Dialysis Access
“Catheters, Grafts and Fistulas … Oh My!”
John O. Colonna, II, MD, FACSSurgical Director
Kidney Transplant ProgramSentara Norfolk General
Objectives• Dialysis – scope of the problem• Catheters• AV grafts• AV fistulas• Present DOQI guidelines• Algorithm for chronic access• Algorithm for monitoring /
salvage
Magnitude of Renal Failure
• 300,000 dialysis patients• Dialysis population – inc 10%/yr• Dialysis access is most common
vascular surgery procedure• Problems with dialysis access
are a major reason for hospitalization in renal failure patients
Evaluation of Patients for Dialysis Access
• Urgency of dialysis?• Prior access procedures• Inspection of superficial arm
veins with tourniquet• Venous collateralization?• Pulse assessment (Allen’s test)
Acute Dialysis Options• Percutaneous catheter
Firmer – plastic Bedside insertion In-hospital use
• Tunneled catheter Softer – silicone Operative insertion Potential for long-term use
Advantages•Universally applicable•Multiple access sites•No maturation time – can
be used immediately
Advantages• No direct hemodynamic effects on the circulation• Allows time for maturation of native AVF• Thrombotic complications simple to correct
Insertion of CathetersSite Selection
•Right internal jugular preferred
•Avoid subclavian veins•Previous catheter locations ?•Known stenoses / occlusions ?•Site-Rite examination
Insertion of CathetersTypes of Catheters
• Curved vs. Straight Catheters• Length of catheter determined
by site of access Right IJ – 19 cm Left IJ – 23 cm Femoral – 27 cm Extra long catheters available Adjust for small / pediatric patients
Insertion of CathetersTechnical Considerations
• Positioning• Fluoroscopic guidance• Seldinger technique• Avoid kinking of catheter• Both lumens should irrigate and
aspirate freely• Venography helpful in difficult
cases
Disadvantages• Typically have the shortest
long term patency rates of all permanent access procedures
• Lower blood flow rates obligating longer dialysis times
• External device
Disadvantages• Morbidity
Insertion complications Thrombosis Infection > 3 months - morbidity excessive
• Risk of central vein stenosis or occlusion • Limits chronic access options
Chronic Dialysis Options
• Tunneled dialysis catheter• Arterio – venous graft• Arterio – venous fistula• Peritoneal dialysis• Renal Transplant
Chronic AV Access Principles
• Start distal • Nondominant extremity if veins
are equivalent• Lower extremity less preferable• Catheters are always last resort
AVF / AVG / PD / Tx options exhausted
Hypercoagulable
Preop Planning• Duplex US Vein Mapping
Non-invasive, no IV contrast Reliable vein diameters Assess for central vein stenosis
• Venogram Locate vein branching Identify / treat stenoses
• Noninvasive arterial testing
Chronic Dialysis Options
• AV Graft Subcutaneously placed conduit
between an artery and vein Usually PTFE 10 – 14 day delay before use “Early stick” grafts available
AV GraftComplications
• Graft dysfunction• Graft thrombosis• Graft infection• Steal syndrome• Graft deterioration -
pseudoaneurysms
Chronic Dialysis OptionsAV fistula
• Direct anastomosis between an artery and vein
• Radio-cephalic (Brescia – Cimino)
• Brachio-cephalic (Kaufman)• Brachio-basilic (transposition)• 8-12 week maturation time
AV FistulaComplications
• Failure to mature• Difficulty accessing fistula• Steal syndrome• Aneurysmal degeneration• Excessive flow
AVF Nonmaturation• Inability to cannulate AVF 3-
4mo after creation• Higher incidence in women &
diabetics• Fistulogram
Anastomotic stenosis Inadequate vein Multiple branching / stealing veins
AVF vs. AVG• AV Graft
High short-term patency Ease of cannulation
• AV Fistula Better long-term patency Often a “One and Done” operation Fewer revisions required Minimal risk of infection with AVF
Monitoring AV Access Function
Identifying the Failing Access• Physical Exam
Pulsatile fistula vs. continuous thrill Arm swelling – venous hypertension
• Dialysis Data Elevated Venous pressure Falling K T / V Decreased Urea Reduction Rate Increased Urea Recirculation
Evaluating the Failing Access
• Duplex ultrasound• Fistulogram
Identifies anatomic abnormalities Allows for pre-emptive
percutaneous intervention Guides surgical intervention
AVF Salvage• Balloon vs patch angioplasty for
short segment vein stenosis• Graft interposition for long segment
vein stenosis• Revise vs balloon AVF anastomotic
stenosis• Ligation of stealing vein branches• Balloon angioplasty/stenting for
central venous stenosis
DOQI Guidelines• Dialysis Outcomes Quality Initiative• NKF sponsored• Current goals:
<10% long-term (>90day) catheter usage
>40% functioning AVF/dialysis unit >50% AVF of new access procedures
Chronic AV Access Algorithm
• Radio-cephalic AVF• Brachio-cephalic AVF• Basilic vein transposition• Forearm loop graft• Brachio-axillary AVG• Femoral loop AVG
Conclusions• Catheters for acute dialysis
Complications limit long term usefulness• AVF or AVG for chronic dialysis
AVF superior to AVG• Identification of the failing access
permits pre-emptive intervention• DOQI guidelines
<10% long-term catheter usage >40% functioning AVF/dialysis unit >50% AVF of new access procedures