Long term outcomes of ‘Christmas Tree’ banding for haemodialysis access induced distal ischemia: A 13-year experience

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

Tailored risk assessment and forecasting in intermittent claudication

BackgroundGuidelines 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.MethodsFeature 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.ResultsThe 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.ConclusionThe 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

A preoperative supervised exercise program potentially improves long-term survival after elective abdominal aortic aneurysm repair

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 post-surgery. 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

Molecular mechanisms of action of negative pressure wound therapy: A systematic review

Negative pressure wound therapy (NPWT) has significantly advanced wound care and continues to find new applications. Its effects at a molecular level however, remain a subject of debate. The aim of this systematic review is to summarize the current evidence regarding the molecular mechanisms of action of NPWT. Medline, Embase, EBSCO databases and clinical trial registries were searched from inception to January 2023. Clinical studies, animal models or in-vitro studies that quantitatively or semi-quantitatively evaluated the influence of NPWT on growth factors, cytokine or gene-expression in the circulation or wound-bed were included. Risk of Bias assessment was performed using the RoBANS tool for non-randomized studies, the COCHRANE's Risk of Bias 2(ROB-2) tool for randomized clinical studies, OHAT tool for in-vitro studies or the SYRCLE tool for animal model studies. A descriptive summary was collated and the aggregated data is presented as a narrative synthesis. This review included 19 clinical studies, 11 animal studies and 3 in-vitro studies. The effects of NPWT on 43 biomarkers and 17 gene expressions were studied across included studies. NPWT stimulates modulation of numerous local and circulating cytokines and growth factor expressions to promote an anti-inflammatory profile. This is most likely achieved by downregulation of TNFα, upregulation of VEGF, TGF-β and fibronectin

Supervised Exercise Therapy for Intermittent Claudication: A Propensity Score Matched Analysis of Retrospective Data on Long Term Cardiovascular Outcomes

ObjectiveThis 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).MethodsRetrospective 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.ResultsTwo 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 were greater than 0.75, indicating good predictive accuracy.ConclusionCompletion of SET is associated with better outcomes in patients who completed SET compared to patients who declined or discontinued SET with respect to clinically important cardiovascular outcomes over seven years

Identifying the most clinically effective exercise prescription for patients with intermittent claudication (MAXIMISE) : a component network meta-analysis with concurrent cost-effectiveness analysis

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To conduct a component network meta‐analysis (CNMA) comparing different SEP combinations to identify the most clinically effective exercise prescription for people with IC. To conduct an economic evaluation comparing different SEP combinations for people with IC to identify which are cost‐effective

Identifying the most clinically effective exercise prescription for people with intermittent claudication (MAXIMISE): a component network meta-analysis with concurrent cost-effectiveness analysis

Objectives: This is a protocol for a Cochrane Review (intervention). The objectives are as follows:. To conduct a component network meta-analysis (CNMA) comparing different SEP combinations to identify the most clinically effective exercise prescription for people with IC. To conduct an economic evaluation comparing different SEP combinations for people with IC to identify which are cost-effective.</p