Uploaded byArun Jagannathan
Dialysis access interventions
This document discusses arteriovenous (AV) access for hemodialysis, including fistulas, grafts, and catheters. It provides guidelines on creating and maintaining different types of access based on Kidney Disease Outcomes Quality Initiative (KDOQI) recommendations. Catheters are best for short-term use but carry higher infection risks than fistulas or grafts. Fistulas have the highest patency rates but take longer to mature than grafts. Early detection of access dysfunction through regular monitoring and treatment of stenoses is important to preserve access sites. Complications like infection, ischemia, and stenosis should be referred for imaging and intervention.
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Dialysis access interventions
- 1. Arun Jagannathan MD Vascular& Interventional Radiology Central Illinois Radiological Associates
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- 3. Introduction Arteriovenous graft orfistula Direct communication between artery and vein without an intervening capillary bed Etiology Congenital Acquired Surgically created dialysis graft/fistula Traumatically created Iatrogenically created during cannulation/treatment of artery/vein www.radclinic.com
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- 5. What is KDOQI? KidneyDisease Outcomes Quality Initiative Evidence-based clinical practice guidelines developed by volunteer physicians and health care providers for all stages of chronic kidney disease and related complications, from diagnosis to monitoring and management This presentation utilizes the National Kidney Foundation (NKF) KDOQI Clinical Practice Guidelines 2006 update www.kidney.org www.radclinic.com
- 6. AV Access forDialysis Advent of hemodialysis in the early 60s has provided significantly improved longevity for CKD patients Initially used external AV shunt by Scribner and Quinton Currently provided by catheter, AV fistula, or AV graft Over 250k pts on permanent HD in US currently www.radclinic.com
- 7. HD Access Three primarymethods Catheter Non-tunneled Tunneled AV Fistula AV Graft www.radclinic.com
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- 9. Catheter Access Advantages Immediate access Easyto place if central veins are patent Disadvantages Infection (greater w/ noncuffed/nontunneled) Potential Thrombosis/Occlusion Risks Flow rates limited www.radclinic.com
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- 11. Catheter Access Vein selection,order of preference Right Internal/External Jugular Vein Left Internal/External Jugular Vein Femoral veins (higher infection rates) IVC (tunneled translumbar or transhepatic) Subclavian (LAST RESORT as it may compromise future upper extremity fistula/graft creation) www.radclinic.com
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- 14. Catheter Access Nontunneled (Mahurkar,etc.) SHORT term access (up to 10 days) Tunneled Cuffed Short to medium term access (weeks to months) Bridge to more durable access (AVF, AVG, PD) If a patient with acute onset renal failure is likely to require more than 7-10 days of access, primarily place a tunneled HD catheter www.radclinic.com
- 15. Tunneled Cuffed HDCatheter www.radclinic.com
- 16. Catheter Complications Treat whendialyzer blood flow of 300 cc/min not being attained in a catheter previously able to deliver greater than 350 at prepump pressure -250 torr Dysfunctional catheter (<300) for 2 treatments should be treated in HD unit w/ intraluminal interdialytic thrombolytic lock protocol between 2 treatments If the above fails, send for radiological evaluation www.radclinic.com
- 17. IR Evaluation ofHD Catheter Catheter imaging w/ contrast can identify and treat various issues Residual lumen thrombus -> pharmacologic or mechanical thrombolysis Malpositioned catheter tip -> reposition or exchange Fibrin sheath at tip -> angioplasty/exchange/stripping SVC thrombosis/stenosis -> thrombolysis/angioplasty/stent www.radclinic.com
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- 19. SVC Stenosis (tipmalposition) www.radclinic.com
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- 21. Catheter Infections Treatment Catheter exit-site,no tunnel infection Treat w/ topical and/or oral Abx, not necessary to remove catheter If bacteremic pt is afebrile w/in 48 hrs and stable, catheter salvage might be considered w/ interdialytic Abx lock solution and 3wks of parenteral Abx, f/u Blood Cx in 1 wk Abx lock when f/u cultures indicate reinfection w/ same organism in pt w/ limited access Short-term catheters should be removed when infected www.radclinic.com
- 22. Save the veins! CKD3b or worse (eGFR < 45) pts are predialysis Veins of dorsum of hand preferred IV site Rotate sites if arm veins necessary PICC lines are NOT benign! Incidence of central vein stenosis and occlusion after PICC/Port is 7% Do NOT use PICC lines in predialysis patients (small bore central catheter via IJV for medium term access instead) www.radclinic.com
- 23. If at allpossible… www.radclinic.com
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- 25. Surgical Access: AVFistulas and Grafts Fistulas have a superior longevity compared to grafts (85% vs 50% patency at 2 yrs) but take longer to mature Up to 1/3 of fistulas fail to mature Fistulas can remain patient at flow rates of as low as 80 cc/min Grafts require flow rates of > 450 cc/min to prevent thrombosis www.radclinic.com
- 26. AV Fistula Creation Usuallynondominant arm Radiocephalic or Brescia-Cimino is anastamosis of radial artery to cephalic vein Braciocephalic fistula is brachial artery to cephalic vein in the antecubital region Average of 4-6 wks for maturation Preferred sites radiocephalic > braciocephalic > transposed brachial basilic www.radclinic.com
- 27. AV Fistula Fistula Advantages Lowerinfection rates Higher blood flow rates Lower thrombosis/stenosis rates Disadvantages Longer maturation time Potential for steal syndrome Aneurysm formation www.radclinic.com
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- 29. AV Graft Creation Artificialvessel (graft) made of synthetic material such as PTFE or sterilized animal vessel connects the native artery to vein Preferred sites forearm loop > forearm straight > upper arm > chest wall > lower extremity www.radclinic.com
- 30. AV Graft Advantage Can beused much sooner Disadvantages Higher restenosis rates usually at venous anastomosis Higher thrombosis rates Higher infection rates Potential steal Pseudoaneurysms www.radclinic.com
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- 33. Detection of AccessDysfunction Prospective surveillance of fistulae/grafts for hemodynamically significant stenosis, combined with correction of anatomic stenosis, improves patency rates and reduces incidence of thrombosis www.radclinic.com
- 34. Physical Examination Look (inspection) Aneurysms Fistulathat does not collapse w/ arm elevation likely has outflow stenosis Palpable strictures Downstream stenosis can produce venous dilatation Arm edema Prolonged bleeding after needle withdrawal www.radclinic.com
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- 36. Physical Examination Touch (palpation)and listen (auscultate) Strong pulse is NOT evidence of good flow! Bruit over access system that is only systolic is abnormal, should be continuous Palpable thrill at the arterial, middle, and venous segments of graft predicts flow > 450 cc/min Palpable thrill at axilla predicts > 500 cc/min www.radclinic.com
- 37. Access Flow Number oftechniques to measure www.radclinic.com
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- 41. Recirculation Return of dialyzedblood to dialyzer without equilibration with systemic arterial circulation Not a recommended technique for assessing grafts Up to 1/3 of dysfunctional fistulae will show increased recirculation, but often occurs late www.radclinic.com
- 42. When to referfor evaluation Do not respond to a single isolated abnormal value, trend analysis is the key Flow rate < 600 in grafts and < 400-500 in fistulae Venous segment static pressure ratio greater than 0.5 in grafts or fistulae Arterial segment static pressure ratio greater than 0.75 in grafts Persistent abnormalities -> graftogram/fistulogram! www.radclinic.com
- 43. Treatment of Fistulae Complications Intervenefor Inadequate flow Significant venous stenosis Aneurysm formation in primary fistula (also correct postaneurysmal stenosis) Ischemia www.radclinic.com
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- 45. Access Evaluation forIschemia Patients prone to develop ischemia Elderly Hypertensive History of PAD Diabetes Not common (1-4%) but critical to recognize Most occur early, but up to a quarter develop months to years later www.radclinic.com
- 46. Access Evaluation forIschemia Stage I, pale/blue and/or cold hand without pain Stage II, pain during exercise and/or HD Stage III, pain at rest Stage IV, ulcers/necrosis/gangrene www.radclinic.com
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- 48. Ischemia -- EmergentReferral to Vascular Access Surgeon Treatments Angioplasty of arterial stenosis proximal to anastomosis Ligation of peripheral radial artery DRIL (distal revascularization—interval ligation) Pts w/ venous anastomosis to brachial artery, anastomosis is bridged by venous bypass, after which the artery is ligated closely peripheral to the anastomosis Low flow rates and ischemia, proximal AV anastomosis technique with ligation of the previous anastomosis and placement of a new more proximal one with blood brought to the vein by an interposed vein graft or small caliber PTFE graft www.radclinic.com
- 49. Surgical Steal Tx DRIL– distal revascularization with interval ligation RUDI – revision using distal inflow www.radclinic.com
- 50. Infection Rare, but potentiallylethal If at anastomosis, immediate surgery w/ resection More often at cannulation sites, rest and treat w/ Abx (treat like subacute bacterial endocarditis, 6 wks) www.radclinic.com
- 51. Graft Complications Extremity edema Persisting> 2 wks require contrast imaging to evaluate central veins with plasty as necessary Stent placement if acute elastic recoil after plasty or if stenosis recurs within 3 months Indicators of risk for graft rupture (evaluate urgently) Poor eschar formation Spontaneous bleeding Rapid expansion of pseudoaneurysm Severe degeneration of graft material www.radclinic.com
- 52. Graft Complications Indications forrevision/repair AVGs w/ severe degeneration or pseudoaneurysm (PSA) should be repaired if… Number of cannulation sites limited by large or multiple PSAs PSA threatens viability of overlying skin PSA is symptomatic Possible infection AVOID cannulation of PSA, especially if enlarging www.radclinic.com
- 53. Graft Complications Treat stenosisw/ angioplasty or surgery if > 50% in diameter and… Abnormal physical exam Decreasing intragraft flow (< 600) Elevated static pressure within graft www.radclinic.com
- 54. Take Home Points Savethe veins! PICC lines and subclavian catheters are NOT benign, and should almost NEVER be used in dialysis or predialysis patients Surveillance of AV fistulae and grafts is crucial in order to intervene early and prevent loss of a potential access site Open line of communication between dialysis center, radiology, and surgical services is imperative www.radclinic.com
- 55. Infrascrotal Femoro-Femoral Perineal BypassGraft Not to be wished upon your worst enemy! www.radclinic.com
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