Permanent vascular access survival in children on long-term chronic hemodialysis

Vascular access challenges in hemodialysis children

BACKGROUND

Hemodialysis (HD) success is dependent mainly on vascular access (VA). The aim of this study is to share the experience of Pediatric Nephrology Unit (PNU), Cairo University Children's Hospital (CUCH), with VA-related obstacles in end stage kidney disease (ESKD) HD children.

METHODS

This is a retrospective analysis of VA related data of 187 ESKD children received regular HD over 3 year duration (2019-2021). Kaplan-Meier curves were used to present arteriovenous fistula (AVF) and cuffed catheters survivals.

RESULTS

Uncuffed central venous catheter (CVC) was the primary VA for HD in up to 97.3% with 2.7% of patients had AVF performed and attained maturation before initiation of regular HD. Fifty-six (29.9%) patients have inserted 120 tunneled CVCs. AVFs & AV grafts (AVF) were performed in 79 (42.2%) and 6 (3.2%) patients respectively. There were 112 uncuffed CVCs implanted beneath the screen in Rt internal jugular vein (IJV) (44%) Lt IJV (17%), right internal mammary vein (2.7%) while Trans hepatic (TH) technique was used to place 39 uncuffed CVCs (34%) in the inferior vena cava (IVC). Catheter-related bacteremia (CRB) was the most frequent complication in uncuffed and cuffed CVCs (2.58 / 100 catheters day and 10.1 /1000 catheter days respectively). AVFs achieved a high success rate (83%) after 757.71 ± 512.3 functioning days.

CONCLUSION

Native AVF is the preferred VA for pediatric HD but its creation is limited by the small sized vessels where non-cuffed CVC could be a reasonable relatively long-term alternative. Challenging situations (occluded central veins) could benefit from TH technique of CVC insertion in IVC.

Effects of hemodialysis access type on right heart geometry in adolescents

INTRODUCTION

This study aimed to investigate the complication frequency and the changes in right heart geometry with different access types in the pediatric population.

METHODS

We included 32 consecutive patients aged between 10 and 19 and who underwent hemodialysis sessions via permanent hemodialysis catheter (n_HC = 18) or arterio-venous fistula (n_AVF = 14) between January 2013 and March 2018. We recorded and compared the complication frequency and the changes in echocardiography findings with different access types.

FINDINGS

Demographic data were similar in both groups. Number of new access creation (n_HC = 15 vs n_AVF = 1) and all complications (n_HC = 19 vs n_AVF = 6) were significantly higher in hemodialysis catheter group and the statistical analysis showed the superiority of arterio-venous fistula group in comparison of event-free survival (event-free patients; n_AVF = 8 (57%), n_HC = 3 (16%); p = 0.02). Control echocardiography showed impressive delta-change in right atrium diameter (p = 0.04), right ventricular end-diastolic volume (p = 0.004), right ventricular end-systolic volume (p < 0.001), and right ventricular free wall thickness (p = 0.009) in arterio-venous fistula group, but no significant difference between two groups in terms of delta-change of right ventricular ejection fraction (p = 0.35), fractional area change (p = 0.21), and tricuspid annular plane systolic excursion (p = 0.13) parameters.

CONCLUSION

Arterio-venous fistula has lower risk of complications, but overloading stress on right heart chambers triggers remodeling process and geometrical changes, which can be early pieces of evidence of delayed right heart dysfunction in pediatric hemodialysis patients.

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.

Autologous arteriovenous fistulas for hemodialysis using microsurgery techniques in children weighing less than 20 kg

BACKGROUND

This study aimed to describe the efficiency and longevity of arteriovenous fistula (AVF) for hemodialysis (HD) in children weighing ≤20 kg.

METHODS

We collected data of all AVFs created using microsurgery techniques between 1988 and 2015. Success was considered as the ability to use the AVF for HD. Primary and secondary patency rates were measured.

RESULTS

Forty-eight AVFs (35 forearm, 13 upper arm) were created in 41 children with a median weight of 13.5 kg (range 5.5-20). The need for a second AVF was significantly higher in younger and thinner children at the time of AVF creation (p = 0.046 and p = 0.019, respectively). Successful use for HD occurred in 42 AVFs (87.5%), while six (12.5%) resulted in failure for early thrombosis or nonmaturation. Median time to first cannulation was 18.8 weeks (range 2-166.3). Primary and secondary patency rates at 1, 5, and 10-year follow-ups were 54.2%, 29.2%, and 13.7%; and 85.4%, 57.7%, and 33%, respectively. Almost one third of thromboses after first AVF cannulation were observed at kidney transplantation (KT) perioperatively. At the end of the follow-up (median duration 5.07 years, range 0-17.95), one patient was still on HD via AVF, two died of unrelated reason, and 38 were transplanted-one of whom returned to HD with a new AVF.

CONCLUSIONS

AVF using microsurgery techniques is feasible in young children, showing an early failure rate of 12.5%. Time to first cannulation may be rather long, but secondary patency is excellent. Thrombosis rate is high during KT.

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.

Outcomes of Arteriovenous Fistula for Hemodialysis in Pediatric and Adolescent Patients

Purpose:

This retrospective review aimed to report the outcomes of arteriovenous fistula (AVF) and to evaluate the suitability of AVF as a permanent vascular access in pediatric populations.

Materials and Methods:

Data were collected for all patients aged 0 to 19 years who underwent AVF creation for hemodialysis between January 2000 and June 2014.

Results:

Fifty-two AVFs were created in 47 patients. Mean age was 15.7±3.2 years and mean body weight was 46.7±15.4 kg. Of the 52 AVFs, 43 were radiocephalic AVFs, 7 were brachiocephalic AVFs and 2 were basilic vein transpositions. With a mean follow-up of 49.7±39.2 months, primary patency was 60.5%, 51.4%, and 47.7% at 1, 3, and 5 years, respectively and secondary patency was 82.7%, 79.2% and 79.2% at 1, 3, and 5 years, respectively. Age, body weight, AVF type, the presence of a central venous catheter, use of anticoagulation therapy, and history of vascular access failure were not significantly associated with patency rates. There were 9 cases (17.3%) of primary failure; low body weight was an independent predictor. Excluding cases of primary failure, the mean duration of maturation was 10.0±3.7 weeks. During follow-up, 20 patients (42.6%) underwent kidney transplantation, with a median interval to transplantation of 36 months.

Conclusion:

AVF creation in children and adolescents is associated with acceptable long-term durability, primary failure rate and maturation time. Considering the waiting time and limited kidney graft survival, placement of AVFs should be considered primarily even in patients expected to receive transplantation.

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.

Vascular access for long-term hemodialysis/hemodiafiltration patients

PURPOSE

We investigated the characteristics of patients who received long-term hemodialysis/hemodiafiltration (HD/HDF) treatment for over 30 years at our group of hospitals and type of vascular access (VA) used.

SUBJECTS AND METHODS

As of August 2014, 950 patients were receiving HD/HDF treatment at one of our hospitals. Of those, we investigated 41 (4.3%) undergoing long-term treatment in regard to their characteristics and VA type. The items subjected to analysis were sex, primary illness, age at time of dialysis initiation, present age, duration (years) of HD/HDF, type of arteriovenous fistula (AVF) and arteriovenous graft (AVG), history of surgery and AVF persistence rate.

RESULTS

The subjects consisted of 22 men and 19 women, and their mean HD/HDF duration was 33.4 ± 2.8 years. For primary illness, the majority (n = 31) had chronic glomerulonephritis. The age at time of dialysis initiation was 31.7 ± 7.76 years and present age was 64.5 ± 7.65 years. They had received 3.8 VA surgeries. For present VA type, 23 patients (56.0%) had an AVF and 13 (31.7%) an AVG, while 4 AVF patients (9.7%) had a history of AVG use. One patient (2.4%) had a superficialized artery. The mean HD/HDF duration of the 13 AVG patients was 7 years and the longest was 18 years. AVF persistence rate estimated by the Kaplan-Meier method was 75% at 30 years after dialysis initiation.

CONCLUSIONS

The present results suggest that the ratio of patients with AVG increased with prolonged HD/HDF treatment. AVG has a higher probability of complications and lower patency as compared to AVF, thus careful management is needed. On the other hand, AVG contributes more to a good long prognosis, as it offers efficient dialysis. In cases of vascular deterioration due to long-term hemodialysis, it is inevitable to change from AVF to AVG, thus the ratio of AVG patients is expected to increase in cases of long-term HD/HDF.

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

Purpose

Even though early transplantation is still the first-line therapy in paediatric patients with end-stage renal disease (ESRD), up to 30% of these patients still require haemodialysis (HD). Creating an arteriovenous fistula (AVF) is quite challenging, particularly in children, leading to disproportional use of catheters. In this paper, we describe our experience in the creation of AVF with currently no in-dwelling catheters in children and adolescents on HD.

Methods

From January 2009 to December 2013, there were 34 patients rated as unfit for transplantation for at least the next 6 months or who had already been on HD through a central venous catheter (CVC). Three patients aged between 12 months and 3 years and weighing 9-12 kg were not suitable for AVF. Finally 31 patients, from 6 to 19 years of age with a mean weight of 43.3 ± 14.5 kg (19-80 kg), were assigned to the alternative of AVF.

Results

During the above-mentioned time period, 31 patients were provided with 32 AVFs; 26 received a distal radiocephalic fistula, five a Gracz-type fistula and one a brachio-basilic fistula. All but two fistulae matured primarily, within an average time of 45 (range: 16-191) days until the first dialysis. The fistula's 1-year primary and primary assisted patency rates were 78% and 94%, respectively.

Conclusions

The creation of a native vascular access is an effective and durable procedure in paediatric and adolescent patients. It reduces using of CVCs and is appropriate both for long-term treatment and as a bridging procedure until renal transplantation.

Reducing central venous catheters in chronic hemodialysis--a commitment to arteriovenous fistula creation in children

BACKGROUND

An internal permanent vascular access [arteriovenous fistula (AVF) or arteriovenous graft (AVG)] is preferred over central venous catheters (CVC) for chronic hemodialysis. However, CVC remain the most commonly used access in children. The objective of this study was to evaluate our experience with AVF.

METHODS

We conducted a retrospective chart review of children aged 1-18 years on chronic hemodialysis from 2001 to 2012. Patients were divided into three time periods: 2001-2005, 2006-2009 and 2010-2012. A systematic approach to AVF placement was introduced in our department in 2006 which resulted in a greater number of AVF being placed and used, but the access failure rate was still higher than desired. In 2010, a more experienced vascular surgeon was contacted to perform AVF surgery in our most difficult AVF candidates.

RESULTS

Sixty-five AVF were created in 55 patients (67.3 % male). The median age of the patients was 14 (3-18) years. Forty-one (63.1 %) AVF were used successfully, and this number increased from 52.6 to 57.6 to 92.3 % over the three time periods, respectively. Over time, AVF use rates increased and CVC use decreased. By 2012 only 7.7 % of our patients were using a CVC. The primary patency rate was 42.9 % at 1 year; secondary patency rates were 100 and 93.8 % at 1 and 2 years, respectively. Infection and hospitalization rates were higher for CVC than for AVF [0.8 vs. 0.1 infections per access-year (p < 0.001) and 0.9 vs. 0.2 hospitalizations per access-year (p < 0.001)].

CONCLUSIONS

With a dedicated approach and vascular access team it is possible to decrease CVC and increase AVF use in children on hemodialysis. In our study, increased AVF use resulted in decreased access-related infection and hospitalization rates.

Outcome of tunnelled central venous catheters used for haemodialysis in children weighing less than 15 kg

PURPOSE

Central venous catheters (CVC) are frequently used for haemodialysis (HD) in children. However, there is paucity of information on the outcomes of CVCs when used for HD in very young patients. Our objective is to report the success, safety and complication rates of CVCs used for HD in children weighing less than 15 kg.

MATERIALS AND METHODS

This is a single-center retrospective study of all patients with end-stage renal disease (ESRD) weighing <15kg, who underwent a tunneled CVC placement for HD, between July 2006 and June 2012 at our institution. Analysed data included clinical background, age and weight at initiation of HD, outcome of HD, CVC vein insertion site, reason for removal, and catheter survival (in days).

RESULTS

Thirty-one CVC were placed in 11 patients weighing <15 kg, 8 males and 3 females. The main causes of ESRD were renal dysplasia and congenital nephrotic syndrome. At the beginning of HD, mean age was 27.5 (range 5-60) months and mean weight was 10.4 kg (4.5-13 kg). The preferred insertion site was the right internal jugular vein (90%). Mean duration of HD was 312 days. Mechanical factors were the main reason for catheter removal (39%). Mean catheter survival was 110 days/catheter.

CONCLUSIONS

We believe our study provides relevant information and encouraging data to support the use of CVC for HD in this cohort of infants; however, further improvement in prevention of catheter thrombosis and management of infections needs to be achieved.

A comparison of arteriovenous fistulas and central venous lines for long-term chronic haemodialysis

BACKGROUND

Despite the Fistula First initiative there is still reluctance to use arteriovenous fistulas (AVF) for chronic haemodialysis (HD) in children. Our aim was to compare outcomes of AVFs and central venous lines (CVL) in children on chronic HD in a centre where AVF is the primary choice for vascular access.

PATIENTS AND METHODS

This was a retrospective case notes analysis of access complications, dialysis adequacy and laboratory outcomes in children who underwent dialysis for at least a year by AVF (n = 20, median age 14.2 years, range (2.9-16.5) and CVL (n = 5, median age 2.4 years, range 2.0-12.2) between January 2007 and December 2010.

RESULTS

Primary access failure rate (patient-months) was 1 per 78.8 for AVF (n = 5) and 1 per 15.5 for CVLs (n = 7, p = 0.3). Failure thereafter was 1 per 131.3 and 1 per 18.5 for AVF and CVLs respectively (n = 3 and 6 respectively; p = 0.2). The annualised hospitalisation rate for access malfunction was 0.44% and 3.1% for AVFs and CVLs respectively (p = 0.004). Patients with AVFs had a lower infection rate of 0.25 per 100 patient-months compared with CVL at 3.2 per 100 (p = 0.002). There was no difference in dialysis adequacy or laboratory values between AVF and CVL groups. Access survival rates (including both primary and secondary access failure) were significantly higher for AVF compared with CVL (p = 0.0002, hazard ratio = 0.15, 95% confidence interval 0.04-0.37).

CONCLUSIONS

Patients with AVF spend less time in hospital than those dialysed by CVLs and have a much lower access infection rate. These findings emphasise the need to use AVF as first-line access for paediatric patients on chronic HD.