier: NCT02652078

Abstract Introduction Current remote methods of surgical site infection diagnosis have high specificity but lack sensitivity in diagnosis. This study evaluates the acceptability, reliability and validity of a novel hybrid clinician-patient remote outcome measure (ASSIST) for detecting SSI. Methods Patients completed the Bluebelle wound healing questionnaire (WHQ) at 30 days post-surgery and additionally submitted wound image(s). Images were reviewed two independent clinicians. Internal consistency of the unidimensional scale was assessed. Inter-rater and intra-rater reliability assessments were performed. Sensitivity and specificity for SSI discrimination against face-to-face CDC diagnosis were evaluated and receiver operator characteristic (ROC) curve plotted with calculation of the area under the curve. Results 69 participants were included and no questionnaires contained missing items. The single scale showed strong Internal consistency (α = 0.9). Intra-rater reliability was good with intraclass correlation (ICC) of 0.818 (95% CI, 0.672-0.903, p<0.001). Inter-rater agreement was excellent (ICC 0.915, 95% CI 0.733-0.903, p<0.001). Sensitivity and specificity for SSI diagnosis were excellent at 91.7% and 97.6% respectively. Discrimination for SSI was high with an area under the receiver operating characteristic curve of 0.966 (95%CI 0.913-1.000). Discussion The ASSIST measure is acceptable, reliable, and valid for diagnosis of SSI. Implementation can be safely utilised in both patient-initiated follow-up or at pre-determined time points for safe post discharge surveillance.

Introduction: Current surgical site infection (SSI) prevention guidance indicates low-quality evidence supporting many of their recommendations. Subsequently, there is substantial variation in practice and often implementation of unsubstantiated interventions. There is therefore a need to rapidly evaluate best practices to prevent SSI. This survey aimed to evaluate current practice in the prevention of SSI and equipoise regarding potential interventions to reduce SSI rates in major lower limb amputation (MLLA) and groin incisions. Methods: A cross-sectional national survey was developed from current international guidelines to prevent SSI, following CHERRIES and CROSS checklists. A study steering committee directed internal validation prior to dissemination via single stage sampling of the membership of the Vascular Society of Great Britain and Ireland. Results: The survey received 58 responses from clinicians across 38 NHS trusts. Most respondents were consultant vascular surgeons (91%; 53/58). Preoperatively, there was variable practice in the use of preoperative bathing, surgical site preparation, antibiotic prophylaxis duration and the use of incise drapes for both MLLA and groin incisions. Intraoperatively there was little consensus for wound irrigation, drain insertion, changing gloves and instruments prior to skin closure, skin closure technique, and the use of dressings for both MLLA and groin incisions. The majority of respondents were willing to randomise patients to most interventions. Nearly three-quarters (72%; 42/58) of respondents agreed or strongly agreed that a combined outcome measure of SSI and wound dehiscence would be the ideal primary outcome in a trial investigating SSI prevention in MLLA. Conclusions: Despite significant heterogeneity in practice to prevent SSI, the majority of surgeons surveyed showed they would be willing to randomise to interventions in a randomised controlled trial. This key finding is important in the design of future studies.

BACKGROUND:Utilising point-of-care ultrasound for assessment and cannulation of vascular access in people receiving haemodialysis has shown positive clinical results. Nonetheless, there is variation in how renal health care professionals worldwide embrace this method, and there's a lack of research on the factors that promote or hinder its adoption. OBJECTIVES:To explore regional differences, and barriers and facilitators, to the use of point-of-care ultrasound for assessment and cannulation of vascular access in haemodialysis. DESIGN:Exploratory descriptive cross-sectional web-based survey. PARTICIPANTS:Healthcare clinicians working in haemodialysis responsible for cannulation of arteriovenous fistula or grafts. RESULTS:The survey was completed by 645 health care clinicians from 38 countries. 75% to 93% of respondents from Australia/New Zealand, Canada, Europe and United Kingdom/Ireland reported access to ultrasound, compared to 26% (n = 43/167) from the United States. United States respondent's reported lower levels of ultrasound training than other regions. Facilitators for using ultrasound were: the availability of ultrasound training (87%, n = 558), to reduce miscannulations (76%, n = 255/336) and to improve patient outcomes (73%, n = 246/336). Point-of-care ultrasound barriers were lack of access to ultrasound education (82%, n = 196/239), lack of ultrasound machines (33%, n = 212/645) or believing that ultrasound was someone else's role (38%, n = 29/86). CONCLUSIONS:This study revealed national and regional differences related to haemodialysis point-of-care ultrasound. Understanding the regions requiring more education and implementation of ultrasound and what motivates staff, or deters from using ultrasound, is crucial for effectiveness of future implementation and workplace change initiatives.

BackgroundSurgical site infections (SSIs) pose a significant challenge to healthcare systems by elevating patient morbidity and mortality and driving up financial costs. Preoperative skin preparation is crucial for preventing SSIs; however, certain traditional methods of hair removal have been found to increase the risk of SSI development. Mechanical epilation and waxing constitute two relatively explored methods of hair removal, which may hold potential to accelerate wound healing due to the activation of stem cells within hair follicles. This review assesses the efficacy of preoperative hair removal via waxing and mechanical epilation in reducing SSI incidence.MethodsThis systematic review was prospectively registered with PROSPERO (ref: CRD42023423798) and a protocol previously published in a peer-reviewed journal. All findings are reported according to PRISMA guidelines. A comprehensive search of Medline, Embase, CENTRAL, ClinicalTrials.gov and CINAHL. Inclusion criteria encompassed adult patients undergoing any surgical procedure, comparing waxing or epilation against other hair removal methods or no hair removal, with SSI incidence as the primary outcome. There was no restriction on study size or quality to ensure a comprehensive literature evaluation.ResultsThe review found no studies meeting the selection criteria out of 576 records screened.Discussion/conclusionThis review has identified no literature regarding the use of waxing and mechanical epilation as methods of preoperative hair removal. The lack of experimental evidence combined with the potential physiological advantages of these techniques indicate that this could be a valuable area of future research. These techniques may represent novel approaches to SSI prevention, particularly beneficial in high-risk surgical disciplines like vascular surgery.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=423798, PROSPERO (CRD42023423798).

OBJECTIVES:This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the safety and clinical effectiveness of endovascular rectal artery embolisation (RAE) for symptomatic haemorrhoids.

Background Surgical ligation and stripping (surgery) and endothermal ablation are both effective treatments for varicose veins, improving quality of life (QoL) up to 5 years. Few data are available on long-term outcomes. The aim of this study was to evaluate the outcomes 10 years after interventions in an RCT. Previously this RCT demonstrated that endothermal ablation is associated with superior postprocedural QoL, more rapid recovery, and lower rates of early clinical recurrence. This analysis reports outcomes at 10 years. Methods Patients with symptomatic varicose veins owing to unilateral great saphenous vein reflux were randomized to either surgery or endovenous laser ablation (EVLA). Outcomes at 10 years included clinical recurrence and QoL. Results Data were obtained for 206 of 280 patients (73.6%) at 10 years. Both groups retained significant QoL improvement compared with pretreatment levels (Aberdeen Varicose Vein Questionnaire (AVVQ), Short Form 36 (SF-36 (R)), and EQ-5D (TM); P < 0.001). Clinical disease progression from baseline was observed in only 10.7% of patients. The clinical recurrence rate was lower in the EVLA group (37 versus 59%; P = 0.005). The number needed to treat with EVLA to avoid one clinical recurrence within 10 years was five. This was associated with significantly higher (better) generic QoL scores with EVLA in several SF-36 (R) domains, including bodily pain (median 84 (i.q.r. 51-100) versus 62 (41-84); P = 0.009) and general health (77 (62-87) versus 67 (52-82); P = 0.017). AVVQ scores in the EVLA group were also lower (better) (3.1 (0-7.7) versus 6.3 (0.7-13.3); P = 0.029). Conclusion Both surgery and endothermal ablation are effective treatments for varicose veins at 10 years, with durable improvement in QoL and a very low rate of disease progression. However, endothermal ablation was associated with superior clinical and QoL outcomes. Registration number: NCT00759434 (http://www.clinicaltrials.gov).

Background Guidelines recommend cardiovascular risk reduction and supervised exercise therapy as the first line of treatment in intermittent claudication, but implementation challenges and poor patient compliance lead to significant variation in management and therefore outcomes. The development of a precise risk stratification tool is proposed through a machine-learning algorithm that aims to provide personalized outcome predictions for different management strategies. Methods Feature selection was performed using the least absolute shrinkage and selection operator method. The model was developed using a bootstrapped sample based on patients with intermittent claudication from a vascular centre to predict chronic limb-threatening ischaemia, two or more revascularization procedures, major adverse cardiovascular events, and major adverse limb events. Algorithm performance was evaluated using the area under the receiver operating characteristic curve. Calibration curves were generated to assess the consistency between predicted and actual outcomes. Decision curve analysis was employed to evaluate the clinical utility. Validation was performed using a similar dataset. Results The bootstrapped sample of 10 000 patients was based on 255 patients. The model was validated using a similar sample of 254 patients. The area under the receiver operating characteristic curves for risk of progression to chronic limb-threatening ischaemia at 2 years (0.892), risk of progression to chronic limb-threatening ischaemia at 5 years (0.866), likelihood of major adverse cardiovascular events within 5 years (0.836), likelihood of major adverse limb events within 5 years (0.891), and likelihood of two or more revascularization procedures within 5 years (0.896) demonstrated excellent discrimination. Calibration curves demonstrated good consistency between predicted and actual outcomes and decision curve analysis confirmed clinical utility. Logistic regression yielded slightly lower area under the receiver operating characteristic curves for these outcomes compared with the least absolute shrinkage and selection operator algorithm (0.728, 0.717, 0.746, 0.756, and 0.733 respectively). External calibration curve and decision curve analysis confirmed the reliability and clinical utility of the model, surpassing traditional logistic regression. Conclusion The machine-learning algorithm successfully predicts outcomes for patients with intermittent claudication across various initial treatment strategies, offering potential for improved risk stratification and patient outcomes.

BackgroundThrough-knee amputation (TKA) has potential advantages over above-knee amputation (AKA) but is rarely performed in the United Kingdom (UK). This mixed methods study aimed to explore clinicians' perceptions of TKA compared to AKA.MethodAn online survey of vascular surgeons, prosthetists, and physiotherapists between May 2019 and April 2020. Follow-up semi-structured interviews explored themes from the survey. Thematic analysis was used to draw conclusions from the data.ResultsSeventy-eight clinicians returned surveys, and follow-up interviews were completed with 21 clinicians. Reported advantages of TKA include its long lever and the femoral condyles to anchor (suspend) the prosthesis. Perceived disadvantages include poor wound healing and unsatisfactory prosthetic appearance. The interviews uncovered ineffective communication along the amputation pathway, contributing to a compartmentalised approach to amputation surgery and rehabilitation. Clinicians with strong feelings against TKA and a lack of desire/perceived ability to drive change from clinicians in favour of TKA are barriers to increasing its use.ConclusionCurrent TKA surgery and rehabilitation practice is based on personal opinions, assumptions, or "accepted wisdom" and lacks an underpinning evidence base. Overall, opinions of TKA are divided, with conflicting views between different professional groups, highlighting the importance of multidisciplinary decision-making.Implications for rehabilitationThrough-knee amputation has advantages and disadvantages compared to above-knee amputation which have been observed in clinical practice.Decision regarding level of amputation should involve multiple members of the multidisciplinary team.Lack of amputation pathway guidance and communication barriers prevent effective multidisciplinary collaboration.

Objective: A preoperative supervised exercise program (SEP) improves cardiorespiratory fitness and perioperative outcomes for patients undergoing elective abdominal aortic aneurysm (AAA) repair. The aim of this study was to assess the effect of a preoperative SEP on long-term survival of these patients. A secondary aim was to consider long-term changes in cardiorespiratory fitness and quality of life. Methods: Patients scheduled for open or endovascular AAA repair were previously randomized to either a 6-week preoperative SEP or standard management, and a significant improvement in a composite outcome of cardiac, pulmonary, and renal complications was seen following SEP. For the current analysis, patients were followed up to 5 years postsurgery. The primary outcome for this analysis was all-cause mortality. Data were analyzed on an intention to treat (ITT) and per protocol (PP) basis, with the latter meaning that patients randomized to SEP who did not attend any sessions were excluded. The PP analysis was further interrogated using a complier average causal effect (CACE) analysis on an all or nothing scale, which adjusts for compliance. Additionally, patients who agreed to follow-up attended the research center for cardiopulmonary exercise testing and/or provided quality of life measures. Results: ITT analysis demonstrated that the primary endpoint occurred in 24 of the 124 participants at 5 years, with eight in the SEP group and 16 in the control group (P = .08). The PP analysis demonstrated a significant survival benefit associated with SEP attendance (4 vs 16 deaths; P = .01). CACE analysis confirmed a significant intervention effect (hazard ratio, 0.36; 95% confidence interval, 0.16-0.90; P = .02). There was no difference between groups for cardiorespiratory fitness measures and most quality of life measures. Conclusions: These novel findings suggest a long-term mortality benefit for patients attending a SEP prior to elective AAA repair. The underlying mechanism remains unknown, and this merits further investigation.

Background Arteriovenous fistulas are considered the best option for haemodialysis provision, but as many as 30% fail to mature or suffer early failure. Objective To assess the feasibility of performing a randomised controlled trial that examines whether, by informing early and effective salvage intervention of fistulas that would otherwise fail, Doppler ultrasound surveillance of developing arteriovenous fistulas improves longer-term arteriovenous fistula patency. Design A prospective multicentre observational cohort study (the ‘SONAR’ study). Setting Seventeen haemodialysis centres in the UK. Participants Consenting adults with end-stage renal disease who were scheduled to have an arteriovenous fistula created. Intervention Participants underwent Doppler ultrasound surveillance of their arteriovenous fistulas at 2, 4, 6 and 10 weeks after creation, with clinical teams blinded to the ultrasound surveillance findings. Main outcome measures Fistula maturation at week 10 defined according to ultrasound surveillance parameters of representative venous diameter and blood flow (wrist arteriovenous fistulas: ≥ 4 mm and > 400 ml/minute; elbow arteriovenous fistulas: ≥ 5 mm and > 500 ml/minute). Mixed multivariable logistic regression modelling of the early ultrasound scan data was used to predict arteriovenous fistula non-maturation by 10 weeks and fistula failure at 6 months. Results A total of 333 arteriovenous fistulas were created during the study window (47.7% wrist, 52.3% elbow). By 2 weeks, 37 (11.1%) arteriovenous fistulas had failed (thrombosed), but by 10 weeks, 219 of 333 (65.8%) of created arteriovenous fistulas had reached maturity (60.4% wrist, 67.2% elbow). Persistently lower flow rates and venous diameters were observed in those fistulas that did not mature. Models for arteriovenous fistulas’ non-maturation could be optimally constructed using the week 4 scan data, with fistula venous diameter and flow rate the most significant variables in explaining wrist fistula maturity failure (positive predictive value 60.6%, 95% confidence interval 43.9% to 77.3%), whereas resistance index and flow rate were most significant for elbow arteriovenous fistulas (positive predictive value 66.7%, 95% confidence interval 48.9% to 84.4%). In contrast to non-maturation, both models predicted fistula maturation much more reliably [negative predictive values of 95.4% (95% confidence interval 91.0% to 99.8%) and 95.6% (95% confidence interval 91.8% to 99.4%) for wrist and elbow, respectively]. Additional follow-up and modelling on a subset ( n = 192) of the original SONAR cohort (the SONAR-12M study) revealed the rates of primary, assisted primary and secondary patency arteriovenous fistulas at 6 months were 76.5, 80.7 and 83.3, respectively. Fistula vein size, flow rate and resistance index could identify primary patency failure at 6 months, with similar predictive power as for 10-week arteriovenous fistula maturity failure, but with wide confidence intervals for wrist (positive predictive value 72.7%, 95% confidence interval 46.4% to 99.0%) and elbow (positive predictive value 57.1%, 95% confidence interval 20.5% to 93.8%). These models, moreover, performed poorly at identifying assisted primary and secondary patency failure, likely because a subset of those arteriovenous fistulas identified on ultrasound surveillance as at risk underwent subsequent successful salvage intervention without recourse to early ultrasound data. Conclusions Although early ultrasound can predict fistula maturation and longer-term patency very effectively, it was only moderately good at identifying those fistulas likely to remain immature or to fail within 6 months. Allied to the better- than-expected fistula patency rates achieved (that are further improved by successful salvage), we estimate that a randomised controlled trial comparing early ultrasound-guided intervention against standard care would require at least 1300 fistulas and would achieve only minimal patient benefit. Trial Registration This trial is registered as ISRCTN36033877 and ISRCTN17399438. Funding This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR135572) and is published in full in Health Technology Assessment ; Vol. 28, No. 24. See the NIHR Funding and Awards website for further award information.

Introduction:We assess if ultrasound surveillance of newly-created arteriovenous fistulas (AVFs) can predict nonmaturation sufficiently reliably to justify randomized controlled trial (RCT) evaluation of ultrasound-directed salvage intervention.Methods:Consenting adults underwent blinded fortnightly ultrasound scanning of their AVF after creation, with scan characteristics that predicted AVF nonmaturation identified by logistic regression modeling.Results:Of 333 AVFs created, 65.8% matured by 10 weeks. Serial scanning revealed that maturation occurred rapidly, whereas consistently lower fistula flow rates and venous diameters were observed in those that did not mature. Wrist and elbow AVF nonmaturation could be optimally modeled from week 4 ultrasound parameters alone, but with only moderate positive predictive values (PPVs) (wrist, 60.6% [95% confidence interval, CI: 43.9-77.3]; elbow, 66.7% [48.9-84.4]). Moreover, 40 (70.2%) of the 57 AVFs that thrombosed by week 10 had already failed by the week 4 scan, thus limiting the potential of salvage procedures initiated by that scan's findings to alter overall maturation rates. Modeling of the early ultrasound characteristics could also predict primary patency failure at 6 months; however, that model performed poorly at predicting assisted primary failure (those AVFs that failed despite a salvage attempt), partly because patency of at-risk AVFs was maintained by successful salvage performed without recourse to the early scan data.Conclusion:Early ultrasound surveillance may predict fistula maturation, but is likely, at best, to result in only very modest improvements in fistula patency. Power calculations suggest that an impractically large number of participants (>1700) would be required for formal RCT evaluation.

Abstract Introduction The NHS must provide a net zero service by 2045. Innovative strategies are required to quantify, evaluate and implement environmentally friendly interventions into practice. The study evaluates the feasibility and sustainability of remote post-operative follow-up using novel methodology. Methods Patients were reviewed remotely and face-to-face at 30 days post-operatively. A prospective life-cycle assessment(LCA) approach to carbon footprint analysis was used to calculate carbon emissions kgCO2e. Patient postcodes were applied to conversion factors to calculate travel emissions. Median(IQR) kgCO2e saved were presented. Carbon offsetting values are based on kgCO2e sequestered by a standardised UK variety tree. Results 31 participants(M:F 2.4, 66.7±11.7 years) were included. The median return distance for patient travel was 42.5km(7.2-58.7). Median reduction using remote follow-up was 41.2 kgCO2e(24.5-80.3) per patient(P<0.001). Using remote follow-up is equivalent to planting 1 tree for every 6.9 patients reviewed. Every readmission with SSI results in an additional 1219.93 kgCO2e. Discussion This model shows that the prospective LCA approach is achievable. Implementation of an asynchronous follow-up model is effective in substantially reducing the carbon footprint of a tertiary vascular surgical centre. Further work is needed to corroborate these findings on a larger scale and incorporate kgCO2e into cost analysis of SSI monitoring strategies.

IntroductionSurgical site infections (SSI) are the most common healthcare-associated infections; however, access to healthcare services, lack of patient awareness of signs, and inadequate wound surveillance can limit timely diagnosis. Telemedicine as a method for remote postoperative follow-up has been shown to improve healthcare efficiency without compromising clinical outcomes. Furthermore, telemedicine would reduce the carbon footprint of the National Health Service (NHS) through minimising patient travel, a significant contributor of carbon dioxide equivalent (CO2e) emissions. Adopting innovative approaches, such as telemedicine, could aid in the NHS Net-Zero target by 2045. This study aimed to provide a comprehensive analysis of the feasibility and sustainability of telemedicine postoperative follow-up for remote diagnosis of SSI.MethodsPatients who underwent a lower limb vascular procedure were reviewed remotely at 30 days following the surgery, with a combined outcome measure (photographs and Bluebelle Wound Healing Questionnaire). A hybrid life-cycle assessment approach to carbon footprint analysis was used. The kilograms of carbon dioxide equivalent (kgCO2e) associated with remote methods were mapped prospectively. A simple outpatient clinic review, i.e., no further investigations or management required, was modelled for comparison. The Department of Environment, Food, and Rural Affairs (DEFRA) conversion factors plus healthcare specific sources were used to ascertain kgCO2e. Patient postcodes were applied to conversion factors based upon mode of travel to calculate kgCO2e for patient travel. Total and median (interquartile range) carbon emissions saved were presented for both patients with and without SSI.ResultsAltogether 31 patients (M:F 2.4, ±11.7 years) were included. The median return distance for patient travel was 42.5 (7.2–58.7) km. Median reduction in emissions using remote follow-up was 41.2 (24.5–80.3) kgCO2e per patient (P < 0.001). The carbon offsetting value of remote follow-up is planting one tree for every 6.9 patients. Total carbon footprint of face-to-face follow-up was 2,895.3 kgCO2e, compared with 1,301.3 kgCO2e when using a remote-first approach (P < 0.001). Carbon emissions due to participants without SSI were 700.2 kgCO2e by the clinical method and 28.8 kgCO2e from the remote follow-up.DiscussionThis model shows that the hybrid life-cycle assessment approach is achievable and reproducible. Implementation of an asynchronous digital follow-up model is effective in substantially reducing the carbon footprint of a tertiary vascular surgical centre. Further work is needed to corroborate these findings on a larger scale, quantify the impact of telemedicine on patient's quality of life, and incorporate kgCO2e into the cost analysis of potential SSI monitoring strategies.

Abstract Introduction Guidelines recommend cardiovascular risk reduction and supervised exercise therapy as the initial treatment for patients with intermittent claudication(IC). However, implementation challenges and poor patient compliance lead to significant variation in management and therefore outcomes. We propose a precise machine learning derived decision support system that aims to provide personalised outcome predictions across different management strategies. Methods Feature selection was performed using the least absolute shrinkage and selection operator method. The model was developed using a bootstrapped sample of 10,000 patients based on 255 patients from our vascular centre. The model considered 27 baseline characteristics, compliance to best medical therapy/smoking cessation and treatment strategy. The model was validated using a separate dataset of 254 patients. This model was then used to build a prototype interactive decision support system which was evaluated using calibration curves, decision curve analyses and area under the receiver operator characteristic (AUROC) curves. Results The AUROC curves demonstrated excellent discrimination for the risk of progression to chronic limb threatening ischaemia at two years(0.892) and five years(0.866) and likelihood of major adverse cardiovascular events(0.836), major adverse limb events(0.891) and revascularisation(0.896)within 5 years, regardless of the treatment strategy. Calibration curves demonstrated good consistency between predicted and actual outcomes and decision curve analyses confirmed clinical utility. The tool maintained an accuracy of >80% and an effect size of >0.5. Conclusion Our decision support system successfully predicts outcomes in IC regardless of treatment strategy, offering potential for improved risk stratification and patient outcomes.

OBJECTIVE:The purpose of this study was to assess the feasibility of delivering extracorporeal shockwave therapy (ESWT) to patients with diabetic foot ulcers (DFUs). It also aimed to explore any potential clinical effect of ESWT on wound healing and investigate whether ESWT offers any patient-reported benefits. METHOD:In this single-centre, mixed methods feasibility study, patients with a DFU who met the eligibility criteria underwent ESWT three times over a seven-day period. Primary outcome was feasibility of delivering the intervention. Secondary outcomes included wound size, number of DFUs healed at 12 weeks and quality of life (QoL). Semi-structured interviews explored participants' experience of undergoing ESWT. RESULTS:Of 106 patients screened, 24 (22.6%) were recruited. Following recruitment, two patients were withdrawn from the study with 22 patients included in the final analysis. The mean attendance at clinic was 90.9% and 65.1% for follow-up. The mean score for acceptability and tolerability was 9.86±0.48 (95% confidence interval (CI): 9.62-10.01) and 9.15±2.57 (95% CI: 7.87-10.42), respectively. There were no serious adverse events or side-effects. Of the DFUs, 45.5% healed during follow-up and QoL scores improved until eight weeks. Key themes identified from the qualitative interviews were: desire for fast healing; improved QoL; flexibility of new treatments; and accessibility of transport. CONCLUSION:This study has shown that it is possible to recruit and retain patents into a single-arm study of ESWT for DFUs. This study supports development of a large randomised control trial to determine the clinical and cost-effectiveness of ESWT for DFU healing.