Arteriovenous Fistula Creation Research Articles

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.

Association of race and ethnicity with initial surgical hemodialysis access type in a safety net system

ObjectivesPrior studies have found lower arteriovenous fistula (AVF) creation rates in Black and Hispanic patients. Whether this is due to health care disparities or other differences is unclear. Our objective was to evaluate the racial/ethnic differences in initial surgical access type within a high-volume, safety net system with predominantly Black and Hispanic populations. MethodsA retrospective review of initial hemodialysis (HD) access in consecutive cases between 2014 and 2019 was conducted from all five safety net hospitals in a health care system that primarily treats underserved patients. Patient data collected included race, ethnicity, sex, comorbidities, and initial arteriovenous (AV) access type (AV fistula [AVF] vs AV graft [AVG]). The rates of cephalic vein-based AVF (CAVF; radiocephalic, brachiocephalic) were compared with basilic and brachial vein AVF (BAVF), because the latter are performed as two stages. Bivariate and multivariate logistic regression models were adjusted for demographic and clinical variables to evaluate the relationship between race/ethnicity, surgical access type, and comorbid conditions. ResultsWe included 1334 patients (74% Hispanic, 9% Black, 7% Asian, 2% White, 8% other) who underwent first-time surgical HD access creation. The majority were male (818 [63%]). Medical comorbidities were equal among groups, except for chronic obstructive pulmonary disease and stroke, which were higher in Black patients (P < .005 and P = .005, respectively). Overall, 1303 patients (98%) underwent AVF creation and 31 AVG creation (2%), with no difference between race/ethnicity in AVF vs AVG creation. Of the AVF cohort, 991 (76%) had a CAVF and 312 (24%) had a BAVF. Males were more likely than females to get a CAVF (65% vs 35%; P = .002). ConclusionsWithin our safety net health system, where most patients are under-represented minorities, nearly all patients undergoing HD access had an AVF as their initial surgery with no difference in race/ethnicity. AVF type received differed by race, with Black patients twice as likely to undergo BAVF, which required two stages. Further studies are needed to identify the reasons for these differences.

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.

Basilic vein tunnel transposition versus elevation transposition for brachiobasilic arteriovenous fistula creation: A systematic review and meta-analysis

This study aimed to compare basilic vein tunnel transposition (BVTT) to basilic vein elevation transposition (BVET) technique for superficialization of a basilic arteriovenous fistula. This is a systematic review and meta-analysis comparing outcomes between BVTT and BVET for brachiobasilic arteriovenous fistula (AVF) creation. Primary endpoints were primary patency at several time intervals during follow-up and postoperative local complications, whereas secondary endpoints included primary assisted patency and secondary patency. A random effects model meta-analysis was conducted, and the I2 statistic was used to assess heterogeneity. Nine eligible studies were identified, including 543 patients (247 in the BVTT group and 296 in the BVET group). BVTT group was associated with inferior primary patency rate at 6 months compared to BVET group (three studies; OR: 0.43; 95% CI: 0.22–0.83; I2 = 0%; p = 0.012). However, primary patency rates were similar between the two study groups at 12 months (six studies; OR: 0.64; 95% CI: 0.33–1.22; I2 = 40.7%; p = 0.176), and at 24 months (six studies; OR: 0.86; 95% CI: 0.32–2.29; I2 = 74.9%; p = 0.764). No significant differences in terms of primary assisted patency, secondary patency, and postoperative complications were detected between the groups. More specifically, wound infection (BVTT: n = 9/150; BVET: n = 6/186; OR: 1.39; 95% CI: 0.48–4.06; I2 = 0%; p = 0.542) and healing of the scar, particularly regarding arm edema (BVTT: n = 18/100; BVET: n = 27/165; OR: 1.11; 95% CI: 0.57–2.18; I2 = 0%; p = 0.755) and hematoma formation (BVTT: n = 14/173; BVET: n = 42/209; OR: 0.40; 95% CI: 0.13–1.19; I2 = 49%; p = 0.101), did not differ significantly between the two study groups. BVET achieved superior primary patency at 6 months compared to BVTT, but this benefit seems to be lost during longer follow-up intervals. Therefore, both surgical techniques provide similar long-term outcomes.

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 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.

Distal AVF creation with marginal calcified radial artery: Multicentric experience of intraoperative intravascular lithotripsy.

The first-choice vascular access to starting dialysis in patients with End Stage Renal Disease (ESRD) is autogenous distal arteriovenous-fistula (AVF) to spare vascular district avoiding proximal fistula complications. One of most significant exclusion criteria to create distal AVF is still now the presence of huge calcification of the feeding artery due to large numbers of early failure (EF) and failure in maturation (FTM). In recent years the possibility to use new devices able to deliver intravascular lithotripsy (IVL) to treat high calcified stenosis could be a possibility to recruit these marginal arteries to create distal AVF. ESRD patients with totally calcified radial artery wall were enrolled to participate to this prospective, single arm, multicentric study. The selected patients were treated with intraoperative IVL at surgical time, during anastomosis creation to soften calcified radial artery. Patients were followed 1 month after surgery with eco-doppler, for flow and vessels maturation assessment. At 3 month was investigated how many patients have started dialysis treatment with two needle cannulation and good efficiency. Nineteen distal forearm radio-cephalic fistula were built in 19 patients. One-month doppler assessment showed mean AVF flow of 743 ml/min and efferent vein caliper of 6.46 mm. At 3 months 14 patient have started stable 2 needles dialysis (other three patients were not yet dialysis dependent CKD). Were observed one immediate failure, one failure in maturation, and two late failures at 4 and 16 months respectively. Sixteen months primary and secondary patency was 78.9% and 89.5% respectively. These results showed how intraoperative IVL could help to recruit huge calcified marginal artery to create autogenous distal forearm AVF, avoiding proximal AVF, risking distal ischemia syndrome, and sparing vascular district to eventually rebuilt more proximal AVF in future.

Oblique versus Straight skin incision: The impact of incision type on postoperative outcomes in distal radiocephalic arteriovenous fistula creation

Aim: The type of skin incision utilized in arteriovenous (AV) fistula creation may significantly influence the patency, maturation, and overall outcomes of the fistulas. An oblique skin incision may offer distinct advantages in preventing early AV fistula failure by reducing skin tension and minimizing pressure on the newly formed anastomosis. This study aims to compare the postoperative early period outcomes of oblique versus straight skin incision techniques, with a focus on their impact on AV fistula success. Material and Methods: 2020 to 2023, all patients with created AV fistula via distal antebrachial vessels with oblique and straight skin incisions were enrolled. Retrospectively, the patients’ demographics, comorbidities were collated from the hospital data. All patients were operated with local anesthesia for radiocephalic AV fistula creation. The characteristics of the vessels were determined through preoperative Doppler ultrasonography mapping. Evaluations were conducted on primary patency, early maturation, and the incidence of early thrombosis. Results: In Total, 182 patients were operated for AV fistula creation. The mean age was 57±17 years and there was a male predominance with %68. We performed 74 patients AVF creation via straight skin incision and 108 via oblique skin incision. Despite there being no differences in comorbidities and demographic characteristics between the two groups, the group with a straight skin incision exhibited a higher incidence of early thrombosis (p=0.03), a lower maturation rate (p=0.03), and reduced primary patency (p=0.01). Conclusion: Oblique skin incision could be a feasible alternative to conventional straight incision with a higher early AVF patency and lower thrombosis rates. Reducing the pressure on and keeping the incision away from the new anastomosis may be crucial for achieving better outcomes.

Predicting factors for early failure of vascular access in hemodialysis patients.

This study aimed to investigate the incidence of early failure of vascular access for hemodialysis, and determine which factors measured in duplex ultrasound study could predict early failure. We performed a retrospective review of patients who underwent arteriovenous fistula (AVF) or arteriovenous graft (AVG) creation for hemodialysis between September 2019 and January 2023. Early failure was defined as any event that required surgical or endovascular intervention within 6 months following AVF or AVG creation. A total of 189 patients were included. Early failure occurred in 36 patients (19.0%), which included 22 AVFs and 14 AVGs. In the patients who underwent AVF, the preoperative venous diameter, postoperative venous and arterial diameters, and flow volume of AVF all were significantly smaller in the early failure group compared to the patent group. In AVG, the preoperative venous diameter was the only parameter that differed between the 2 groups. A sonographic score was defined based on these factors. In a multivariable analysis, male sex, a previous history of AVF or AVG creation, and sonographic score were found to be significantly associated with early failure. The postoperative venous diameter in AVF and the preoperative venous diameter in AVG were highly predictive of early failure (areas under the curves 0.92 and 0.82, respectively). Venous diameter measured 6 weeks following AVF operation and preoperative venous diameter in AVG were highly predictive of early failure among the duplex ultrasound parameters. Surveillance strategies in the early phase following vascular access creation can be based on these factors.

What are the observed procedural costs of vascular access surgery? Protocol for a systematic review

IntroductionA central component in the introduction of a novel surgical procedure or technique is an evaluation of its cost efficiency when compared with a benchmark standard of care. Accurate assessment...

Assessment of anatomic variations of the brachial artery bifurcation using vascular Doppler ultrasound: a cross-sectional study.

Anatomical variations in arteries of the upper limb, such as presence of an accessory brachial artery, are common and widely described in the literature, mainly in cadaveric studies, but it is now possible to diagnose them using vascular Doppler ultrasound. To identify the incidence of accessory brachial artery using vascular Doppler ultrasound and compare the findings with cadaveric studies. This was a prospective study that examined 500 upper limbs of 250 volunteers assessed with vascular Doppler ultrasound using the Sonosite Titan portable ultrasound machine. 15.6% of the participants in our study had the accessory brachial artery anatomical variation. Our percentage is in line with the average rates found in cadaveric studies, which ranged from 0.2% to 22%. Being aware of this variation is fundamental in procedures such as peripheral venipuncture, arteriovenous fistula creation, catheterization, forearm flaps, emergency surgeries on the limb and even correction of fractures by cast. The accessory brachial artery is a frequent variant in the upper limb. The percentage of individuals with an accessory brachial artery in our study was 15.6%, which agrees with data from the literature on cadaveric studies.

Lipectomy as an alternative for superficialization of autologous AVF in obese patients: experience of a referral center in Amazon.

The preferred vascular access for hemodialysis is a native arteriovenous fistula (AVF) because it offers the best results in the short and long terms, lower morbidity and mortality, and has additional advantages in relation to central venous catheters or arteriovenous grafts. However, obesity can present an additional challenge because of the barrier of subcutaneous cellular tissue covering the surface of the vein to be punctured. The authors review their experience with excision of subcutaneous tissue (lipectomy) overlying upper arm cephalic vein arteriovenous fistulas in obese patients. Consecutive vascular access patients undergoing lipectomy for cannulation with difficult access because of vein depth were reviewed. Cephalic vein depth was measured by ultrasound in all cases. Twenty-two patients were reviewed (15 men and 7 women), with a mean body mass index of 34.0 kg/m2 (range: 28-40 kg/m2). Mean age was 58.4 years. The mean preoperative vein depth of 7.9 mm (range: 7.0-10.0 mm) was reduced to 4.7 mm (range: 3.0-6.0 mm) (P 0.01). The mean follow-up period for patients was 13.2 months. Four patients were lost to follow-up and four died during the period due to causes unrelated to vascular access. Obesity should not be a limiting factor to creation of a native AVF, since lipectomy is a relatively simple option for superficialization, enabling functioning native and deep arteriovenous fistulas in obese patients.

Regional Anesthesia for Arteriovenous Fistula Creation Significantly Increases Venous Diameter

Regional Anesthesia for Arteriovenous Fistula Creation Significantly Increases Venous Diameter

Effect of Different Methods of Anesthesia on Surgically Created Arteriovenous Fistula

Aim of the study was to determine the advantages of peripheral nerve blocks (PNB) versus local infiltration anesthesia (LIA) in the formation of arteriovenous fistula (AVF) surgically created for hemodialysis treatmentType of study: prospective non-randomized study. Approved by the ethics committee of JLF UK in Martin.Type of workplace: clinical workplace of a university hospital.Material and method. The cohort of patients (N=40) who required arteriovenous fistula (AVF) creation was divided into 2 groups, 20 patients each: patients operated under peripheral nerve blockade and patients operated under local infiltration anesthesia. The preserved function of the fistula was monitored 24 hours, 6 weeks and one year after the operation, without revision. Patient inclusion criteria included: age 19–75 years, ASA 3–4, weight 40–120 kg, BMI up to 40. Statistical treatment of data included Mann-Whitney exact test, Fisher's test, t-test, Shapiro–Wilk normality test.Results. After 24 hours, all fistulas created with peripheral nerve blockade were functional whereas only 90% developed under local infiltration anesthesia remained functional (P&gt;0.05 between groups). However, after 6 weeks, 80% of fistulas created under peripheral nerve block were functional, compared to 50% of functional fistulas created in patients under local infiltration anesthesia (P=0.048). One year after surgery, the difference remained as a trend since 55% of fistulas created under peripheral nerve block remained functional while only 35% of fistulas created in patients receiving local infiltration anesthesia were functional without complications (P=0.097).Conclusion. In our study, the peripheral nerve block anestesia seem superior in term of improved survival of created fistula compared to local infiltration anesthesia.

Effect of umbilical cord mesenchymal stem cells on hypoxia-inducible factor-1 alpha (HIF-1α) production in arteriovenous fistula (AVF) animal model: A preliminary study.

Hypoxia-inducible factor-1 alpha (HIF-1α) is a transcription factor that plays a crucial role in cellular responses to hypoxia, such as in the development of intimal hyperplasia, a common complication in arteriovenous fistula (AVF) creation. While the application of umbilical cord mesenchymal stem cells (UC-MSCs) has shown promise in various regenerative medicine applications, including tissue repair and angiogenesis, the effect of UC-MSCs on HIF-1α level in the AVF has not been tested. Therefore, the aim of this study was to evaluate the effect of UC-MSCs administration on HIF-1α levels in the AVF animal model. An experimental study was conducted on 28 local male rabbits (Lepus domestica) using a post-test-only design. The rabbits were divided randomly into four groups: normal rabbit group (negative control), placebo-treated AVF rabbit group (positive control), AVF rabbits treated with in-situ UC-MSCs injection (one dose, 106 UC-MSCs/kg body weight), and AVF rabbits treated with intravenous UC-MSCs (one dose, 106 UC-MSCs/kg body weight (BW). HIF-1α level was measured using ELISA method after 28 days post-treatment. All data were analyzed using the one-way analysis of variance (ANOVA) and continued with the Duncan's post-hoc test. The data indicated that the levels of HIF-1α were different among all four groups (p<0.001). The post-hoc analysis revealed that the HIF-1α levels in both UC-MSC treated groups were significantly lower compared to untreated AVF rabbits (p<0.05). This study suggests that UC-MSCs could be a promising therapy to prevent and reduce intimal hyperplasia in AVF.

Predicting recurrent interventions after radiocephalic arteriovenous fistula creation with machine learning and the PREDICT-AVF web app.

Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines discourage ongoing access salvage attempts after two interventions prior to successful use or more than three interventions per year overall. The goal was to develop a tool for prediction of radiocephalic arteriovenous fistula (AVF) intervention requirements to help guide shared decision-making about access appropriateness. Prospective cohort study of 914 adult patients in the United States and Canada undergoing radiocephalic AVF creation at one of the 39 centers participating in the PATENCY-1 or -2 trials. Clinical data, including demographics, comorbidities, access history, anatomic features, and post-operative ultrasound measurements at 4-6 and 12 weeks were used to predict recurrent interventions required at 1 year postoperatively. Cox proportional hazards, random survival forest, pooled logistic, and elastic net recurrent event survival prediction models were built using a combination of baseline characteristics and post-operative ultrasound measurements. A web application was created, which generates patient-specific predictions contextualized with the KDOQI guidelines. Patients underwent an estimated 1.04 (95% CI 0.94-1.13) interventions in the first year. Mean (SD) age was 57 (13) years; 22% were female. Radiocephalic AVFs were created at the snuffbox (2%), wrist (74%), or proximal forearm (24%). Using baseline characteristics, the random survival forest model performed best, with an area under the receiver operating characteristic curve (AUROC) of 0.75 (95% CI 0.67-0.82) at 1 year. The addition of ultrasound information to baseline characteristics did not substantially improve performance; however, Cox models using either 4-6- or 12-week post-operative ultrasound information alone had the best discrimination performance, with AUROCs of 0.77 (0.70-0.85) and 0.76 (0.70-0.83) at 1 year. The interactive web application is deployed at https://predict-avf.com. The PREDICT-AVF web application can guide patient counseling and guideline-concordant shared decision-making as part of a patient-centered end-stage kidney disease life plan.

Heating the scanning environment during ultrasound upper limb mapping: Impact on arteriovenous fistula creation outcomes and sonographer's perceptions of heating method useability

AbstractAimThis study explores the impact on arteriovenous fistula (AVF) creation and maturation of four methods of heating the scanning environment during ultrasound upper limb mapping, and sonographer perceived useability of the environments.MethodA retrospective audit at Orange and Bathurst hospitals involving patients who underwent ultrasound upper limb mapping (2016–2022). Patients were scanned using warm gel and three additional methods of warming. Two sonographers provided their preference and opinions on each environment. Data on AVF type, brachial artery blood flow (QBRA), AVF maturity status at 3 and 6 months and intervention within this timeframe was retrieved. Data from the three additional heated environments was combined for analysis (heated environments) against the heated gel only environment (gel environment).ResultsEighty‐five patients met selection criteria. There was no significant difference in the proportion of successfully created AVFs between the heated and the gel environments (90% vs. 94%). A greater percentage of AVFs mapped in the heated environments reached maturity without intervention compared to the gel environment (70% vs. 48%, respectively). There was a statistically significant higher QBRA in the AVFs mapped in the heated environments (1.25 L/min) that reached maturity by 3 months without intervention compared to the gel environment (0.95 L/m; p = .008). Sonographers found a warm blanket/electric throw the easiest methods of heating the scanning environment.ConclusionUsing an electric throw and/or a warm blanket during ultrasound upper limb mapping is practical and optimises the scan environment, which provides surgeons with quality information that ultimately improves AVF creation outcomes.

Frailty screening for determination of hemodialysis access placement

ObjectiveChoosing the right hemodialysis vascular access for frail patients remains difficult because the patient's preferences and the likelihood of access function and survival must be considered. We hypothesize that patients identified before arteriovenous (AV) access as frail by the PRISMA-7 score may have worse outcomes, indicating that fistula creation may not be the most clinically beneficial option and it would be in the best interest of the patient to receive either AV graft (AVG) placement or dialysis through a percutaneous catheter. Our pilot study aims to determine whether an association exists between patient frailty as defined by PRISMA-7 and newly created AV fistula (AVF) and AVG access outcomes. MethodsThis was a single institutional prospective cohort study of patients undergoing new AVF or AVG intervention from April 2021 to May 2023. Patients were assessed using the PRISMA-7 frailty questionnaire before their AV access surgery. Patients were grouped by frailty score and score groups were examined for trends. Univariable analysis was performed for baseline differences between frail and nonfrail patients. Failure to achieve maturation, postoperative infection, and 180-day mortality difference was also investigated for frail vs nonfrail patients. Univariable analysis was performed for nonmaturation using standard comorbidities, arterial and venous diameters, and frailty. Multivariable binary logistic regression was performed for the outcome of nonmaturation using frailty as one of the variables in conjunction with the univariable risks associated with nonmaturation. ResultsA total of 40 patients undergoing new AV access placement were investigated, among whom 53% were designated as frail (PRISMA-7 score ≥3). When comparing the frail and nonfrail new AV access groups, the access (AVF and AVG combined) failed in 48% (10/21) of the frail patients, but only failed in 5% (1/19) of the nonfrail patients 1 (P = .012). When distinguishing between AV access types, AVF creations followed the overall trend with 60% of AVF access (9/15) sites in frail patients failing to mature when compared with nonfrail patients, who all had fistulas that matured to use (P = .049). Surgical site infection was absent in all frail patients and present in 5% of nonfrail patients (1/19). Both 30-day and 60-day readmission rates were higher in the frail group compared with the nonfrail group. There was 180-day mortality present in 5 of frail patients % (1/21) and absent in nonfrail patients. Multivariable analysis revealed that both frailty (adjusted odd ratio, 10.19; 95% confidence interval, 1.20-82.25); P = .033) and younger age (adjusted odd ratio, 0.953; 95% confidence interval, 0.923-0.983; P = .002) both had a significant association with nonmaturation. Power analysis revealed a power statistic of 0.898 indicating a probability of type 2 error of 10.02% with a P value of .002. Hosmer-Lemeshow goodness of fit for the logistic regression had 75% overall accuracy for the model. ConclusionsPatient frailty is significantly associated with an increased incidence of AV access failure to mature.

Short-term mortality and revisions to promote maturation after arteriovenous fistula creation

ObjectiveArteriovenous fistula (AVF) for hemodialysis access is traditionally considered superior to grafts due to infection resistance and purported improved patency. However, challenges to AVF maturation and limited patient survival may reduce AVF benefits. The objective of this study is to identify factors associated with risk of AVF requiring revision before maturation and/or mortality within 2 years of creation. MethodsWe performed a retrospective review of 250 AVFs created between May 2017 and November 2020 at a single institution. Maturation was defined as the date the surgeon deemed the AVF ready for use or the patient successfully used the AVF for dialysis. The Risk Analysis Index was used to calculate frailty. The primary outcome was a composite of endovascular/surgical revision to promote maturation and/or mortality within 2 years of AVF creation (REVDEAD). The primary outcome was categorized as met if the patient required a revision to promote maturation or if the patient experienced mortality within 2 years of AVF creation, or if both occurred. REVDEAD was compared with those who did not meet the primary outcome and will be referred to as NOREVDEAD. ResultsSurvival at 2 years after AVF creation was 82%, and 54 (22%) patients underwent AVF revision. Of those, 31 (59%) patients progressed to AVF maturation. Of the 250 AVFs, 91 (36%) met the primary outcome of REVDEAD and 159 (64%) did not (NOREVDEAD). There was no difference between the REVDEAD and NOREVDEAD groups in age (P = .18), sex (P = .75), White race (P = .97), Hispanic ethnicity (P = .62), obesity (P = .76), coronary artery disease (P = .07), congestive heart failure (P = .29), diabetes mellitus (P = .78), chronic obstructive pulmonary disease (P = .10), dialysis status (P = .63), hypertension (P = .32), peripheral arterial disease (P = .34), or dysrhythmia (P = .13). There was no difference between the groups in the forearm vs the upper arm location of AVF (P = .42) or the vein diameter (P = .58). Forearm access, as opposed to upper arm AVF creation, was associated with higher rate of revision before maturation (P = .05). More patients in REVDEAD were frail or very frail (60% vs 48%, P = .05). Of the AVFs that matured, maturation required longer time in REVDEAD at 110.0 ± 9.1 days vs 78.8 ± 5.6 days (mean ± standard deviation) (P = .003). Adjusted for the vein diameter and the forearm vs the upper arm, frailty increased the odds of REVDEAD by 1.9 (95% confidence interval: 1.1, 3.3). ConclusionsFrail patients who underwent AVF were significantly more likely to die within 2 years of AVF creation with no significant association between frailty and the need for revisions to promote maturation. Forearm AVFs were more likely to require revisions; in patients who are frail, with a high likelihood of 2-year mortality, graft may be more appropriate than AVF. If AVF is being considered in a frail patient, upper arm AVFs should be prioritized over forearm AVFs.

The Benefits and Cost-Effectiveness of Arteriovenous (AV) Fistula Screening in Haemodialysis Patients.

Background Ultrasound (US) monitoring of arteriovenous fistulas (AVFs) presents contradictory findings. These differences may be attributed to variances in the chosen surveillance strategy, the specific type of fistula being monitored, and the precise technique used for ultrasound scanning. In this study, we are trying to assess the benefits and cost-effectiveness of US scanning of AVF. Patients and methods This was a descriptive, retrospective, and observational study. The study sample consisted of patients diagnosed with end-stage renal disease (ESRD) on hemodialysis who had AVF for dialysis either by native vein or using prosthetic grafts. We excluded all the patients whose fistula failed to mature, failed to attend the surveillance scan at six weeks, or had absent records or incomplete data. We retrieved the data of the patients who underwent AVF creation at Glan Clwyd Hospital between April 2020 and April 2023. The data was analysed using statistical software (SPSS) version 21 (IBM Corp., Armonk, NY, USA). Results Ninety-eight patients were studied. Stenosis 43.9% (n = 43) was the predominant complication, followed by thrombosis (15.3%;n = 15)while the remaining complications (bleeding, pseudoaneurysm) were less prominent. On the other hand, a total of 37.8% (n = 37) did not experience any complications. Primary patency ranged from 2 to 87 months with a mean of 9 ± 13.2 months SD, and secondary patency ranged from 1 to 24 months with a mean of 1.3 ± 3.9 months SD. The mean cost of a surveillance scan for AVF is 2520 USD, and the mean cost of intervention is 1332 + 1258 USD SD. Out of all the patients, 52 (53%) underwent intervention to salvage the AVF, 2 (2%) received open surgical intervention, and 50 (51%) underwent endovascular intervention. Considering the AVF failure to work, 29.6% (n = 29) had fistulas that failed to work, and 70.4% (n = 69) were still working. Conclusion Routine duplex scanning in six-month periods to diagnose failing AV fistulas is not cost-effective when compared to diagnosing failing or failed AV fistulas based on clinical symptoms.