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Doppler ultrasound of A-V access for hemodialysis

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Doppler ultrasound of A-V access for hemodialysis

  1. 1. Doppler US of A-V access for hemodialysis Samir Haffar M.D. Department of Internal Medicine Al-Mouassat University Hospital – Damascus – Syria
  2. 2. Doppler US of A-V access for hemodialysis  Normal Doppler US of upper extremity  Preoperative US vascular mapping  Type of A-V access for hemodialysis  Normal Doppler US of A-V access for hemodialysis  Routine surveillance in asymptomatic patients  Complications of A-V access for hemodialysis  Conclusion
  3. 3. Doppler US of A-V access for hemodialysis  Normal Doppler US of upper extremity  Preoperative US vascular mapping  Type of A-V access for hemodialysis  Normal Doppler US of A-V access for hemodialysis  Routine surveillance in asymptomatic patients  Complications of A-V access for hemodialysis  Conclusion
  4. 4. Anatomy of aortic arch & subclavian artery Right SCA originates from innominate (brachiocephalic) artery Left SCA originates directly from aortic arch SCA has several branches: VA & mammary (internal thoracic) artery Thrush A et al. Peripheral vascular ultrasound. Elsevier Churchill Livingstone, 2nd edition, 2005.
  5. 5. Arterial anatomy of upper extremity Thrush A et al. Peripheral vascular ultrasound. Elsevier Churchill Livingstone, 2nd edition, 2005. LSA Common origin with CCA from A BA High bifurcation of brachial artery RA High origin from axillary artery UA High origin from axillary artery Anatomical variations
  6. 6. Normal brachial artery Deklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646. Diameter from intima to intima Perpendicular to arterial wall Sagittal US scan Sagittal color Doppler Homogenous velocities Good visualisation of arterial bords
  7. 7. Normal duplex US of peripheral arteries High resistance flow Normal brachial arteryTriphasic flow
  8. 8. Venous anatomy of upper extremity Deklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646. Superficial system Basilic vein Drains medial side of upper limb Penetrates fascia in lower arm to join brachial vein Cephalic vein Drains lateral side of upper limb Join axillary vein in infraclavicular region
  9. 9. 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
  10. 10. Vein compressibility Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749. Compression Regular thin wall Diameter: 5.2 mm Basilic vein Vein fully compressed Basilic vein
  11. 11. Color & pulsed Doppler of cephalic vein Mihmanli I et al. J Ultrasound Med 2001 ; 20 : 217 – 222. Normal lumen blush Normal respiratory phasicity
  12. 12. Doppler US of A-V access for hemodialysis  Normal Doppler US of upper extremity  Preoperative US vascular mapping  Type of A-V access for hemodialysis  Normal Doppler US of A-V access for hemodialysis  Routine surveillance in asymptomatic patients  Complications of A-V access for hemodialysis  Conclusion
  13. 13. Doppler US criteria for good outcome Evaluation of nondominant arm first • Peripheral arteries Diameter at least 1.6 mm Hyperemic response Patent palmar arch (US Allen test) • Peripheral veins AVF: ≥ 2 mm without tourniquet ≥ 2.5 mm with tourniquet Graft: at least 4 mm with tourniquet • Central veins Respiratory phasicity “indirect assessment” Transmitted cardiac pulsatility Valsalva (flow drops to baseline) Silva MB et al. J Vasc Surg 1998 ; 27 : 302 – 308. Robbin ML et al. Radiology 2000 ; 217 : 83 – 88.
  14. 14. Measurement of artery diameter Ferring M et al. Nephrol Dial Transplant 2008 ; 23 : 1809 – 1815. Radial artery (M mode) Point of artery insonated over time Diameter at peak systole: 2.1 mm Diameter in diastole: 2 mm From intima to intima Perpendicular to arterial wall Diameter: 2.2 mm Radial artery (B mode) Blooming effect
  15. 15. Arterial hyperemic response Useful to predict risk of arterial steal Wiese P et al. Nephrol Dial Transplant 2004 ; 19 : 1956 – 1963. Clenched fist (3 min) : high-resistance flow (triphasic) Released fist : low-resistance flow (monophasic) & RI < 0.70 Failure of such response regarded as CI to AVF
  16. 16. Pourcelot’s resistance index Resistance Index (RI): Systolic – End Diastolic / Systolic
  17. 17. Color Doppler of the palmar arch Reversed flow Flow via ulnar artery Occlusion of radial artery while imaging arch Color Doppler of palmar artery Mozersky DJ et al. Am J Surg. 1973 ; 126 : 810 – 812. Levitov A et. Critical care ultrasonography. McGraw-Hill Medical, NY, USA, 2009. US may may improve accuracy of Allen’s test First reported in 1973
  18. 18. Radial artery at wrist Segmental occlusive lesions Calcified wall with marked shadowing Parmley MC et al. Am J Surg 2002 ; 184 : 568 – 572.
  19. 19. Spontaneity Phasicity Compressibility Lumen echogenicity Wall irregularity Diameter Veins examined from wrist to distal end of clavicle Mihmanli I et al. J Ultrasound Med 2001 ; 20 : 217 – 222.
  20. 20. Cephalic vein wall Marked wall irregularity Wall thickening especially on posterior side Mihmanli I et al. J Ultrasound Med 2001 ; 20 : 217 – 222.
  21. 21. Robbin ML et al. Radiology 2000 ; 217 : 83 – 88. Normal caliber of SCV 50% stenosis of BCV Corresponding venogram Abnormal respiratory phasicity No decrease to baseline with inspiration Doppler US of patent SCV Central vein stenosis Paget Schroetter syndrome
  22. 22. Central vein stenosis Paget Schroetter syndrome Robbin ML et al. Radiology 2000 ; 217 : 83 – 88. Doppler US of patent SCV Abnormal respiratory phasicity Monophasic flow Suspicion of CV stenosis/occlusion Corresponding venogram Severe stenosis of BCV at its junction with SMV Second channel adjacent to stenosis Recognition of central vein stenosis is CI to use of that extremity
  23. 23. Upper extremity arterial mapping Brown PWG. Eur J Vasc Endovasc Surg 2006 ; 31 : 64 – 69.
  24. 24. Upper extremity vein mapping Cephalic vein Mendes RR et al. J Vasc Surg 2002 ; 36 : 460 – 3. Eight representative measurement sites of CV: Diameter with & without tourniquet Depth from skin
  25. 25. Preoperative vascular mapping Robbin ML et al. Radiology 2000 ; 217 : 83 – 88. 50-year-old man with nonpalpable cephalic vein in wrist Scheduled to receive forearm graft Transverse cephalic veinRadial artery at wrist 3.7 mm Wrist 2.8 mm Middle forearm 2.7 mm Antecubital area 2.8 mm Adequate diameters for AVF placement
  26. 26. Preoperative vascular mapping Duplex sonography of upper limb arteries & veins performed in conjunction with clinical examination in all patients for whom an AVF is being considered * National Kidney Foundation’s Kidney Disease Outcomes Quality Initiative National Kidney Foundation. Am J Kidney Dis 2006 ; 48(Suppl. 1) : S1 – S322. Recommendations of NKF-KDOQI*
  27. 27. Doppler US of A-V access for hemodialysis  Normal Doppler US of upper extremity  Preoperative US vascular mapping  Type of A-V access for hemodialysis  Normal Doppler US of A-V access for hemodialysis  Routine surveillance in asymptomatic patients  Complications of A-V access for hemodialysis  Conclusion
  28. 28. Brescia-Cimino A-V fistula Brescia MJ, Cimino JE, Appel K, et al. N Engl J Med 1966 ; 275 : 1089 – 92. Side of artery to end of vein At anatomical snuffbox or wrist Surgeons who invented AVF: Brescia, Cimino, & Appel Most commonly used
  29. 29. Types of Arterio-Venous Fistula Finlay DE et al. RadioGraphics 1993 ; 13 : 983 – 999. Side of artery to side of vein End of artery to side of vein Side of artery to end of vein Brescia-Cimino AVF End of artery to end of vein
  30. 30. Types of A-V grafts (PTFE – Polyurethane ) Curr Probl Surg 2011 ; 48 : 443 – 517. Forearm Barachial artery to brachial vein “Loop graft” Upper arm Radial artery to axillary vein “Straight graft”
  31. 31. A-V access for hemodialysis in preferential order Type Description  Forearm AVF Radial artery to cephalic vein Radial artery to basilic vein Radial artery to other suitable vein (transposition*) AVF placement preferable to graft placement Nondominant arm is preferred site for access placement * Transposition AVFs placed in veins other than cephalic vein Robbin ML et al. Radiology 2000 ; 217 : 83 – 88.  Upper arm AVF Brachial artery to cephalic vein Brachial artery to basilic vein Brachial artery to other suitable vein (transposition*)  Forearm graft Brachial artery & antecubital vein (loop graft)  Upper arm graft Brachial artery & high brachial or basilic vein  Thigh graft CFA to CFV
  32. 32. Distribution of AVF & graft use in Europe & the United States Huijbregts HJ et al. Eur J Vasc Endovasc Surg 2006 ; 31 : 284 – 287. Following percentiles of each distribution provided for the 10th, 25th, 50th (median), 75th, & 90th percentiles
  33. 33. Radio-cephalic fistula at wrist MA (8 prospective & 30 retrospective studies – 4579pts) High primary failure rate Moderate patency rates at 1 year of follow-up * Sidawy AN et al. J Vasc Surg 2002 ; 35 : 603 – 610. Rooijens PP et al. Eur J Vasc Endovasc Surg 2004 ; 28 : 583 – 589. • Primary failure rate* Thrombosis or failure to mature at 6 weeks 15.3% (95% CI: 12.7 – 18.3%) [from 10% to 30%] • Primary patency rate at 1 year of follow-up* From creation until intervention to maintain or re-establish patency, thrombosis or time of patency measurement 62.5% (95% CI: 54.0 – 70.3%)
  34. 34. Doppler US of A-V access for hemodialysis  Normal Doppler US of upper extremity  Preoperative US vascular mapping  Type of A-V access for hemodialysis  Normal Doppler US of A-V access for hemodialysis  Routine surveillance in asymptomatic patients  Complications of A-V access for hemodialysis  Conclusion
  35. 35. Doppler US of A-V access for hemodialysis Abundant gel & minimal pressure on skin Longitudinal & transverse scan from feeding artery to anastomosis Longitudinal & transverse scan from draining vein as far as possible Perivascular space: functional stenosis from abscess, hematoma, seroma Edenberg Jan et al. Tidsskr Nor Legeforen nr. 2009 ; 129 : 1635 – 8.
  36. 36. Normal Doppler US in AVFs • 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 > 500 mL/min Dilatation of feeding artery & draining vein after several years of use Schäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011.
  37. 37. Normal Doppler US in AVFs Brachio-basilic fistula Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749. Brachial artery Monophasic flow Large diastolic component Brachio-basilic fistula Arterialized vein
  38. 38. Doppler US of polyurethane graft Three-layered material – Cannulation within 24 h Wiese P et al. Nephrol Dial Transplant 2003 ; 18 : 1397 – 1400. 1 year follow-up Signal from whole graft Early post-operative Strong reflection from graft 1 year follow-up Signal at site of single cannulation 1 year follow-up Signal at sites of repeat cannulation
  39. 39. Volume = Cross-sectional area . Mean velocity . 60 (mL/min) (cm2) (cm/sec) Cross-sectional area (cm2): π d2 / 4 d: diameter Measurement of flow volume Hoskins P et al. Diagnostic US: physics and equipment. Cambridge university press, Cambridge, UK. 2nd ed, 2010.
  40. 40. Place of flow volume measurement • Arteriovenous fistula Feeding artery Brachial artery in middle upper arm Recommended by some authors Within fistula Turbulent flow (spectral broadening) Draining vein Abrupt change in diameter in older AFV Changes in lumen shape (elliptical) Recommended by other authors • Graft Investigated along the entire access Schäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011.
  41. 41. Measurement of flow volume /Feeding artery Diameter perpendicular to axis Sample volume across width of vessel Sample volume in same site of diameter measurement Correct estimation of angle TAMV: 3 – 5 cardiac cycles Deklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646.
  42. 42. Measurement of flow volume in feeding artery Deklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646. Normal flow in distal radial artery Flow volume (fistula open) – Flow volume (fistula closed) Normal volume in upper limb: 100 mL/min (neglected) Reversed flow in distal radial artery Flow volume (proximal a) + Flow volume (distal a)
  43. 43. Sources of error in volume measurement • Diameter Measuring accuracy (blooming effect) Main source Assumption of circular cross-section Variation during cardiac cycle Variation during respiration (veins) • Doppler angle As small as possible & < 60 Box steering & transducer shifting • Mean velocity Setting of transmitted & received gain Over or underestimation Schäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin, 2nd edition, 2011.
  44. 44. Error percentage in volume measurements & vessel diameter Schäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011. Errors ranging from 0.2 to 1.0 mm
  45. 45. Doppler phenomenon? Doppler shift frequency (fd): ft – fr Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when. Elsevier Churchill Livingstone, London, 2nd edition, 2005. ft fr ∆ F = 2 F0 V Cos Ө / C
  46. 46. Angle of insonation & Doppler effect Kim Min Ju et al. Curr Probl Diagn Radiol 2009 ; 38 : 53 – 60. Angles between 30 to 60 usually used for Doppler acquisition
  47. 47. Error percentage in velocity measurements & angle of insonation Angle of insonation > 60 should not be used
  48. 48. Doppler angle correction in AVF Pieturaa R et al. Eur J Radiol 2005 ; 55 : 113 – 119.
  49. 49. Adjusting spectral Doppler gain Gain setting too low Correct gain setting Gain setting too high Kruskal JB et al.RadioGraphics 2004 ; 24 : 657 – 675.
  50. 50. Tips for volume flow measurement • Avoid significant turbulence (circular flow) • Accurate determination of vessel diameter • Adequate insonation angle (≤ 60⁰) • Sample volume covers entire area of vessel • No significant diversion of blood through accessory vein • Flow determined in feeding artery if complex vein anatomy • Various algorithms used by manufacturers (by up to 30%) Gelbfish GA. Tech Vasc Interventional Rad 2008 ; 11 : 156 – 166. Slight errors in one parameter lead to erroneous numbers
  51. 51. Interpretation of fistula flow volume A-V access for hemodialysis Flow volume (mL/min) Normal value Forearm fistula Upper arm fistula 600 – 800 900 – 1200 Schäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011. Mature fistula ≥ 500 High risk of occlusion AVF Graft < 300 < 650 High-output cardiac failure Adult Children > 3.000 > 700
  52. 52. Doppler US of A-V access for hemodialysis  Normal Doppler US of upper extremity  Type of A-V access for hemodialysis  Preoperative US vascular mapping  Normal Doppler US of A-V access for hemodialysis  Routine surveillance in asymptomatic patients “Mature fistula”  Complications of A-V access for hemodialysis  Conclusion
  53. 53. Causes of immature fistula  Stenosis at or near the fistula Angioplasty – surgical revision  One or more accessory veins Ligation  Deep draining vein Fistula surgically placed in more superficial soft tissues Immature fistula can be converted into usable fistula with correction of underlying problem Singh P et al. Radiology 2008 ; 246 : 299 – 305.
  54. 54. Sonographically mature fistula Doppler US exam 6 – 8 weeks after surgery • AP diameter of draining vein At least 4 mm • Distance from skin to anterior wall Less than 5 mm • Flow volume At least 500 mL/min Robbin ML. Radiology 2002 ; 225 : 59 – 64. Singh P et al. Radiology 2008 ; 246 : 299 – 305. Should meet the 3 following criteria Criteria different from clinically mature fistula
  55. 55. Doppler US for routine surveillance • AP diameter of draining vein in transverse scan Usually thin wall: cursors within vein walls • Distance from skin to anterior wall of draining vein • Veins branching off within first 10 cm of anastomosis AP diameter & distance from anastomosis • Flow volume Straight segment of artery or vein Repeat 3 – 5 times with average Singh P et al. Radiology 2008 ; 246 : 299 – 305.
  56. 56. Mature fistula/Good diameter & depth Anteroposterior diameter of draining vein: 6 mm Distance from skin surface to anterior vein wall: 4.8 mm Singh P et al. Radiology 2008 ; 246 : 299 – 305. Transverse US of draining vein
  57. 57. Mature fistula/Good flow volume Brachio-basilic fistula Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749. Diameter: 7.9 mm TAMV: 93.2 cm/sec over 3 cardiac cycles Flow volume: 2.741 mL/min
  58. 58. Immature fistula/Large accessory vein Singh P et al. Radiology 2008 ; 246 : 299 – 305. Large accessory vein which may limit maturation of fistula Search for all accessory veins within first 10 cm of anastomosis Transverse US of draining vein
  59. 59. Immature fistula/Small & deep vein Draining vein Vein too small (3.1 mm) Vein too deep (7.6 mm) Singh P et al. Radiology 2008 ; 246 : 299 – 305.
  60. 60. Immature fistula/Low flow volume Radio-cephalic fistula Left radial artery Flow volume : 86 mL/min Left cephalic vein Flow volume : 130 mL/min Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.
  61. 61. Routine surveillance in asymptomatic patients No RCTs of Doppler surveillance in this setting Routine surveillance by combination of clinical examination, direct flow measurement, & duplex US should be performed When stenosis > 50% is accompanied by hemodynamic or clinical abnormalities, angioplasty is recommended * National Kidney Foundation’s Kidney Disease Outcomes Quality Initiative National Kidney Foundation. Am J Kidney Dis 2006 ; 48(Suppl. 1) : S1 – S322. Recommendations of NKF-KDOQI*
  62. 62. Doppler US of A-V access for hemodialysis  Normal Doppler US of upper extremity  Type of A-V access for hemodialysis  Preoperative US vascular mapping  Normal Doppler US of A-V access for hemodialysis  Routine surveillance in asymptomatic patients  Complications of A-V access for hemodialysis  Conclusion
  63. 63. Complications of A-V access for hemodialysis  Stenosis & occlusion  Aneurysm & pseudoaneurysm  Arterial steal syndrome  High-output cardiac failure Hematoma Seroma Lymphocele  Infected & non-infected collections
  64. 64. Mechanisms & sites of stenosis • AVF Feeding artery Atherosclerosis (SC, axillary) • Graft Intimal hyperlplasia (shear stress) Anastomosis between graft & vein Draining vein Intimal hyperplasia (valves) Puncture-induced dissection Proximal – distal Anastomosis Turbulence (most common) Central veins Catheters (SC, axillary) Schäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011.
  65. 65. Venous stenosis from intimal hyperplasia Edenberg Jan et al. Tidsskr Nor Legeforen nr. 2009 ; 129 : 1635 – 8. Venous stenosis 3 cm from anastomosis Power Doppler ultrasound
  66. 66. US Doppler criteria for significant stenosis (> 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
  67. 67. Measurement of luminal diameter reduction Edenberg Jan et al. Tidsskr Nor Legeforen nr. 2009 ; 129 : 1635 – 8. Wiese P et al. Nephrol Dial Transplant 2004 ; 19 : 1956 – 1963. Residual lumen 1.1 mmOriginal lumen 5.1 mm 78 % diameter stenosis Original lumen – Residual lumen x 100% of diameter stenosis Original lumen =
  68. 68. Color criteria of significant stenosis Pronounced aliasing at site of stenosis Junction of basilic & axillary vein
  69. 69. 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 < 250 mL/min Proximal High-resistance flow (RI > 0.70) Distal Delayed systolic upstroke * Flow volume adequate for hemodialysis Schäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin, 2nd edition, 2011.
  70. 70. PSV ratio Robbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131. Proximal: 2 cm proximal to stenosis Stenosis: same Doppler angle if possible
  71. 71. Significant stenosis of AVF at anastomosis Radio-cephalic fistula PSV ratio: 3.4 Arterio-venous anastomosis PSV: 438 cm/s Radial artery PSV: 130 cm/s Grogan J et al. J Vasc Surg 2005 ; 41 : 1000 – 6.
  72. 72. Proximal venous stenosis Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749. Pronounced aliasing at site of stenosis Peak Systolic Velocity: 610 cm/s Cephalic vein – Mid upper arm
  73. 73. Distal venous stenosis Deklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646. Pronounced aliasing at site of stenosis Peak Systolic Velocity: 340 cm/s Junction of basilic & axillary vein
  74. 74. Stenosis of graft insertion on vein Deklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646. Rail aspect of the graft Aliasing on color Doppler Peak Systolic Velocity : 400 cm / s
  75. 75. Pseudo-diagnosis of significant stenosis Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749. PSV: 570 cm/sec Brachio-basilic fistulaBrachial artery PSV: 350 cm/sec Volume flow:1.1 L/min High inflow Basilic vein PSV: 175 cm/sec Volume flow:1.8 L/min High outflow High PSV in anastomosis due to high flow volume & large vessels
  76. 76. Occlusion of brachiocephalic fistula Triphasic waveform RI = 1 (thrombosed fistula) Brachial artery Occlusion of fistula Thrombus within draining vein Brachio-cephalic fistula Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.
  77. 77. Thrombosis in draining vein of AVF Edenberg Jan et al. Tidsskr Nor Legeforen nr. 2009 ; 129 : 1635 – 8. Pieturaa R et al. Eur J Radiol 2005 ; 55 : 113 – 119. Complete thrombosis Partial thrombosis
  78. 78. Complications of A-V access for hemodialysis  Stenosis & occlusion  Aneurysm & pseudoaneurysm  Arterial steal syndrome  High-output cardiac failure Hematoma Seroma Lymphocele  Infected & non-infected collections
  79. 79. Aneurysm Develops in AVF functioning for many years • Good function Lumen not filled with thrombus Intact skin • Intervention Intra-luminal thrombus rarely needed Compromise of overlying skin Steadily & rapidly enlarged Obstructive kinks • Operation Proximal A-V access of arterialized vein Prosthetic graft Padberg FT et al. J Vasc Surg 2008 ; 48 : 55S – 80S.
  80. 80. Diffuse aneurysmal dilation Schäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011. Secondary to wall degeneration or downstream stenosis Feeding artery Draining vein Anastomosis
  81. 81. True venous aneurysm Diffuse aneurysmal dilation Bourquelot P et al. Nephrol Ther 2009 ; 5 : 239 – 248. Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749. Raise concern from the staff Radio-cephalic AVF Color Doppler US
  82. 82. Pseudoaneurysm • Incidence 2 – 10 % during functional life of graft Less frequent in AVF • Doppler US Color Doppler: “yin -yang pattern” Pulsed Doppler: “to-and-fro waveform” Perianeurysmal fluid collection suggest infection • Location Puncture site Observation if small & stable Treatment if expanding Anastomotic Generally requires surgery Infection is common cause Padberg FT et al. J Vasc Surg 2008 ; 48 : 55S – 80S.
  83. 83. Anastomotic pseudoaneurysm on A-V graft Kabalci YM et al. Transplant Proc 2006 ; 38 : 2816 – 2818. Brachio-basilic graft 2 months ago Anastomotic pseudoaneurysm of graft is rare
  84. 84. Pseudoaneurysm Color Doppler “yin -yang pattern” Pulsed Doppler “to-and-fro waveform” Schäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011.
  85. 85. Perivascular space with pulsatile flow Bidirectional blood flow Typical “yin-yang sign” Pseudoaneurysm of radial artery Color duplex US Thrombin injection under US control Complete thrombosis after thrombin injection Carrafiello G et al. Injury Extra 2006 ; 37 : 78 – 81.
  86. 86. Complications of A-V access for hemodialysis  Stenosis & occlusion  Aneurysm & pseudoaneurysm  Arterial steal syndrome  High-output cardiac failure Hematoma Seroma Lymphocele  Infected & non-infected collections
  87. 87. Hematoma Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749. AV access punctured thrice weekly for hemodialysis Serial examinations to monitor evolution of hematoma
  88. 88. Complications of A-V access for hemodialysis  Stenosis & occlusion  Aneurysm & pseudoaneurysm  Arterial steal syndrome  High-output cardiac failure Hematoma Seroma Lymphocele  Infected & non-infected collections
  89. 89. Radial artery steal Finlay DE et al. RadioGraphics 1993 ; 13 : 983 – 999. Ulnar artery flow contributes to fistula flow via palmar arches Retrograde flow in distal radial artery
  90. 90. Arterial steal syndrome Clinical diagnosis – Incidence (1 – 4 %) • Risk factor Brachial arterial, DM, female gender • Symptoms Steal phenomenon Silent (70% of RC-AVF) Steal syndrome Mild: pain during dialysis Severe: rest pain, ulceration Common cause of neuropathy • Doppler US Reversed flow: complete – only in diastole Dynamic study: gentle compression of AVF • Treatment Ligation, banding, rerouting Padberg FT et al. J Vasc Surg 2008 ; 48 : 55S – 80S.
  91. 91. Radial arterial steal Frequent in asymptomatic patients Wiese P et al. Nephrol Dial Transplant 2004 ; 19 : 1956 – 1963. Fistula supplied by proximal radial artery (red, antegrade flow) Fistula supplied by distal radial artery (blue, retrograde flow)
  92. 92. Reversed flow in distal RA after AVF Goldfeld M et al. AJR 2000 ; 175 : 513 – 516. Reversed flow during entire cardiac phase
  93. 93. Arterial steal syndrome Radial-cephalic fistula Yilmaz C et al. AJR 2009 ; 193 : W567. RA distal to anastomosis Antegrade flow during systole Retrograde flow during diastole Gentle compression of fistula Restoration of antegrade flow Elevated systolic flow Elevated diastolic flowBidirectional flow
  94. 94. Hand ischemia in A-V access for hemodialysis • Arterial steal syndrome Most common • Proximal arterial stenosis Overlooked • Atherosclerosis in hand & forearm Arteriography • Regional venous hypertension • Emboli of thrombosed A-V access Doppler US Padberg FT et al. J Vasc Surg 2008 ; 48 : 55S – 80S.
  95. 95. Digital ischemia from emboli of thrombosed AVF 7 reported cases in the literature Journet J et al. Néphrologie & Thérapeutique 2010 ; 6 : 121 – 124. Digital ischemia 4 fingers of right hand Regression of ishemia 6 mth after operation Partial thrombosis of RC-AVF
  96. 96. Complications of A-V access for hemodialysis  Stenosis & occlusion  Aneurysm & pseudoaneurysm  Arterial steal syndrome  High-output cardiac failure Hematoma Seroma Lymphocele  Infected & non-infected collections
  97. 97. High-output cardiac failure Rare &unusual complication • Symptom Symptoms of right heart failure Nicoladoni-Branham sign: ↓ PR after AVF occlusion • Diagnosis Flow volume > 3 L/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 Padberg FT et al. J Vasc Surg 2008 ; 48 : 55S – 80S.
  98. 98. Conclusion • Doppler uplex US should be interpreted in conjunction with clinical findings including adequacy of dialysis • Results should be discussed within multidisciplinary team: Nephrologist, vascular surgeon, & interventional radiologist • Stenosis in early postop period interpreted with caution They may be secondary to transient edema • Duplex sonography is central to prevention, detection, and management of complications Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.
  99. 99. References 1. Kerr SF et al. Duplex sonography in the planning & evaluation of arteriovenous fistula for hemodialysis Clin Radiol 2010;65:744-749. 2. Wiese P et al. Color Doppler ultrasound in dialysis access. Nephrol Dial Transplant 2004;19:1956-1963. 3. Padberg FT et al. Complications of arteriovenous hemodialysis access: recognition and management. J Vasc Surg 2008;48:55S-80S. 4. Konner K et al. The arteriovenous fistula. J Am Soc Nephrol 2003; 14:1669-1680. 5. Pieturaa R et al. Color Doppler ultrasound assessment of well- functioning mature arteriovenous fistulas for haemodialysis access. Eur J Radiol 2005;55:113-119. 6. Deklunder G et al. Exploration des vaisseaux du membre supérieur: Doppler et échotomographie. EMC-Radiologie 2004;1:632-646.
  100. 100. Thank You

Notas del editor

  • The arm develops good collateral circulation around diseased segments.Subclavian artery diameter: 0.6 - 1.1 cmAxillary artery diameter of : 0.6 - 0.8 cm Deep brachial: divides from main trunk of brachial artery in upper arm &amp; acts as collateral around elbow if brachial artery occluded distally.Common interosseous artery: important branch of ulnar artery in upper forearm &amp; act as collateral if radial &amp; ulnar arteries are occluded.The radial artery supplies deep palmar arch in the hand, and ulnar artery supplies superficial palmar arch.There are usually communicating arteries between the two systems.In some people only one of the wrist arteries will supply the palm arch system.The fingers are supplied by the palmar digital arteries
  • Blush: تورد احمرار
  • Vein diameters have considerable day-to-day variation and depend on examination conditions (ambient temperature and patient position). Therefore, veins should be evaluated under optimal conditions &amp; venous distensibility tested in the case of apparently small veins.
  • The Doppler spectrum, especially at reactive hyperaemia useful to predict the risk of low flow steal
  • In 1929, Dr. Edgar van Nuys Allen described a maneuver in which the dual palmar circulation could be tested by obstructing both radial and ulnar arterial flow, then releasing either ulnar or radial to see if palmar circulation was restored. Compression of both radial and ulnar arteries is used while the fist is clenched, then the fist is relaxed revealing blanched palm. For the test results to be defined as positive for radial artery insufficiency, the blanching continues 5 seconds or more after release of radial artery compression while the ulnar artery compression continues. For the test results to be defined as positive the ulnar artery insufficiency,blanching continues 5 seconds or more after release of ulnar artery compression while the radial artery compression continues.The importance of this test is to ascertain the duality of the circulation, so that if one of the arteries was obstructed (from thrombus or spasm after puncture), the palmar circulation would not be compromised. Although there is some debate as to the value of Allen’s test in predicting who is at risk of hand ischemia, the test continues to be performed on a routine basis, especially in the setting of radial artery harvesting for coronary bypass grafting.
  • Measurements of the vein diameter were recorded from the ultrasound scan images at eight representative sites:the wrist, distal forearm, mid forearm, proximal forearm, antecubital fossa, distal upper arm, mid upper arm, and proximal upper arm.
  • The ground-breaking article by Brescia and Cimino in 1966 revolutionized the creation of the vascular access, and the Cimino fistula was soon used in almost all dialysis patients.To minimize the risk of hand ischemia, candidates for a radialcephalic AV fistula should have a normal preoperative Allen’s test to confirm a patent palmar arch.
  • All these techniques have advantages and disadvantages.
  • Poly Tetra Fluoro Ethylene (PTFE):Maturation period of 2–3 weeks for primary cannulation.Polyurethane:Three-layered polyurethane material. It is claimed that solid non-permeable medial layer has self-sealing properties, allowing a cannulation within 24 hafter implantation.Similar patency rates compared with ePTFE grafts
  • PTFE grafts currently account for 80% of primary vascular accesses created in the United States, but they are less frequently used in other countries. It has been increasingly recognized that outcomes of PTFE grafts are poorer.
  • Doppler spectrum showing the measurement of PSV &amp; EDV.Mean velocity can be calculated from the Doppler spectrum, displayed by the black line. A large sample volume allow the blood velocity at anterior and posterior walls, as well as in center of the vessel, to be estimated but may not detect the flow along the lateral wall. Time-averaged mean velocity (TAM) can be found by averaging the mean velocity over one or more complete cardiac cycles. Volume flow can be calculated by multiplying the TAM measurement by the cross-sectional area of the vessel.Reference:Thrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when.Elsevier Churchill Livingstone, London, 2nd edition, 2005.
  • Bloom: يزدهر - ينتفخIn B-mode images, the vessel walls appear larger than their true anatomic size. This is due to the so-called blooming effect resulting from strong reflection of the ultrasound beam at the boundary between tissues of different acoustic impedance. The measurement errors can be minimized and systematized by using the leading-edge method and a low gain. Using the leading-edge method, the diameter is measured from the reflection of the outer wall to that of the oppositeinner wall
  • The larger the angle of insonation, the greater the potential source of error in velocity measurement.
  • c’est l’évolution du débit au cours de mesures successives, plus que sa valeur absolue au cours d’un examen, qui est importante.
  • In the US, hemodialysis is typically performed at a dialysis blood flow rate of 350–450 mL/min for 3.5–4 hours three times/week.Flow volume At least 500 mL/minFlow withdrawn at hemodialysis 350 mL/minFlow to keep the fistula patent 150 mL/min
  • Several investigators have suggested that duplex sonography could also be valuable in the routine surveillance of fistulae in asymptomatic patients based on the premise that the timely treatment of stenosis should help not only to prevent occlusion but also, in the early postoperative period, to facilitate fistula maturation.
  • La détermination de l’indice de résistance, normalement inférieur à 0,70, dans le cas d’une fistule non compliquée, permet de détecter très simplement la présence d’un obstacle à l’écoulement sur le circuit de la FAV. Un indice de résistance supérieur à 0,70 est évocateur d’une sténose critique de la veine de drainage associée à un haut risque dethrombose de la fistule.Un indice de résistance égal à 1 signe le diagnostic de thrombose de la fistule.
  • velocity measurements should not be interpreted in isolation in particular an elevated peak systolic velocity through an anastomosis may simply represent high flow volume in association with relatively large calibre inflow and outflow vessels
  • Incidence: 1.8% in arteriovenous fistulas and 4.3% in arteriovenous graftsIn patients with unrecognized or uncorrected steal, persistence of severe ischemia may produce devastating results such as a nonfunctional extremity with unremitting chronic pain or gangrene with loss of digits or limbs. Ischemic monomelic neuropathy: Rare but devastating complication.The term refers to combination of ischemia &amp; neuropathy in a single limb (melos is Greek for limb).Recognition of IMN is difficult because it occurs so infrequently.The KDOQI Clinical Practice Guideline recommends emergency vascular access surgical consultation for these symptoms.Other causes of neuropathy : uremic neuropathy, diabetic neuropathy, carpal tunnel syndrome, and other compartment syndromes, such as the cubital or ulnar nerve compression syndrome.
  • 74-year-old woman with a right-arm radiocephalic fistula presented with hand pain, coldness, and trophic changes in the distal aspects of the second and fourth fingers. Duplex Doppler examination revealed a patent fistula with a flow volume of 840 mL/min. No perianastomotic venous or arterial stenosis was detected.
  • Typical symptoms and findings are those of right heart failure: Dyspnea at rest, dyspnea on exertion, orthopnea, paroxysmal nocturnal dyspnea, reduced exercise tolerance, peripheral edema, pulmonary edema, cardiomegaly, increased blood volume, &amp; tachycardia. One report estimated that the mean slowing of the pulse rate in recognized high-output cardiac failure was approximately 7 beats/min.Improved methods for noninvasive characterization of AV access flow and cardiac output will distinguish AV access–related high-output cardiac failure from other common causes of these symptoms, such as anemia, HTN, inadequate dialysis, and fluid/electrolyte retention.

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