This presentation is very helpful for vascular sergeons, interventional radiologists and sonographers that how to map Vasculature before construction of AV fistula for hemodialysis, how to check its patency, how to check its proper functioning ,to comment on its failure and decide when to reintervene.

1. Role of Sonographic Imaging in
management of AV Fistula
Dr. Muhammad Bin Zulfiqar
PGR IV FCPS Services Institute of Medical
Sciences / Hospital
radiombz@gmail.com
Special thanks to Samir Haffer MD

2. Role of Imaging in AV Fistula
• Anatomy
– Pictorial
– Vascular
• Preprocedure vascular mapping
• Type of AVF access for hemodialysis
• Normal doppler USG of AV fistula
• Complications

3. Abreu M. E. et. al. Upper Extremity Venous Ultrasound Doppler: Clinical Perspectives, Technical Procedures and
Pictorial Review. ECR 2013; C-2631

4. Anatomy of Upper
Limb Arteries

7. Venous Anatomy of upper Extremity
• Basilic Vein: drains medial side of upper limb and
penetrates deep fascia in lower arm to join brachial vein
• Cephalic Vein: drains lateral side of upper limb and joins
axillary vein in the infraclavicular fossa.

8. Normal Venous Flow
• Spontaneity: spontaneous flow without
augmentation
• Phasicity: Flow changes with respiration
• Compression: Transverse Plane
• Augmentation: Compression distal to site of
examination, Patency below site of examination
• Valsalva: Deep breath, strain while holding
breath, Patency above site of examination

9. Vein Compressibility
• On right side vein diameter is 5.2 mm which is
completely compressible.

10. Color doppler evaluation of cephalic vein
• Ultrasound image shows normal lumen blush
and phasicity with respiration
Mihmanli l et al. J Ultrasound Med 2001; 20:217-222

11. Preprocedure Vascular Mapping

12. Doppler Ultrasound Criteria for good
outcome
• Evaluation of nondominent arm first
• Peripheral Arteries: Diameter at least 1.6 mm
Hyperemic response
Patent palmer arch (US Allen test)
• Peripheral veins: AVF: >2mm without tourniquet
>2.5 mm with tourniquet
Graft: at least 4mm with tourniquet
• Central Veins (Indirect assessment): Respiratory Phasicity
Transmitted cardiac pulsatility
Valsalva (flow drops to baseline)

13. Measurement of Artery Diameter
Radial Artery (B Mode) Radial Artery (M Mode)
From intima to intima
Perpendicular to arterial wall
Diameter 2.2 mm
Blooming Effect
Point of artery insonated over time
Diameter at peak systole: 2.1 mm
Diameter at diastole: 2.0 mm

14. Color Doppler of Palmer Arch
Allen's Test: Ultrasound may improve accuracy
of allen’s test.

15. Veins examined from wrist to distal end of
clavicle
• Spontaneity
• Phasicity
• Compressibility
• Lumen echogenicity
• Wall irregularity
• Diameter
Mihmanli l et al. J Ultrasound Med 2001; 20:217-222

16. Central Vein Stenosis
Paget Schroetter Syndrome
Robbin ML et al. Radiology 2000; 217: 83-88

17. Central Vein Stenosis
Paget Schroetter Syndrome
• On right side monophasic flow is seen with abnormal respiratory
phasicity indirectly favoring central vein stenosis / occlusion.
• Conventional venogram confirms severe stenosis of brachiocephalic
vein at its junction with SVC. A second channel is seen adjacent to
stenosis.
• Recognition of central vein stenosis is Contraindication to use of
that extremity for AV fistula
Robbin ML et al. Radiology 2000; 217: 83-88

18. Preoperative Vascular Mapping
Recommendation of NKF-KDOQI
• Duplex sonography of upper limb vasculature
(arteries and veins) is performed in
conjunction with clinical examination in all
patients for whom AVF is being considered.
NKF—National Kidney Foundation
KDOQI—Kidney Disease Outcome Quality Institute
National Kidney Foundation Am J Kidney Dis 2006;48(Suppl.l):Sl-S322

19. Types of Arteriovenous Fistula
• Diagrams illustrate the types of arteriovenous anastomosis,
with the radial artery and cephalic vein at the wrist being the
most commonly used vessels. Arrows indicate direction of
flow. A = side of artery to side of vein (the most common
anastomosis), B = end of artery to side of vein, C = end of vein
to side of artery, D = end of artery to end of vein.
Finlay DE et al. RadioGraphics 1993;13:983-999

21. Types of AV Bridge Grafts
Diagrams illustrate the types of
arteriovenous bridge grafts, with
the grafts shown in purple. A =
artery, V = vein.
(a) Straight radial artery to an
antecubital vein (venous
anastomosis may be made to any
suitable vein in the antecubital
fossa).
(b) Forearm loop, with the brachial
artery to an antecubital vein.
(c) Straight brachial artery to the
brachial vein.
(d) Thigh “loop,” with the superficial
femoral artery to the greater
saphenous vein.
Finlay DE et al. RadioGraphics 1993;13:983-999

24. Normal Doppler USG in AV Fistulas
• Feeding Artery Monophasic flow
Large diastolic component
• Anastomosis Perivascular tissue vibration
Very turbulent flow over long stretch
• Draining vein Pulsatile Flow (arterialized vein)
• Volume Flow >500ml/min
Dilatation of feeding artery &draining vein after
several years.

25. Normal Doppler USG in AV Fistulas
• Monophasic flow with
large diastolic component
is seen in Brachial Artery
limb of fistula.
• Arterialized flow is seen in
Basilic Vein limb of fistula
Ker SF et al. Radiol 2010;65:744-749

26. Measurement of flow volume
Volume = Cross sectional area x Mean velocity x 60
(ml/min) (cm square) (cm/sec)

28. 3000

29. Routine Surveillance in asymptomatic
patients
• Routine surveillance can be done by
combination of clinical examination, direct
flow measurement and duplex US.
• When stenosis > 50% with hemodynamic and
clinical abnormalities angioplasty is
recommended.
NKF—National Kidney Foundation
KDOQI—Kidney Disease Outcome Quality Institute
National Kidney Foundation Am J Kidney Dis 2006;48(Suppl.l):Sl-S322

30. Mature Fistula Sonographic Evaluation
• Doppler US exam is performed at 6-8 weeks
after procedure.
• Criteria:
– Ap dimeter of draining vein At least 4 mm
– Distance from skin to ant wall Less than 5 mm
– Flow volume At least 500 ml/min
• Criteria are different for clinically mature
fistula.

31. Causes Of Immature Fistula
Stenosis at or near the fistula
Angioplasty—Surgical correction
One or more accessory veins
Ligation
Deep draining vein
Fistula surgically placed in a more superficial soft
tissue
Immature fistula can be converted into usable
fistula with correction of underlying problem
Singh, P. et al. Radiology 2007;246:299-305

32. Mature fistula good diameter good depth
• Us transverse image demonstrates AP
diameter of draining vein is 6.6 mm and
distance from skin to anterior vein wall is 4.8
mm
Singh, P. et al. Radiology 2007;246:299-305

33. Immature Fistula with Large accessory vein
• A large accessory vein is seen which hinders
maturation of fistula.
• We have to search for all accessory veins within first 10
cm of anastomosis.
Singh, P. et al. Radiology 2007;246:299-305

35. Complications of AV Fistula
• Stenosis and Occlusion
• Aneurysm and Pseudoaneurysm
• Infected and non infected collections
– Hematoma
– Seroma
– Lymphocele
• Arterial steel syndrome
• High cardiac output failure

36. Intimal Hyperplasia with Venous Stasis
• Power doppler US image shows venous stasis
3 cm from intimal hyperplastic vascular
segment.

37. US doppler criteria for significant stenosis
(more than 50% diameter reduction)
• US criteria Percentage of diameter reduction
• Color criteria Pronounced aliasing at site of stenosis
• Duplex criteria PSV ratio
PSV should not be interpreted in isolation

38. Measurement of luminal diameter reduction

39. Duplex criteria for significant stenosis (>50%)
• Direct signs
Feeding artery PSV ratio > 2
Anastomosis PSV ratio > 3 – PSV >400 cm/sec
Draining vein PSV ratio > 3 – PSV >300 cm/sec
• Indirect signs
Flow volume < 250ml/min
Proximal High resistance flow (RI > 0.70)
Distal Delayed systolic upstroke

40. PSV Ratio
Proximal: 2 cm proximal to stenosis
Stenosis: same doppler angle if possible

44. Aneurysm
May develop in long standing functional AV fistula
• Good function Lumen not filled with thrombus
Intact skin
• Intervention Intraluminal thrombus
rarely needed Compromise of overlying skin
Steadily and rapidly enlarged
Obstructive kinks
• Operation Proximal A-V access of arterialized vein
Prosthetic graft

45. True Venous Aneurysm
Diffuse Aneurysmal Dilatation

46. Pseudoaneurysm

47. Hematoma
• AV access punctured thrice weekly for hemodialysis.
• Serial examinations are required to monitor evolution
of hematoma
Kerr SF et al. Clin Radiol2010;65:P744-749

49. Radial Artery Stenosis
• Ulnar artery flow contributes to fistula flow via palmer
arches
• Retrograde flow in distal radial artery
Finlay De et al. Radiographics 1993;13:983-999

50. Radial arterial steal
Frequent in asymptomatic patients
• Fistula supplied by proximal radial artery(red, antegrade flow)
• Fistula supplied by distal radial artery (blue, retrograde flow)

51. High cardiac output failure
Symptom Symptoms of right heart failure
Nicoladni-Branham sign: dec PR after AVF occlusion
Diagnosis Flow volume >3L/min
Flow volume/cardiac output>30%(screening)
Cardiac output>2.3 L/min/m₂
Sine qua none; improvement after treatment
Treatment Ligation: sacrifice of access
Banding: more attractive option

52. Take Home Message
• Doppler USG and clinical findings helps in long
term management of fistula
• Its management is multidisciplinary:
Nephrologist, Vascular Surgeon, Interventional
Radiologist
• Stenosis in early postop period may be due to
edema
• Doppler USG is central to prevention,
detection and management of complications.

53. THANK YOU