AV Fistula Creation in Paediatric Patients: Outcome is Independent of Demographics and Fistula Type Reducing Usage of Venous Catheters

Long-Term Experience of Arterio-Venous Fistula Surgery in Children on Hemodialysis

Background: Arterio-venous fistulas (AVF) are used as first-line access for hemodialysis (HD) in the pediatric population. The aim of this investigation was to describe a single-center experience in the creation of AVF, together with its patency in children. Methods: This single-center retrospective study included all patients aged ≤18 years with AVFs created between 1993 and 2023. The collected data included patients' demographics, hemodialysis history, intraoperative data, and required reinterventions in order to determine the impact of these variables on primary, primary-assisted, and secondary patency. Results: Fifty-seven patients were analyzed with a median age of 15 years (range, 7-18 years). Fifty-four forearm and four upper arm fistulas were performed. The median follow-up was 6.9 years (range, 0-23 years). The primary failure rate was 10.5%. The primary patency rate was 67.6%, 53.6%, 51.4%, and 38.1% after 1, 3, 5, and 10 years; primary-assisted patency was 72.9%, 62.8%, 60.6%, and 41.5%; and secondary patency was 87.3%, 81.3%, 76.8%, and 66.6% after 1, 3, 5, and 10 years in the studied population. Conclusions: AVFs showed an acceptable rate of primary failure and excellent long-term patency. In this context, AVFs are an appropriate option for HD access, especially in pediatric patients.

Good outcomes for arteriovenous fistula with buttonhole cannulation for chronic hemodialysis in children and adolescents

BACKGROUND

Arteriovenous fistula (AVF) is the preferred access for chronic hemodialysis (HD) in children and adolescents, but central venous catheter use is still high.

METHODS

Retrospective chart review of children and adolescents with AVF created between January 2003 and December 2015 was performed to assess primary failure (PF), maturation time, functional primary and functional cumulative patency, and potential risk factors for AVF dysfunction.

RESULTS

Ninety-nine AVF were created in 79 patients (54% male; 7-24 years; 16-147 kg) by experienced surgeons. Duplex ultrasonography vein mapping was used to assist with site selection. PF occurred in 17 AVF (17%) in 14 patients. Patient age, gender, ethnicity, underlying disease, time on dialysis, and AVF site were not associated with PF or patency. Coagulation abnormality was positively associated with PF (p = 0.03). Function was achieved in 82 AVF (83%) in 77 patients (97%). Median maturation time was 83 days (range 32-271). AVF were accessed via buttonholes. Functional primary patency was 95%, 84%, and 53% at 1, 2, and 5 years. Overall 1- and 2-year functional cumulative patency was 95%, but lower for small patients 16-30 kg (88%) and those greater than 80 kg (91%). The 5-year patency rate was 80%, but significantly lower for 16-30 kg (59%) and greater than 80 kg (55%). Risk analysis showed significantly better patency for 31-45 kg and 46-80 kg groups (p < 0.01), non-obese BMI (p = 0.01), and buttonhole self-cannulation (p = 0.03).

CONCLUSIONS

This study provides more information about successful AVF with buttonhole cannulation in pediatric hemodialysis patients lending additional support for AVF use in pediatrics. A higher resolution version of the Graphical abstract is available as Supplementary information.

The cost of hospitalizations for treatment of hemodialysis catheter-associated blood stream infections in children: a retrospective cohort study

BACKGROUND

Hospitalization costs for treatment of hemodialysis (HD) catheter-associated blood stream infections (CA-BSI) in adults are high. No studies have evaluated hospitalization costs for HD CA-BSI in children or identified factors associated with high-cost hospitalizations.

METHODS

We analyzed 160 HD CA-BSIs from the Standardizing Care to Improve Outcomes in Pediatric End-stage Kidney Disease (SCOPE) collaborative database linked to hospitalization encounters in the Pediatric Health Information System (PHIS) database. Charge-to-cost ratios were used to convert hospitalization charges reported in PHIS database to estimated hospital costs. Generalized linear mixed modeling was used to assess the relationship between higher-cost hospitalization (cost above 50^th percentile) and patient and clinical characteristics. Generalized linear regression models were used to assess differences in mean service line costs between higher- and lower-cost hospitalizations.

RESULTS

The median (IQR) length of stay for HD CA-BSI hospitalization was 5 (3-10) days. The median (IQR) cost for HD CA-BSI hospitalization was $18,375 ($11,584-$36,266). ICU stay (aOR 5.44, 95% CI 1.62-18.26, p = 0.01) and need for a catheter procedure (aOR = 6.08, 95% CI 2.45-15.07, p < 0.001) were associated with higher-cost hospitalization.

CONCLUSIONS

Hospitalizations for HD CA-BSIs in children are often multiple days and are associated with substantial costs. Interventions to reduce CA-BSI may reduce hospitalization costs for children who receive chronic HD. A higher resolution version of the Graphical abstract is available as Supplementary information.

Clinical profile and outcome of arterio-venous fistulae in children on maintenance hemodialysis belonging to a low resource setting

INTRODUCTION

Arterio-venous fistula (AVF) is the recommended access of choice in children on maintenance hemodialysis. The challenges of creating and maintaining a fistula in children are many. The objective of our study was to study the clinical profile and outcomes of arteriovenous fistulae in children from a resource limited setting METHODS: A retrospective analysis of children who have had an AVF for maintenance hemodialysis from 2010 to 2020 was done. The centre protocol for creation and management of complications was followed. Failure of fistula to mature and failure to use fistula after it had been used were defined was primary failure and secondary failure respectively. Primary patency was defined as the time from maturation to first complication requiring intervention. The primary and secondary failure rates, risk factors for loss of primary patency and fistula survival were studied.

RESULTS

Thirty-six children (38 AVF) with median age of 11 (8,13) years were included. Brachio-cephalic anastomosis was the most common site (75%) of AVF. The primary and secondary failure rates were 5.5%(2/36) and 8.8%(3/34) respectively. The median time to loss of primary patency was 32 (16, 61.5) months. There were no particular risk factors identified for loss of primary patency. The 1- and 5-year survival was 91% and 73% respectively.

CONCLUSIONS

In resource limited settings, AVF is a feasible and durable access for maintenance hemodialysis in children with low failure rates.

Study on prediction of arterio-venous fistula maturation by flow mediated dilatation and AVF blood flow

BACKGROUND

The physiology and pathology of AVF maturation depends on the vessels characteristics and its ability to remodel. Outcome of AVF using flow mediated dilatation (FMD), AVF blood flow and diameter has been studied.

METHODOLOGY

Present observational study included single stage AVF (both Radiocephalic and Brachiocephalic) in consecutive CKD five patients (n = 158) prospectively over 1 year. Demographic and Doppler ultrasound parameters of upper limb (for vessel diameter and FMD) at baseline were recorded. Blood flow, diameter and depth of AVF were studied at 2, 6 and 12 weeks and their association with clinical maturation (usage of fistula with two needles for 75% of dialysis sessions during 15 day period) was studied (n = 129, after excluding lost to followup and expired patients; accordingly cohort was divided in matured (M) or non-matured (NM) groups. Clinical and radiological parameters between both groups were compared; receiver operator curve (ROC) and correlation of Doppler parameters were analysed.

RESULTS

Of 129 AVF, 67.4% were matured and 32.5% non-matured. Mean age was 40 years with male predominance75% in both the groups. The mean arterial diameter for distal (NM = 1.96 ± 0.58 and M = 2.02 ± 0.41) and proximal AVF (NM = 3.37 ± 0.82 and M = 3.36 ± 0.75) was not statistically different in both the groups. The matured fistula group had a mean FMD of 11.67 ± 4.09 as against FMD value of 9.365 ± 3.55 in the failed fistula group (p value 0.01). For maturation prediction, sensitivity and specificity of blood flow at 2 weeks were 86.2% and 59.5% and at 6 weeks 96.6% and 64.3%, respectively. In multivariate analysis predictors for AVF maturation were FMD (adjusted odds ratio (AOR) = 1.15) and blood flow (AOR = 1.67).

CONCLUSION

Second and Sixth week AVF blood flow was found to be predicting AVF maturation. Higher baseline FMD correlated with the AVF maturation, but not with vessel diameter.

Update on the creation and maintenance of arteriovenous fistulas for haemodialysis in children

Arteriovenous fistulas (AVFs) are widely used for haemodialysis (HD) in adults with stage 5 chronic kidney disease (CKD 5) and are generally considered the best form of vascular access (VA). The 'Fistula First' initiative in 2003 helped to change the culture of VA in adults. However, this cultural change has not yet been adopted in children despite the fact that a functioning AVF is associated with lower complication rates and longer access survival than a central venous line (CVL). For children with CKD 5, especially when kidney failure starts early in life, there is a risk that all VA options will be exhausted. Therefore, it is essential to develop long-term strategies for optimal VA creation and maintenance. Whilst AVFs are the preferred VA in the paediatric population on chronic HD, they may not be suitable for every child. Recent guidelines and observational data in the paediatric CKD 5 population recommend switching from a 'Catheter First' to 'Catheter Last' approach. In this review, recent evidence is summarized in order to promote change in current practices.

Hemodialysis and peritoneal dialysis access related outcomes in the pediatric and adolescent population

BACKGROUND

There is paucity of comparative data on the objective performance of arteriovenous fistulas (AVF), grafts (AVG), hemodialysis (HD) catheter and peritoneal dialysis (PD) catheter in the pediatric population.

METHODS

A retrospective analysis of all patients <21 years in the United States Renal Database System who had an AVF, AVG, HD catheter or PD catheter placed for dialysis access between 1/2007 and 12/2014 was performed. Multivariable cox regression was used to evaluate mortality, patency (primary, primary-assisted and secondary), maturation and catheter survival.

RESULTS

The 11,575 patients studied comprised of 9445 (82%) HD, 1435 (12%) PD, 528 (4.6%) HD to PD and 167 (1.4%) PD to HD patients. The HD subcohort comprised of 1296 (13.7%) AVF initiates, 199 (2.1%) AVG initiates, 1347 (14.3%) AVF converts after initial HD catheter use, 292 (3.1%) AVG converts and 6311 (67%) patients who persistently utilized HD catheters. There was no difference between PD and HD in patients 0-5 (aHR: 1.36; 95% CI: 0.89-2.07; P = 0.15) and 6-12 years (aHR: 1.05; 95% CI: 0.72-1.52; P = 0.8). However, PD was associated with 73% and 76% increase in mortality relative to HD among patients in the 13-17 (aHR: 1.73; 95% CI: 1.35-2.21; P < 0.001) and 18-20 (aHR: 1.76; 95% CI: 1.38-2.24; P < 0.001) age categories. AVG was associated with 78% increase in mortality compared to AVF (aHR: 1.78; 95% CI: 1.41-2.25; P < 0.001). Persistent use of HD catheters was associated with 29% increase in mortality (aHR: 1.29; 95% CI: 1.07-1.57; P = 0.009) compared to initiation and persistent use of AVF. Conversion from HD catheter to AVF was associated with 66% decrease in mortality compared to persistent HD catheter use (aHR: 0.34; 95% CI: 0.28-0.40; P < 0.001). Primary, primary assisted and secondary patency were higher for AVF compared to AVG.

CONCLUSION

There was no difference in risk adjusted mortality between HD and PD in children less than 13 years. PD is associated with higher mortality compared to HD in adolescents. Initiation of HD with AVF is associated with better patency and patient survival relative to AVG and persistent use of HD catheters in pediatric patients irrespective of transplant potential. Conversion from HD catheter to AVF or AVG in patients who inevitably initiate HD with a catheter is associated with better survival compared to persistent HD catheter use.

TYPE OF STUDY

Retrospective cohort study.

LEVEL OF EVIDENCE

Level II.

Vascular access in children requiring maintenance haemodialysis: a consensus document by the European Society for Paediatric Nephrology Dialysis Working Group

BACKGROUND

There are three principle forms of vascular access available for the treatment of children with end stage kidney disease (ESKD) by haemodialysis: tunnelled catheters placed in a central vein (central venous lines, CVLs), arteriovenous fistulas (AVF), and arteriovenous grafts (AVG) using prosthetic or biological material. Compared with the adult literature, there are few studies in children to provide evidence based guidelines for optimal vascular access type or its management and outcomes in children with ESKD.

METHODS

The European Society for Paediatric Nephrology Dialysis Working Group (ESPN Dialysis WG) have developed recommendations for the choice of access type, pre-operative evaluation, monitoring, and prevention and management of complications of different access types in children with ESKD.

RESULTS

For adults with ESKD on haemodialysis, the principle of "Fistula First" has been key to changing the attitude to vascular access for haemodialysis. However, data from multiple observational studies and the International Paediatric Haemodialysis Network registry suggest that CVLs are associated with a significantly higher rate of infections and access dysfunction, and need for access replacement. Despite this, AVFs are used in only ∼25% of children on haemodialysis. It is important to provide the right access for the right patient at the right time in their life-course of renal replacement therapy, with an emphasis on venous preservation at all times. While AVFs may not be suitable in the very young or those with an anticipated short dialysis course before transplantation, many paediatric studies have shown that AVFs are superior to CVLs.

CONCLUSIONS

Here we present clinical practice recommendations for AVFs and CVLs in children with ESKD. The Grading of Recommendations Assessment, Development, and Evaluation (GRADE) system has been used to develop and GRADE the recommendations. In the absence of high quality evidence, the opinion of experts from the ESPN Dialysis WG is provided, but is clearly GRADE-ed as such and must be carefully considered by the treating physician, and adapted to local expertise and individual patient needs as appropriate.

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 patency for arteriovenous fistulae and grafts in pediatric hemodialysis patients

BACKGROUND

Hemodialysis (HD) guidelines recommend permanent vascular access (PVA) in children unlikely to receive kidney transplant within 1 year of starting HD. We aimed to determine predictors of primary and secondary patency of PVA in pediatric HD patients.

METHODS

Retrospective chart reviews were performed for first PVAs in 20 participating centers. Variables collected included patient demographics, complications, interventions, and final outcome.

RESULTS

There were 103 arterio-venous fistulae (AVF) and 14 AV grafts (AVG). AVF demonstrated superior primary (p = 0.0391) and secondary patency (p = 0.0227) compared to AVG. Primary failure occurred in 16 PVA (13.6%) and secondary failure in 14 PVA (12.2%). AVF were more likely to have primary failure (odds ratio (OR) = 2.10) and AVG had more secondary failure (OR = 3.33). No demographic, clinical, or laboratory variable predicted primary failure of PVA. Anatomical location of PVA was predictive of secondary failure, with radial having the lowest risk compared to brachial (OR = 12.425) or femoral PVA (OR = 118.618). Intervention-free survival was predictive of secondary patency for all PVA (p = 0.0252) and directly correlated with overall survival of AVF (p = 0.0197) but not AVG. Study center demonstrated statistically significant effect only on intervention-free AVF survival (p = 0.0082), but not number of complications or interventions, or outcomes.

CONCLUSIONS

In this multi-center pediatric HD cohort, AVF demonstrated primary and secondary patency advantages over AVG. Radial PVA was least likely to develop secondary failure. Intervention-free survival was the only predictor of secondary patency for AVF and directly correlated with overall access survival. The study center effect on intervention-free survival of AVF deserves further investigation.

Timing of first arteriovenous fistula cannulation in children on hemodialysis

BACKGROUND

Due to lower complication rates in comparison to central venous catheter (CVC) arteriovenous fistulas (AVFs) are now the preferred hemodialysis access. Recommendations for the first access cannulation range from 6 to 12 weeks, which could lead to temporary or even permanent preference for CVC while awaiting the maturation of the newly created AVF. The aim of this study was to evaluate the influence of first cannulation of AVFs on primary (PP) and secondary (SP) patency rates in children on hemodialysis (HD).

METHODS

This was a retrospective cohort study of 42 pediatric patients with a median age of 14 (range 7-17) years. At the time of surgical AVF creation 21 patients (end-stage renal disease) were still on HD via CVC or peritoneal catheter, while 21 were pre-emptive with initiation of HD expected within a few weeks. All patients received an AVF by the same experienced surgeon between February 1993 and May 2014. Primary failure (PF) was defined as the inability to use the AVF even once due to absent maturation or occlusion within 4 weeks after creation. PP was defined as the interval from time of access placement to any intervention designed to maintain or reestablish patency, to access thrombosis or the time of measurement of patency, while SP was defined as the total lifespan from creation to access abandonment, end of follow-up or loss.

RESULTS

Primary failure was observed in six (14.3 %) of 42 AVFs (all radiocephalic fistulas) within the first 10 days after cannulation. Excluding PF, the PP/SP rates at 1, 3, 6, 12, 18 and 24 months were 100/100, 91/99, 86/98, 76/95, 55/85 and 44/77 %, respectively. There was a significant decrease in PP when first cannulation was performed within the first 30 days after creation compared to first cannulation performed after 30 days (p = 0.004). In terms of PP/SP outcome and timing of the first cannulation, there was no significant difference in thee outcome of PP/SP between first cannulation within the first 45 days after creation and that after 45 days (p = 0.091/0.883).

CONCLUSIONS

The findings suggest that cannulation of AVF within 30 days after surgical creation reduces PP, while SP may be influenced less by time until cannulation. We also found no significant differences in PP after maturing periods of >45 days.

Pediatric patients undergoing arteriovenous fistula surgery without intraoperative heparin

INTRODUCTION

Arteriovenous fistula (AVF) creation in children could be extremely challenging for vascular surgeons due to small vessels with a high tendency of vasospasm. This could be one reason for primary failures (PF) and early access thrombosis. There exists no guideline for the need of intraoperative heparin administration during hemodialysis fistula creation. The aim of this study was to evaluate the effect of intra-operative heparin administration on immediate outcome.

METHODS

Medical records of 42 pediatric patients aged between 7 and 17 years were retrospectively reviewed. All received an AVF under inpatient conditions by exclusively one vascular surgeon with many years of professional experience. The intraoperative anticoagulation standards changed by the years 2001 based on the decision of the vascular surgeon. Therefore, we build two groups (group 1: 14 patients with 5000 IU of intravenous heparin during surgery and group 2: 28 patients without heparin). Major complications included hematoma or bleeding leading to surgery. PF was defined as the inability to use the AVF even once due to absent maturation or occlusion within 4 weeks after creation.

RESULTS

We found 6 (14%) PF with the need of immediate surgical access revision (three from group 1 and three from group 2; p = 0.350). There were no bleedings leading to surgery in all cases, but 5 (12%) hematomas without the need of surgical revision (three from group 1 and two from group 2; p = 0.736).

CONCLUSIONS

We found no benefit of heparin administration during clamping the arteries while performing the arteriovenous fistula in pediatric patients.

A dedicated vascular access clinic for children on haemodialysis: Two years' experience

BACKGROUND

Arteriovenous fistula (AVF) formation for long-term haemodialysis in children is a niche discipline with little data for guidance. We developed a dedicated Vascular Access Clinic that is run jointly by a transplant surgeon, paediatric nephrologist, dialysis nurse and a clinical vascular scientist specialised in vascular sonography for the assessment and surveillance of AVFs. We report the experience and 2-year outcomes of this clinic.

METHODS

Twelve new AVFs were formed and 11 existing AVFs were followed up for 2 years. All children were assessed by clinical and ultrasound examination.

RESULTS

During the study period 12 brachiocephalic, nine basilic vein transpositions and two radiocephalic AVFs were followed up. The median age (interquartile range) and weight of those children undergoing new AVF creation were 9.4 (interquartile 3-17) years and 26.9 (14-67) kg, respectively. Pre-operative ultrasound vascular mapping showed maximum median vein and artery diameters of 3.0 (2-5) and 2.7 (2.0-5.3) mm, respectively. Maturation scans 6 weeks after AVF formation showed a median flow of 1277 (432-2880) ml/min. Primary maturation rate was 83 % (10/12). Assisted maturation was 100 %, with two patients requiring a single angioplasty. For the 11 children with an existing AVF the maximum median vein diameter was 14.0 (8.0-26.0) mm, and the median flow rate was 1781 (800-2971) ml/min at a median of 153 weeks after AVF formation. Twenty-two AVFs were used successfully for dialysis, a median kt/V of 1.97 (1.8-2.9), and urea reduction ratio of 80.7 % (79.3-86 %) was observed. One child was transplanted before the AVF was used.

CONCLUSIONS

A multidisciplinary vascular clinic incorporating ultrasound assessment is key to maintaining young children on chronic haemodialysis via an AVF.