Hemodialysis Vascular Access Research Articles

Abstract 1130: Tenascin-C In Arteriovenous Fistula Failure: Unraveling Venous Remodeling Dynamics

Background: AVF are the preferred vascular access for hemodialysis, with superior patency and lower infection rates than grafts or catheters. Nevertheless, AVF patency is reduced by both early thrombosis and NIH, culminating in diminished utilization due to one-year patency rates as low as 40-50%. Tenascin-C (TnC), an ECM glycoprotein with limited adult expression, is transiently present at sites of tissue injury and inflammation. TnC has been implicated in playing a role in the development of NIH. Hypothesis: Sustained TnC expression contributes to NIH, potentially leading to AVF failure. Methods: Female and male wild-type C57Bl/6 mice, aged 9-11 weeks, had sham surgery or AVF creation by puncturing the infrarenal aorta into the inferior vena cava (IVC) with a 25-gauge needle. Doppler ultrasound confirmed AVF presence. Tissue samples were collected for IF, WB, and qPCR. Human matched vein and AVF tissue were obtained from patients undergoing planned two-stage AVF creation surgeries and analyzed with IF. In vitro analysis of human dermal microvascular endothelial cells (HDMEC) was performed to investigate the role of TnC in thrombomodulin expression. Results: TnC expression significantly increased in the AVF by day 7, returning to baseline by day 21 and reaching negligible levels by day 42. The spatial and temporal regulation of TnC expression post-AVF creation correlated with ECM remodeling and inversely with thrombomodulin. Both mice and human studies demonstrated differential regulation of TnC and thrombomodulin in patent and occluded AVF. In HDMEC, TnC knockdown suppressed NF-kB expression and increased thrombomodulin expression, while exogenous TnC had the opposite effect. Conclusion: TnC plays a pivotal role in driving pathological inflammation, with its expression being both temporally and spatially regulated during venous remodeling post-AVF creation. Persistent TnC expression is noted in occluded mouse and human AVF, leading to decreased thrombomodulin expression and heightened thrombogenicity. Sustained TnC expression regulates the shift from physiological to pathological venous remodeling, underscoring the crucial role of the immune response in this process and highlighting potential translational therapeutic strategies.

Remote Surveillance Technology of Dialysis Arteriovenous Access: Retrospective Evaluation in a UK Renal Centre

Background: Early identification of dysfunctional arteriovenous haemodialysis (HD) vascular access (VA) is important for timely referral and intervention. Method: We retrospectively calculated VA risk score using Vasc-Alert surveillance software technology from HD treatment sessions in 2 satellite HD units over 18 months. We included in the analysis HD patients dialysing with arteriovenous fistula or graft (AVF/G) with available Vasc-Alert data for≥ 2 months. For group one (eventful) that included patients who developed vascular access thrombosis or stenosis over the study period, we collected Vasc-Alert risk score 2 months prior to the event and, for group two (uneventful), over 5 consecutive months. Vasc-Alert technology utilises routinely collected data during HD to calculate VA risk score and triggers an alert if the score is ≥7 in 3 consecutive dialysis sessions. Patients with >2 alerts (vascular access score ≥7) per month were considered to have positive alerts. Results: From 140 HD patients, 81 patients dialysed via AVF/G. 77/81 had available Vasc-Alert data and were included in the final analysis. Out of 17 eventful patients, 11 (64.7%) had positive alerts 2 months prior to the vascular event. Out of the 60 patients without vascular events, 20 patients (33.3%) had positive alert. Vasc-Alert’s sensitivity and specificity for vascular events were 64.7% and 66.6%, respectively. Within the 6 patients with thrombosed access, 2 patients (33.3%) detected by Vasc-Alert were not detected with clinical monitoring. Conclusion: Vascular access risk score can be a useful non-invasive vascular access surveillance method to assist clinical decision making.

Vascular Access Perception and Quality of Life of Haemodialysis Patients.

Background: Patient quality of life is widely used as a non-clinical determinant of care. For patients undergoing hemodialysis, vascular access is vital to the delivery of hemodialysis and its function may affect not only the clinical outcome of treatment but also the overall quality of life of the patient, highlighting the need for increased efforts to improve the quality of hemodialysis vascular access care. The objective of this study was to evaluate the correlation between vascular access perception and quality of life in patients undergoing hemodialysis. Methods: A total of 202 patients with active hemodialysis vascular access were included in the study. Quality of life was assessed using the Kidney Disease Quality of Life Instrument (KDQOL™) questionnaire, while vascular access perception was evaluated using the Vascular Access Questionnaire (VAQ). Results: The study presented evidence on the influence of vascular access for hemodialysis patients on their quality of life. This impact is related to factors directly associated with vascular access, such as the type of access and the patient's subjective evaluation of the access. Conclusions: The perception of vascular access is one of the factors that determines the quality of life of hemodialysis patients. The quality of life of hemodialysis patients decreases as the number of vascular access-related problems increases.

Efficacy of cilostazol in promoting the maturation of newly created arteriovenous fistula in patients with end-stage renal disease: a systematic review and meta-analysis

BACKGROUND Arteriovenous fistula (AVF) is considered the gold standard for vascular access in hemodialysis. However, achieving the successful maturation of AVF remains a challenge. Cilostazol, a phosphodiesterase-3 inhibitor, has shown promise in enhancing AVF maturation. This study aimed to assess the clinical efficacy of cilostazol in promoting AVF maturation. METHODS This meta-analysis was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A comprehensive systematic literature search was performed using PubMed, ScienceDirect, Cochrane Library, ProQuest, and Google Scholar to identify studies investigating the efficacy of cilostazol on the maturation of newly created AVF in patients with end-stage renal disease and published up to August 2023. The intervention group received perioperative cilostazol therapy, while the control group did not receive cilostazol. The outcomes were the maturation rate of AVF and AVF-related complications. Meta-analysis was conducted using Review Manager software version 5.3. RESULTS 5 studies involving 549 patients were included. The intervention group comprised 228 patients, while the control group comprised 321 patients. In the pooled analysis, patients in the intervention group had a significantly higher rate of AVF maturation (odds ratio [OR] = 2.18, 95% confidence interval [CI]: 1.29–3.68, p = 0.003, I2 = 47%) and a lower rate of AVF-related complications (OR = 0.46, 95% CI: 0.28–0.77, p = 0.003, I2 = 27%) compared to the control. CONCLUSIONS Cilostazol was associated with a higher rate of AVF maturation and a lower rate of AVF-related complications.

Snuffbox Versus Wrist Radiocephalic Arteriovenous Fistulas: 10 Years Experience.

Background The wrist radiocephalic arteriovenous fistula (RCAVF) is the initial suggested procedure for establishing hemodialysis vascular access (HVA) in the most distal site of the upper limb. The anatomical snuffbox arteriovenous fistula (SBAVF) is barely utilised, despite its remote location. In this study, we aimed to analyse and compare the results of SBAVF and RCAVF in terms of their maturity, patency, and failure rates. Methodology This descriptive, retrospective study compared outcomes between SBAVF and RCAVF in terms of maturation, patency, and failure. All patients with chronic kidney disease who attended and underwent either procedure at Betsi Cadwaladr University Health Board between 2013 and 2023 were studied. Results In a period of 10 years, 179 patients were included. Overall, 102 (57%) were male and 77 (43%) were female, with a male-to-female ratio of 1.3:1. Wrist radiocephalic fistula was the dominant type of surgery done in 76% (n = 136), while the snuffbox radiocephalic fistula was done in fewer than 24% (n = 43) of patients. Most patients underwent a successful arteriovenous (AV) fistula (n = 105, 58.7%), in contrast to 67 patients whose fistulas failed. There was a significant relationship between fistula failure and complications (p = 0.000). There was no significant effect of the fistula site, hypertension, diabetes, cardiac diseases, smoking, peripheral vascular disease, or central vein stenosis on the failure of the AV fistula (p = 0.127, 0.534, 0.510, 0.397, 0.017, 0.68, and 0.371, respectively). Conclusions The snuffbox AV fistula is a suitable and feasible first choice for patients on hemodynamic therapy.

Correlation between Duration of Placement of Non-tunneled Hemodialysis Catheter and Positive Bacterial Culture Incidence in Hemodialysis Patients

Non-tunneling hemodialysis catheter is one of the most convenient vascular accesses for hemodialysis in End Stage Kidney Disease (ESRD) patients. However, these catheters have the highest morbidity among all available accesses. Current guidelines recommend that non-tunneled hemodialysis catheters be placed for no more than 2 weeks to prevent bacterial contamination. This study was conducted in Dr. Hasan Sadikin General Hospital, Bandung, Indonesia, throughout January-December 2021. A correlation test with a prospective observational analysis design was applied to find the link between the duration of non-tunneled hemodialysis catheter placement and the incidence of positive bacterial culture on the catheter. Pearson correlation test was used to see the strength of the correlation, with a significance limit of 0.05. This study involved 28 subjects. The most common location for catheter placement was in the jugular vein, and laboratory examinations showed no correlation between leukocyte values and positive bacterial culture results. Hypertension and diabetes mellitus were not significant risk factors (p-value 0.887). At ≤14 days of catheter placement, only 1 (6.7%) of the subjects presented a positive culture result. Most of the positive bacterial culture results were found at a duration of 15-30 days of placement, (n=8; 53.3%). The results of the Pearson test showed a p-value of 0.036 and an r-value of 0.399, indicating a significant result with a strong correlation between the two variables. The duration of placement of hemodialysis catheters has a positive correlation with the incidence of positive bacterial cultures, which can increase the risk of systemic infection associated with hemodialysis catheters.

Risk factors for repeated percutaneous transluminal angioplasty of hemodialysis vascular access after initial intervention.

Percutaneous transluminal angioplasty (PTA) is a significant intervention to deal with occlusion and stenosis of vascular access. The study aimed to explore the risk factors of repeated PTA (re-PTA) after the initial intervention in patients undergoing hemodialysis. This retrospective study included 180 patients who underwent successful PTA for the first time between March 2016 and December 2020. Information on demographic, clinical, anatomical, and medication variables was collected. Survival curves were plotted using Kaplan-Meier analysis and the risk factors associated with re-PTA were analyzed using univariate and multivariate Cox proportional hazards analyses. The primary clinical patency rates at 6, 12, and 24months after PTA were found to be 85.2%, 70.7%, and 58.6%, respectively. The univariate Cox proportion hazards analysis revealed the association of non-antiplatelet agents (HR 2.368 95% CI 1.351 to 4.150, p = .003) and arteriovenous graft (AVG) (HR 2.096 95% CI 1.147 to 3.831, p = .016) with re-PTA. However, only non-antiplatelet therapy showed statistical significance (HR 2.368 95% CI 1.351 to 4.150, p = .003) in multivariate Cox proportional hazards analysis. Among the patients undergoing hemodialysis, the use of antiplatelet agents was associated with a lower risk of re-PTA. Therefore, the use of antiplatelet drugs may reduce the rates of re-PTA and help in maintaining the patency of vascular access.

Effect of blood viscosity on the hemodynamics of arteriovenous fistulae based on numerical investigation

Arteriovenous fistula (AVF) is the most commonly used vascular access for hemodialysis in patients with end-stage renal disease. Vascular diseases such as atherosclerosis and thrombosis, triggered by altered hemodynamic conditions, are the main causes of access failure. Changes in blood viscosity accelerate access dysfunction by affecting local velocities and wall shear stress (WSS) distribution in the circulation. Numerical simulation was employed to analyze and compare the hemodynamic behavior of AVF under different blood viscosities (0.001–0.012 Pa∙s). An idealized three-dimensional model with end-to-side anastomosis was established. Transient simulations were conducted using pulsatile inlet velocity and outflow as boundary conditions. The simulation results reveal the blood flow state of AVF under different viscosity physiological conditions and derive the rule of change. When blood viscosity increases, the local velocity in the disturbed region slows down and the stagnation time becomes longer, resulting in increased deposition of substances. As blood viscosity increases, the level of shear stress on the entire wall of the fistula increases accordingly. WSS values at high viscosities above 0.007 Pa∙s showed significantly larger low-shear regions near the anastomosis and increased chances of inducing atheromatous plaques. This research has revealed the correlation between blood dynamic viscosity and the hemodynamic behavior of AVF. Elevated whole blood viscosity increases the incidence of access obstruction and vascular disease leading to fistula failure. The study provides a basis for optimizing the distribution of hemodynamic parameters in the fistula for hemodialysis patients.

Risk of infections related to endovascular catheters and cardiac implantable devices in hemodialysis patients.

Patients requiring dialysis are extremely vulnerable to infectious diseases. The high burden of comorbidities and weakened immune system due to uremia and previous immunosuppressive therapy expose the patient on dialysis to more infectious events than the general population. The infectious risk is further increased by the presence of endovascular catheters and implantable cardiologic devices. The former is generally placed as urgent vascular access for dialysis and in subjects requiring hemodialysis treatments without autogenous arteriovenous fistula. The high frequency of cardiovascular events also increases the likelihood of implanting indwelling implantable cardiac devices (CIED) such as pacemakers (PMs) and defibrillators (ICDs). The simultaneous presence of CVC and CIED yields an increased risk of developing severe prosthetic device-associated bloodstream infections often progressing to septicemia. Although, antibiotic therapy is the mainstay of prosthetic device-related infections, antibiotic resistance of biofilm-residing bacteria reduces the choice of infection eradication. In these cases, the resolution of the infection process relies on the removal of the prosthetic device. Compared to CVC removal, the extraction of leads is a more complex procedure and poses an increased risk of vessel tearing. As a result, the prevention of prosthetic device-related infection is of utmost importance in hemodialysis (HD) patients and relies principally on avoiding CVC as vascular access for HD and placement of a new class of wireless implantable medical devices. When the combination of CVC and CIED is inevitable, prevention of infection, mainly due translocation of skin bacteria, should be a mandatory priority for healthcare workers.

Role of Doppler Evaluation in Assessing the Maturation of the Arteriovenous Fistula for Hemodialysis: An Observational Study.

Introduction Arteriovenous fistulas (AVFs) are the preferred type of vascular access for hemodialysis due to their lower risk of complications. This study aimed to determine the role of Doppler evaluation in assessing AVF. Materials and methods We conducted an 18-month prospective observational study of 33 hemodialysis patients who underwent a procedure for the creation of AVF at the Department of Radio-Diagnosis at Sri Devaraj Urs Academy of Higher Education and Research.Patients were evaluated using color Doppler ultrasound. Participants underwent a careful history and clinical examination to diagnose the disease. All relevant parameters were documented in a structured study proforma. AVF maturation was assessed postoperatively at four weeks using Doppler ultrasound color flow evaluation by looking for vascular components (flow volume, vein, and arterial diameter). Data were analyzed using CoGuide V 1.0.3 Statistical Software (CoGuide, Bangalore, India). Results A total of 33 patients, with a mean age of 54.6 ± 7.8 years, were evaluated. Of the 33 participants, 24 (72.7%) were male, and nine (27.3%) were female. The majority (47%, n=16) of participants had diabetes mellitus, eight (24%) had hypertension, and 10 (29%) had both diabetes mellitus and hypertension. A brachiocephalic fistula was created in 45.5% of participants, and 33.33% had radiocephalic anastomoses. Five participants were diagnosed with AVF complications: two had a pseudoaneurysm, and three had a cephalic vein thrombus. Clinical and demographic characteristics (age, vascular components, and complications) were not significantly related to AVF maturation. Conclusions Doppler ultrasound plays an important role in selecting vessels for AVF preoperatively and assessing AVF maturation postoperatively, thus reducing the primary fistula failure rate. The findings suggest that Doppler evaluation can be a reliable tool for assessing AVF maturation and predicting surgical success, which could help healthcare providers make informed decisions about the best course of treatment for their patients. Continued research is warranted in this area to further understand the role of Doppler ultrasound in evaluating AVF surgery.

Early experience with endovascular arteriovenous fistula creation

Background: Patients opting for haemodialysis as a form of renal replacement therapy require prompt and reliable vascular access. The gold standard for delivering high-quality and safe haemodialysis is through the creation of an arteriovenous fistula (AVF), typically formed at the wrist or elbow. This intervention promotes increased blood flow through superficial veins, fortifying them for repeated needle insertion during haemodialysis treatment. The emergence of percutaneous endovascular arteriovenous fistula (pAVF) introduces a non-surgical alternative for AVF creation. This method eliminates the need for incisions, reducing the likelihood of surgical scarring and changes in vein appearance. Advantages of pAVF encompass the potential for accelerated convalescence, enhanced comfort for the patient, and a diminished adverse effect on body image perception. These non-surgical options may motivate patients to undergo the procedure promptly, enhancing the timeliness of vascular access for haemodialysis and positively impacting overall health outcomes. These relatively new interventions are evolving, enabling the refinement of more efficient and safer techniques. Dialysis nurses play a crucial role in overall success, necessitating further training and development of their skills and knowledge for needling these new fistulas. With an increasing number of successful cases and more readily available information, these non-surgical techniques are gaining popularity among patients, particularly those conscious about their body image. Aim: The goal is to outline an early experience with a comprehensive approach to planning a percutaneous endovascular arteriovenous fistula service at King's College Hospital. Method: This article describes the referral process, screening, clinical assessments, procedural elements and cannulation. Insights are drawn from a single-centre experience in the UK with the WavelinQ System (BD). Emphasis will be placed on key staffing needs, particularly related to patient selection and dialysis nurse training. Conclusion: By addressing these essential considerations, a pAVF service can be successfully implemented.

Intraoperative transit time flow measurement predicts maturation of radiocephalic arteriovenous fistulas

ObjectiveThe arteriovenous fistula (AVF) is the first choice for gaining vascular access for hemodialysis. However, 20% to 50% of AVFs fail within 4 months after creation. Although demographic risk factors have been described, there is little evidence on the intraoperative predictors of AVF maturation failure. The aim of this study was to assess the predictive value of intraoperative transit time flow measurements (TTFMs) on AVF maturation failure. MethodsIn this retrospective cohort study, intraoperative blood flow, measured using TTFM, was compared with AVF maturation after 6 weeks in 55 patients. Owing to its significantly higher prevalence and risk of nonmaturation, the radiocephalic AVF (RCAVF) was the main focus of this study. A recommended cutoff point for high vs low intraoperative blood flow was determined for RCAVFs, using a receiver operating characteristic curve. ResultsThe average intraoperative blood flow in RCAVFs was 156 mL/min. Patients with an intraoperative blood flow equal or lower than the determined cutoff point of 160 mL/min, showed a 3.03 times increased risk of AVF maturation failure after 6 weeks, compared with patients with a higher intraoperative blood flow (P < .001). ConclusionsThe intraoperative blood flow in RCAVFs measured by TTFM provides an adequate means of predicting AVF nonmaturation 6 weeks after surgery. For RCAVFs, a cutoff point for intraoperative blood flow of 160 mL/min is recommended for maximum sensitivity and specificity to predict AVF maturation failure after 6 weeks.

Temporal trends in hemodialysis access creation during the fistula first era

ObjectiveAlthough forearm arteriovenous fistulas (AVFs) are the preferred initial vascular access for hemodialysis based on national guidelines, there are no population-level studies evaluating trends in creation of forearm vs upper arm AVFs and arteriovenous grafts (AVGs). The purpose of this study was to report temporal trends in first-time permanent hemodialysis access type, and to assess the effect of national initiatives on rates of AVF placement. MethodsRetrospective cross-sectional study (2012-2022) utilizing the Vascular Quality Initiative database. All patients older than 18 years with creation of first-time upper extremity surgical hemodialysis access were included. Anatomic location of the AVF or AVG (forearm vs upper arm) was defined based on inflow artery, outflow vein, and presumed cannulation zone. Primary analysis examined temporal trends in rates of forearm vs upper arm AVFs and AVGs using time series analyses (modified Mann-Kendall test). Subgroup analyses examined rates of access configuration stratified by age, sex, race, dialysis, and socioeconomic status. Interrupted time series analysis was performed to assess the effect of the 2015 Fistula First Catheter Last initiative on rates of AVFs. ResultsOf the 52,170 accesses, 57.9% were upper arm AVFs, 25.2% were forearm AVFs, 15.4% were upper arm AVGs, and 1.5% were forearm AVGs. From 2012 to 2022, there was no significant change in overall rates of forearm or upper arm AVFs. There was a numerical increase in upper arm AVGs (13.9 to 18.2 per 100; P = .09), whereas forearm AVGs significantly declined (1.8 to 0.7 per 100; P = .02). In subgroup analyses, we observed a decrease in forearm AVFs among men (33.1 to 28.7 per 100; P = .04) and disadvantaged (Area Deprivation Index percentile ≥50) patients (29.0 to 20.7 per 100; P = .04), whereas female (17.2 to 23.1 per 100; P = .03), Black (15.6 to 24.5 per 100; P < .01), elderly (age ≥80 years) (18.7 to 32.5 per 100; P < .01), and disadvantaged (13.6 to 20.5 per 100; P < .01) patients had a significant increase in upper arm AVGs. The Fistula First Catheter Last initiative had no effect on the rate of AVF placement (83.2 to 83.7 per 100; P=.37). ConclusionsDespite national initiatives to promote autogenous vascular access, the rates of first-time AVFs have remained relatively constant, with forearm AVFs only representing one-quarter of all permanent surgical accesses. Furthermore, elderly, Black, female, and disadvantaged patients saw an increase in upper arm AVGs. Further efforts to elucidate factors associated with forearm AVF placement, as well as potential physician, center, and regional variation is warranted.

Follow-up evaluation of snuffbox arteriovenous fistula as an alternative site for hemodialysis - a case series in a lower-middle country

Link of Video Abstract: https://youtu.be/MSeO8kuKhGc Introduction: The preferred vascular access for hemodialysis in chronic kidney disease patients is the arteriovenous fistula (AVF). It is recommended to create AVFs as distally as possible. The snuffbox, situated at the far end of the wrist, is infrequently utilized for AVF insertion due to the prevalent smaller vessel calibers. Case: This case series involves seven patients with chronic kidney disease scheduled for first AVF placement in the snuffbox region, with an average age of 56.71 years. All patients showed an average radial artery caliber of 20.3mm, a mean peak systolic velocity of 67.14 cm/s, and a cephalic vein caliber of 22.7mm, according to preoperative vascular ultrasound. The AVF placement involved an end-to-side anastomosis. All patient demonstrated anastomosis clinical maturation, the primary patency rate was 86%. Follow-up Doppler examinations revealed that patients achieving functional patency had an average caliber of 5.22mm and an average flow rate of 810.65 ml/s. Conclusion: SAVF are created less frequently due to predominantly smaller vessel caliber. However, it can be a viable alternative site for fistula implantation. Vascular mapping is required to ensure that both vessels have minimum 2 mm caliber. Maturation in SAVF have comparable results with the other sites.

Safety and efficacy of a new covered stent in hemodialysis vascular access outflow stenosis: A Brazilian multicenter retrospective study.

Vascular stenosis commonly leads to dysfunction in hemodialysis vascular access. Although percutaneous transluminal angioplasty is an established treatment, stent utilization has increased in the last decade as an alternative solution to extend the access function. This study evaluated the safety and initial results of a new impermeable covered stent for treating vascular access outflow stenosis. Investigators retrospectively analyzed 114 hemodialysis patients treated with polytetrafluorethylene-covered stents from September 2018 to September 2022 across four centers. Lesions treated were de novo or restenotic and located in the venous graft anastomosis, outflow segment, cephalic arch, and basilic swing point. Patients were followed by in-person physical examination at 1, 3, and 6 months, and Duplex ultrasound was performed to evaluate the vascular access circuit and in-stent restenosis. The primary efficacy endpoint was target lesion primary patency at 1, 3, and 6 months. Secondary endpoints included access circuit primary patency and secondary patency at 1, 3, and 6 months. The primary safety endpoint was freedom from local or systemic serious adverse events through 30 days post-procedure. Forty-four patients had thrombosed access at the initial presentation, and 41 patients presented with recurrent stenosis. The target lesion primary patency rates at 1, 3, and 6 months were 100%, 89.4%, and 74%, respectively. The access circuit primary patency rates were 100% at 1 month, 85% at 3 months, and 62.7% at 6 months. The secondary patency rates at 1, 3, and 6 months were 100%, 96.4%, and 94.6%, respectively. In the adjusted multivariate Cox regression analysis, only recurrent lesions and female gender were associated with reduced primary patency rates. No serious adverse event was observed through the first 30 days post-procedure. In this retrospective analysis, a new covered stent was shown to be safe and effective for treating peripheral outflow stenosis in vascular access.

First-in-human feasibility study of the aXess graft (aXess-FIH): 6-Month results.

The creation of an arteriovenous fistula (AVF) is considered the most effective hemodialysis (HD) vascular access. For patients who are not suitable for AVF, arteriovenous grafts (AVGs) are the best access option for chronic HD. However, conventional AVGs are prone to intimal hyperplasia, stenosis, thrombosis, and infection. Xeltis has developed an AVG as a potential alternative to currently available AVGs based on the concept of endogenous tissue restoration. The results of the first 6-month follow-up are presented here. The aXess first-in-human (FIH) study [NCT04898153] is a prospective, single-arm, multicenter feasibility study that evaluates the early safety and performance of the aXess Hemodialysis Graft. A total of 20 patients with end-stage renal disease were enrolled across six European investigational sites. At 6-months follow-up, all grafts were patent with primary and secondary patency rates were 80% and 100%, respectively. Three patients required a re-intervention to maintain graft patency, while one re-intervention was required to restore patency. One graft thrombosis and zero infections were reported. The expected advantages of the novel aXess Hemodialysis Graft over conventional AVGs would be evaluated by the analysis on long-term safety and effectiveness during the 5-year follow-up of the currently ongoing trial.

Establishing Long-Term Haemodialysis Vascular Access with Permcath in Children with Chronic Kidney Disease: A Single-Centre Retrospective Analysis

Background: In some regions, the types and sizes of tunneled central venous catheters (CVCs) are limited. Objective: The objective of this study was to review our experience with 10F Quinton Permcath catheters used for long-term vascular access in children of various ages and weights with chronic renal failure. Methods: Children with renal failure on maintenance hemodialysis who underwent placement of the 10F Quinton Permcath between June 2017 and June 2023 at the First Affiliated Hospital of Jinan University were included. We collected clinical data from children with the Permcath, including patients' gender, age, weight, and height. Additionally, data on catheter-related complications were gathered. Imaging data of the patients were obtained to compare the catheter route on imaging and the position of the catheter tip in each case. This enabled an analysis of the characteristics of vascular access establishment and its correlation with catheter-related complications in 11 children implanted with 10F Quinton Permcath. Results: Among the 11 children on maintenance hemodialysis with catheters, five were male, and six were female, with a median age of 9 years (range 8 - 10). The median body weight of the included patients was 23.00 kg (range: 19.95 - 24.30 kg). Eight cases involved placement in the right internal jugular vein (IJV), with the catheter tip located at the level of T8 in two cases, T5 in one case, and T7 in the remaining cases, with no early catheter dysfunction. Three patients underwent catheter placement in the left IJV, with the catheter tip located at the level of T5, T4, and the T7/T8 intervertebral space, respectively, and two cases of early catheter dysfunction occurred in two patients. There were no acute complications in the 11 cases following catheter insertion. Conclusions: Whenever feasible, the right IJV should be the preferred choice for establishing vascular access for the 10F Quinton Permcath in children with chronic kidney disease, regardless of age and weight. The tunnel route and catheter length within the tunnel can be adjusted to ensure the appropriate placement of double-lumen tunnelled cuffed catheters (TCC).

Evaluating patient perspectives of endovascular created arteriovenous fistulas for dialysis access (EndoAVF)

BackgroundPatient reported experience measures are contemporary quality indicators that focus on evaluation of healthcare delivery processes. While surgical arteriovenous fistulas (otherAVF) are preferred for haemodialysis vascular access, fears about surgery and complications often result in refusal/delays. A new technique of endovascular arteriovenous fistula creation (EndoAVF) has been developed and as part of it’s ongoing introduction into our unit, the patient perspective was felt critical to its evaluation. The Vascular Access Questionnaire (VAQ) provides a mechanism for identifying and scoring perceptions in this setting.MethodPatients who had previously undergone EndoAVF formation were approached to undertake the VAQ as part of a service evaluation of their experience. In addition to the components of the VAQ, data questions relating to the patient’s perception of their access were gathered. Results were compared with a matched historical cohort of surgically created fistulas (otherAVF) patients.ResultsPatient satisfaction and self-reported ease of use with EndoAVF were high. Overall VAQ scores were similar between the EndoAVF and the surgically created cohort. Functionally, there was no significant difference in perception of their fistula by patients, irrespective of them being created surgically or radiologically.ConclusionAlthough numbers in this report are small limiting exploration of preserved inherent heterogeneity, we provide a useful initial patient reported experience and perspectives on comparative functional use of radiologically and surgically created AVFs. As real world experience gathers, future larger cohorts with adequate sampling may allow exploration of patient reported experiences and outcome measures.

Vascular access challenges in hemodialysis children.

Hemodialysis (HD) success is dependent mainly on vascular access (VA). The aim of this study is to share the experience of Pediatric Nephrology Unit (PNU), Cairo University Children's Hospital (CUCH), with VA-related obstacles in end stage kidney disease (ESKD) HD children. This is a retrospective analysis of VA related data of 187 ESKD children received regular HD over 3year duration (2019-2021). Kaplan-Meier curves were used to present arteriovenous fistula (AVF) and cuffed catheters survivals. Uncuffed central venous catheter (CVC) was the primary VA for HD in up to 97.3% with 2.7% of patients had AVF performed and attained maturation before initiation of regular HD. Fifty-six (29.9%) patients have inserted 120 tunneled CVCs. AVFs & AV grafts (AVF) were performed in 79 (42.2%) and 6 (3.2%) patients respectively. There were 112 uncuffed CVCs implanted beneath the screen in Rt internal jugular vein (IJV) (44%) Lt IJV (17%), right internal mammary vein (2.7%) while Trans hepatic (TH) technique was used to place 39 uncuffed CVCs (34%) in the inferior vena cava (IVC). Catheter-related bacteremia (CRB) was the most frequent complication in uncuffed and cuffed CVCs (2.58 / 100 catheters day and 10.1 /1000 catheter days respectively). AVFs achieved a high success rate (83%) after 757.71 ± 512.3 functioning days. Native AVF is the preferred VA for pediatric HD but its creation is limited by the small sized vessels where non-cuffed CVC could be a reasonable relatively long-term alternative. Challenging situations (occluded central veins) could benefit from TH technique of CVC insertion in IVC.

Vascular access for hemodialysis in Italy: What a national survey reveals.

Since in Italy there are no official data on vascular access (VA) for hemodialysis the Vascular Access Project Group (VAPG) of the Italian Society of Nephrology (SIN) designed a national survey. A 35-question survey was designed and sent it to the Italian facilities through the SIN website. The basic questions were the prevalence, the location, and the surveillance of VA, the bedside use of ultrasound, the use of fluoroscopy for central venous catheter (CVC) placement, and of buttonhole technique, the role of nephrologist in the access creation. The questionnaire was completed in June 2022 by 161 facilities. The survey registered 15,499 patients, approximately one-third of the Italian dialysis population. The prevalence of arteriovenous fistula (AVF), arteriovenous Graft (AVG), and CVC were 61.8%, 3.7%, and 34.5% respectively. The AVF location was 50% in distal forearm, 20% in meanproximal forearm, 30% in upper arm. For AVF creation, nephrologists were involved in 72% of facilities while for CVC placement in 62%. As regards VA monitoring, 21% of the facilities did not have a surveillance protocol; 60% did not register AVF thrombosis and 53% did not register CVC infections. Most of facilities use the fluoroscope during CVC placement, 37% when needed, and 22% never. Ultrasound-guided puncture of complex AVFs was used by 80% of facilities. Buttonhole puncture was used in 5% of patients. Some considerations emerge from the survey data: (1) The increasing CVC prevalence compared to DOPPS 5 study. (2) The low rate of AVG prevalence. (3) The nephrologist is the operator in many VA procedures. (4) The fluoroscopy for CVC placement and the US-guide puncture of the complex AVF are widely used in most facilities. (5) The practice of the buttonhole is not widespread. (6) When the operator is the nephrologist more distal fistulas are performed.