Doppler ultrasound of A-V access for hemodialysis

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  • 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 & acts as collateral around elbow if brachial artery occluded distally.Common interosseous artery: important branch of ulnar artery in upper forearm & act as collateral if radial & 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 & 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 & 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 & 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, & 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.
  • Doppler ultrasound of A-V access for hemodialysis

    1. 1. Doppler US of A-V access for hemodialysisSamir Haffar M.D.Department of Internal MedicineAl-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 arteryRight SCA originates from innominate (brachiocephalic) arteryLeft SCA originates directly from aortic archSCA has several branches: VA & mammary (internal thoracic) arteryThrush A et al. Peripheral vascular ultrasound. Elsevier Churchill Livingstone, 2nd edition, 2005.
    5. 5. Arterial anatomy of upperextremityThrush A et al. Peripheral vascular ultrasound. Elsevier Churchill Livingstone, 2nd edition, 2005.LSA Common origin with CCA from ABA High bifurcation of brachial arteryRA High origin from axillary arteryUA High origin from axillary arteryAnatomical variations
    6. 6. Normal brachial arteryDeklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646.Diameter from intima to intimaPerpendicular to arterial wallSagittal US scan Sagittal color DopplerHomogenous velocitiesGood visualisation of arterial bords
    7. 7. Normal duplex US of peripheral arteriesHigh resistance flowNormal brachial arteryTriphasic flow
    8. 8. Venous anatomy of upper extremityDeklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646.Superficial systemBasilic vein Drains medial side of upper limbPenetrates fascia in lower arm to join brachial veinCephalic vein Drains lateral side of upper limbJoin 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 examinationPatency below site of examination Valsalva Deep breath, strain while holding breathPatency above site of examination
    10. 10. Vein compressibilityKerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.CompressionRegular thin wallDiameter: 5.2 mmBasilic veinVein fully compressedBasilic vein
    11. 11. Color & pulsed Doppler of cephalic veinMihmanli I et al. J Ultrasound Med 2001 ; 20 : 217 – 222.Normal lumen blushNormal 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 outcomeEvaluation of nondominant arm first• Peripheral arteries Diameter at least 1.6 mmHyperemic responsePatent palmar arch (US Allen test)• Peripheral veins AVF: ≥ 2 mm without tourniquet≥ 2.5 mm with tourniquetGraft: at least 4 mm with tourniquet• Central veins Respiratory phasicity“indirect assessment” Transmitted cardiac pulsatilityValsalva (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 diameterFerring M et al. Nephrol Dial Transplant 2008 ; 23 : 1809 – 1815.Radial artery (M mode)Point of artery insonated over timeDiameter at peak systole: 2.1 mmDiameter in diastole: 2 mmFrom intima to intimaPerpendicular to arterial wallDiameter: 2.2 mmRadial artery (B mode)Blooming effect
    15. 15. Arterial hyperemic responseUseful to predict risk of arterial stealWiese 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 < 0.70Failure of such response regarded as CI to AVF
    16. 16. Pourcelot’s resistance indexResistance Index (RI): Systolic – End Diastolic / Systolic
    17. 17. Color Doppler of the palmar archReversed flowFlow via ulnar arteryOcclusion of radial arterywhile imaging archColor Dopplerof palmar arteryMozersky 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 testFirst reported in 1973
    18. 18. Radial artery at wristSegmental occlusive lesionsCalcified wall with marked shadowingParmley MC et al. Am J Surg 2002 ; 184 : 568 – 572.
    19. 19. SpontaneityPhasicityCompressibilityLumen echogenicityWall irregularityDiameterVeins examined from wrist to distal end of clavicleMihmanli I et al. J Ultrasound Med 2001 ; 20 : 217 – 222.
    20. 20. Cephalic vein wallMarked wall irregularityWall thickening especially on posterior sideMihmanli I et al. J Ultrasound Med 2001 ; 20 : 217 – 222.
    21. 21. Robbin ML et al. Radiology 2000 ; 217 : 83 – 88.Normal caliber of SCV50% stenosis of BCVCorresponding venogramAbnormal respiratory phasicityNo decrease to baseline with inspirationDoppler US of patent SCVCentral vein stenosisPaget Schroetter syndrome
    22. 22. Central vein stenosisPaget Schroetter syndromeRobbin ML et al. Radiology 2000 ; 217 : 83 – 88.Doppler US of patent SCVAbnormal respiratory phasicityMonophasic flowSuspicion of CV stenosis/occlusionCorresponding venogramSevere stenosis of BCVat its junction with SMVSecond channel adjacent to stenosisRecognition of central vein stenosis is CI to use of that extremity
    23. 23. Upper extremity arterial mappingBrown PWG. Eur J Vasc Endovasc Surg 2006 ; 31 : 64 – 69.
    24. 24. Upper extremity vein mappingCephalic veinMendes RR et al. J Vasc Surg 2002 ; 36 : 460 – 3.Eight representative measurement sites of CV:Diameter with & without tourniquetDepth from skin
    25. 25. Preoperative vascular mappingRobbin ML et al. Radiology 2000 ; 217 : 83 – 88.50-year-old man with nonpalpable cephalic vein in wristScheduled to receive forearm graftTransverse cephalic veinRadial arteryat wrist3.7 mmWrist2.8 mmMiddle forearm2.7 mmAntecubital area2.8 mmAdequate diameters for AVF placement
    26. 26. Preoperative vascular mappingDuplex sonography of upper limb arteries & veinsperformed in conjunction with clinical examination in allpatients for whom an AVF is being considered* National Kidney Foundation’sKidney Disease Outcomes Quality InitiativeNational 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 fistulaBrescia MJ, Cimino JE, Appel K, et al. N Engl J Med 1966 ; 275 : 1089 – 92.Side of artery to end of veinAt anatomical snuffbox or wristSurgeons who invented AVF:Brescia, Cimino, & AppelMost commonly used
    29. 29. Types of Arterio-Venous FistulaFinlay DE et al. RadioGraphics 1993 ; 13 : 983 – 999.Side of artery to side of veinEnd of artery to side of veinSide of artery to end of veinBrescia-Cimino AVFEnd of artery to end of vein
    30. 30. Types of A-V grafts (PTFE – Polyurethane )Curr Probl Surg 2011 ; 48 : 443 – 517.ForearmBarachial artery to brachial vein“Loop graft”Upper armRadial artery to axillary vein“Straight graft”
    31. 31. A-V access for hemodialysis in preferential orderType Description Forearm AVF Radial artery to cephalic veinRadial artery to basilic veinRadial artery to other suitable vein (transposition*)AVF placement preferable to graft placementNondominant arm is preferred site for access placement* Transposition AVFs placed in veins other than cephalic veinRobbin ML et al. Radiology 2000 ; 217 : 83 – 88. Upper arm AVF Brachial artery to cephalic veinBrachial artery to basilic veinBrachial 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 StatesHuijbregts HJ et al. Eur J Vasc Endovasc Surg 2006 ; 31 : 284 – 287.Following percentiles of each distribution provided forthe 10th, 25th, 50th (median), 75th, & 90th percentiles
    33. 33. Radio-cephalic fistula at wristMA (8 prospective & 30 retrospective studies – 4579pts)High primary failure rateModerate 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 weeks15.3% (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-establishpatency, thrombosis or time of patency measurement62.5% (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 hemodialysisAbundant gel & minimal pressure on skinLongitudinal & transverse scan from feeding artery to anastomosisLongitudinal & transverse scan from draining vein as far as possiblePerivascular space: functional stenosis from abscess, hematoma, seromaEdenberg Jan et al. Tidsskr Nor Legeforen nr. 2009 ; 129 : 1635 – 8.
    36. 36. Normal Doppler US in AVFs• Feeding artery Monophasic flowLarge diastolic component• Anastomosis Perivascular tissue vibrationVery turbulent flow over long stretch• Draining vein Pulsatile flow (arterialized vein)• Volume flow > 500 mL/minDilatation of feeding artery & draining veinafter several years of useSchäberle W. Ultrasonography in vascular diagnosis.Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011.
    37. 37. Normal Doppler US in AVFsBrachio-basilic fistulaKerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.Brachial arteryMonophasic flowLarge diastolic componentBrachio-basilic fistulaArterialized vein
    38. 38. Doppler US of polyurethane graftThree-layered material – Cannulation within 24 hWiese P et al. Nephrol Dial Transplant 2003 ; 18 : 1397 – 1400.1 year follow-upSignal from whole graftEarly post-operativeStrong reflection from graft1 year follow-upSignal at site of single cannulation1 year follow-upSignal 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 / 4d: diameterMeasurement of flow volumeHoskins P et al. Diagnostic US: physics and equipment.Cambridge university press, Cambridge, UK. 2nd ed, 2010.
    40. 40. Place of flow volume measurement• Arteriovenous fistulaFeeding artery Brachial artery in middle upper armRecommended by some authorsWithin fistula Turbulent flow (spectral broadening)Draining vein Abrupt change in diameter in older AFVChanges in lumen shape (elliptical)Recommended by other authors• GraftInvestigated along the entire accessSchäberle W. Ultrasonography in vascular diagnosis.Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011.
    41. 41. Measurement of flow volume /Feeding arteryDiameter perpendicular to axisSample volume across width of vesselSample volume in same site of diameter measurementCorrect estimation of angleTAMV: 3 – 5 cardiac cyclesDeklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646.
    42. 42. Measurement of flow volume in feeding arteryDeklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646.Normal flow in distal radial arteryFlow volume (fistula open) – Flow volume (fistula closed)Normal volume in upper limb: 100 mL/min (neglected)Reversed flow in distal radial arteryFlow 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-sectionVariation during cardiac cycleVariation during respiration (veins)• Doppler angle As small as possible & < 60Box steering & transducer shifting• Mean velocity Setting of transmitted & received gainOver or underestimationSchäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin, 2nd edition, 2011.
    44. 44. Error percentage in volume measurements& vessel diameterSchäberle 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 – frThrush A, Hartshorne T. Peripheral vascular ultrasound: How, why and when.Elsevier Churchill Livingstone, London, 2nd edition, 2005.ftfr∆ F = 2 F0 V Cos Ө / C
    46. 46. Angle of insonation & Doppler effectKim 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 insonationAngle of insonation > 60 should not be used
    48. 48. Doppler angle correction in AVFPieturaa R et al. Eur J Radiol 2005 ; 55 : 113 – 119.
    49. 49. Adjusting spectral Doppler gainGain setting too lowCorrect gain settingGain setting too highKruskal 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 volumeA-V access for hemodialysis Flow volume (mL/min)Normal valueForearm fistulaUpper arm fistula600 – 800900 – 1200Schäberle W. Ultrasonography in vascular diagnosis.Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011.Mature fistula ≥ 500High risk of occlusionAVFGraft< 300< 650High-output cardiac failureAdultChildren> 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 fistulaAngioplasty – surgical revision One or more accessory veinsLigation Deep draining veinFistula surgically placed in more superficial soft tissuesImmature fistula can be converted into usable fistulawith correction of underlying problemSingh P et al. Radiology 2008 ; 246 : 299 – 305.
    54. 54. Sonographically mature fistulaDoppler 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/minRobbin ML. Radiology 2002 ; 225 : 59 – 64.Singh P et al. Radiology 2008 ; 246 : 299 – 305.Should meet the 3 following criteriaCriteria different from clinically mature fistula
    55. 55. Doppler US for routine surveillance• AP diameter of draining vein in transverse scanUsually thin wall: cursors within vein walls• Distance from skin to anterior wall of draining vein• Veins branching off within first 10 cm of anastomosisAP diameter & distance from anastomosis• Flow volume Straight segment of artery or veinRepeat 3 – 5 times with averageSingh P et al. Radiology 2008 ; 246 : 299 – 305.
    56. 56. Mature fistula/Good diameter & depthAnteroposterior diameter of draining vein: 6 mmDistance from skin surface to anterior vein wall: 4.8 mmSingh P et al. Radiology 2008 ; 246 : 299 – 305.Transverse US of draining vein
    57. 57. Mature fistula/Good flow volumeBrachio-basilic fistulaKerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.Diameter: 7.9 mmTAMV: 93.2 cm/sec over 3 cardiac cyclesFlow volume: 2.741 mL/min
    58. 58. Immature fistula/Large accessory veinSingh P et al. Radiology 2008 ; 246 : 299 – 305.Large accessory vein which may limit maturation of fistulaSearch for all accessory veins within first 10 cm of anastomosisTransverse US of draining vein
    59. 59. Immature fistula/Small & deep veinDraining veinVein 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 volumeRadio-cephalic fistulaLeft radial arteryFlow volume : 86 mL/minLeft cephalic veinFlow volume : 130 mL/minKerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.
    61. 61. Routine surveillance in asymptomatic patientsNo RCTs of Doppler surveillance in this settingRoutine surveillance by combination of clinical examination,direct flow measurement, & duplex US should be performedWhen stenosis > 50% is accompanied by hemodynamicor clinical abnormalities, angioplasty is recommended* National Kidney Foundation’sKidney Disease Outcomes Quality InitiativeNational 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 failureHematomaSeromaLymphocele Infected & non-infected collections
    64. 64. Mechanisms & sites of stenosis• AVF Feeding artery Atherosclerosis (SC, axillary)• Graft Intimal hyperlplasia (shear stress)Anastomosis between graft & veinDraining vein Intimal hyperplasia (valves)Puncture-induced dissectionProximal – distalAnastomosis 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 hyperplasiaEdenberg Jan et al. Tidsskr Nor Legeforen nr. 2009 ; 129 : 1635 – 8.Venous stenosis 3 cm from anastomosisPower 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 ratioPSV: should not be interpreted in isolation
    67. 67. Measurement of luminal diameter reductionEdenberg 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 mm78 % diameter stenosisOriginal lumen – Residual lumenx 100% of diameter stenosisOriginal lumen=
    68. 68. Color criteria of significant stenosisPronounced aliasing at site of stenosisJunction of basilic & axillary vein
    69. 69. Duplex criteria for significant stenosis (> 50%)• Direct signsFeeding artery PSV ratio ≥ 2Anastomosis PSV ratio ≥ 3 – PSV > 400 cm/sec*Draining vein PSV ratio ≥ 3 – PSV > 300 cm/sec*• Indirect signsFlow volume < 250 mL/minProximal High-resistance flow (RI > 0.70)Distal Delayed systolic upstroke* Flow volume adequate for hemodialysisSchäberle W. Ultrasonography in vascular diagnosis. Springer-Verlag, Berlin, 2nd edition, 2011.
    70. 70. PSV ratioRobbin ML et al. Ultrasound Clin 2006 ; 1 : 111 – 131.Proximal: 2 cm proximal to stenosisStenosis: same Doppler angle if possible
    71. 71. Significant stenosis of AVF at anastomosisRadio-cephalic fistulaPSV ratio: 3.4Arterio-venous anastomosisPSV: 438 cm/sRadial arteryPSV: 130 cm/sGrogan J et al. J Vasc Surg 2005 ; 41 : 1000 – 6.
    72. 72. Proximal venous stenosisKerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.Pronounced aliasing at site of stenosisPeak Systolic Velocity: 610 cm/sCephalic vein – Mid upper arm
    73. 73. Distal venous stenosisDeklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646.Pronounced aliasing at site of stenosisPeak Systolic Velocity: 340 cm/sJunction of basilic & axillary vein
    74. 74. Stenosis of graft insertion on veinDeklunder G et al. EMC-Radiologie 2004 ; 1 : 632 – 646.Rail aspect of the graftAliasing on color DopplerPeak Systolic Velocity : 400 cm / s
    75. 75. Pseudo-diagnosis of significant stenosisKerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.PSV: 570 cm/secBrachio-basilic fistulaBrachial arteryPSV: 350 cm/secVolume flow:1.1 L/minHigh inflowBasilic veinPSV: 175 cm/secVolume flow:1.8 L/minHigh outflowHigh PSV in anastomosis due to high flow volume & large vessels
    76. 76. Occlusion of brachiocephalic fistulaTriphasic waveformRI = 1 (thrombosed fistula)Brachial arteryOcclusion of fistulaThrombus within draining veinBrachio-cephalic fistulaKerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.
    77. 77. Thrombosis in draining vein of AVFEdenberg 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 failureHematomaSeromaLymphocele Infected & non-infected collections
    79. 79. AneurysmDevelops in AVF functioning for many years• Good function Lumen not filled with thrombusIntact skin• Intervention Intra-luminal thrombusrarely needed Compromise of overlying skinSteadily & rapidly enlargedObstructive kinks• Operation Proximal A-V access of arterialized veinProsthetic graftPadberg FT et al. J Vasc Surg 2008 ; 48 : 55S – 80S.
    80. 80. Diffuse aneurysmal dilationSchäberle W. Ultrasonography in vascular diagnosis.Springer-Verlag, Berlin Heidelberg, 2nd edition, 2011.Secondary to wall degeneration or downstream stenosisFeeding arteryDraining veinAnastomosis
    81. 81. True venous aneurysmDiffuse aneurysmal dilationBourquelot P et al. Nephrol Ther 2009 ; 5 : 239 – 248.Kerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.Raise concern from the staffRadio-cephalic AVF Color Doppler US
    82. 82. Pseudoaneurysm• Incidence 2 – 10 % during functional life of graftLess 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 & stableTreatment if expandingAnastomotic Generally requires surgeryInfection is common causePadberg FT et al. J Vasc Surg 2008 ; 48 : 55S – 80S.
    83. 83. Anastomotic pseudoaneurysm on A-V graftKabalci YM et al. Transplant Proc 2006 ; 38 : 2816 – 2818.Brachio-basilic graft 2 months agoAnastomotic pseudoaneurysm of graft is rare
    84. 84. PseudoaneurysmColor 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 flowBidirectional blood flowTypical “yin-yang sign”Pseudoaneurysm of radial arteryColor duplex US Thrombin injection under US controlComplete thrombosis afterthrombin injectionCarrafiello 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 failureHematomaSeromaLymphocele Infected & non-infected collections
    87. 87. HematomaKerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.AV access punctured thrice weekly for hemodialysisSerial 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 failureHematomaSeromaLymphocele Infected & non-infected collections
    89. 89. Radial artery stealFinlay DE et al. RadioGraphics 1993 ; 13 : 983 – 999.Ulnar artery flow contributes to fistula flow via palmar archesRetrograde flow in distal radial artery
    90. 90. Arterial steal syndromeClinical diagnosis – Incidence (1 – 4 %)• Risk factor Brachial arterial, DM, female gender• Symptoms Steal phenomenon Silent (70% of RC-AVF)Steal syndrome Mild: pain during dialysisSevere: rest pain, ulcerationCommon cause of neuropathy• Doppler US Reversed flow: complete – only in diastoleDynamic study: gentle compression of AVF• Treatment Ligation, banding, reroutingPadberg FT et al. J Vasc Surg 2008 ; 48 : 55S – 80S.
    91. 91. Radial arterial stealFrequent in asymptomatic patientsWiese 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 AVFGoldfeld M et al. AJR 2000 ; 175 : 513 – 516.Reversed flow during entire cardiac phase
    93. 93. Arterial steal syndromeRadial-cephalic fistulaYilmaz C et al. AJR 2009 ; 193 : W567.RA distal to anastomosisAntegrade flow during systoleRetrograde flow during diastoleGentle compression of fistulaRestoration of antegrade flowElevated systolic flowElevated 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 USPadberg FT et al. J Vasc Surg 2008 ; 48 : 55S – 80S.
    95. 95. Digital ischemia from emboli of thrombosed AVF7 reported cases in the literatureJournet J et al. Néphrologie & Thérapeutique 2010 ; 6 : 121 – 124.Digital ischemia4 fingers of right handRegression of ishemia6 mth after operationPartial thrombosisof RC-AVF
    96. 96. Complications of A-V access for hemodialysis Stenosis & occlusion Aneurysm & pseudoaneurysm Arterial steal syndrome High-output cardiac failureHematomaSeromaLymphocele Infected & non-infected collections
    97. 97. High-output cardiac failureRare &unusual complication• Symptom Symptoms of right heart failureNicoladoni-Branham sign: ↓ PR after AVF occlusion• Diagnosis Flow volume > 3 L/minFlow volume/cardiac output ≥ 30% (screening)Cardiac output > 2.3 L/min/m2Sine qua none: improvement after treatment• Treatment Ligation: sacrifice of accessBanding: more attractive optionPadberg FT et al. J Vasc Surg 2008 ; 48 : 55S – 80S.
    98. 98. Conclusion• Doppler uplex US should be interpreted in conjunction withclinical findings including adequacy of dialysis• Results should be discussed within multidisciplinary team:Nephrologist, vascular surgeon, & interventional radiologist• Stenosis in early postop period interpreted with cautionThey may be secondary to transient edema• Duplex sonography is central to prevention, detection, andmanagement of complicationsKerr SF et al. Clin Radiol 2010 ; 65 : 744 – 749.
    99. 99. References1. Kerr SF et al. Duplex sonography in the planning & evaluation ofarteriovenous fistula for hemodialysis Clin Radiol 2010;65:744-749.2. Wiese P et al. Color Doppler ultrasound in dialysis access. NephrolDial Transplant 2004;19:1956-1963.3. Padberg FT et al. Complications of arteriovenous hemodialysisaccess: 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

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