1. Dialysis Access
Interventions
“Preservation of arteriovenous access”
Matt Hawkins, MD
Assistant Professor – Emory University SOM

2. Introduction
• Understand basic construction and
function of AV fistulas and grafts
• Review endovascular interventions for
non-thrombosed AV fistulas and grafts
• Review endovascular interventions for
thrombosed fistulas and grafts

3. Construction and Function

4. Construction and Function
• NKF-KDOQI = at least 65% fistulas
• All new patients with ESRD
• Typical fistula failure rates after
construction = 15%-25%
• Fistula maturity time = 3-4 months
• Balloon-assisted maturation = 74-94%
salvage of non-maturing fistulas

5. Construction and Function
• Fistulas are ready to use when:
• Flow > 600 mL/min
• Vein diameter > 0.6 cm
• Depth under the skin < 0.6 cm
• Diameter > 4mm and flow > 500 mL/min =
95% likelihood of successful dialysis1
1:Robbin et al. Hemodialysis arteriovenous fistula maturity: US evaluation. Radiology 2002.

6. Construction and Function
• AV Grafts – looped configuration from
brachial artery to brachial vein preferred.
• May be used within 14 days of placement
• Primary 1 yr patency = 40%
• Secondary 1 yr patency = 60-90%
• Most common reason for graft failure?

7. Construction and Function
• SURVEILLANCE
• Flows < 400 mL/min
• Increased bleeding after dialysis
• Increased pulsatility
• Increased swelling
• 50-90% decrease in thrombosis rate with
monitoring and surveillance and with early
venous stenosis angioplasty

8. Endovascular Interventions
• NON-THROMBOSED FAILING ACCESS
• Comparably miserable for surgical and
endovascular repair (25% patency at 6
months)

9. Endovascular Interventions
• NON-THROMBOSED FAILING ACCESS
• Commonly Venous outflow in FISTULAS
• Brachiocephalic = cephalic arch (39%)
• Primary patency rate w/ angioplasty
(3, 6, & 12 mos) = 96%, 83%, 75%
• Brachiobasilic transposition = “swing”
site
• Arterial stenoses = < 15%

10. Endovascular Interventions
• NON-THROMBOSED FAILING ACCESS
• PTFE graft angioplasty results:
• 50% 6 month primary patency
• Angioplasty-enabled patency = 68% at
1 year; 51% at 2 years
• Secondary patency rates = 82% at 1
year; 65% at 2 years

11. Endovascular Interventions
• NON-THROMBOSED FAILING ACCESS
• PTFE graft angioplasty results:
• NKF-KDOQI endorses Secondary
patency of:
• 70% at 1 year
• 60% at 2 years
• 50% at 3 years

12. Endovascular Interventions
• NON-THROMBOSED FAILING ACCESS
• Venous outflow stenosis in a graft,
consider covered stent

13. Endovascular Interventions
• PTFE stent = 38% 6 month patency of circuit
• Angioplasty = 20%
• PTFE stent = 32% freedom from
intervention
• Angioplasty = 16%

14. Endovascular Interventions
• NON-THROMBOSED FAILING ACCESS
• Fistula angioplasty results:
• WIDELY VARIABLE
• 55% 6 month primary patency
• 80% 6 month assisted primary patency
• 82% 6 month secondary patency
Clark et al. Outcome and prognostic factors of restenosis after percutaneous treatment
of native hemodialysis fistulas. JVIR 2002.

15. Endovascular Interventions
• NON-THROMBOSED FAILING ACCESS

16. Endovascular Interventions
• NON-THROMBOSED FAILING ACCESS

17. Endovascular Interventions
• NON-THROMBOSED FAILING ACCESS

18. DE-CLOT

19. Endovascular Interventions
• THROMBOSED ACCESS
• Pre-procedure work-up
• K+
• Right-to-left shunt
• Prior procedures

20. Endovascular Interventions
• THROMBOSED ACCESS

21. Endovascular Interventions
• THROMBOSED ACCESS

22. Endovascular Interventions
• THROMBOSED ACCESS
• Outcomes for PTFE grafts:
• 90% initial clinical success (at least 1
round of dialysis)
• 1 year primary patency = 11-26%
• 1 year secondary patency = 51-69%
• Surgical and endovascular methods
demonstrate similar patency rates

23. Endovascular Interventions
• THROMBOSED ACCESS
• Outcomes for FISTULAS:
• Technical success 75-100%
• 18-60% primary patency at 6 months
• 60-80% primary assisted patency at 6
months

24. Endovascular Interventions
• THROMBOSED ACCESS
• Three ways to declot thrombosed access:
1. Pulse-spray thrombolysis
2. Lyse-and-wait (“Lyse-and-go”)
3. Mechanical thrombectomy
They all work!

25. How do we declot
dialysis access?

26. Endovascular Interventions
• TECHNIQUE

27. Endovascular Interventions
• TECHNIQUE
• Micropuncture access both directions
• Infuse 4 mg tPa in 10mL saline
• Split between the two catheters
• Wait, prep remainder of equipment

28. Endovascular Interventions
• TECHNIQUE
• 6F sheaths, bilaterally (radio-opaque tip)
• Wire access both directions
• Pull-back venogram to level of venous
outflow clot
• Heparin
• Venous outflow angioplasty/balloon
maceration (start with 6 mm Conquest)

29. Endovascular Interventions
• TECHNIQUE
• Compliant balloon (Python/Fogarty) over
wire in artery (through anastamosis)
• Pull back arterial plug into shunt
• Repeat venous outflow
angioplasty/maceration
• Repeat angiogram
• Treat residual stenosis within the dialysis
circuit and centrally

30. Endovascular Interventions
• TECHNIQUE

31. Endovascular Interventions
• TECHNIQUE

32. Endovascular Interventions
• TECHNIQUE

33. Endovascular Interventions
• TECHNIQUE

34. Endovascular Interventions
• OTHER CONSIDERATIONS
• Venous collateral embolization
• Ischemia/steal syndromes
• Venous hypertension (central occlusion)
• Aneurysms/pseudoaneurysms

35. Endovascular Interventions
• OTHER CONSIDERATIONS
• Current coding:
• Access 36147, 36148
• Angiography 35476, 75978
• Thrombectomy 36870
• Stent 37236, 37238
• Venous embolization 37241
• TOTAL = 27.52 RVU

36. Endovascular Interventions
• COMPLICATIONS
• Arterial embolization (up to 10%)
• Peri-graft bleeding
• Vein rupture from angioplasty

37. Endovascular Interventions
• SUMMARY
• As a general rule: 6 month primary
patency following angioplasty = 50%
• Stent grafts may be superior to
angioplasty at the venous anastamosis of
grafts
• As a general rule: 50-67% 1 year
secondary patency after thrombosis

38. REFERENCES

39. Matt Hawkins, MD
@MattHawkinsMD
matt.hawkins@emory.edu