Predictors of successful arteriovenous fistula maturation

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

OBJECTIVE

Some studies suggest that regional anesthesia provides better patency for arteriovenous fistula (AVF) for hemodialysis access as compared to local and general anesthesia. This study evaluates the impact of anesthetic modality on long term fistula function at 12 months.

METHODS

A retrospective review of patients undergoing cephalic vein-based hemodialysis 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 vs upper arm AVFs. Bivariate and multivariate logistic regression models evaluated the relationship between anesthetic modality and fistula function at 12 months.

RESULTS

There 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 = .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 = .343). Multivariate regression analysis identified that history of AVF/arteriovenous graft (odds ratio [OR], 0.24; P = .007), receiving intraoperative systemic anticoagulation (OR, 2.49; P < .001), and vein diameter (OR, 1.85; P = .039) as independently associated with AVF functional patency at 12 months.

CONCLUSIONS

There was no association between anesthetic modality and functional patency of cephalic-based AVFs at 12 months. Further studies are needed to better define which patients may benefit from regional anesthesia.

Vascular dialysis access created in a paretic arm of a patient with a history of cerebral stroke: A case report

A patent vascular access is of crucial importance for patients on dialysis. There is no literature describing the success rate and complications of creating dialysis fistulae in a paretic arm. In addition, the risk for non-maturation of dialysis fistula is thought to be high due to the inactivity, muscle atrophy, vascular changes, and higher risk of thrombosis in paretic limbs. Here we describe a case of a successful creation and maturation of a native dialysis fistula.

Malnutrition: A risk factor for vascular access problems

BACKGROUND

Vascular access problems are leading causes of morbidity, hospitalization, and impaired quality of life in chronic hemodialysis patients. Native arteriovenous fistula is the gold standard of vascular access. Geriatric nutritional risk index (GNRI), has recently been shown to be an easy and objective instrument for assessing nutritional status in these patient groups. Considering the association between arteria-venous fistula patency and inflammation, as well as the fact that inflammation is a component of malnutrition, the objective of this study was to determine the relation of malnutrition identified by GNRI with fistula patency.

METHODS

This is a single-center, retrospective, observational study. Hemodialysis patients with AVF were included in the research. Preoperative and postoperative GNRI values were computed and laboratory data were recorded. The patients were analyzed in two groups as the ones without thrombosis history (Group 1) and with thrombosis history (Group 2). According to GNRI, patients were investigated in four groups: G0 (non-risk group, >98), G1 (low risk, 92-98), G2 (moderate risk, 82-91), and G3 (high risk, 82).

RESULTS

Of the 331 patients, 60.1% (199) were male and the average age was 55 ± 15 years. Preoperative GNRI levels were significantly higher in group 1. In correlation analysis, patency time was positively correlated with preoperative GNRI values. Among the preoperative GNRI groups, the G3 group had a patency duration of 6 months (4.9-7.04), whereas the G0 group had a patency length of 37.59 (35.5-39.65) months. By linear regression analysis, preoperative GNRI and postoperative albumin level were determined to be the significant indicators of patency time.

CONCLUSION

GNRI a new tool for detecting malnutrition was strongly associated with fistula patency in hemodialysis patients. Detection of malnutrition before fistula operation may be helpful for the future follow up of the patients in terms of fistula patency.

Heterogeneous gene expression during early arteriovenous fistula remodeling suggests that downregulation of metabolism predicts adaptive venous remodeling

Clinical outcomes of arteriovenous fistulae (AVF) for hemodialysis remain inadequate since biological mechanisms of AVF maturation and failure are still poorly understood. Aortocaval fistula creation (AVF group) or a sham operation (sham group) was performed in C57BL/6 mice. Venous limbs were collected on postoperative day 7 and total RNA was extracted for high throughput RNA sequencing and bioinformatic analysis. Genes in metabolic pathways were significantly downregulated in the AVF, whereas significant sex differences were not detected. Since gene expression patterns among the AVF group were heterogenous, the AVF group was divided into a 'normal' AVF (nAVF) group and an 'outliers' (OUT) group. The gene expression patterns of the nAVF and OUT groups were consistent with previously published data showing venous adaptive remodeling, whereas enrichment analyses showed significant upregulation of metabolism, inflammation and coagulation in the OUT group compared to the nAVF group, suggesting the heterogeneity during venous remodeling reflects early gene expression changes that may correlate with AVF maturation or failure. Early detection of these processes may be a translational strategy to predict fistula failure and reduce patient morbidity.

The role of glomerular filtration rate in AVF success: Should we intervene earlier?

INTRODUCTION

End-stage kidney disease (ESKD) patients require life-sustaining kidney replacement therapies, with the natural arteriovenous fistula (AVF) being the preferred vascular access due to its low infection risk, high patency, and fewer complications. Factors like vessel diameter, gender, diabetes, age, and surgical technique influence AVF maturation.

METHOD

Our study focused on short-term AVF creation success, specifically examining estimated glomerular filtration rate (eGFR) levels using the CKD-EPI formula. Patients were categorized according to their eGFR levels to observe the effects of fistula timing and the severity of kidney disease.

RESULTS

No significant demographic or outcome differences between eGFR groups have been observed except for gender. AVF maturation was notably associated with distal vein diameter (>2 mm), while other factors did not significantly impact maturation rates. As a secondary outcome, it was concluded that the recording of patients' blood pressure values at preoperative and perioperative levels led to the conclusion that blood pressure levels may have an impact on fistula maturation.

CONCLUSION

To ensure vascular access effectiveness, optimizing blood pressure, determining vein diameter, strategic AVF timing, and reducing catheter usage are crucial. Our study aimed to identify eGFR levels conducive to optimal AVF outcomes. Although significant results could not be obtained in this regard, it is considered worthwhile to re-examine the effect of blood pressure in secondary outcomes. Additionally, prospective studies may be appropriate for reevaluating the effect of GFR.

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

Background

Arteriovenous fistulas are considered the best option for haemodialysis provision, but as many as 30% fail to mature or suffer early failure.

Objective

To assess the feasibility of performing a randomised controlled trial that examines whether, by informing early and effective salvage intervention of fistulas that would otherwise fail, Doppler ultrasound surveillance of developing arteriovenous fistulas improves longer-term arteriovenous fistula patency.

Design

A prospective multicentre observational cohort study (the 'SONAR' study).

Setting

Seventeen haemodialysis centres in the UK.

Participants

Consenting adults with end-stage renal disease who were scheduled to have an arteriovenous fistula created.

Intervention

Participants underwent Doppler ultrasound surveillance of their arteriovenous fistulas at 2, 4, 6 and 10 weeks after creation, with clinical teams blinded to the ultrasound surveillance findings.

Main outcome measures

Fistula maturation at week 10 defined according to ultrasound surveillance parameters of representative venous diameter and blood flow (wrist arteriovenous fistulas: ≥ 4 mm and > 400 ml/minute; elbow arteriovenous fistulas: ≥ 5 mm and > 500 ml/minute). Mixed multivariable logistic regression modelling of the early ultrasound scan data was used to predict arteriovenous fistula non-maturation by 10 weeks and fistula failure at 6 months.

Results

A total of 333 arteriovenous fistulas were created during the study window (47.7% wrist, 52.3% elbow). By 2 weeks, 37 (11.1%) arteriovenous fistulas had failed (thrombosed), but by 10 weeks, 219 of 333 (65.8%) of created arteriovenous fistulas had reached maturity (60.4% wrist, 67.2% elbow). Persistently lower flow rates and venous diameters were observed in those fistulas that did not mature. Models for arteriovenous fistulas' non-maturation could be optimally constructed using the week 4 scan data, with fistula venous diameter and flow rate the most significant variables in explaining wrist fistula maturity failure (positive predictive value 60.6%, 95% confidence interval 43.9% to 77.3%), whereas resistance index and flow rate were most significant for elbow arteriovenous fistulas (positive predictive value 66.7%, 95% confidence interval 48.9% to 84.4%). In contrast to non-maturation, both models predicted fistula maturation much more reliably [negative predictive values of 95.4% (95% confidence interval 91.0% to 99.8%) and 95.6% (95% confidence interval 91.8% to 99.4%) for wrist and elbow, respectively]. Additional follow-up and modelling on a subset (n = 192) of the original SONAR cohort (the SONAR-12M study) revealed the rates of primary, assisted primary and secondary patency arteriovenous fistulas at 6 months were 76.5, 80.7 and 83.3, respectively. Fistula vein size, flow rate and resistance index could identify primary patency failure at 6 months, with similar predictive power as for 10-week arteriovenous fistula maturity failure, but with wide confidence intervals for wrist (positive predictive value 72.7%, 95% confidence interval 46.4% to 99.0%) and elbow (positive predictive value 57.1%, 95% confidence interval 20.5% to 93.8%). These models, moreover, performed poorly at identifying assisted primary and secondary patency failure, likely because a subset of those arteriovenous fistulas identified on ultrasound surveillance as at risk underwent subsequent successful salvage intervention without recourse to early ultrasound data.

Conclusions

Although early ultrasound can predict fistula maturation and longer-term patency very effectively, it was only moderately good at identifying those fistulas likely to remain immature or to fail within 6 months. Allied to the better- than-expected fistula patency rates achieved (that are further improved by successful salvage), we estimate that a randomised controlled trial comparing early ultrasound-guided intervention against standard care would require at least 1300 fistulas and would achieve only minimal patient benefit.

Trial Registration

This trial is registered as ISRCTN36033877 and ISRCTN17399438.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: NIHR135572) and is published in full in Health Technology Assessment; Vol. 28, No. 24. See the NIHR Funding and Awards website for further award information.

The difference in diameter between radial artery and cephalic vein correlates with primary patency of radio-cephalic arteriovenous fistula

INTRODUCTION

Autogenous radio-cephalic arteriovenous fistula (RCAVF) is preferred for chronic hemodialysis access. However, RCAVF still suffers from disappointing survival due to fistula dysfunction, with intimal hyperplasia (IH) as an underlying cause of this condition. The inconsistency of radial artery diameter (DRA) and cephalic vein diameter (DCV) is one of the factors affecting the shear disturbance, which is believed to trigger the onset of IH. However, there are no reports correlating the difference in DRA and DCV with RCAVF outcomes.

METHODS

This was a retrospective cohort study. Consecutive patients (n = 233) with a new RCAVF created were included if they underwent duplex ultrasound examination to evaluate preoperatively the radial artery diameter (DRA) and cephalic venous diameter (DCV). We then calculated radial artery-cephalic vein diameter difference (DCV minus DRA, termed DCV-DRA hereafter) and evaluated the association of the preoperative DCV-DRA with primary patency of RCAVF at 12 months. Subgroup analysis was also performed to explore effect modification by age, gender, radial artery diameter, and cephalic vein diameter with DCV-DRA.

RESULTS

After adjusting for age, gender, weight, and mean arterial pressure, the preoperative DCV-DRA was associated with primary patency of RCAVF at 12 months (adjusted Odds ratio [aOR], 1.524 per 1-mm increase; 95% confidence interval [95% CI], 1.048-2.218). The primary patency of RCAVF at 12 months was achieved in 69.4%, 71.8%,and 87.3% of patients with a preoperative DCV-DRA of ⩽-0.6 mm, (-0.5)-0.5 mm, and ⩾0.6 mm, respectively. P for trend was 0.029. Patients with DCV-DRA of ⩾0.6 mm had a much higher chance of 12-month patency than patients with DCV-DRA of ⩽-0.6 mm (aOR, 3.574; 95% CI, 1.276-10.010). Age, gender, radial artery diameter, and cephalic vein diameter did not modify the association of DCV-DRA with primary patency of RCAVF at 12 months.

CONCLUSIONS

Preoperative DCV-DRA may be an under-recognized predictor of RCAVF patency.

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

OBJECTIVE

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.

DATA SOURCES AND REVIEW METHODS

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.

RESULTS

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).

CONCLUSION

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.

Early Ultrasound Surveillance of Newly-Created Hemodialysis Arteriovenous Fistula

Introduction

We assess if ultrasound surveillance of newly-created arteriovenous fistulas (AVFs) can predict nonmaturation sufficiently reliably to justify randomized controlled trial (RCT) evaluation of ultrasound-directed salvage intervention.

Methods

Consenting adults underwent blinded fortnightly ultrasound scanning of their AVF after creation, with scan characteristics that predicted AVF nonmaturation identified by logistic regression modeling.

Results

Of 333 AVFs created, 65.8% matured by 10 weeks. Serial scanning revealed that maturation occurred rapidly, whereas consistently lower fistula flow rates and venous diameters were observed in those that did not mature. Wrist and elbow AVF nonmaturation could be optimally modeled from week 4 ultrasound parameters alone, but with only moderate positive predictive values (PPVs) (wrist, 60.6% [95% confidence interval, CI: 43.9-77.3]; elbow, 66.7% [48.9-84.4]). Moreover, 40 (70.2%) of the 57 AVFs that thrombosed by week 10 had already failed by the week 4 scan, thus limiting the potential of salvage procedures initiated by that scan's findings to alter overall maturation rates. Modeling of the early ultrasound characteristics could also predict primary patency failure at 6 months; however, that model performed poorly at predicting assisted primary failure (those AVFs that failed despite a salvage attempt), partly because patency of at-risk AVFs was maintained by successful salvage performed without recourse to the early scan data.

Conclusion

Early ultrasound surveillance may predict fistula maturation, but is likely, at best, to result in only very modest improvements in fistula patency. Power calculations suggest that an impractically large number of participants (>1700) would be required for formal RCT evaluation.

Small Arteriovenous Anastomosis in Fistula Creation: Establishing a Functional Vascular Access while Minimizing Steal Syndrome

BACKGROUND

The size selection of the arteriovenous (AV) anastomosis in dialysis access creation requires a careful balance: the diameter must be large enough to accommodate sufficient flow for hemodialysis but small enough to minimize the complication of steal syndrome. Steal syndrome affects up to 10% of patients after creation of dialysis access with sometimes devastating consequences. Conventional teaching recommends a 7-10 mm anastomosis. We sought to assess the efficacy of using a smaller (5-6 mm) anastomosis in new arteriovenous fistula (AVF) creation.

METHODS

We conducted a comparative retrospective analysis of patients who underwent fistula creation with a small versus regular size anastomosis at any upper extremity anatomic site between March 2019 and October 2020 at our institution. Anatomic sites included radiocephalic, brachiocephalic, and brachiobasilic. All AV anastomoses were measured intraoperatively to be 5-6 mm in diameter for the small size groups and 8-10 mm for the regular size group. Endpoints included steal syndrome, functional patency, primary patency, and secondary patency.

RESULTS

Out of 110 patients who underwent an AVF creation, 59.1% received a 5-6 mm anastomosis with a median follow-up time of 10 ± 6 months. Patients' demographics and comorbidities were relatively similar between the 2 groups except for a higher rate of hyperlipidemia (55.4% vs. 28.9%, P = 0.008) in the small size group. Patients in the small size group were more likely to undergo a radiocephalic fistula (40% vs. 4.5%, P < 0.001) and to have a smaller mean vein diameter on preoperative duplex ultrasound (3.2±1 mm vs. 3.9±1 mm, P = 0.0016) when compared to their regular size counterparts. During follow-up, none of the patients in the small group developed steal syndrome (0% vs. 9%, P = 0.015). At 1 year, patients in the regular size group achieved higher rates of primary patency (67.9% vs. 46.9%, P = 0.02); however, no difference was seen in 1-year primary-assisted patency (84.9% vs. 73.6%, P = 0.3), secondary patency (89.6% vs. 79.5%, P = 0.3), or functional patency (87.7% vs. 82.2%, P = 0.64) between the small and regular size groups, respectively.

CONCLUSIONS

The use of a 5-6 mm anastomosis in the creation of new AVFs of the upper extremities appears to be a technically safe option for dialysis access. Our experience suggests that smaller anastomosis still creates enough flow to maintain a functional AV access while minimizing the incidence of steal syndrome. Additionally, even with smaller vein sizes preoperative, adequate dialysis access can be created via a small sized anastomosis, including distal arm access. Larger studies with longer follow-up are needed to evaluate long-term outcomes of small anastomosis fistulas.

Obesity drives secondary procedures to achieve access maturation in end-stage renal disease

BACKGROUND

Establishing long-term arteriovenous access is an important component in the long-term care of a patient with end-stage renal disease. The increasing frequency of obesity is reported to impact the access management of end-stage renal disease patients. This study aims to evaluate the outcomes of arteriovenous fistulae (AVF) in obese and nonobese patients.

METHODS

A retrospective review of all patients over ten years with primary autogenous AVF (radiocephalic, brachiocephalic, and brachial-basilic) was undertaken at a single center. Patients were subcategorized by body mass index into nonobese, class I, II, and III obesity. Outcomes of maturation (successful progression to hemodialysis), reintervention, functional dialysis (continuous hemodialysis for 3 consecutive months), and patency were examined.

RESULTS

From January 1999 to December 2019, 2311 patients (67% female; mean age, 61 ± 15 years) underwent primary AVF placement (12% radiocephalic, 53% brachiocephalic, and 35% brachial basilic). Forty-one percent were nonobese, 29% had class I obesity, 19% had class II obesity, and 11% had class III obesity. The majority of patients were diabetic and Hispanic. The 30-day major adverse cardiovascular event rate was elevated in class II (0.20%) and class III (0.50%) obesity compared with class I obesity (0.15%) and nonobese (0.05%). The 30-day morbidity rate was higher in all classes of obesity (0.5% vs0.3% vs 0.2% vs 0.05% for class III vs class II vs class I obesity and nonobese, respectively). Early thrombosis was significantly increased in class II (9%) and class III obesity (12%) compared with class I obesity (5%) and nonobese (3%). There was a two-fold increase in procedures to effect maturation in class II (51%) and class III (74%) obesity compared with class I obesity (22%) and nonobese (34%). Secondary patency at 3 years was significantly lower in class III (62 ± 4%) and class II (79 ± 3%) compared with class I obesity (87 ± 2%) and nonobese (93 ± 4%). All classes of obesity required significantly more secondary Interventions per year compared with nonobese (3.9 vs 3.1 vs 2.5 vs 1.4 secondary interventions per year for class III vs class II vs class I obesity and nonobese, respectively).

CONCLUSIONS

Advancing obesity class is associated with an increased number of procedures to achieve AVF maturation and is associated with poorer patency and functionality as the category of obesity advances.

Model and online calculator for prediction of fistula maturation based on vein dilation and age: A retrospective cohort study in a single-center

OBJECTIVE

A model that considers the characteristics of dialysis patients may help predict successful fistula maturation. We evaluated factors associated with radiocephalic arteriovenous fistula (RCAVF) maturation at 3 months in dialysis patients with end-stage renal disease (ESRD).

METHODS

A total of 184 patients who received an initial RCAVF at Beijing Haidian Hospital (Haidian Section of Peking University Third Hospital) were recruited. Fistula maturation was assessed within 3 months. Patient characteristics and preoperative vascular assessment indices were examined. Factors associated with fistula maturation were analyzed using logistic regression and least absolute shrinkage and selection operator (LASSO) binary logistic regression. Boostrapping was used for internal validation.

RESULTS

The development data consisted of 184 ESRD patients receiving an initial RCAVF, 140 (76%) of whom achieved fistula maturation. The main predictors of RCAVF maturation in the final model were sex, age-adjusted vein dilation (eVD), radial artery volume (Vartery), and diastolic blood pressure. The difference of vein diameter with and without a tourniquet was significantly larger in the mature RCAVF group (3.0 ± 0.5 vs. 2.2 ± 0.5 mm). The area under receiver operating characteristic (AUROC) curve for prediction of fistula maturation was 0.77, and the Hosmer-Lemeshow statistic indicated agreement between observed and predicted values (P = 0.792). Analysis of internal validation using bootstrapping indicated the C-index was 0.75.

CONCLUSION

The ratio of vein dilation and age were the major predictors of fistula maturation at 3 months in our patients. The resulting online prediction model may help in clinical decision-making for patients receiving a RCAVF.

Early Follow-Up after Arteriovenous Fistula Creation is Associated with Improved Access-Related Outcomes

BACKGROUND

Up to 60% of arteriovenous fistulas (AVF) require intervention to assist maturation, which prolongs the time until it can be used for hemodialysis (HD). Current guidelines recommend early postoperative AVF examination to detect and address immaturity to decrease time to maturation. This study evaluates how the timing of postoperative follow-up to assess AVF maturity affects patients' outcomes.

METHODS

All patients who underwent AVF creation between 2017 and 2021 in an academic medical center were retrospectively reviewed, excluding patients lost to follow-up or not on HD. Outcomes were compared between patients that had delayed follow-up to assess AVF maturity, >8 weeks post surgery, versus early follow-up, <8 weeks post-surgery. AVF evaluation for maturity consisted of physical examination and duplex ultrasound. Primary endpoints were time to first cannulation (interval from AVF creation to first successful cannulation) and time to catheter-free dialysis (interval from AVF creation to central venous catheter removal).

RESULTS

A total of 400 patients were identified: 111 in the delayed follow-up group and 289 in the early follow-up group. The median time to follow-up was 78 days (interquartile range [IQR], 66-125) in the delayed follow-up group versus 39 days (IQR, 36-47) in the early follow-up group, (P < 0.0001). The maturation rate was 87% in the delayed follow-up group versus 81% in the early follow-up group, (P = 0.1) and both groups had similar rates of interventions to assist maturation (66% vs. 57%, P = 0.2). The early follow-up group had a significantly shorter median time to first cannulation (50 vs. 88 days; P < 0.0001) and shorter time to catheter-free HD (75 vs. 118 days; P <0.0001). At 4 months after AVF creation, the incidence of first cannulation was 74% in the early follow-up group versus 63% in the delayed follow-up group (P = 0.001). Similarly, the incidence of catheter-free dialysis was 65% in the early follow-up group versus 50% in the delayed follow-up group at 4 months postoperatively, (P = 0.036).

CONCLUSIONS

Early postoperative follow-up for evaluation of fistula maturation is associated with reduced time to first successful cannulation of AVF for HD and reduced time to catheter-free dialysis.

Vein and artery diameter influence on arteriovenous fistula maturation and patency in a Mexican population

BACKGROUND

There is no consensus of the optimal arterial and venous sizes on arteriovenous fistula (AVF) function and patency. The purpose of our study was to determine the influence of vein and artery sizes on maturation and patency in autologous first time AVF in a vascular access clinic of Mexican Social Security.

METHODS

Approved IRB single-center retrospective study in patients referred for their first AVF from 01/2018/ to 04/2020. Perianastomotic inner vein diameter and single inner artery diameter was recorded by duplex ultrasound. Outcomes were: failure to mature (FTM) and cumulative primary patency survival.

RESULTS

Eighty-six AVF's were created (mean age 45.5 ± 15.1 years; 62.8% male; mean BMI 25.9 ± 4.3 kg/m2). About 86% were brachiocephalic AVF. Eight (8.1%) AVF had FTM. Mean follow-up was 19.7 ± 8.5 months. Two-year patency survival was 81.4%. FTM vein and artery diameters (2.1 ± 0.3 and 2.8 ± 0.7 mm respectively) were smaller than successful AVF's (3.1 ± 0.9 and 3.5 ± 0.6 mm) (p < 0.05). ROC curve calculated a 2.15 mm vein diameter cutoff (AUC: 0.86) and a 2.95 mm artery diameter cutoff (AUC: 079) for FTM AVF's (83% sensitivity, 72% specificity both) (p < 0.05). AVF's created with a vein diameter <2.15 mm and <2.95 mm artery diameter had statistically significant lower patency survival than AVF's with larger vein and artery diameters (p < 0.05).

CONCLUSION

Vein diameter <2.15 mm and artery diameter <2.95 mm influences AVF maturation and patency in a Mexican population.

Mid-term cumulative patency of fistula and PTFE grafts among hemodialysis patients: A retrospective, single-center study from Palestine

BACKGROUND

Due to the long waiting time for kidney transplantation, most End-Stage renal disease patients are commenced on either hemodialysis or peritoneal dialysis. Reusable fistulas have the lowest risk for death, cardiovascular events, and infections among all vascular accesses. This study aims to report the outcomes of the arteriovenous fistulas and PTFE grafts and the related predictive clinical and demographic variables.

METHODS

This retrospective study reviewed the charts of all hemodialysis patients between January 2017 and January 2021 at the Dialysis Center of An-Najah National University Hospital, Nablus, Palestine. Our outcomes were a primary failure, primary and secondary patency, and the related factors. Survival analysis using the Kaplan-Meier method was conducted, and the log-rank test was used to compare patency rates. The Cox proportional hazards regression model tested factors relevant to primary and secondary patency rates in univariate and multivariate analyses.

RESULTS

A total of 312 procedures were performed during the study period. Primary failure was 7.1% for AVF, 13.9% for arterio-venous graft (AVG) procedures. Peripheral arterial disease and left-sided AVF were associated with more primary failure rates. AVF, primary patency rates at 1, 2, and 3 years were 82%, 69%, and 59%, respectively, while secondary patency rates at 1, 2, and 3 years were 85%, 72%, and 63%, respectively. Factors associated with increased AVF patency in a proportional hazard model were younger age and dual antiplatelet administration.

CONCLUSION

Our study adds further evidence that autogenous AVF has better results than prosthetic AVG in both primary and secondary patency rates as well as less primary failure rates. Therefore, we encourage further longitudinal studies that assess the benefits of using antiplatelet on AVF outcome versus risks of bleeding, especially with dual agents.

The Effect of Obesity on Outcomes After Arteriovenous Fistulae Creation: A Systematic Review

BACKGROUND

Establishing reliable vascular access is critical for hemodialysis in end-stage renal disease (ESRD). In recent years, the global health burden of ESRD has grown, matched by a rise in prevalence of obesity. Currently, more and more arteriovenous fistulae (AVFs) are being created for obese patients with ESRD. This is a growing concern as creating arteriovenous (AV) access in obese ESRD patients can be more challenging and may be associated with poorer outcomes.

METHODS

We performed a literature search with multiple electronic databases. We included studies that compared outcomes after autogenous upper extremity AVF creation between obese and nonobese patients. The relevant outcomes were postoperative complications, outcomes related to maturation, outcomes related to patency, and outcomes related to reintervention.

RESULTS

We included 13 studies with a total of 305,037 patients. We found a significant association between obesity and poorer early and late AVF maturation. Obesity was also strongly associated with lower primary patency rates and a higher need for reintervention.

CONCLUSIONS

This systematic review found that higher body mass index and obesity are associated with poorer AVF maturation outcomes, poorer primary patency, and higher reintervention rates.

Arteriovenous fistula in functional motor disability

Arteriovenous fistula (AVF) is the preferred route for vascular access in patients with chronic kidney disease on maintenance haemodialysis. Many studies have demonstrated the positive effects of perioperative hand exercise on fistula maturation. Here, we present our experience of radio cephalic AVF creation in patients with neuromuscular disorders who had difficulty performing isometric hand exercises. We created AVF in three patients with neurological disorders. First patient had essential tremor, which created difficulty during hand exercises and surgery while the other two patients had right hemiparesis. Perioperative isometric exercises have been shown to help in maturation of AVF. Due to neurological involvement, our patients had difficulty performing hand exercises. All had successful AVF despite taking longer than usual time to mature. Creation of AVF in neuromuscular diseases is feasible. A preoperative Doppler ultrasound to assess the vessels might help in making an informed decision. This might spare such patients the only functional arm.

Plasma Interleukin-6 Level Predicts the Risk of Arteriovenous Fistula Dysfunction in Patients Undergoing Maintenance Hemodialysis

Systemic inflammation has been proposed as a relevant factor of vascular remodeling and dysfunction. We aimed to identify circulating inflammatory biomarkers that could predict future arteriovenous fistula (AVF) dysfunction in patients undergoing hemodialysis. A total of 282 hemodialysis patients were enrolled in this prospective multicenter cohort study. Plasma cytokine levels were measured at the time of data collection. The primary outcome was the occurrence of AVF stenosis and/or thrombosis requiring percutaneous transluminal angioplasty or surgery within the first year of enrollment. AVF dysfunction occurred in 38 (13.5%) patients during the study period. Plasma interleukin-6 (IL-6) levels were significantly higher in patients with AVF dysfunction than those without. Diabetes mellitus, low systolic blood pressure, and statin use were also associated with AVF dysfunction. The cumulative event rate of AVF dysfunction was the highest in IL-6 tertile 3 (p = 0.05), and patients in tertile 3 were independently associated with an increased risk of AVF dysfunction after multivariable adjustments (adjusted hazard ratio = 3.06, p = 0.015). In conclusion, circulating IL-6 levels are positively associated with the occurrence of incident AVF dysfunction in hemodialysis patients. Our data suggest that IL-6 may help clinicians identify those at high risk of impending AVF failure.

Association of Shear Stress with Subsequent Lumen Remodeling in Hemodialysis Arteriovenous Fistulas

BACKGROUND

Blood flow-induced wall shear stress is a strong local regulator of vascular remodeling, but its effects on arteriovenous fistula (AVF) remodeling are unclear.

METHODS

In this prospective cohort study, we used computational fluid dynamics simulations and statistical mixed-effects modeling to investigate the associations between wall shear stress and AVF remodeling in 120 participants undergoing AVF creation surgery. Postoperative magnetic resonance imaging data at 1 day, 6 weeks, and 6 months were used to derive current wall shear stress by computational fluid dynamic simulations and to quantify subsequent changes in AVF lumen cross-sectional area at 1-mm intervals along the proximal artery and AVF vein.

RESULTS

Combining artery and vein data, prior mean wall shear stress was significantly associated with lumen area expansion. Mean wall shear stress at day 1 was significantly associated with change in lumen area from day 1 to week 6 (11% larger area per interquartile range [IQR] higher mean wall shear stress, 95% confidence interval [95% CI], 5% to 18%; n =101), and mean wall shear stress at 6 weeks was significantly associated with change in lumen area from 6 weeks to month 6 (14% larger area per IQR higher, 95% CI, 3% to 28%; n =52). The association of mean wall shear stress at day 1 with lumen area expansion from day 1 to week 6 differed significantly by diabetes ( P =0.009): 27% (95% CI, 17% to 37%) larger area per IQR higher mean wall shear stress without diabetes and 9% (95% CI, -1% to 19%) with diabetes. Oscillatory shear index at day 1 was significantly associated with change in lumen area from day 1 to week 6 (5% smaller area per IQR higher oscillatory shear index, 95% CI, 3% to 7%), and oscillatory shear index at 6 weeks was significantly associated with change in lumen from 6 weeks to month 6 (7% smaller area per IQR higher oscillatory shear index, 95% CI, 2% to 11%). Wall shear stress spatial gradient was not significantly associated with subsequent remodeling. In a joint model, wall shear stress and oscillatory shear index statistically significantly interacted in their associations with lumen area expansion in a complex nonlinear fashion.

CONCLUSIONS

Higher wall shear stress and lower oscillatory shear index were associated with greater lumen expansion after AVF creation surgery.

Primary Balloon Angioplasty Versus Hydrostatic Dilation for Arteriovenous Fistula Creation in Patients with Small-Caliber Cephalic Veins: A Systematic Review and Meta-Analysis

BACKGROUND

For arteriovenous fistula (AVF) presence of a venous segment with adequate diameter is essential which is lacking in many patients. To find the optimal augmentation technique in patients with small-caliber cephalic vein (i.e., cephalic vein diameter <3 mm), studies compared primary balloon angioplasty (PBA) versus hydrostatic dilation (HD); however, it remained debatable. This systematic review seeks to determine which technique is preferable.

METHODS

We searched MEDLINE, PubMed, Embase, and Google Scholar. Primary outcomes were 6-month primary patency, reintervention, and working AVF. Secondary outcomes were immediate success, the AVF's maturation time (day), and surgical site infection.

RESULTS

Three randomized controlled trials yielding 180 patients were included, of which 89 patients were in the PBA group. The odds ratio (OR) of primary patency was significantly higher in the PBA group (OR 6.09, 95% confidence interval [CI], 2.36-15.76, P = 0.0002), the OR of reintervention was significantly lower in the PBA group (OR 0.16, 95% CI, 0.06-0.42, P = 0.0002), and the OR of working AVF was greater in PBA group (OR 4.22, 95% CI, 1.31-13.59, P = 0.02). The OR of immediate success was significantly greater in the PBA group (OR 11.42, 95% CI, 2.54-51.42, P = 0.002), and the AVF maturation time was significantly shorter in patients who underwent PBA (mean difference -20.32 days, 95% CI, -30.12 to -10.52, P = 0.0001). The certainty of the evidence was high.

CONCLUSIONS

PBA of small cephalic veins with diameter ≤2.5 cm is a safe, feasible, and efficacious augmentation method for AVF creation. This technique achieves favorable maturation outcomes, and PBA is superior to the standard hydrostatic dilatation technique.

Nurses' Use of Ultrasound Location for Puncturing Arteriovenous Fistulas in Hemodialysis

Puncturing an arteriovenous fistula (AVF) in chronic hemodialysis (HD) patients is a source of difficulty even for experienced dialysis nurses. The objective of this study was to compare the failure rate of AVF puncture by the usual technique (visual or by palpation) and after ultrasound location. This nonrandomized prospective single-center study was carried out at the Safi HD Hospital Center for 16 weeks in two successive phases, with the time between each phase dedicated to training nurses in locating punctures by ultrasound. We first evaluated 30 HD patients (300 HD sessions, i.e., 600 punctures) without ultrasound location, then the same patients (300 sessions, i.e., 600 punctures) using ultrasound location for all punctures. Ultrasound location carried out by a single nurse did not show a significant reduction in the rate of failure to puncture the AVF compared with the standard method (2.6% vs. 4%, P = 0.07). However, the rate of complications at the puncture site, recourse to medical advice, or mobilization of a second nurse were significantly reduced (P < 0.05). This single-center study showed no advantage of this approach for the effective cannulation of AVF in HD patients known to be not difficult to cannulate.

Upper limb exercise for arteriovenous fistula maturation in people requiring permanent haemodialysis access

BACKGROUND

The failure of arteriovenous fistulas (AVF) to mature is a major problem in patients with kidney failure who require haemodialysis (HD). Preoperative planning is an important factor in increasing functional AVF. Upper limb exercise has been recommended to gain AVF maturation. Studies of pre- and post-operative upper limb exercises in patients with kidney failure patients have been reported; however, the optimal program for this population is unknown due to inconsistent results among these programs.

OBJECTIVES

We aimed to determine if upper limb exercise would be beneficial for AVF maturation (prior to and post AVF creation) in patients with kidney failure and to improve AVF outcomes. This review also aimed to identify adverse events related to upper limb exercise.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 15 March 2022 through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov, and other resources (e.g. reference list, contacting relevant individuals, and grey literature).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs, comparing upper limb exercise training programs with no intervention or other control programs before or after AVF creation in patients with kidney failure. Outcome measures included time to mature, ultrasound and clinical maturation, venous diameter, blood flow in the inflow artery, dialysis efficacy indicator, vascular access function (functional AVF), vascular access complications, and adverse events.

DATA COLLECTION AND ANALYSIS

Study selection and data extraction were taken by four independent authors. Bias assessment and quality assessment were undertaken independently by two authors. The effect estimate was analysed using risk ratio (RR) with 95% confidence intervals (CI) for dichotomous data, or mean difference (MD) or standardised mean difference (SMD) for continuous data. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

Nine studies (579 participants) were included, and seven studies (519 participants) conducting post-operative exercise training could be meta-analysed. Three comparisons were undertaken: (i) isotonic exercise training versus no intervention; (ii) isometric versus isotonic exercise training; and (iii) isotonic (high volume) versus isotonic exercise training (low volume). Due to insufficient data, we could not analyse pre-operative exercise training. Overall, the risk of bias was low for selection and reporting bias, high for performance and attrition bias, and unclear for detection bias. Compared to no intervention, isotonic exercise training may make little or no difference to ultrasound maturation (2 studies, 263 participants: RR 1.09, 95% CI 0.94 to 1.25; I² = 0%; low certainty evidence), but may improve clinical maturation (2 studies, 263 participants: RR 1.14, 95% CI 1.02 to 1.27; I² = 0%; low certainty evidence). Compared to isotonic exercise training, isometric exercise training may improve both ultrasound maturation (3 studies, 160 participants: RR 1.56, 95% CI 1.21 to 2.00; I² = 22%; low certainty evidence) and clinical maturation (3 studies, 160 participants: RR 1.80, 95% CI 1.18 to 2.76; I² = 53%; low certainty evidence). Venous diameter (3 studies, 160 participants: MD 0.84 mm, 95% CI 0.45 to 1.23; I² = 0%; low certainty evidence) and blood flow in the inflow artery (3 studies, 160 participants: MD 140.62 mL/min, 95% CI 38.72 to 242.52; I² = 0%; low certainty evidence) may be greater with isometric exercise training. It is uncertain whether isometric exercise training reduces vascular access complications (2 studies, 110 participants: RR 2.54, 95% CI 0.38 to 17.08; I² = 47%; very low certainty evidence). It is uncertain whether high volume isotonic exercise training improves venous diameter (2 studies, 93 participants: MD 0.19 mm, 95% CI -0.75 to 1.13; I² = 34%; very low certainty evidence) or blood flow in the inflow artery (1 study, 15 participants: MD -287.70 mL/min, 95% CI -625.99 to 60.59; very low certainty evidence) compared to low volume isotonic exercise training. None of the included studies reported time to mature, dialysis efficacy indicator, vascular access function, or adverse events.

AUTHORS' CONCLUSIONS

Our findings suggest that the current research evidence examining upper limb exercise programs is of low quality, attributable to variability in the type of interventions used and the overall low number of studies and participants.

Artery-to-Fistula Diameter Ratio as a Predictor of Early Re-Occlusion of Immature Right Radio-Cephalic Arteriovenous Fistula after Primary PTA

Percutaneous transluminal angioplasty (PTA) is widely performed for arteriovenous fistula (AVF) that fails to mature after initial formation. We observed that some immature AVFs re-occlude earlier than others. We sought to investigate the predictors for early post-intervention failure of immature fistulas after primary PTA. We retrospectively reviewed the records and angiographic images of patients who had immature fistulas and thereby received PTA between 2013 and 2019 at our center. We investigated the short-term post-intervention outcomes of the patients within 90 days post-PTA. Patients who had re-occlusion within the period were defined as the early failure group and the rest as the patent group. We investigated factors associated with early failure. There were 80 eligible patients with 22 brachio-cephalic (BC) and 58 radio-cephalic (RC) AVFs. The median age of the patients was 64 years [range, 38–87]. There were 51 (63%) males and 29 (36%) females. Among the 58 RC AVFs, 10 (17%) patients had early failure. Logistic regression analysis showed that a larger artery to fistula (A/F) diameter ratio was the sole independent predictor of early failure after primary PTA (odd ratio 2.29 [1.023–5.147], p value = 0.044). Although further studies on a larger scale are required to confirm the clinical significance, a larger A/F diameter ratio was a potential predictor of early re-occlusion in immature fistulas after primary PTA.

Pre-existing Systolic Dysfunction is the Most Powerful Predictor of Failed Arteriovenous Fistula Maturation

BACKGROUND

Patients requiring hemodialysis access creation often have significant comorbid conditions, which may impact access maturation. Underlying cardiac dysfunction likely plays an important role in the maturation of arteriovenous fistulae (AVF). The effect of specific parameters of cardiac function on successful AVF creation has not previously been explored.

METHODS

A retrospective chart analysis of patients undergoing first-time AVF creation at a single center from 2011 to 2018 was performed. Patients with a transthoracic echocardiogram within the 12 months prior to surgery were included. Standard demographic and perioperative variables were collected, in addition to echocardiographic and vascular mapping data. The primary outcome was access maturation, defined as the use of the access site for hemodialysis at 3, 6, and 12 months after surgery.

RESULTS

A total of 121 patients met inclusion criteria with a cumulative AVF maturation rate of 57% (69/121) in this select population. Patients with pre-existing systolic cardiac dysfunction were more than 5 times less likely to see their AVF mature by one year postsurgery (OR = 0.17, P = 0.018). Preoperative venous diameter, access site location, and the type of fistula did not differ significantly between patients with and without systolic dysfunction. Selection of the cephalic vein as the venous anastomosis and diastolic dysfunction (≥ Grade 2) were also associated with lower rates of access maturation, although these associations were less robust.

CONCLUSIONS

Systolic cardiac dysfunction is the most important nonmodifiable variable associated with failed AVF maturation. Patients requiring hemodialysis with significant pre-existing cardiac dysfunction may not be appropriate for permanent access creation, and long-term catheter use should be seriously considered as an alternative.

Clinical and ultrasound evaluation for hemodialysis access creation

Chronic kidney disease (CKD) is an emerging global burden with an increasing number of patient's requiring renal replacement therapy (RRT), with hemodialysis being the most prevalent dialysis modality. A functioning vascular access remains the main constrain for an adequate treatment. Clinical and, in some patients, ultrasound evaluation are fundamental for better access planning. Access planning is dependent not only on patient clinical characteristics and preference but also in vascular patrimony. As such, ultrasound evaluation aids in characterizing patient arterial and venous upper arm anatomy and provides information for which access would better suit each patient. Doctors dealing with CKD patients should be familiar with the role of ultrasound and Doppler use in access planning.

Systemic microvascular endothelial function with arteriovenous fistula creation in chronic kidney disease

Background:

This study aimed to determine changes in microvascular endothelial function with upper arm arteriovenous fistula (AVF) creation and maturation in patients with chronic kidney disease (CKD).

Materials and Methods:

This prospective cross-sectional study was performed at Hospital Universiti Sains Malaysia, a tertiary hospital in Malaysia. Forty CKD patients (stage 4–5) who were scheduled for elective AVF creation over the upper extremity for maintenance hemodialysis were recruited using convenience sampling method. Microvascular endothelial-dependent vasodilation was measured using laser Doppler flowmetry and the process of iontophoresis preoperatively and postoperatively at weeks 2 and 6. Fistula maturation was assessed at week 6.

Results:

Thirty-two patients had successful AVF maturation. Endothelial-dependent vasodilation (acetylcholine (Ach)% was higher (246.48 [standard deviation (SD) 209.38] vs. 104.95 [SD 43.29], P = 0.001) while systolic blood pressure was lower (142.25 [SD 21.50] vs. 162.25 [SD 13.26], P = 0.017) in this group as compared to unsuccessful AVF group. No significant changes were seen in overall microvascular endothelial-dependent vasodilation during the 6-week study period (day 0, 246.48 [SD 209.38]; week 2, 201.14 [SD 198.19]; and week 6, 203.53 [SD 145.89]).

Conclusion:

Upper arm AVF creation does not affect microvascular endothelial function up to 6 weeks post operation and may not contribute to the success of AVF maturation. However, the lower microvascular endothelial-dependent vasodilation and higher systolic blood pressure in unsuccessful AVF subjects need to be further studied.

A cost-effectiveness analysis of the introduction of a specialised consultation with duplex ultrasound assessment prior to vascular access surgery for haemodialysis

INTRODUCTION

Duplex ultrasound (DUS) is increasingly used before vascular access (VA) surgery for haemodialysis. However, the cost-effectiveness of this approach is unknown. Our objective was to assess whether the introduction of a specialised consultation with DUS assessment modifies the cost and the time delay to achieve a first VA valid for haemodialysis.

PATIENTS AND METHODS

Prospective cohort of patients undergoing a first VA (June 2014-July 2017) after a specialised consultation with DUS (ECO group). They were compared with a historical cohort (January 2012-May 2014) where VA was indicated exclusively by clinical evaluation (CLN group). We analysed the cost related to visits, DUS assessments, interventions, hospital admissions and graft materials to achieve a first VA valid for haemodialysis at least during 1 month.

RESULTS

86 patients in the CLN group were compared with 92 in the ECO group. Patients in the ECO group were younger (68.4 vs. 64.0 years; P=.038) but no other differences were seen among groups. The average cost to achieve a first AV valid for haemodialysis was significantly lower in the ECO group (2707 vs. 3347€; P=.024). There was a higher cost associated with DUS assessments in the ECO group yet the CLN group had a higher cost related to follow-up visits, successive surgical interventions, prosthetic material, days of hospital admission and catheters. The mean time needed to achieve a first AV valid for haemodialysis was also shorter in the ECO group (49.9 vs. 82.9 days, P=.002).

CONCLUSION

The introduction of a specialised vascular access consultation with DUS prior to VA surgery has reduced the cost necessary to achieve a first VA valid for haemodialysis. From the patient's point of view this has meant less interventions and hospital admissions and a shortening of the time delay.

Evaluation of Factors Affecting Wrist Radio-Cephalic Arteriovenous Fistula Maturation: A Single Institutional Observational Study

Background: Chronic renal failure is the most common indication for which arterio-venous (AV) fistula creation surgery is being performed. Various studies have found that native arteriovenous fistulas are the best in long-term patency with lower complications. We conducted this study to find out the role of preprocedural duplex ultrasound (DUS) in predicting outcomes of radio-cephalic fistula in the wrist in the North-Karnataka population. Methods: This prospective study was conducted from May 2019 to July 2020 on 50 patients who were hemodialysis-dependent and underwent AV fistula creation with age from 20 to 70 years. All the patients underwent preoperative DUS and were followed up post-operatively after one, two, and six weeks. Hemodialysis was initiated through the constructed fistula once it was mature, and the maximum blood flow through the fistula was measured. SPSS version 20.0 was used for statistical analysis. Results: Among 50 subjects, the overall cumulative success of AVF maturation was 86% (43), and failure to mature rate was 14% (7). Logistic regression of maturation outcome in the wrist autologous arteriovenous fistula for individual factors showed statistically significant results (P < 0.05) for the diameter of the radial artery > 1.6 mm and the distensibility of the cephalic vein > 0.4 mm. Conclusions: Vein distensibility and radial artery diameter are key factors in predicting successful AVF maturation. The use of intraoperative papaverine instillation directly on vessels can improve arteriovenous fistula outcomes.

Maturation and survival of arteriovenous fistula: The challenge starts from the preoperative assessment stage

BACKGROUND

It is necessary to assess the association between the preoperative indicators and the maturation and survival of arteriovenous fistula (AVF).

METHODS

We retrospectively identified 236 patients with a new AVF created between 2016 and 2018 in our Dialysis Center.

RESULTS

Multivariate Logistic regression showed that preoperative arterial diameter (odds ratio [OR] = 1.452, 95% confidence interval [CI] [1.233, 1.710], p < 0.001), preoperative venous diameter (OR = 1.296, 95% CI [1.166, 1.477], p < 0.001), left ventricular ejection fraction (LVEF) (OR = 1.187, 95% CI [1.103, 1.277], p < 0.001), and diabetes mellitus (OR = 0.245, 95% CI [0.107, 0.560], p = 0.01) were independent influential factors for AVF maturation. Two years after the AVF surgery follow-up, multivariate Cox proportional-hazards model showed that the preoperative arterial diameter (OR = 0.510, 95% CI [0.320, 0.813], p = 0.005), preoperative venous diameter (OR = 0.940, 95% CI [0.897, 0.985], p = 0.010) and diabetes mellitus (OR = 1.785, 95% CI [1.117, 2.855], p = 0.016) was prognostic factors of AVF survival. The Kaplan-Meier method showed that the primary survival of AVF in patients with different preoperative arterial diameter was statistically significant (log-rank χ²  = 15.415, p < 0.001), while the secondary survival was not statistically significant (log-rank χ²  = 0.131, p = 0.717).

CONCLUSION

In our cohort, the preoperative arterial and venous diameter and diabetes mellitus were independent influential factors for AVF maturation and prognostic factors of AVF survival. However, the preoperative LVEF only associated with the maturation of AVF. Meanwhile, smaller arterial diameter (≤2.15 mm) was associated with AVF maturation failure, but did not impact secondary survival of AVF.

Effect of cilostazol on arteriovenous fistula in hemodialysis patients

BACKGROUND

The maturation and patency of permanent vascular access are critical in patients requiring hemodialysis. Although numerus trials have been attempted to achieve permanently patent vascular access, little have been noticeable. Cilostazol, a phosphodiesterase-3 inhibitor, has been shown to be effective in peripheral arterial disease including vascular injury-induced intimal hyperplasia. We therefore aimed to determine the effect of cilostazol on the patency and maturation of permanent vascular access.

METHODS

This single-center, retrospective study included 194 patients who underwent arteriovenous fistula surgery to compare vascular complications between the cilostazol (n=107) and control (n=87) groups.

RESULTS

The rate of vascular complications was lower in the cilostazol group than in the control group (36.4% vs. 51.7%; p=0.033), including maturation failure (2.8% vs. 11.5%; p=0.016). The rate of reoperation due to vascular injury after hemodialysis initiation following fistula maturation was also significantly lower in the cilostazol group than in the control group (7.5% vs. 28.7%; p<0.001). However, there were no significant differences in the requirement for percutaneous transluminal angioplasty (PTA), rate of PTA, and the interval from arteriovenous fistula surgery to PTA between the cilostazol and control groups.

CONCLUSION

Cilostazol might be beneficial for the maturation of permanent vascular access in patients requiring hemodialysis.

Upper limb anatomy and preoperative mapping

Vascular access is absolutely essential for haemodialysis due to its relationship with quality of dialysis and associated morbidity. Therefore, it must be monitored and continuously surveilled from the moment it is created to prevent failure in maturation and thrombosis. Multidisciplinary collaboration is necessary when the main aim is to achieve the adequate vascular access flow with the fewest possible complications. The starting point, and probably the main one, is vascular access planning. This planning requires both a deep understanding of the anatomy of the upper limb and enough skill to examine it by Doppler ultrasound. The aim of this article is to review the anatomical and haemodynamical concepts of the arterial and venous vascular tree and explain how to perform ultrasound mapping, optimising the technical resources provided by this tool. Likewise, adequate access creation criteria that minimise the risk of failure and associated complications will be discussed.

Adjuvant heparinization before manipulation of artery reduces early failure in primary arteriovenous fistula for end-stage renal disease patients

BACKGROUND

Arteriovenous fistula (AVF) is the most preferred vascular access for hemodialysis patients, and early failure of AVF is one of the most avoidable complications of this procedure. We retrospectively evaluated whether adjuvant systemic heparinization just before arterial manipulation could reduce early failure of primary AVF.

METHODS

Three hundred and fifty-six patients with end-stage renal failure who underwent primary AVF surgery from April 2009 to September 2020 were enrolled in this study. The patients were divided into two groups based on whether they received adjuvant heparinization or not. Patient backgrounds, frequency of early AVF failure, and bleeding events were compared between the two groups. Multivariate Cox regression analysis identified risk factors for early AVF failure.

RESULTS

Early failure of AVF was observed in only 2 of 157 patients (1.2%) in the adjuvant group, and the incident was significantly lower than observed in the non-adjuvant group, i.e., 17 of 199 patients (8.5%) (p = 0.002). Bleeding events were not significantly different between the two groups. Seven of 157 patients (4.5%) in the adjuvant group and 7 of 199 patients (3.5%) in the non-adjuvant group experienced bleeding events (p = 0.785). Female sex, use of steroids, hypoalbuminemia, venous stenosis in pre-surgical evaluation, arterial spasm in the perioperative period, new-onset venous stenosis after AVF anastomosis, technical failure of surgery, no early cannulation after surgery, and non-adjuvant heparinization were related to early AVF failure in the multivariate regression analysis.

CONCLUSION

Adjuvant systemic heparinization therapy just before arterial manipulation reduced early failure of primary AVF without increasing bleeding events.

Effect of cilostazol on arteriovenous fistula in hemodialysis patients

BACKGROUND

The maturation and patency of permanent vascular access are critical in patients requiring hemodialysis. Although numerus trials have been attempted to achieve permanently patent vascular access, little have been noticeable. Cilostazol, a phosphodiesterase-3 inhibitor, has been shown to be effective in peripheral arterial disease including vascular injury-induced intimal hyperplasia. We therefore aimed to determine the effect of cilostazol on the patency and maturation of permanent vascular access.

METHODS

This single-center, retrospective study included 194 patients who underwent arteriovenous fistula surgery to compare vascular complications between the cilostazol (n=107) and control (n=87) groups.

RESULTS

The rate of vascular complications was lower in the cilostazol group than in the control group (36.4% vs. 51.7%; p=0.033), including maturation failure (2.8% vs. 11.5%; p=0.016). The rate of reoperation due to vascular injury after hemodialysis initiation following fistula maturation was also significantly lower in the cilostazol group than in the control group (7.5% vs. 28.7%; p<0.001). However, there were no significant differences in the requirement for percutaneous transluminal angioplasty (PTA), rate of PTA, and the interval from arteriovenous fistula surgery to PTA between the cilostazol and control groups.

CONCLUSION

Cilostazol might be beneficial for the maturation of permanent vascular access in patients requiring hemodialysis.

A cost-effectiveness analysis of the introduction of a specialised consultation with duplex ultrasound assessment prior to vascular access surgery for haemodialysis

INTRODUCTION

Duplex ultrasound (DUS) is increasingly used before vascular access (VA) surgery for haemodialysis. However, the cost-effectiveness of this approach is unknown. Our objective was to assess whether the introduction of a specialised consultation with DUS assessment modifies the cost and the time delay to achieve a first VA valid for haemodialysis.

PATIENTS AND METHODS

Prospective cohort of patients undergoing a first VA (June 2014-July 2017) after a specialised consultation with DUS (ECO group). They were compared with a historical cohort (January 2012-May 2014) where VA was indicated exclusively by clinical evaluation (CLN group). We analysed the cost related to visits, DUS assessments, interventions, hospital admissions and graft materials to achieve a first VA valid for haemodialysis at least during 1 month.

RESULTS

Eighty-six patients in the CLN group were compared with 92 in the ECO group. Patients in the ECO group were younger (68.4 vs. 64.0 years; P=.038) but no other differences were seen among groups. The average cost to achieve a first AV valid for haemodialysis was significantly lower in the ECO group (2707 vs. 3347€; P=.024). There was a higher cost associated with DUS assessments in the ECO group yet the CLN group had a higher cost related to follow-up visits, successive surgical interventions, prosthetic material, days of hospital admission and catheters. The mean time needed to achieve a first AV valid for haemodialysis was also shorter in the ECO group (49.9 vs. 82.9 days, P=.002).

CONCLUSION

The introduction of a specialised vascular access consultation with DUS prior to VA surgery has reduced the cost necessary to achieve a first VA valid for haemodialysis. From the patient's point of view this has meant less interventions and hospital admissions and a shortening of the time delay.

Effectiveness and safety of repeated percutaneous intervention in an office-based endovascular center in maintaining hemodialysis access

OBJECTIVES

Percutaneous dialysis access interventions are routinely used to maintain the patency of dialysis access despite the lack of data regarding their long-term effectiveness. This retrospective study was undertaken to study the effectiveness and safety of percutaneous dialysis access interventions in arm fistulas and bridge grafts in an office-based endovascular center.

METHODS

Patients who had a percutaneous dialysis access intervention in their upper extremity access site, performed at a single office-based endovascular center over a nine-year period (2007-2016) were included in this study. The patients' demographic factors, patency, and complications were analyzed. Patients were entered in the study after first percutaneous dialysis access intervention.

RESULTS

A total of 298 limbs in 259 patients had 913 procedures carried out over a nine-year period. There were 190 access arteriovenous fistulas and 108 arteriovenous grafts. The two most common arteriovenous fistulas were the brachiocephalic fistula (n = 74, 39%) and radio cephalic fistula (n = 69, 36%). Arteriovenous grafts were most commonly placed in the upper arm (n = 66, 61%) followed by the forearm (n = 42, 39%). The mean overall patency for all limbs was 50.86 months. Arteriovenous fistulas had a significantly longer patency than arteriovenous grafts (51.65 vs. 42.09 months; P = 0.01). In addition, patients with two or more percutaneous dialysis access intervention in their arteriovenous fistula had significantly greater patency than those with only one percutaneous dialysis access intervention (58.5 vs. 7.6 months; hazard ratio 0.41; P = 0.0008). This was not true for the arteriovenous graft group. Women represented 49% of the patient group. Their accesses had shorter patency than men (39.8 vs. 60 months; P = 0.0007).

CONCLUSIONS

This data support the use of repeated percutaneous dialysis access intervention to maintain long-term patency of dialysis access sites in an office-based endovascular center. Overall, fistulas have longer patency than grafts and women have poorer outcomes as compared to men.

Clinical and ultrasound evaluation for hemodialysis access creation

Chronic kidney disease (CKD) is an emerging global burden with an increasing number of patient's requiring renal replacement therapy (RRT), with hemodialysis being the most prevalent dialysis modality. A functioning vascular access remains the main constrain for an adequate treatment. Clinical and, in some patients, ultrasound evaluation are fundamental for better access planning. Access planning is dependent not only on patient clinical characteristics and preference but also in vascular patrimony. As such, ultrasound evaluation aids in characterizing patient arterial and venous upper arm anatomy and provides information for which access would better suit each patient. Doctors dealing with CKD patients should be familiar with the role of ultrasound and Doppler use in access planning.

Factors Affecting the Patency of Radiocephalic Arteriovenous Fistulas Based on Clinico-Radiological Parameters

Arteriovenous fistulas are an important means of vascular access for long-term haemodialysis in patients with end-stage renal disease (ESRD). We evaluated the outcome of radiocephalic arteriovenous fistulas (RCAVFs) in 55 patients operated upon in our hospital in southern India. We studied the outcome of RCAVF surgery with the demographic factors, duration of diabetes, the diameter of the radial artery and cephalic vein, and any signs of atherosclerosis in the radial artery. We found that a small cephalic vein size of ≤ 2 mm, a negative cephalic vein tap test, a thickened, non-compressible, calcified radial artery on palpation, and evidence of atherosclerosis on radiological investigations were associated with a significant chance of RCAVF failure. A clinico-radiological grading of atherosclerosis for peripheral arteries is also proposed. Any patient presenting to the microsurgeon with a small cephalic vein size, a negative cephalic vein tap test, a thickened, non-compressible, calcified vessel on palpation, and tram-track calcification or whole vessel calcification or severely atherosclerotic vessel on radiological evaluation must be approached with caution regarding RCAVF creation and must be prepared for an arteriovenous fistula (AVF) creation at a higher level.

A Korean perspective on the 2019 Kidney Disease Outcomes Quality Initiative guidelines for vascular access: what has changed and what should be changed in practice?

The Kidney Disease Outcomes Quality Initiative (KDOQI) guidelines are developed by the National Kidney Foundation in the United States; however, the guidelines have an impact on most international societies, including those in Korea. The KDOQI recently released the updated 2019 guidelines for vascular access based on numerous papers and controversies concerning vascular access since 2006, when the first guidelines were published. The new KDOQI guidelines have undergone significant changes compared to previous guidelines, including a change in the philosophy regarding a patient-centered approach using an end-stage kidney disease “Life-Plan.” In addition, there are newly developed or revised definitions and some key differences from previous guidelines. The process of adapting guidelines needs to be individualized to hemodialysis practice in each country, while agreeing with general principles and philosophy; therefore, we summarize changes in the updated guidelines and discuss the application and implementation of the new principles and concepts of the guidelines for vascular access care in Korea.

Simulator-based hemodialysis cannulation skills training: a new horizon?

In accordance with the recently released Kidney Disease Outcomes Quality Initiative  (KDOQI) guidelines, there is a significant need for focused efforts on improving hemodialysis cannulation outcomes. Toward this, structured and meaningful training of our clinical personnel who cannulate in dialysis clinics is a priority. With the availability of advanced sensors and computing methods, simulators could be indispensable tools for standardized skills assessment and training. In this article we present ways in which sensor data could be used to quantify cannulation skill. As with many other medical specialties, implementation of simulator-based training holds the promise of much-needed improvement in end-stage kidney disease patient outcomes.

Higher body mass index is associated with reinterventions and lower maturation rates after upper extremity arteriovenous access creation

OBJECTIVE

A patient's body mass index (BMI) can affect both perioperative and postoperative outcomes across all surgical specialties. Given that obesity and end-stage renal disease are growing in prevalence, we aimed to evaluate the association between BMI and outcomes of upper extremity arteriovenous (AV) access creation.

METHODS

A retrospective single-institution review was conducted for AV access creations from 2014 to 2018. Patient demographics, comorbidities, and AV access details were recorded. BMI groups were defined as normal weight (18.5-24.9 kg/m²), overweight (25-29.9 kg/m²), obese (30-39.9 kg/m²), and morbidly obese (>40 kg/m²). Perioperative complications and long-term outcomes including access maturation (defined as access being used for hemodialysis or the surgeon's judgment that access was ready for use in patients not yet on hemodialysis), occlusion, and reintervention were evaluated.

RESULTS

A total of 611 upper extremity AV access creations were performed on patients who were normal weight (29.6%), overweight (31.3%), obese (29.6%), and morbidly obese (9.5%). Access type included brachiocephalic (43.2%), brachiobasilic (25.5%), and radiocephalic (14.2%) fistulas and AV grafts (14.2%). Median age was 60.9 years, and 59.6% were male. Univariable analysis showed no difference between BMI groups for perioperative steal, hematoma, home discharge, or 30-day primary patency. Freedom from reintervention at 2 years on Kaplan-Meier analysis differed by BMI (44.5% ± 4.6% normal weight, 29% ± 3.8% overweight, 39.8% ± 4.3% obese, 34.7% ± 8% morbidly obese; P = .041). There was no difference in 2-year freedom from new access creation or survival. AV access maturity within 180 days differed between BMI groups (74.3% normal weight, 66% overweight, 65.7% obese, 46.6% morbidly obese; P < .001). On multivariable analysis, failure to mature within 180 days was associated with overweight (odds ratio [OR], 1.93; 95% confidence interval [CI], 1.14-3.29; P = .002), obese (OR, 2.12; 95% CI, 1.19-3.47; P = .009), and morbidly obese (OR, 3.68; 95% CI, 1.85-7.3; P < .001) relative to normal weight BMI. AV access reintervention was associated with overweight (hazard ratio [HR], 1.83; 95% CI, 1.34-2.5), obese (HR, 1.56; 95% CI, 1.12-2.16), and morbidly obese (HR, 1.69; 95% CI, 1.1-2.58; P = .02) relative to normal weight BMI. BMI was not independently associated with long-term readmission or survival.

CONCLUSIONS

Obesity is associated with higher rates of AV access failure to mature and reintervention. Surgeons performing access creation on obese patients must consider this for planning and setting expectations. Weight loss assistance may need to be incorporated into treatment algorithms.

Early Predictors of Arteriovenous Fistula Maturation: A Novel Perspective on an Enduring Problem

BACKGROUND

Preoperative ultrasound mapping is routinely used to select vessels meeting minimal threshold diameters for surgical arteriovenous fistula (AVF) creation but fails to improve AVF maturation rates. This suggests a need to reassess the preoperative ultrasound criteria used to optimize AVF maturation.

METHODS

We retrospectively identified 300 catheter-dependent patients on hemodialysis with a new AVF created between 2010 and 2016. We then evaluated the associations of preoperative vascular measurements and hemodynamic factors with unassisted AVF maturation (successful use for dialysis without prior intervention) and overall maturation (successful use with or without prior intervention). Multivariable logistic regression was used to identify preoperative factors associated with unassisted and overall AVF maturation.

RESULTS

Unassisted AVF maturation associated with preoperative arterial diameter (adjusted odds ratio [aOR], 1.50 per 1-mm increase; 95% confidence interval [95% CI], 1.23 to 1.83), preoperative systolic BP (aOR, 1.16 per 10-mm Hg increase; 95% CI, 1.05 to 1.28), and left ventricular ejection fraction (aOR, 1.07 per 5% increase; 95% CI, 1.01 to 1.13). Overall AVF maturation associated with preoperative arterial diameter (aOR, 1.36 per 1-mm increase; 95% CI, 1.10 to 1.66) and preoperative systolic BP (aOR, 1.17; 95% CI, 1.06 to 1.30). Using receiver operating curves, the combination of preoperative arterial diameter, systolic BP, and left ventricular ejection fraction was fairly predictive of unassisted maturation (area under the curve, 0.69). Patient age, sex, race, diabetes, vascular disease, obesity, and AVF location were not associated with maturation.

CONCLUSIONS

Preoperative arterial diameter may be an under-recognized predictor of AVF maturation. Further study evaluating the effect of preoperative arterial diameter and other hemodynamic factors on AVF maturation is needed.

Outcomes of arteriovenous fistula creation: A Jordanian experience

Objective:

The arteriovenous fistula is considered the preferred hemodialysis access due to its lower complication rate and longer patency. The aim of this study is to report the outcomes of arteriovenous fistula creation and to study the predictive factors for these outcomes.

Study design and method:

This is a retrospective study of all patients who underwent autogenous arteriovenous fistula creation procedure by a single surgeon during the period from October 2011 till December 2017.

Material:

All the procedures were performed at an academic referral center by a single surgeon. All patients who underwent arteriovenous fistula creation in the upper limb during the study period were included. All patients were diagnosed with end-stage renal disease and referred for arteriovenous fistula creation either before or after initiating hemodialysis.

Method:

Data were collected from the patients’ charts. The primary outcomes were the primary failure and secondary patency rates. Secondary outcome was to find the factors associated with decreased patency. The Kaplan–Meier curve with the log-rank test was used to describe the patency while univariate and multivariate analyses were done to the factors considered relevant to the patency.

Results:

The total number of procedures was 291; of which, 18 were lost to follow-up. The primary failure rate was 12%. Secondary patency rate at 1 and 5 years was 79% and 53%, respectively. Diabetes mellitus and fistulae placed on right side were associated with decreased patency.

Conclusion:

The primary failure rate was relatively low in this study but the long-term functionality of the arteriovenous fistulae needs to be improved.

Clinical Outcomes of Arteriovenous Graft in End-Stage Renal Disease Patients with an Unsuitable Cephalic Vein for Hemodialysis Access

Background

As the population of patients with end-stage renal disease has grown older, the proportion of patients with poorly preserved vasculature has concomitantly increased. Thus, arteriovenous grafts (AVG) have been used more frequently to access blood vessels for hemodialysis. Despite this increasing demand, studies of AVG are limited. In this study, we examined the surgical outcomes of upper-limb AVG creation.

Methods

Among the arteriovenous fistula formation procedures performed between January 2014 and March 2019 at Dankook University Hospital, 42 cases involved AVG creation. We compared patients in whom the axillary vein was used (group A; brachioaxillary AVG [B-Ax AVG]; n=20) with those in whom upper limb veins were used (group B; brachiobasilic AVG or brachioantecubital AVG; n=22).

Results

The 1-year primary patency rate was higher in group A than in group B (57.9% vs. 41.7%; p=0.262). The incidence of postoperative complications was not significantly different between groups.

Conclusion

AVG using the axillary vein showed no major differences in safety or functionality compared to AVG using other veins. Therefore, accounting for age, underlying disease, and expected patient lifespan, B-Ax AVG can be considered an acceptable surgical method.

KDOQI Clinical Practice Guideline for Vascular Access: 2019 Update

The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (KDOQI) has provided evidence-based guidelines for hemodialysis vascular access since 1996. Since the last update in 2006, there has been a great accumulation of new evidence and sophistication in the guidelines process. The 2019 update to the KDOQI Clinical Practice Guideline for Vascular Access is a comprehensive document intended to assist multidisciplinary practitioners care for chronic kidney disease patients and their vascular access. New topics include the end-stage kidney disease "Life-Plan" and related concepts, guidance on vascular access choice, new targets for arteriovenous access (fistulas and grafts) and central venous catheters, management of specific complications, and renewed approaches to some older topics. Appraisal of the quality of the evidence was independently conducted by using a Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach, and interpretation and application followed the GRADE Evidence to Decision frameworks. As applicable, each guideline statement is accompanied by rationale/background information, a detailed justification, monitoring and evaluation guidance, implementation considerations, special discussions, and recommendations for future research.

Selecting important predictors for arteriovenous fistula maturation in older hemodialysis patients by using random survival forests

BACKGROUND

Placing an arteriovenous fistula (AVF) in older hemodialysis patients at great risk of primary failure leads to prolonged dependency on central venous catheter (CVC). A model which accurately predicts AVF maturation can facilitate better clinical determination for AVF placement.

METHODS

We assembled a retrospective cohort of 14 892 patients aged 67 years and older who started hemodialysis with a CVC between 7/1/2010 and 6/30/2012 and had a subsequent, incident AVF placement from the United States Renal Data System (USRDS). We used random survival forests (RSF) with competing risks to identify important predictors for AVF maturation.

RESULTS

Approximately 49.7% patients achieved AVF maturation and 13.6% had a competing event. The median time to maturation was 4 (IQR: 3-5) months. Patient's gender had the highest variable importance (VIMP, 0.0027), followed by race, being institutionalized, days on hemodialysis without an AVF, estimated glomerular filtration rate, and body mass index with borderline importance (VIMP ≥0.0005). The out-of-bag (OOB) error rate of the RSF was 45.3% and 45.8% for AVF maturation in the training and validation data sets, respectively.

CONCLUSIONS

Predictors in USRDS data have limited ability to predict AVF maturation. Patient's gender might be considered as the most important predictor for AVF maturation.

Predictors of time to first cannulation for arteriovenous fistula in pediatric hemodialysis patients: Midwest Pediatric Nephrology Consortium study

BACKGROUND

Permanent vascular access (PVA) is preferred for long-term hemodialysis. Arteriovenous fistulae (AVF) have the best patency and the lowest complication rates compared to arteriovenous grafts (AVG) and tunneled cuffed catheters (TCC). However, AVF need time to mature. This study aimed to investigate predictors of time to first cannulation for AVF in pediatric hemodialysis patients.

METHODS

Data on first AVF and AVG of patients at 20 pediatric dialysis centers were collected retrospectively, including demographics, clinical information, dialysis markers, and surgical data. Statistical modeling was used to investigate predictors of outcome.

RESULTS

First PVA was created in 117 children: 103 (88%) AVF and 14 (12%) AVG. Mean age at AVF creation was 15.0 ± 3.3 years. AVF successfully matured in 89 children (86.4%), and mean time to first cannulation was 3.6 ± 2.5 months. In a multivariable regression model, study center, age, duration of non-permanent vascular access (NPVA), and Kt/V at AVF creation predicted time to first cannulation, with study center as the strongest predictor (p < 0.01). Time to first cannulation decreased with increasing age (p = 0.03) and with increasing Kt/V (p = 0.01), and increased with duration of NPVA (p = 0.03). Secondary failure occurred in 10 AVF (11.8%). Time to first cannulation did not predict secondary failure (p = 0.29), but longer time to first cannulation tended towards longer secondary patency (p = 0.06).

CONCLUSIONS

Study center is the strongest predictor of time to first cannulation for AVF and deserves further investigation. Time to first cannulation is significantly shorter in older children, with more efficient dialysis treatments, and increases with longer NPVA duration.

Predictors of Primary Functional Maturation of Autogenous Radiocephalic Arteriovenous Fistula in a Cohort of Asian Patients

BACKGROUND

The aim of this study was to investigate the predictors of autogenous radiocephalic arteriovenous fistula (RCAVF) maturation.

METHODS

This was a retrospective analysis of patients undergoing RCAVF creation from June 2013 to December 2018 at a single medical center. Comparison of the variables between the matured and nonmatured group was performed.

RESULTS

A total of 277 patients (men, 173; 62.5%) with a mean age of 56.6 ± 16.9 years underwent primary RCAVF creation during the study period. The mean diameter of the cephalic vein and radial artery were 2.4 ± 0.6 mm (range 1.5 to 4.3 mm) and 2.3 ± 0.5 mm (range 1.5 to 4.0 mm), respectively. Primary functional maturation was achieved in 236 patients (236/277, 85%). There was no statistical significance between the matured and nonmatured group in terms of age (56.4 ± 14.8 vs. 58.1 ± 15.1, respectively; P = 0.498), coronary arterial disease (12% vs. 17%, respectively; P = 0.449), diabetes mellitus (42% vs. 39%, respectively; P = 0.864), smoking (26% vs. 22%, respectively; P = 0.699), or antiplatelet therapy (23% vs. 24%, respectively; P = 0.844). However, female gender (35% vs. 54%, respectively; P = 0.024), peripheral arterial disease (9% vs. 22%, respectively; P = 0.025), and small vein (2.4 ± 0.5 mm vs. 2.0 ± 0.5 mm, respectively; P < 0.01) and artery (2.4 ± 0.5 vs. 2.1 ± 0.4, respectively; P < 0.01) diameter were associated with the failure of maturation. The best cutoff diameter for the cephalic vein and radial artery was 1.85 mm and 2.05 mm, respectively.

CONCLUSIONS

In this cohort of patients undergoing RCAVF creation, vein and artery diameter on preoperative ultrasound mapping was the predictor of functional maturation. Female gender and presence of peripheral arterial disease were associated with failure of maturation.