Arteriovenous Fistula Patency Research Articles

#2778 The Charlson Index can be used prospectively to identify patients who will need a close follow up of surveillance for the vascular access

Abstract Background and Aims The primary screening methods for monitoring vascular access in haemodialysis involve measuring access blood flow and dialysis venous pressure. However, challenges are present in both aspects, potentially hindering the attainment of desired results. Research in this field is crucial to identify the optimal combination of intensive clinical monitoring and supplementary surveillance for effective outcomes. For this reason, we aim to describe the impact of comorbidities and patency of native arteriovenous fistulae (nAVF). Method Descriptive study of prevalent patients on haemodialysis, carried out by consulting electronic medical records over a period of 35 months. Demographic and vascular access-related variables were included. Primary and secondary patency was calculated for all accesses. Patients with upper limb AVF were classified according to distal and proximal access location; and the Charlson Index was used to categorise patients according to comorbidities. Kaplan Meyer survival curves were used to contrast the impact of comorbidities on the different patency. Results 52 patients, age 70.7 ± 1.57 years, 69.2% male, 42.3% diabetic, Charlson index with a median of 7 (6.5 - 7.73), 98.1% with a native fistula, the most frequent nAVF location in our population was humerocephalic (63.5%) and a predominance of the left upper extremity (65.4%). According to the location of the access, adjusted by the Charlson index, it is evident that in proximal accesses (humerocephalic and basilic humerus nAVF), with a Charlson Index less than or equal to 7, the time required to reach an event was statistically significantly longer (Log Rank Test (Mantel-Cox): primary patency p=0.057 and secondary patency p=0.069). This comparison was not significant in distal fistulas. Conclusion Using the Charlson comorbidity index information, we transformed it into an accessible and valuable tool for maintaining vascular access patency. Close follow-up in patients with proximal nAVF and high Charlson comorbidity index could be beneficial.

#2833 Charlson comorbidity index predicts early failure and overall survival of vascular access among diabetic dialysis patients.

Abstract Background and Aims Vascular access (VA) survival is a determinant factor in the morbidity and mortality of haemodialysis patients, directly influencing their quality of life. Some studies have described the influence of diabetes on the reduced survival of arteriovenous fistulas as an independent factor; however, the correlation between other comorbidities in diabetic patients with vascular access survival has been less well documented. Therefore, our aim is to describe the relationship between comorbidities in diabetic haemodialysis patients and arteriovenous fistula (AVF) patency. Method Descriptive, observational and retrospective study in prevalent patients included in a haemodialysis programme by consulting electronic records over a period of 35 months. Demographic variables; related to vascular access and primary and secondary patency of all accesses were included. The Charlson Comorbidity Index was used to categorise diabetic patients according to comorbidities. Kaplan Meyer survival curves were used to contrast the impact of comorbidities on the different patency. Results 22 patients, mean age 68.36 ± 10.9 years, 68.18% male, 31.82% female, Charlson index with a median of 6.5 (5 - 8), 95.45% had a native fistula, with humero-cephalic location being more frequent (72.72%) and predominance of the left upper arm (68.18%). The time required to reach an event in both primary patency and secondary patency in diabetic patients was longer in patients with a Charlson index less than or equal to 7, this being statistically significant (Log Rank Test (Mantel-Cox): primary patency p=0.022 and secondary patency p=0.032). Conclusion The Charlson Comorbidity Index in our population is a significant factor in arteriovenous fistula survival.

#2709 Genome wide association study regarding disturbed AVF patency

Abstract Background and Aims Veins are frequently exposed to arterial circulation, as coronary artery bypass grafts (CABG) and as a peripheral venous bypass to treat atherosclerotic disease, or in the case of arterio-venous fistulas (AVF) to provide a vascular access for hemodialysis. Therapeutic success is dependent on proficient venous remodeling after introduction in the arterial circulation to sustain the increased hemodynamic pressure. Frequently observed adverse outcomes after the aforementioned procedures include the stenosis or total occlusion of the vein, requiring surgical or interventional treatment or leading to bypass/ AVF failure. Hereditary factors associated with disturbed venous patency have been previously investigated in all three conditions. For example, distinct VEGF-A as well as TGF-beta polymorphisms have been identified to correlate with AVF failure. In the present analysis we aimed at investigating whether genetic polymorphisms associated with disturbed venous patency after AVF creation are similar to findings in CABG and peripheral bypass patients in a genome wide association study. Method The analyses were conducted in White Europeans (N= 425,406) in the UK Biobank using regenie software. This software employs a linear mixed model that accounts for the impact of population structure and individual relatedness. Out of approximately 805,000 variants, we selected 606,201 high-quality variants to construct a relatedness model for regenie. These selected variants were identified by a genotyping rate exceeding 80%, minor allele frequencies greater than 1%, and Hardy-Weinberg equilibrium p-values below 10^-8. We adjusted for age, sex, BMI, smoking, and history venous thromboembolism. We assessed the association of 9,757,417 imputed SNPs, each having a minimum allele count of 12 and a minimum info score of 0.3. Results In total, 768 patients underwent at least 1 surgery for AVF creation. Out of those, 341 (44.4%) had a recorded procedure or diagnosis associated with disturbed fistula patency. The controls included 6067 CABGs and 384 peripheral bypasses with 76 (1.3%) and 67 (17.4%) recorded events, respectively. We found no genome wide significant associations for the tested SNPs and patency-related AVF complications (Fig. 1). Additionally, we also found no genome wide significant associations after combining the phenotypes (Fig. 2). Conclusion Multiple studies have evaluated genetic associations and adverse clinical outcomes after AVF creation. Nevertheless, the generalizability of these findings might be limited at least partially due to small sample sizes. While the sample size of the present analysis is similar to previous research efforts and therefore also comparably low, the lack of consistency in results might be suggestive of the difficulties research in this field faces. Additionally, we found no indication that impaired venous patency after AVF creation is related to complications after coronary or peripheral bypass surgery regarding genetic patient profiles. However, whether this is due to differences in pathophysiology and related genetic predispositions or due to the limited sample size and incidence rates of the present study remains to be determined in follow-up investigations.

The influence of near-infrared therapy on arteriovenous fistula patency in haemodialysis patients: A multicentre, randomised, controlled clinical trial.

Arteriovenous fistula (AVF) is the preferred vascular access for patients undergoing haemodialysis (HD). AVF malfunction remains a major clinical problem and is a significant independent risk factor for death. Although far-infrared (FIR) therapy has been shown to reduce complications and improve the patency rate of AVFs in various studies, it has been cautiously recommended by the Kidney Disease Outcome Quality Initiative (KDOQI) guidelines for AVF care due to insufficient evidence. Therefore, it is necessary to identify more effective methods for preventing AVF dysfunction. Many in vitro studies and few clinical studies have examined the effects of near-infrared (NIR) therapy on the vasculature. This study will examine the effects of NIR therapy on AVF. A randomised, controlled, open-label, multicentre trial will compare the effect of NIR on AVF patency after 1 year of therapy with that of a control group of patients with existing AVF. One group of patients received NIR treatment above their AVFs, whereas the control group received regular care. The primary outcome is the primary fistula patency rate within 12 months. In addition, acute changes in inflammatory, vasodilatory and haemodynamic parameters after a single treatment in the first 40 participants will be examined. This study was registered in the Clinical Trials Registry (ChiCTR2300071305) at https://register.clinicaltrials.gov/. This study will explore the long-term and acute effects of NIR on AVFs. The study findings will provide information that can be used to develop new technical support for the prevention of AVF dysfunction in patients undergoing haemodialysis.

Heat therapy preconditioning improves the skeletal muscle contractile and mitochondrial function in a mouse model of access-related hand dysfunction

Introduction: Hemodialysis via arteriovenous fistula (AVF) is a life-line treatment for patients with end-stage kidney disease. However, hemodialysis access-related hand dysfunction (ARHD) including ischemia, muscle weakness and alterations in mitochondrial function is prevalent following AVF placement. We tested the hypothesis that two-weeks of daily heat therapy prior to AVF surgery would improve hindlimb function in a mouse model of ARHD. Methods: Adult male C57BL/6J mice (N=9-11/group) were fed a 0.2% adenine diet to induce chronic kidney disease. Following two weeks of the initial adenine diet, animals were randomly allocated to heat therapy (HT) or control (CON) groups. Animals assigned to HT were exposed to environmental heat at 40°C in a climate chamber for 30 min/day, six days/week, for two weeks while the control mice were exposed to room temperature (~22°C). The AVF was created using the left common iliac artery and vein 24-48 hours after the last treatment session. Laser Doppler perfusion to the ventral paw was assessed post-operatively (POD) and AVF patency was verified using a high-frequency duplex ultrasound system three days prior to euthanasia. Following 14 days of recovery, in situ tibialis anterior (TA) muscle contractility and gastrocnemius muscle mitochondrial function were assessed. RNA sequencing analysis of the hindlimb skeletal muscle (N=4/group) was performed. Results: Compared to baseline, the level of blood urea nitrogen was similarly elevated ( P<0.05) in both groups following four weeks of adenine diet. In both groups, blood perfusion to the paw was decreased by ~50% immediately after AVF creation and progressively recovered to ~80% at POD13 without a treatment effect ( P=0.4467). No differences in body weight and muscle mass in the TA, extensor digitorum longus, and soleus muscles were observed (all P>0.05). Notably, however, the absolute ( P=0.0250) and specific force ( P=0.0101) frequency relationship of the TA muscle were significantly improved in the animals exposed to HT. In addition, compared with control animals, HT mice had significant improvement in oxidative phosphorylation (OXPHOS) in both pyruvate ( P=0.0145) and octanoylcarnitine ( P=0.0196) fueled conditions. RNA sequencing results revealed that genes involved in nervous system development and metabolism were significantly different between HT and CON groups. Conclusion: Daily application of heat therapy for two weeks prior to the AVF surgery has beneficial effects on both skeletal muscle contractile and mitochondrial function suggesting this pre-habilitation strategy may mitigate the risk of ARHD in patients undergoing AVF surgery. Funding Support: National Institutes of Health grant R01HL148597 and American Heart Association grant POST903198. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Salvage Aneurysmorrhaphy as an Adaptable and Still Pertinent Technique in the Management of Challenging True Aneurysms of Arteriovenous Fistulas: A Case Series of Different Variations, With Illustrative Surgical Pictures

IntroductionAneurysmorrhaphy, described as reduction aneurysmoplasty, partial aneurysmectomy, or vessel wall recalibration, can be considered a suitable surgical plan for true aneurysms of arteriovenous fistulas (AVFs), allowing for a dynamic approach to reconstruction of aneurysmal AVFs of different severities, ensuring salvage of the native access. ReportSix challenging cases of AVF aneurysms are presented, some with extremely dilated and tortuous megafistulas, for which three surgical technique variations were performed. The patients had a mean age of 59.2 years, 50% were female, with brachiocephalic (n = 5, 83.3%) or brachiobasilic (n = 1, 16.7%) AVFs. The fistulas were created an average of 4.67 years previously, and the aneurysms had an average maximum diameter of 37.5 mm (range 25 – 60 mm). Surgical indications were rupture risk, thrombosis, or outflow stenosis compromising haemodialysis, infections, and concerns for quality of life (affected by post-puncture bleedings, disfiguring aesthetics, pain, and discomfort). The surgical techniques were simple aneurysmorrhaphy (n = 3, 50%), aneurysmorrhaphy with partial excision of aneurysmatic segment with end to end anastomosis of venous ends (n = 2, 33.3%), and aneurysmorrhaphy with establishment of new venous outflow (n = 1, 16.7%). All AVFs were patent post-operatively and at follow up (mean 5.6 months, median one month). Haemodialysis was resumed through the AVFs at a mean of 2.17 weeks post-operatively, with placement of an alternative route for haemodialysis in the meantime. No patients experienced post-operative complications. DiscussionExperience with the more challenging cases shows that aneurysmorrhaphy can still be considered an acceptable, flexible, and pertinent method for salvage of megafistulas, giving the surgeon the much needed versatility to adapt to anatomical and pathological variations, with high patency rates and minimum complications, especially when other treatment options are not possible in complicated cases. AVF salvage through aneurysmorrhaphy allows for a dynamic approach to the reconstruction of severely tortuous, dilated veins, ensuring patency of the native AVF.

Doppler ultrasound surveillance of recently formed haemodialysis arteriovenous fistula: the SONAR observational cohort study.

Arteriovenous fistulas are considered the best option for haemodialysis provision, but as many as 30% fail to mature or suffer early failure. 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. A prospective multicentre observational cohort study (the 'SONAR' study). Seventeen haemodialysis centres in the UK. Consenting adults with end-stage renal disease who were scheduled to have an arteriovenous fistula created. 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. 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. 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. 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. This trial is registered as ISRCTN36033877 and ISRCTN17399438. 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.

Effect of Arteriovenous fistula patency on blood pressure in patients of renal transplantation

Effect of Arteriovenous fistula patency on blood pressure in patients of renal transplantation

A systematic review of prediction models on arteriovenous fistula: Risk scores and machine learning approaches.

Failure-to-mature and early stenosis remains the Achille's heel of hemodialysis arteriovenous fistula (AVF) creation. The maturation and patency of an AVF can be influenced by a variety of demographic, comorbidity, and anatomical factors. This study aims to review the prediction models of AVF maturation and patency with various risk scores and machine learning models. Literature search was performed on PubMed, Scopus, and Embase to identify eligible articles. The quality of the studies was assessed using the Prediction model Risk Of Bias ASsessment (PROBAST) Tool. The performance (discrimination and calibration) of the included studies were extracted. Fourteen studies (seven studies used risk score approaches; seven studies used machine learning approaches) were included in the review. Among them, 12 studies were rated as high or unclear "risk of bias." Six studies were rated as high concern or unclear for "applicability." C-statistics (Model discrimination metric) was reported in five studies using risk score approach (0.70-0.886) and three utilized machine learning methods (0.80-0.85). Model calibration was reported in three studies. Failure-to-mature risk score developed by one of the studies has been externally validated in three different patient populations, however the model discrimination degraded significantly (C-statistics: 0.519-0.53). The performance of existing predictive models for AVF maturation/patency is underreported. They showed satisfactory performance in their own study population. However, there was high risk of bias in methodology used to build some of the models. The reviewed models also lack external validation or had reduced performance in external cohort.

Ruminant model for hemodialysis cannulation.

Preventative strategies that minimize hemodialysis access complications remain limited. This study aimed to address this gap by developing a Caprine cannulation model to investigate the impact of repeated cannulations on vascular access patency rates. In this pilot study, a meta-analysis was conducted using experimental control data from four trials to explore the impact of Caprine breed (independent variable) on the dependent variables that affect hemodialysis cannulation, including AVF growth, AVF depth, and flow rate. Arteriovenous Fistulas (AVFs) were created using the carotid artery and jugular vein in the necks of seven goats from the French alpine, dwarf, and pygmy breeds. All seven AVFs exhibited vessel remodeling patterns similar to that observed in humans and remained patent, enabling hemodialysis access over the 6 month study. Over the course of 18 weeks, a total of 291 cannulations were completed using standard 15 g dialysis needles without complications demonstrating the feasibility of using the Caprine species as a cannulation model. The ease of access coupled with the animals' cooperative behavior further contributes to the suitability of the Caprine species for hemodialysis investigations. Notably, no infections or clinically significant incidents were observed throughout the study. The stability of AVF patency and flow underscores the viability and potential of the Caprine species animal model as a valuable research platform for exploring interventions aimed at improving vascular access survival in hemodialysis patients.

Effect of early cannulation with metal needles on arteriovenous fistula patency in patients undergoing hemodialysis.

Autogenous arteriovenous fistula (AVF) is the preferred vascular access mode. However, the earliest possible time for AVF puncture and whether premature puncture affects the AVF patency rate remain unclear. In this multicenter retrospective cohort study, adult uremic patients who underwent AVF surgery for the first time at Taizhou Hospital or Enze Hospital of Zhejiang Province between September 1, 2018 and August 31, 2021 were enrolled. All patients were followed up for 1 year after puncture, and the status of fistula establishment and puncture, subsequent patency, loss to follow-up, renal transplantation, conversion to peritoneal dialysis, abandonment of the fistula, and death, were recorded. A total of 465 patients with AVFs were included in this study, including 59 (12.7%) patients with fistulas that were cannulated within 30 days. In the early puncture group, the levels of serum creatinine and urea nitrogen were higher, while the levels of hemoglobin and albumin were lower, suggesting that these patients needed urgent dialysis. Furthermore, the rate of non-cuffed catheter use was higher, while the rate of cuffed catheter use was lower, and femoral vein puncture was preferred over internal jugular vein puncture. The mean duration of catheter indwelling was shorter in the early puncture group (19 vs 70 days, p < 0.001). The estimated AVF primary and cumulative functional patency at 12 months was 81.1% versus 82.3% and 98.3% versus 98.7% in the early puncture and control groups, respectively. Kaplan-Meier analysis revealed no significant difference in AVF primary and cumulative functional patency between the two groups. In patients with an established fistula in urgent need of hemodialysis, to avoid new catheterization, a puncture can be performed within 30 days in those with well-developed blood vessels after adequate ultrasound and clinical evaluation without affecting the patency of the fistula.

Association of anesthetic modality and other variables on 1-year functional patency of cephalic-based arteriovenous fistulae.

ObjectivesSome studies suggest that regional (RA) provides better patency for arteriovenous fistula (AVF) for hemodialysis (HD) access as compared to Local (LA) and General Anesthesia (GA). This study evaluates the impact of anesthetic modality on long term fistula function at 12 months. MethodsA retrospective review of patients undergoing cephalic vein-based HD access in consecutive cases between 2014 and 2019 was conducted from five safety net hospitals. The primary endpoint was functional patency at 12 months. Subset analysis individually evaluated cephalic based lower forearm and wrist versus upper arm AVFs. Bivariate and multivariate logistic regression models evaluated the relationship between anesthetic modality and fistula function at 12 months. ResultsThere were 818 cephalic based fistulas created during the study period. The overall 12-month functional patency rate was 78.7%, including an 81.3% patency for upper arm AVF and 73.3% for wrist AVF (p=0.009). There was no statistically significant difference among patients with functional and nonfunctional AVFs at 12 months with respect to anesthetic modality when comparing regional, local, and general anesthesia (p=0.343). Multivariate regression analysis identified that history of AVF/AVG (OR 0.24, p=0.007), receiving intraoperative systemic anticoagulation (OR 2.49, p<0.001), and vein diameter (OR 1.85, p=0.039) as independently associated with AVF functional patency at 12 months. ConclusionThere was no association between anesthetic modality and functional patency of cephalic based-AVF at 12 months. Further studies are needed to better define which patients may benefit from regional anesthesia.

Elevated Leukocyte Glucose Index Is Associated with Long-Term Arteriovenous Fistula Failure in Dialysis Patients.

(1) Background: Arteriovenous fistula (AVF) is the preferred type of vascular access for dialysis in patients with end-stage kidney disease (ESKD). However, the primary patency of AVF at one year is under 70% due to several risk factors and comorbidities. Leukocyte glucose index (LGI), a new biomarker based on blood leukocytes and glucose values, has been found to be associated with poor outcomes in cardiovascular disease. The aim of this study is to analyze the impact of LGI on the long-term primary patency of AVF following dialysis initiation. (2) Methods: We conducted a retrospective observational study in which we initially enrolled 158 patients with ESKD admitted to the Vascular Surgery Department of the Emergency County Hospital of Targu Mures, Romania, to surgically create an AVF for dialysis between January 2020 and July 2023. The primary endpoint was AVF failure, defined as the impossibility of performing a chronic dialysis session due to severe restenosis or AVF thrombosis. After follow-up, we categorized patients into two groups based on their AVF status: "functional AVF" for those with a permeable AVF and "AVF failure" for those with vascular access dysfunction. (3) Results: Patients with AVF failure had a higher prevalence of atrial fibrillation (p = 0.013) and diabetes (p = 0.028), as well as a higher LGI value (1.12 vs. 0.79, p < 0.001). At ROC analysis, LGI had the strongest association with the outcome, with an AUC of 0.729, and an optimal cut-off value of 0.95 (72.4% sensitivity and 68% specificity). In Kaplan-Meier survival analyses, patients in the highest tertile (T3) of LGI had a significantly higher incidence of AVF failure compared to those in tertile 1 (p = 0.019). Moreover, we found that patients with higher baseline LGI values had a significantly higher risk of AVF failure during follow-up (HR: 1.48, p = 0.003). The association is independent of age and sex (HR: 1.65, p = 0.001), cardiovascular risk factors (HR: 1.63, p = 0.012), and pre-operative vascular mapping determinations (HR: 3.49, p = 0.037). (4) Conclusions: In conclusion, high preoperative values of LGI are positively associated with long-term AVF failure. The prognostic role of the biomarker was independent of age, sex, cardiovascular risk factors, and pre-operative vascular mapping determinations.

The risk factors for arteriovenous fistula dysfunction in maintenance hemodialysis patients: A cross-sectional study.

Arteriovenous fistula (AVF) dysfunction is a prevalent complication among maintenance hemodialysis patients. However, the factors influencing AVF patency remain unclear. To address this, we conducted a study aimed at identifying factors contributing to AVF dysfunction in this patient population. The study compared clinical data, vascular calcification score, and laboratory data focusing on blood cell composition and coagulation in 100 maintenance hemodialysis patients in whom an AVF had been inserted from January through September of 2022. The patients were divided into a group in which the AVF functioned without issues and a group in which the AVF was dysfunctional, defined as not able to provide a blood flow of greater than 200 mL/min. Patients in the 2 groups (56 in the dysfunctional AVF group and 44 in the group with satisfactory AVF function) were similar demographically. Compared with the normally functioning AVF group, the AVF dysfunction group exhibited significantly higher Agatston calcium scores (20.5 [1.28, 298] median [Q1, Q3] vs. 1.14 [0.00, 11.6]; p = 0.01), elevated triglyceride levels (1.1 [0.6, 1.2] mmol/L vs. 0.5 [0.3, 0.8]; p < 0.01), increased prothrombin activity (113 ± 22.1% vs. 99.4 ± 23.1; p < 0.01), lower prothrombin time (10.4 [9.8, 10.8] s vs. 11.0 [10.3, 11.5]; p < 0.01), higher red blood cell (RBC) counts (3.5 ± 0.7 · 1012/L vs. 3.0 ± 0.7; p < 0.01), and elevated hemoglobin levels (98.0 ± 21.8 g/L vs. 84.9 ± 24.2; p < 0.01). Higher C-reactive protein (20.2 [3.3, 20.2] mg/L vs. 17.8 [6.2, 17.8]; p = 0.01) and procalcitonin levels (0.9 [0.4, 0.9] ng/mL vs. 0.5 [0.2, 0.7]; p < 0.01) were also noted. Logistic regression analysis indicated that platelet/lymphocyte ratio, monocyte/lymphocyte ratio, and RBC count were factors associated with AVF dysfunction. Increased monocyte/lymphocyte ratio and RBC count correlated with higher risk, while a higher platelet/lymphocyte ratio was associated with lower risk. Arteriovenous fistula dysfunction in maintenance hemodialysis patients is associated with higher proportions of specific hematological parameters, particularly elevated RBC count, and altered platelet/lymphocyte and monocyte/lymphocyte ratios.

Potential Clinical Implications of Senotherapies for Cardiovascular Disease.

Aging is a major risk factor for cardiovascular diseases (CVDs) and accumulating evidence indicates that biological aging has a significant effect on the onset and progression of CVDs. In recent years, therapies targeting senescent cells (senotherapies), particularly senolytics that selectively eliminate senescent cells, have been developed and show promise for treating geriatric syndromes and age-associated diseases, including CVDs. In 2 pilot studies published in 2019 the senolytic combination, dasatinib plus quercetin, improved physical function in patients with idiopathic pulmonary fibrosis and eliminated senescent cells from adipose tissue in patients with diabetic kidney disease. More than 30 clinical trials using senolytics are currently underway or planned. In preclinical CVD models, senolytics appear to improve heart failure, ischemic heart disease, valvular heart disease, atherosclerosis, aortic aneurysm, vascular dysfunction, dialysis arteriovenous fistula patency, and pre-eclampsia. Because senotherapies are completely different strategies from existing treatment paradigms, they might alleviate diseases for which there are no current effective treatments or they could be used in addition to current therapies to enhance efficacy. Moreover, senotherapies might delay, prevent, alleviate or treat multiple diseases in the elderly and reduce polypharmacy, because senotherapies target fundamental aging mechanisms. We comprehensively summarize the preclinical evidence about senotherapies for CVDs and discuss future prospects for their clinical application.

Endovascular Fistula Salvage for Preserving Arteriovenous Fistula Failure in Haemodialysis Patient: Tertiary Referral Hospital, a Single-Centre Experience

Abstract: Efficacy of endovascular intervention for the preservation of failing accesses is very important in hemodialysis patients. This study aimed to determine the efficacy of endovascular balloon angioplasty in preserving the patency of hemodialysis arteriovenous fistula (AVF) failure. This was a retrospective study of hemodialysis patients who received endovascular intervention due to access difficulties. A single-center study was created between January 2022 and June 2022. Fistulography was conducted on patients suspected of having access stenosis, and balloon angioplasty was performed in the same setting if stenosis of 50% was confirmed. Post-operative complications and access restenosis or failure were monitored. The results obtained 69 patients with hemodialysis access failure due to AVF stenosis, occlusion, and thrombosis that were admitted or referred to our hospital. The majority of patients were 40-60 years (50.7%); 88.4% patients were male and 11.6% were female, with a mean age of 56.3±11.6 (range, 18–77). The sites of AVF failure were brachiocephalic (81.1%) and radiocephalic (18.9%). There was no complication recorded. The procedure succes rate was 81.1%. In conclusion, endovascular balloon angioplasty is effective in restoring hemodialysis access patency. Recurrence is common, and interventions must be repeated. Keeping access open can save lives. Percutaneous transluminal angioplasty (PTA) can be used to achieve safely and successfully repair arteriovenous fistulas failure. Keywords: angioplasty; arteriovenous fistula; arteriovenous graft; hemodialysis

Two-Year Cumulative and Functional Patency after Creation of Endovascular Arteriovenous Hemodialysis Fistulae

PurposeTo assess 2-year cumulative and functional patency of endovascular arteriovenous fistulae (endoAVF) created with the WavelinQ device. Materials and MethodsPatients who had fistulae created at a single center from December 2019 to December 2020 were included in this retrospective study. Forty-three patients underwent endoAVF creation (22 females, 21 males). Data collected included patient demographics, location of fistula creation, interventions performed, and brachial artery flow before and after creation. Two-year cumulative and functional patency rates were assessed with Kaplan–Meier method, and variables that affected patency and maturation were examined using Cox proportional hazards model. ResultsTechnical success was 95% (41/43), and in 4 patients, the fistula did not mature for dialysis use (9.7%). For the remaining 37 patients with endoAVF maturation, 25 had ulnar–ulnar fistulae, 10 had radial–radial fistulae, and 2 had interosseous artery–vein fistulae. Mean maturity time was 73 days, and brachial artery flow of >886 mL/min was predictive of maturation. Mean tunneled dialysis catheter removal time was 133 days. Number of interventions per patient-year was 0.38, where 8 were maturation procedures (5 vein elevations/transpositions and 3 coil embolizations) and 21 were maintenance angioplasties. Two-year cumulative/secondary and functional patency rates were 89.4% and 92.1%, respectively, with a mean follow-up of 665.7 days. Examined variables did not impact cumulative or functional patency. One adverse event was migration of coil to the heart, which was successfully retrieved at time of procedure. ConclusionsTwo-year patency of 89.4% and functional patency of 92.1% were observed after endoAVF creation with WavelinQ device.

Analysis of risk factors for late arteriovenous fistula failure and patency rates after angioplasty in hemodialysis patients: a retrospective cohort study.

The incidence of chronic kidney disease (CKD) and end-stage kidney disease (ESKD) is increasing worldwide. Hemodialysis (HD) is the mainstay of renal replacement therapy for patients with ESKD. Risk factors associated with late arteriovenous fistula (AVF) failure in HD patients are poorly investigated. Therefore, the aim of this study was to identify factors associated with late AVF failure in HD patients. Patients with end-stage renal disease (ESRD) who underwent forearm or upper arm AVF angioplasty at Second Affiliated Hospital of Chongqing Medical University between September 2009 and August 2018 were included. Patients were followed up for 36 months. Baseline characteristics were collected using electronic medical records (EMRs). Variables associated with late AVF failure were identified using Cox proportional hazards models. There were 137 patients (64% male, 36% female) included in this study, with 50 (36.5%) experiencing AVF failure. Univariable log-rank analysis showed that age, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), intact parathyroid hormone (iPTH), albumin (ALB), and AVF patency rate were significantly different between patients who did and did not experience AVF failure. Cox regression analysis showed that CRP [P=0.002, hazard ratio (HR) =2.719, 95% confidence interval (CI) for HR: 1.432-5.164], ESR (P=0.030, HR =2.431, 95% CI: 1.088-5.434), iPTH (P=0.013, HR =0.325, 95% CI: 0.133-0.793), and ALB (P=0.040, HR =0.539, 95% CI: 0.299-0.972) were independently associated with AVF failure. Kaplan-Meier survival analysis showed that the cumulative patency rates of AVF at 6, 12, 18, 24, 30, and 36 months were 84%, 74%, 69%, 64%, 64%, and 64%, respectively. CRP, ESR, iPTH, and ALB were associated with AVF failure and should be used as reference in clinical practice.

Comparison of ultrasound features and lesion sites in dysfunctional arteriovenous fistula

This study aimed to investigate ultrasound features of arteriovenous fistula stenosis and their relationship with primary patency after percutaneous transluminal angioplasty (post-intervention primary patency) and compare this classification with that using lesion location. Hemodialysis patients who underwent ultrasound-guided percutaneous transluminal angioplasty for arteriovenous fistula stenosis from July 2020 to December 2021 were retrospectively evaluated. Lesions (excluding inflow arteries) were categorized into five groups based on ultrasound features, and the clinical characteristics and risk factors affecting the post-intervention primary patency of the arteriovenous fistula were analyzed. Among 185 patients, 100 (54.05%), 36 (19.46%), 22 (11.89%), 11 (5.95%), and 16 (8.65%) were classified into the intima-dominant, non-intima-dominant, valve obstruction, vascular calcification, and mixed groups, respectively. The dialysis duration and arteriovenous fistula use time were the highest in the vascular calcification group at 86 (interquartile range: 49–140) and 77 (interquartile range: 49–110) months, respectively. Diabetes mellitus was most common in the intima-dominant group (42.0%). In Kaplan–Meier and univariate Cox analysis, type III lesion location (stenosis in the venous confluence site) was associated with the lower post-intervention primary patency. In the multivariate Cox analysis, percutaneous transluminal angioplasty times (the number of times patients were treated with percutaneous transluminal angioplasty for arteriovenous fistula stenosis dysfunction), vascular calcification, calcification at the lesion site requiring percutaneous transluminal angioplasty, and serum parathyroid hormone levels were independent risk factors for post-intervention primary patency. Ultrasound features showed that calcification of the arteriovenous fistula was detrimental to the post-intervention primary patency of arteriovenous fistula.

Early Ultrasound Surveillance of Newly-Created Hemodialysis Arteriovenous Fistula

IntroductionWe assess if ultrasound surveillance of newly-created arteriovenous fistulas (AVFs) can predict non-maturation sufficiently reliably to justify randomised controlled trial (RCT) evaluation of ultrasound-directed salvage intervention. MethodsConsenting adults underwent blinded fortnightly ultrasound scanning of their AVF after creation, with scan characteristics that predicted AVF non-maturation identified by logistic regression modelling. ResultsOf 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 non-maturation could be optimally modelled from the week four ultrasound parameters alone, but with only moderate positive predictive values (wrist, 60.6% (95% 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.Modelling of the early ultrasound characteristics could also predict primary patency failure at 6 months, but that model performed poorly at predicting assisted primary failure (those AVFs thatfailed despite a salvage attempt), partly because patency of at-risk AVFs was maintained by successful salvage performed without recourse to the early scan data. ConclusionsEarly 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.