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