vascular access in early CKD

2. The best access options for early stage
pediatric CKD
Masoumeh Mohkam
Professor od Pediatric Nephrology, SBMU, Tehran, Iran.
August 2021

3. • Recent data indicate that the incidence of end-stage renal disease
(ESRD) in pediatric patients (age 0–19 years) has increased over
the past two decades.
• Similarly, the prevalence of ESRD has increased threefold over the
same period.
• Choosing the best vascular access option for pediatric HD patients
remains challenging.
Chand. Pediatric Nephrology 2009;24:1121–1128

4. A multidisciplinary team of:
• Nephrologists
• Nurses
• Surgeons
• Interventional radiologists
• Recreational therapists
The ideal vascular access:
• Long use-life
• Low rate of complications

5. NAPRTCS Report
Review of the 2006 Annual report of the North American
Pediatric Renal Trials and Collaborative Studies (NAPRTCS) reveals
that:
Pediatric patients (78.9%) receiving hemodialysis have:
• CVC as primary access (78.9%)
• AVF (12.3%)
• AVG (8.5%)
https://doi.org/web.emmes.com/study/ped/annlrept/an
nlrept.html

6. • Although AVFs should be generally preferred in most patients,
CVC use may be appropriate in certain settings, including those
patients expected to receive a renal transplant within a short
time and exceptionally small children (weight < 10 kg).
• Despite a national initiative for fistula first in the adult
hemodialysis population, the pediatric nephrology
community in the United States of America utilizes central
venous catheters as the primary dialysis access for most
patients.

7. • A pediatric dialysis unit in Northern Ohio has an average AVF
usage rate of > 80%.
• Microsurgical techniques have been successfully utilized by an
experienced vascular surgeon to create AVFs in three children
under 15 kg in weight.
• Numerous reports of successful creation of AVFs in children have
been reported throughout the world, with primary failure rates
as low as 5%
• Time to maturation may be prolonged, with reports of up to
6 months. Thus, early planning should be undertaken to allow
time for maturation and/or revision if necessary.
Bourquelot P. Pediatr Nephrol 1990;4:156–159

8. (European Best Practice Guidelines on Vascular Access)

9. 1. Patient referral
2. Pre-operative evaluation
3. Strategies for access creation
4. Role of nurses and staff in access management
5. Surveillance of vascular access

10. Patient referral
• An early plan for venous preservation should be a substantial part of
pre-dialysis care and education in any chronic kidney disease (CKD)
patient regardless the choice of treatment modality (Evidence level IV).
• Early referral of CKD patients to the nephrologist and/ or vascular
surgeon is strongly recommended. This is to start a policy to preserve
access sites and to allow adequate time for planning, creation and
maturation of the vascular access.
• Potential chronic hemodialysis (HD) patients should be ideally referred
to the nephrologist and/or surgeon for preparing vascular access when
they reach the stage 4 of their CKD (GFR<30 ml/min/1.73 m2 ) or
earlier in case of rapidly progressive nephropathy or specific clinical
conditions such as diabetes or severe peripheral vascular disease.

11. • The planning stage involves examination and pre-operative vascular
mapping. An autogenous fistula requires at least 6 weeks for
maturation before it can be used.
• Additional time may be required for interventional or surgical revisions
to enhance maturation.
• It is recommended that the fistula is created at least 2–3 months before
the earliest likely date for starting hemodialysis.
• This approach is recommended to minimize the use of catheters and to
reduce catheter-related morbidity and need for hospitalization.
• Early referral to the nephrologist is also required for psychological
preparation for dialysis, discussion of all options for dialysis modality,
interventions to delay progression of renal damage and to correct the
hypertension, anemia and metabolic effects of renal failure

12. Pre-operative assessment
and access planning
• Careful Physical examination
• Assessment of the distal arterial pulse and the presence,
diameter and course of the superficial fore- and upper arm
veins.

13. Pre-operative evaluation
• Clinical evaluation and non-invasive ultrasonography of upper
extremity arteries and veins should be performed before vascular
access creation
• Central vein imaging is indicated in patients with a history of
previous central vein catheters (Evidence level IV).

14. Pre-operative vessel assessment with
ultrasonography
• Pre-operative vessel assessment with ultrasonography enhances the
success of creation and the outcome of autogenous AVF.
• In a randomized trial, the primary AVF failure rate was 25% when
pre-operative assessment depended on physical examination alone,
compared with 6% (P= 0.002) when ultrasonography was used.
• In the study performed by Silva et al. strategies for vascular access
creation were based on pre-operative duplex scanning. Patients with
a radial artery diameter of >=2 mm and a cephalic vein diameter of
>=2.5 mm received radial-cephalic AVFs (RCAVF).
• The percentage of RCAVF creation increased from 14% to 63%, while
the early failure rate decreased from 36% to 8%

15. • Patel study showed that the autogenous fistula creation rate
increased from 61% to 73% after the implementation of pre-
operative duplex scanning.
• Pre-operative ultrasound screening is especially useful in obese
patients.
• AVF rates were similar in 50 patients with body mass index (BMI)
>27 kg/m2 compared with 130 patients with lower BMI when
pre-operative vein mapping was employed.
Patel ST. J Vasc Surg 2003; 38: 439–445
Vassalotti JA. Clin Nephrol 2002; 58: 211–214

16. Minimum vessel size for AVF
• Although definite guidelines regarding minimum vessel size do
not exist, general consensus implies a preferred minimum of
2.5 mm venous diameter.
• Duplex ultrasound scanning by the surgeon, or venography, can
provide information regarding adequate vessel size, venous
stenosis, or occlusion, and should be considered in pediatric
patients so that the best location for AVF placement can be
determined
Gradman WS. Ann Vasc Surg 2005;19:609–612

17. Arterial imaging
• Radial artery diameter predicts the outcome (failure or
dysmaturation) of RCAVF and influences the strategy for
vascular access creation.
• Either thrombosis or failure to maturation in all RCAVFs (radial-
cephalic AVFs) created in patients with a radial artery diameter
of < 1.6 mm.
• Successful RCAVFs had a pre-operatively measured radial artery
diameter of 2.7 mm vs 1.9 mm in failed RCAVFs
• Malovrh showed a significant correlation between radial artery
RI (0.50 vs 0.70), diameter (0.294 vs 0.171 cm), and flow (90 vs
33 ml/min) during preoperative hyperemia testing and the
outcome of AVF creation
Malovrh M. Am J Kidney Dis 2002; 39: 1218–1225

18. Venous imaging
• Vein diameters of 2–2.6 mm have been associated with AVF
failure, while good patency rates were obtained in patients with
RCAVFs where the diameter of the cephalic vein at the wrist
was >2–2.6 mm or upper arm veins >3 mm
• The cephalic vein diameter increase after application of a
proximal tourniquet is an important predictor of success.
• In a group of successfully created AV fistulae, the vein diameter
increased by 48%, while vein diameter only increased by 11.8%
in the group of failed AV fistulae

19. Rukshana Shroff. Pediatric Nephrology2016;31:2337–2344
Twenty-two AVFs
The median age was 9.4 years and weight was 26.9 kg.
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).
Median kt/V of 1.97 (1.8–2.9), and urea reduction ratio of 80.7 % (79.3–86 %) was observed.

20. • 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.
Suh Min Kim. Vasc Specialist Int. 2016;32(3):113–118

21. • The European Society for Paediatric Nephrology Dialysis Working Group (ESPN Dialysis
WG)
• 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.
Rukshana Shroff. Nephrology Dialysis Transplantation 2019;34(10

22. Conclusion
1. Patient referral
2. Pre-operative evaluation
3. Strategies for access creation
4. Role of nurses and staff in access management
5. Minimize the use of central catheters