Vascular access in hemodialysis

1. Chaken Maniyan, MD
Division of Nephrology
Phramongkutklao Hospital and College of Medicine

2. Preparation, selection and placement for permanent VA
Cannulation and accession of VA
Surveillance
Treatment of permanent VA complications
S c o p e

3. Delivers adequate flow rate for prescription
Long life
Low rate of complications
Cannulated easily
Ideal vascular access
NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

4. Temporary Catheter
Cuffed
Non cuffed
AV Fistula
AV Graft
Type of vascular access

5. Fistula Vs Graft

6. Properties of Vascular access
HD cath AVG AVF
Immediate use Yes 2-4 Wks No
Primary failure Less Less More
Survival Short Intermediate Long
Obstruction More Intermediate Less
Infection More Intermediate Less
Handbook of Dialysis ; 5th edition

7. Wrist fistulas
Age > 60 years old
Obesity
Diabetic
Peripheral vascular or cardiovascular
disease
Non white race
Female sex
Risk of AVF primary failure
Handbook of Dialysis ; 5th edition

8. AVF : First, if available
AVG : Next
HD Catheter : Last, should be avoid
Location
Placed distally and moved to
proximal
Selection and placement of hemodialysis access
NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

9. AV fistulas in at least 50% of hemodialysis patients
AV grafts in 40%, and
Dialysis catheters in no more than 10%
KPI of vascular access
NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

10. 1.1 Patients with GFR < 30 mL/min/1.73 m2 should
educated on all modalities of RRT options, including
transplantation (A)
1.2 In patients with CKD stage 4 or 5, forearm and
upperarm veins suitable for placement of vascular access
should NOT be used for venipuncture (B)
Preparation for permanent HD access
NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

11. 1.3 Patients should have a functional permanent VA at initiation of HD
1.3.1 AVF should be placed > 6 months before start of HD.
This timing allows for access evaluation and additional time for revision to ensure
working fistula is available at initiation of dialysis therapy. (B)
1.3.2 A graft should, in most cases, be placed at least 3-6 weeks before start of HD
therapy.
Some newer materials may be cannulated immediately after placement. (B)
AVG (e-PTFE Polytetrafluoroethylene) should not be cannulated before 2 wks
AVG (PU) should not be cannulated before 24 hr
Preparation for permanent HD access
NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

12. Thai Guideline
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14. 1.4.1 History and physical examination (B)
1.4.2 Duplex ultrasound of upper-extremity arteries and
veins, (B)
1.4.3 Central vein evaluation in appropriate patient known
to have a previous catheter or pacemaker. (A)
Evaluations for permanent HD access
NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

15. Important History
NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

16. Important Physical examination
NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

17. Selection of the most appropriate vein and best location of the access
Doppler ultrasonography
Minimal vein and artery size : venous diameter ~ 2.5 mm, artery diameter ~ 2
mm
Vein dilation test
During the Doppler study the proximal vein is occluded
Increase in internal diameter of 50% has been associated with a good
fistula outcome
Duplex ultrasound of upper-extremity arteries and veins

18. Anatomy of upper extremities

19. Radiocephalic AVF (Brescia-Cimino)

20. Snuff-box AVF

21. Brachiocephalic AVF

22. Forearm Loop AVG

23. Upper Arm AVG

24. Easiest
Highest fistula flow
Risk for high output cardiac
failure
Arteriovenous anastomosis
Minimize turbulence and distal steal
Slightly lower fistula flow
Twisting of artery during construction
Side to Side
End to Side

25. Decrease turbulence
Highest venous flow
Minimal venous hypertension
More difficult than side to side
Arteriovenous anastomosis
Least arterial steal and venous
hypertension
Lowest flow of the four configurations
Side to End
End to End

26. AVF should be matured before cannulation
Rule of 6s
Access flow of 600 mL/min
< 0.6 cm below surface of skin
Minimal diameter 0.6 cm
Exercise fistula hand-arm ! isometric exercise
If fistula not matured in 6 wks ! fistulogram for access problem
AVF maturation

27. Needle size
• Initial use : 16-17 gauge, low blood flow rate
• Matured VA: > 15 gauge
• Position and rotation
• Arterial needle
• > 3 cm from arterial anastomosis site
• point upstream or downstream
• Venous needle
• >5 cm from arterial needle
• point downstream
Cannulations

28. Direct pressure over the site
Tip of one or two fingers > 10 minutes
Prolonged bleeding > 20 minutes : Increased intra-access
pressure
Hemostasis post dialysis

29. Patient Education

30. Surveillance
Prolong access longevity
Safe another vessel
Reduce infection rate from insert double lumen catheter
Adequacy of hemodialysis
Frequency of hospitalization
Decrease the cost of hemodialysis access management
Comprehensive Clinical Nephrology, 6th Edition,

31. AV Fistula
•Not as common as AVG
•When it occurs is worse than AVG
•Most common site : bifurcation , valve, pressure site
AV Graft
•Most common complication
•Results in :
–Inefficient dialysis
–Thrombosis
85-90% associated with stenosis
80% of graft loss associated with thrombosis
Venous stenosis & thrombosis

32. Common site of stenosis
Nephrol Dial Transplant (2000) 15: 2029-2036

33. Direct
Doppler ultrasound
Venography
MRA
Angiogram
Method to detect stenosis
Indirect
Physical Examination
VA pressure
VA flow
Recirculation during
dialysis
Handbook of Dialysis ; 5th edition

34. Recommended methods for VA surveillance
AVF AVG
Preferred Intra access flow Intra access flow
PE Static venous P
Dupplex u/s Dupplex u/s
Accept
Recirculation
(non urea based)
PE
Static venous P
Don’t Dynamic venous P
NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

35. Method 1 : Physical examination

36. Look-Feel-Listen

37. Summary of Physical Examination
Inspection Examine for erythema,swelling,gangrene,change of size of aneurysm over time
Palpitation
Feel for intravascular pressure along veins
examine for segmental difference in quality
Feel for elevated/low skin temperature
check the quality of pulsation along arteries and veins
Check for pain caused by finger pressure
Auscultation
Check for presence of typical low-frequency bruit
with systolic and diastolic components
Examine for abnormal high-frequency bruit
produced by turbulence due to stenosis.

38. Pulse augmentation

39. Change in Thrill

40. Lorem Ipsum Dolor
Change in Bruit

41. Arm Raise Technique

42. Clinical Parameters in Vascular Access
Examination
Finding
Normal Outflow Stenosis Inflow Stenosis Central Stenosis Coexisting Inflow and
Outflow Stenosis
Thrill Continuous Louder, higher
pitched, may be
discontinuous if
severe
Discontinuous, or
absent if severe
stenosis
Variable Discontinuous or
absent
Pulse Soft and easily
compressible
Hyperpulsation Hypopulsation Variable Soft and easily
compressible pulse
Access Flow Normal Decreased Decreased Variable Decreased
Augmentation
Test
Normal Good augmentation Poor augmentation Good augmentation Poor augmentation
Arm Elevation
Test
Normal collapse No collapse (fistulas) Normal or enhanced
collapse (fistulas)
No collapse No collapse
Clinical Features No difficulty with
cannulation, normal
bleeding times after
dialysis
Increased venous
pressures, prolonged
bleeding times after
dialysis
Difficulty cannulating,
increased negative
arterial pressures
Edema of the arm,
shoulder and neck,
supraclavicular or
facial swelling,
collateral vessels
visible on the chest
Advances in Chronic Kidney Disease, Vol 22, No 6 (November), 2015: pp 446-452

43. Method 2: Access flow

44. Duplex Doppler Ultrasound (Quantitative colour velocity imaging)
MRA
Variable Flow Doppler Ultrasound (Specs USA)
Ultrasound Dilution Technique
Critline direct transcutaneous (Hema-metrics)
Glucose Pump infusion technique
Urea Dilution technique
Differential Conductivity( GAMBRO)
In Line Dialysance ( FRESENIUS)
Intra access blood flow monitoring
NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

45. Saline dilution and ultrasound detection

46. Access flow : Ultrasound (saline) dilution

47. Within 90 min after HD session
Stop blood pump
Switch A/V line to induce recirculation then start BFR 250 – 300 ml/min
Infusion saline in venous line (post dialyzer)
Sensor detect difference then calculation degree recirculation access blood flow (ml/min)
QA = QBP (1/R – 1)
QBP = blood pump blood flow
R = degree of recirculation
Ultrasound dilution technique

48. K/DOQI : critical level = 500 ml/min
European <300 ml/min
Flow trending threshold = 800 ml/min + decreased
by >25% over 4 months.
Potential for cardiac overload exists > 2000 ml/min.
Access Flow Level Guidelines for Fistulas

49. Access Flow Level Guidelines for Graft
K/DOQI and Europeean : critical level = 600 ml/min
Trending threshold = 1000 ml/min + decreased by >25%
over 4 months
Potential for cardiac overload exists > 2000 ml/min

51. Method 3: Intra access Pressure

52. In AVG graft: PIA is usually <50% of MAP
Pressure drop occurs at arterial anastomosis, unless intragraft
stenosis.
When outflow stenosis develops PIA rises and flow decreases
If PIA >50% of MAP ,AVG flow decreased into thrombosis-prone
range of 600–800 mL/min,.
Intra access Pressure

53. Establish a baseline and follow with trend analysis.
Calibration of pressure transducers within +/-
5mmHg.
Measure MAP in contra lateral arm.
Stop blood pump & clamp venous line proximal to venous drip chamber, on the arterial line the
occlusive roller pump serves as a clamp.
Wait for 30s until venous pressure is stable and then record venous and arterial IAP
Determine height correction h between the access and the drip chamber.
Arterial ratio= (arterial IAP+ Ht.Correction)/ MAP
Venous ratio= (venous IAP + Ht.Correction)/ MAP
Step in static IAP measurement

54. SVP using drip direct method

55. SVP using drip chamber method
Arterial PIA = (arterial IAP + arterial Poffset – arterial P0) / MAP
Venous PIA = (venous IAP + venous Poffset – venous P0) / MAP

56. PIA within AVG and AVF

57. Intra-Access Pressure AVG Profiles
0.1
0.3
0.5
0.7
1.0
Severe Outlet stenosis
Mild Outlet stenosis
Normal
Arterial stenosis
Intra access stenosis
Artery Arterial
limb
Venous
limb
Vein
PIA/MAP
Adapted from NKF KDOQI GUIDELINES Clinical Practice Recommendations 2006 Updates

59. Duplex ultrasound provides information :
Anatomical configuration
Functional state of access via flow volume measurements
Method 4: Doppler (duplex) ultrasound
Advantages
Mobile
Noninvasive
Anatomic /
physiologic data
Disadvantages
Availability
Operator dependent
Flow volume
measurements depend
on machine’s type
Magnasco A, et al. Nephrol Dial Transplant 2012;17:2244

60. ข้อแนะนำเวชปฏิบัติการฟอกเลือดด้วยเครื่องไตเทียม พ.ศ. 2557 สมาคมโรคไตแห่งประเทศไทย

61. Vascular access
complication

62. Early : Non – maturation
Late : Stenosis and thrombosis
Other
•Hand ischemia (Steal syndrome)
•Aneurysm and bleeding
•High flow related heart failure
•Infection
AVF or AVG dysfunction and related complication
Handbook of Dialysis ; 5th edition

63. Technical expertise of the surgeon
Cardiac issues
Low ejection fraction
Diabetics
Female gender
Advanced atherosclerotic disease
Patients with several or large accessory veins
AVF maturation failure

64. 10%–35% of AVF not adequately develop and fail to sustain dialysis therapy
Main culprits
Vascular stenosis (70%) common lesion at close to anastomosis (a juxta-anastomotic
lesion)
Rx: Percutaneous balloon angioplasty salvage a great majority
Accessory vein (30%)
Rx: percutaneous ligation, venous cutdown, or coil insertion) .
Flow should be falls back to pretreatment levels within 1-2 day of procedure.
Endovascular stents and vascular stenosis. - treat stenoses associated with AV grafts
located at or just distal to the graft–vein anastomosis.
AVF dysfunction

65. Edema of the access extremity
Discoloration
Venous pressures ⬆
Recirculation
Blood pump speeds, KT/V, and URRs ⬇
Blood squirting around needles when cannulating
Difficulty with homeostasis postdialysis
Clue for VA stenosis

66. Percutaneous transluminal catheter angioplasty or surgical revisionIndication
Stenosis >50% of internal diameter is detected PLUS one or more
Abnormal physical examination
Previous history of thrombosis,
⇊ access flow
⇈ static IAP
Angioplasties have been required within a short period for the same lesion
surgical revision
AVF Stenosis
Handbook of Dialysis ; 5th edition

67. Stent graft versus balloon angioplasty for failing AVG
N Engl J Med. 2010 Feb 11;362(6):494-503

68. Most common complication of access losses (80%–85%)
Causes of thrombosis include
Stasis of flow
Vascular endothelial injury,
Altered blood coagulability,
Thrombosis

69. Arterial stenosis,
Fistula compression,
Hematoma formation from cannulation injury,
hypovolemia/ hypotension
hypercoagulable states
(high fibrinogen levels, reduced levels of protein S or C,
factor V Leiden mutation, lupus anticoagulant, levated
hematocrit levels due to erythropoietin therapy.
Contributing factors for VA thrombosis

70. AVF.
Percutaneous methods or surgical thrombectomy, depending on the
expertise of each institution
AVG
Thrombosis can be managed by surgical thrombectomy or by mechanical
or pharmacomechanical thrombolysis
For patients with failed thrombectomy and thrombolysis, surgical efforts
should be focused on creating a secondary fistula from the venous drainage
of graft.
Treatment of VA thrombosis
Handbook of Dialysis ; 5th edition

71. Effect of Dipyridamole plus Aspirin on AVG Patency
649 patients with a new AV graft were randomly assigned to aspirin (25 mg
twice daily) plus extended-release dipyridamole (200 mg twice daily)
Modest but significant increase in primary patency at one year (28 VS 23 %).
Both groups had a similar incidence of adverse events (bleeding)
Dixon BS, N Engl J Med. 2009; 360:2191.

72. Antiplatelet Therapy to Prevent Hemodialysis Vascular
Access Failure: Systematic Review and Meta-analysis
Am J Kidney Dis. 2013;61(1):112-122

73. Proper cannulation and decannulation
Sterile precautions for staff
Patient education
Among who high risk for AVG failure with low risk for
bleeding suggest dipyridamole plus aspirin
Not not giving warfarin/fish oil for prevention of thrombosis
and failure of an AV graft of AVF
Maintenance and thrombosis prevention
Handbook of Dialysis ; 5th edition

74. VA at upper arm or femoral fistulas more common , esp if coexistent heart
disease.
⇈ pulmonary arterial flow (associated with high-flow access) aggravate
pulmonary HT
Access flow >2,000 mL/min increase such risk
Other factors should be sought and correct
Anemia
Use of vasodilators (minoxidil, hydralazine) without beta-blocker
Hyperthyroidism
High output cardiac failure

75. MILLER banding procedure
Miller GA, et al. Kidney Int. 2010;77:359–366.

76. Hand Ischemia (Steal syndrome)

77. lead to pain, loss of function, and, rarely, loss of limb.
Mechanism arterial steal” from retrograde flow in distal artery
toward the access but the presence of arterial stenosis or distal
arteriopathy involving small vessels often are contributory.
Hx and PE ( pain, coldness, and paresthesias of distal extremity,
esp during dialysis), which can progress to cyanosis,
pulselessness, ischemic ulcers, and dry gangrene over days to
weeks to months.
Hand Ischemia (Steal syndrome)

78. Onset can be immediately after access creation or insidiously over days to
weeks.
Examination requires comparison with temperature, pulse, and function of
the opposite hand.
diagnosis is based on the clinical symptoms and signs as well as on the
demonstration of poor circulation in the extremity.
Differential diagnosis involves carpal tunnel syndrome, peripheral
vascular disease, neuropathy, nerve trauma, or ischemic monomelic
neuropathy due to the loss of blood supply to nerves.
Hand Ischemia (Steal syndrome)

79. Mild ischemia (No sensory/motor loss can be managed expectantly.
Pain of the hand on exercise due to a “steal” effect (or in extreme
instances, pain at rest) or the appearance of nonhealing ulcers
usually requires surgical intervention.
Loss of motor function of hand is a surgical emergency
Distal revascularization interval ligation procedure
Miller banding method
Management

80. complex and time-consuming procedure
possible only when a suitable vein can be
harvested. Dec
⇊ blood flow by 25%
> 10 cm distance between the proximal bypass
anastomosis and the access anastomosis
prevent retrograde diastolic flow in the graft
Distal revascularization interval ligation DRIL

81. PSEUDOANEURYSM

82. Trauma from repeated cannulation in same area
Prone to get infected or thrombosis.
Can lead to exsanguination and fatal hemorrhage.
Sign of impending rupture
thin and shiny overlying skin
prolonged leaking or ulceration over surface
rapid enlargement of aneurysm.
PSEUDOANEURYSM

83. AV grafts, there is no true expansion of the vessel lumen; the wall of the
“aneurysm,” really a pseudoaneurysm, is formed by a layer of external soft
tissue.
These should be treated by resection and insertion of an interposition graft
rapidly expanding
>12 mm in diameter
threatening the viability of the overlying skin.
Management 0f pseudoaneureysm

84. Clinical : erythema, pain, or purulent exudate from needle sites
Infected access usually requires surgical intervention for debridement or excision.
AVF. Infections are rare and usually caused by staphylococci duration is 6 weeks of
antibiotics.
Graft infection occurs in 5–20% esp. thigh grafts— higher rate of infection.
Prophylactic antimicrobials for AVG undergo procedures such as dental or GU/GI
manipulation.
Septicemia may occur without local signs. In such cases, a technetium-labeled leukocyte
scan
Silent infection in a thrombosed AV graft. elevated CRP levels and ESA resistance
Infection