Prospective long-term study of patency and outcomes of 505 arteriovenous fistulas in patients with chronic renal failure: Authors experience and review of literature

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.

Standardization of Pre-operative Evaluation to Improve the Outcome of Arteriovenous Fistula for Vascular Access of Hemodialysis: A Review of 700 Cases

Background With the advent of COVID-19, mortality rates of end-stage kidney disease (ESKD) rose by 37% which makes its treatment an important part of healthcare. Arteriovenous fistula (AVF) is linked to higher patient survival rates. Cimino-Brescia fistula is the most effective vascular access technique, but it has a high rate of primary failure (PF) and a several-week maturation period before it can be used. The current study aims to verify the preoperative evaluation in improving survival among AVF patients. Methodology The current study is a retrospective analysis of the hospital database from Jan 2022 to July 2023, with patients of a mean age of 60.2 years. The sample size was around 700, including the patients indicated for long-term hemodialysis (HD) with an estimated GFR of less than 20 mm/min/1.73m². Following AVF surgery, post-operative outcomes, PF, and maturation time were considered. Results Among the 757 AVF procedures, 588 (82%) were new cases, and 112 (16%) had prior AVF history on the same side. PF was observed in 126 (18%) AVFs, while 574 (84%) achieved maturation. Age at surgery did not correlate with PF. Male sex and brachiocephalic AVF (BCAVF) had lower PF rates, while female gender, non-BCAVF, and vascular chronic kidney disease (CKD) were independent predictors. Proximal fistulas had a higher failure risk (32%). During surgery, the PF occurred six times more frequently in patients with veins and arteries under 2 mm and without a bruit. Conclusion AVF maturation aims to achieve a functional AVF for easy dialysis, requiring meticulous vein selection, doppler vascular mapping, and a standardized process to reduce PF rates. Factors determining PF include thrill and bruit, flow rates, and comorbidities. These findings can help clinicians make informed decisions and improve outcomes for patients undergoing fistula surgery.

Economics of drug-coated balloons for arteriovenous fistula stenosis in Japan and Korea based on the IN.PACT AV access trial

AIM

The recent IN.PACT AV Access study found drug-coated balloon therapy to be associated with reduced reinterventions compared to percutaneous transluminal angioplasty using standard balloons in the management of arteriovenous fistula stenosis. The economic implications of drug-coated balloon use in Asia, including Japan and Korea, remain unknown.

METHODS

A decision-analytic model was developed to calculate strategy-specific costs for Korea and Japan through 5-year follow-up. The analysis assumed maintained therapy benefit beyond current trial follow-up of 1 year in the base case, with several alternative scenarios explored in sensitivity analysis. Costs were derived from claims and reimbursement data, and projections were evaluated at 3 and 5 years post-index procedure.

RESULTS

Model-projected access circuit reintervention events for drug-coated versus standard balloons were 1.70 versus 2.76 (-1.06) and 2.53 versus 4.10 (-1.57) at 3 and 5 years in the base case. Corresponding 3- and 5-year costs were ₩6 211 103 versus ₩7 605 553 (-₩1 394 451) and ₩7 766 051 versus ₩10 124 954 (-₩2 358 904) in Korea, and ¥1 469 824 versus ¥1 504 161 (-¥34 337) and ¥1 956 931 versus ¥2 106 632 (-¥149 701) in Japan. In scenario analyses, drug-coated balloons remained cost saving at 3- and 5-year follow-up in Korea, but required up to 5 years to reach cost-savings in Japan. Drug-coated balloon use in reinterventions increased projected savings, as did younger treatment age.

CONCLUSION

Treatment of arteriovenous fistulas with the IN.PACT AV drug-coated balloon, based on preliminary data, may lead to meaningful reductions in reintervention costs that would render it cost-saving at timeframes of around 1 year in Korea and between 3 and 5 years in Japan.

Nuances of Arteriovenous Fistula Creation for Vascular Access in Hemodialysis

Background With rising incidence and increased life expectancy of patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD), the number of patients requiring hemodialysis has increased substantially. Vascular access is the lifeline for a patient on hemodialysis (HD), and an arteriovenous fistula (AVF) is the undisputed gold standard for HD access. An effective and long-lasting fistula serves to increase the life expectancy of ESRD patients and improves their quality of life.

Learning Objectives This paper aims to give a comprehensive overview of AVF creation, including the various techniques, patient selection, troubleshooting with decision-making, and common complications. Authors share their experience from previous publications and over 2000 AVF surgeries. They have not only described a new modification of the technique of proximal fistula but have also established a direct correlation between bruit and thrill on operation table and success of fistula surgery.

Conclusion A standardized, protocol-driven multidisciplinary approach with careful patient and site selection, guided by outcome predictors, is vital in AVF surgery. Knowledge about the potential complications of AVFs contributes to their timely detection and allows measures to be taken that might prevent deleterious consequences that range from loss of vascular access to serious morbidity and mortality.

Stretching the boundaries: suitability of an arteriovenous fistula in elderly patients on hemodialysis-a northern India experience

PURPOSE

Considering various factors, such as multiple co-morbidities, unsuitable vessels for access creation, non-maturation, vascular calcifications, the outcome of arteriovenous fistula (AVF) in the elderly population, may not be similar to the younger people. Our study aims to analyze the outcomes of AVF in elderly patients (> 65 year).

METHODS

It was a prospective observational study. Patients of more than 65 years of age in whom AVF was created from January 2012 to December 2015 were included in the study. These patients were followed up for 4 years. The primary endpoint of our study was to assess primary and secondary patency rates.

RESULTS

A total of 450 AVFs were included in the study. The mean age was 68.5 years. The most common site of AVF was radiocephalic (RCAVF) in 70% (n = 315), brachiocephalic (BCAVF) in 24% (n = 108) and basilic vein transposition (BVT) in 6% (n = 27). At 48 months, the primary patency rate of RCAVF, BCAVF, and BVT was 55%, 61.6%, and 60.4%, respectively. The commonest cause of access failure was thrombosis followed by non-maturation.

CONCLUSION

AVF remains the preferred vascular access for hemodialysis even in the elderly population. Failure to mature and thrombosis continue to be a concern with AVF. Location of the AV access does not seem to impact the long-term patency.

Outcomes of radiocephalic fistula created by nephrologists

INTRODUCTION

Arteriovenous fistula is considered as gold standard access for maintenance hemodialysis. Due to increasing burden of end-stage renal disease requiring dialysis, it is important for nephrologists to complement creation of arteriovenous fistula to meet the demand.

METHODS

This retrospective study was designed to assess the outcomes of arteriovenous fistula made by nephrologists at a tertiary care center from North India. The study included all radiocephalic arteriovenous fistula performed by nephrologists between November 2015 and January 2017. All arteriovenous fistulas were performed in patients whose duplex ultrasonography revealed both arterial and venous diameter of at least 2 mm. Data were collected with regard to age, gender, dialysis status, basic diseases, co-morbidities, and mineral bone disease parameters. The predictors of the primary and secondary patency rates were analyzed.

RESULTS

Five hundred patients (age 39.3 ± 14.4 years; 82.4% males; 21.6% diabetics) were included. In total, 83 (16.6%) patients had primary failure and 31 (7%) patients had secondary failure. Diabetes was associated with poor primary and secondary patency rates. Mean survival among the patients without primary failure was 11 months. The primary patency rates at 3, 6, 12, 18, and 21 months were 82%, 78%, 73%, 70%, and 70%, respectively.

CONCLUSION

To conclude, the outcomes of radiocephalic arteriovenous fistulas created by nephrologists are at par with historic outcomes.

Microcalcification in the arterial wall and its relationship to the ultrasound criteria of maturation of the arteriovenous fistula

INTRODUCTION:

A functioning and reliable arteriovenous fistula is a lifeline for individuals suffering from chronic kidney disease. The success and failure to arteriovenous fistula maturation have been frequently related to patient and surgeon factors.

METHOD:

In total, 138 participants with stage IV and V chronic kidney disease were included in this prospective observational study. Preoperative vascular mapping using ultrasound was performed to evaluate the condition and size of the vessels to fulfil the inclusion criteria. Intraoperatively, the vessel size was measured prior to anastomosis under magnified view. A specimen from the arterial wall of 5 mm in diameter was obtained from the arterotomy for histopathology assessment. Arteriovenous maturation was assessed at 6 weeks with the guidance of the ultrasound criteria of rule of sixes.

RESULTS:

From the total of 138 participants, 110 participants (79.7%) had matured arteriovenous fistula in 6 weeks. The mean size of the artery measured intraoperatively was 3.82 ± 1.33 mm and the vein was 4.05 ± 1.20 mm. Microcalcification in the arterial media which was hypothesised to be the cause of the arteriovenous fistula failure was insignificant, with a p value of 0.115. Despite having atherosclerosis in the artery, 83.3% of the arteriovenous fistula matured.

CONCLUSION:

Microcalcification and atherosclerosis are frequently seen in the arteries of chronic kidney disease patients, but they do not explain arteriovenous fistula non-maturation.

Influence of intraoperative findings on immediate flow through radial-cephalic arteriovenous wrist fistulas for hemodialysis access

Background

Adequate flow through a newly created arteriovenous fistula depends on multiple characteristics of the vessels and patient comorbidities. Several studies have related preoperative findings to failure, but few have analyzed the influence of intraoperative findings.

Objectives

To evaluate the predictive value of intraoperative findings on the immediate outcome of radial-cephalic arteriovenous wrist fistulas (RCAVF) by collecting data that are easily measured intraoperatively.

Methods

We designed a cross-sectional study, in which a single surgeon performed 101 RCAVF in 100 patients at a single center. We analyzed the immediate postoperative flow, assessed by thrill intensity immediately after fistula creation, against patient demographics and intraoperative data. The following variables were analyzed: age, sex, comorbidities, length of vein visible at preoperative examination, macroscopic arterial calcification, maximum vein diameter, and length of stenosis-free vein, measured by cannulation with a urethral catheter during the procedure. The chi-square test was used both to eliminate possible bias introduced by side of venous access (left or right), and to determine predictive values of immediate thrill.

Results

Side of access was not associated with any significant differences in variables. Absence of macroscopic arterial calcification, successful venous catheterization using a 6 French catheter or larger, and ability to advance it more than 10 centimeters along the lumen of the proximal vein were correlated with adequate immediate postoperative thrill (p = 0.004, p < 0.001, and p = 0.005, respectively).

Conclusions

In this series of 101 RCAVF, both the diameter of the catheter and its progress through the proximal vein and also absence of arterial calcification had positive predictive value for achieving adequate immediate thrill after vascular access construction.

On Postoperative Day Balloon Angioplasty for Salvage of Newly-Placed, Flow-Limiting Native Arteriovenous Fistula

Purpose:

To report result and usefulness of immediate postoperative balloon angioplasty of de novo arteriovenous fistula (AVF) with limited flow just after creation.

Materials and Methods:

From January 1, 2012 to March 31, 2014, 1,270 patients received native AVF creations in a single vascular clinic. In twenty-four patients (1.9% of total AVF creation), immediate postoperative balloon angioplasty was performed because of limited flow on palpation (only pulsation or no thrill) just after AVF creation. Medical records were reviewed retrospectively; technical success (restoration of AVF flow)/clinical success (growing as functional AVF) rate, maturation time, primary patency rate and fistula survival outcome were analyzed during a mean 10.8 months of follow-up.

Results:

Technical/clinical success rate was 95.8% (23/24 cases); AVF flow was restored after balloon angioplasty, and all the flow-restorated AVFs grew as functional AVFs with mean±standard deviation, 4.5±1.5 weeks of maturation time. In seven (30.4%) patients, a secondary balloon angioplasty was needed to enhance maturation. The overall primary patency after immediate postoperative balloon angioplasty was 69.6% at 1 and 6 months and 59.0% at 12 months. There was 1 complication (operation site hematoma).

Conclusion:

Immediate postoperative balloon angioplasty for salvage of newly-placed, flow-limiting native AVF is a useful, effective and safe procedure.