KDOQI Update 2000
 
NKF KDOQI GUIDELINES 2000
 
 

GUIDELINES FOR VASCULAR ACCESS

I. Patient Evaluation Prior to Access Placement

GUIDELINE 1

Patient History and Physical Examination Prior to Permanent Access Selection

To determine the type of access most suitable for an ESRD patient, a history must be taken and physical examination of the patient’s venous, arterial, and cardiopulmonary systems must be performed. Diagnostic evaluation should be performed when indicated based on patient history or physical examination. (Evidence/Opinion)

Table III-1 outlines relevant aspects of patient history and physical examination and provides the rationale for evaluating them.

Rationale Characteristics of the patient’s arterial, venous, and cardiopulmonary systems will influence which access type and location are most desirable for the patient.13-19 The patient’s life expectancy and planned duration of ESRD therapy also can influence the type and location of the access.

GUIDELINE 2

Diagnostic Evaluation Prior to Permanent Access Selection

A. Venography prior to placement of access is indicated in patients with the following:

1. Edema in the extremity in which an access site is planned (Evidence)

2. Collateral vein development in any planned access site (Evidence)

3. Differential extremity size, if that extremity is contemplated as an access site (Evidence)

4. Current or previous subclavian catheter placement of any type in venous drainage of planned access (Evidence)

5. Current or previous transvenous pacemaker in venous drainage of planned access (Evidence)

6. Previous arm, neck, or chest trauma or surgery in venous drainage of planned access (Opinion)

7. Multiple previous accesses in an extremity planned as an access site (Opinion)

B. Additional or alternate imaging techniques are indicated in selected cases where multiple previous vascular accesses have been placed or when residual kidney function makes contrast studies undesirable. Appropriate techniques include:

1. Doppler ultrasound (Evidence)

2. Magnetic Resonance Imaging (Opinion)

C. Arteriography or Doppler examination is indicated when arterial pulses in the desired access location are markedly diminished (Opinion)

Rationale Venography allows identification of veins suitable for attempted access creation and can be used to exclude sites no longer suitable for access creation. Each of the conditions listed above is associated with vein impairment; each may render a site unsuitable for creating access. Specific factors are as follows:

Extremity edema, collateral vein development, or differential extremity size may indicate inadequate venous drainage or central vein obstruction.14,15,20-22 Detection of the underlying anatomical defect(s) should be attempted by venography. Such defects should be corrected prior to access placement; the site should not be used for access creation if the anatomical defect(s) cannot be detected and corrected.

Subclavian vein cannulation and transvenous pacemaker placement are associated with central vein stenosis and thrombosis.17,20,23-28 Thus, access should never be placed on the same side as an existing transvenous pacemaker or an existing subclavian catheter unless other options have been exhausted. An extremity should not be used for access creation if catheter-induced central vein stenosis or thrombosis on the same side cannot be corrected.

Arm, neck, and chest surgery and trauma are associated with central vein stenosis and obliteration of central veins. Thus, a history of these findings may affect access site choice. Multiple previous access placements may likewise limit availability of veins suitable for access placement.18,19

Doppler studies may be used in lieu of venography at facilities where this modality is available and reliable for venous assessment.29-35 However, this method is less accurate than venography for evaluation of central vein structures.33 Doppler studies or magnetic resonance imaging may be preferred to venography and arteriography in patients with reduced kidney function in whom contrast agents should be avoided.

Table III-1. Patient Evaluation Prior to Access Placement
Consideration Relevance
Patient History
 
History of previous central venous catheter Previous placement of a central venous catheter is associated with central venous stenosis.
Dominant arm To minimize negative impact on quality of life, use of the nondominant arm is preferred.
History of pacemaker use There is a correlation between pacemaker use and central venous stenosis.
History of severe congestive heart failure Accesses may alter hemodynamics and cardiac output.
History of arterial or venous peripheral catheter Previous placement of an arterial or venous peripheral catheter may have damaged target vasculature.
History of diabetes mellitus Diabetes mellitus is associated with damage to vasculature necessary for internal accesses.
History of anticoagulant therapy or any coagulation disorder Abnormal coagulation may cause clotting or problems with hemostasis of accesses.
Presence of comorbid conditions, such as malignancy or coronary artery disease, that limit patient’s life expectancy Morbidity associated with placement and maintenance of certain accesses may not justify their use in some patients.
History of vascular access Previously failed vascular accesses will limit available sites for accesses; the cause of a previous failure may influence planned access if the cause is still present.
History of heart valve disease or prosthesis Rate of infection associated with specific access types should be considered.
History of previous arm, neck, or chest surgery/trauma Vascular damage associated with previous surgery or trauma may limit viable access sites.
Anticipated renal transplant from living donor Temporary access may be sufficient.
Physical Examination  
Physical Examination of Arterial System  
Character of peripheral pulses, supplemented by hand-held Doppler evaluation when indicated An adequate arterial system is needed for access; the quality of the arterial system will influence the choice of access site.
Results of Allen test Abnormal arterial flow pattern to the hand may contraindicate the creation of a radial-cephalic fistula.
Bilateral upper extremity blood pressures Pressures determine suitability of arterial access in upper extremities.
Physical Examination of Venous System  

Evaluation for edema .

Edema indicates venous outflow problems that may limit usefulness of the associated potential access site or extremity for access placement

Assessment of arm size comparability

Differential arm size may indicate inadequate veins or venous obstruction which should influence choice of access site.
Examination for collateral veins Collateral veins are indicative of venous obstruction.
Tourniquet venous palpation with vein mapping Palpation and mapping allow selection of ideal veins for access.
Examination for evidence of previous central or peripheral venous catheterization Use of central venous catheters is associated with central venous stenosis; previous placement of venous catheters may have damaged target vasculature necessary for access.
Examination for evidence of arm, chest, or neck surgery/trauma Vascular damage associated with previous surgery or trauma may limit access sites.
Cardiovascular Evaluation  
Examination for evidence of heart failure Accesses may alter cardiac output.

 

Arteriography is useful to avoid extremity ischemia in patients with diminished pulses in whom access in the extremity is still desired. However, the Work Group concluded that arteriography is only rarely required.

GUIDELINE 3

Selection of Permanent Vascular Access and Order of Preference for Placement of AV Fistulae

A. The order of preference for placement of AV fistulae in patients with kidney failure who will become hemodialysis dependent is:

1. A wrist (radial-cephalic) primary AV fistula (Evidence)

2. An elbow (brachial-cephalic) primary AV fistula (Evidence/Opinion)

B. If it is not possible to establish either of these types of fistula, access may be established using:

1. An arteriovenous graft of synthetic material (eg, PTFE) (Evidence) or

2. A transposed brachial basilic vein fistula (Evidence)

C. Cuffed tunneled central venous catheters should be discouraged as permanent vascular access.

Rationale Wrist (radial-cephalic) and elbow (brachial-cephalic) primary fistulae are the preferred types of access because of the following characteristics:

A. Excellent patency once established13,18,36-43

B. Lower complication rates compared to other access options,13,18,36-43 including lower incidence of conduit stenosis, infection, and vascular steal phenomenon

C. Lower morbidity associated with their creation

D. Improved performance (ie, flow) over time

The Work Group concluded that the advantages of wrist and elbow primary AV fistulae, listed above, outweigh the following potential disadvantages:

A. The vein may fail to enlarge and increase blood flow to satisfactory levels (ie, fail to mature).13,18,43

B. Comparatively long maturation times–1 to 4 months–must elapse following creation of these fistulae before they can be used. Thus, the access must be created several months in advance of the anticipated need for dialysis or an alternative temporary method of vascular access must be used while the fistula matures (see Guideline 7: Preservation of Veins for AV Access, and Guideline 8, Timing of Access Placement).

C. In some individuals, the vein may be more difficult to cannulate than an AV graft.

D. The enlarged vein may be visible in the forearm and perceived as cosmetically unattractive.

The wrist fistula is the first choice of access type because of the following advantages:

A. It is simple to create.

B. It preserves more proximal vessels for future access placement.13,18,43

C. It has few complications. Specifically, the incidence of vascular steal is low, and in mature fistulae, thrombosis and infection rates are low.18,39,40

The only major disadvantage of the wrist (radial-cephalic) fistula is a lower blood flow rate compared to other fistula types. If adequate flow to support the hemodialysis prescription is not achieved within 4 months with a radial-cephalic fistula, then another type of access should be established (see Guideline 8: Timing of Access Placement, and Guideline 9: Access Maturation).

The elbow (brachial-cephalic) primary arteriovenous fistula is the second choice for initial placement of an access. Its advantages include41,44-47:

A. It has a higher blood flow compared to the wrist fistula.

B. The cephalic vein in the upper arm is easy to cannulate and is easily covered, providing a potential cosmetic benefit.

The disadvantages of the elbow (brachial-cephalic) primary AV fistula include:

A. It is slightly more difficult to create surgically than a radial-cephalic fistula.

B. It may result in more arm swelling than a radial-cephalic fistula.

C. It is associated with an increased incidence of steal compared to a radial-cephalic fistula.

If a wrist or elbow fistula cannot be created, a dialysis AV graft using synthetic materials (PTFE or others) or a transposed brachial-basilic fistula is the next choice (see Guideline 4: Type and Location of Dialysis AV Graft Placement). Transposed brachial-basilic fistulae have several disadvantages:

A. The transposition proceedure may create sigificant arm swelling and patient pain.

B. They have a higher incidence of steal and arm swelling than other fistula types.

Tunneled cuffed catheters have a shorter use-life and more complications than AV accesses (see Guideline 23: Treatment of Tunneled Cuffed Catheter Dysfunction, and Guideline 26: Treatment of Infection of Tunneled Cuffed Catheters).

GUIDELINE 4

Type and Location of Dialysis AV Graft Placement

If a primary AV fistula cannot be established, a synthetic AV graft is the next preferred type of vascular access (see Guideline 3: Selection of Permanent Vascular Access and Order of Preferences for Placement of AV Fistulae). (Evidence)

Polytetrafluoroethylene (PTFE) tubes are preferred over other synthetic materials. (Evidence/Opinion)

There is no convincing evidence to support tapered over uniform tubes, externally supported over unsupported grafts, thick- versus thin-walled configurations, or elastic versus nonelastic material. (Opinion)

Grafts may be placed in straight, looped, or curved configurations. Designs that provide the most surface area for cannulation are preferred. (Opinion)

Location of graft placement is determined by each patient's unique anatomical restrictions, the surgeons's skill, and the anticipated duration of dialysis. (Opinion)

Rationale Dialysis AV grafts have the following advantages:

A. Large surface area available for cannulation36,48-50

B. Technically easy to cannulate36

C. Short lag-time from insertion to maturation (in general, not less than 14 days should elapse prior to cannulation to allow healing and incorporation of the graft into local tissues14,36,51; see Guideline 9: Access Maturation)

D. Multiple insertion sites available14,16,36,38, 49,50,52,53

E. Variety of shapes and configurations available to facilitate placement14,16,36,38,48-50,54-56

F. Easy for the surgeon to handle, implant, and construct the vascular anastomoses14,16,36,50,51,54,57-65

G. Comparatively easy to repair surgically16,40,53,62,66,67

The sum of the available data supports PTFE grafts over other biologic and other synthetic materials based on lower risk of disintegration with infection, longer patency, better availability, and improved surgical handling. Biologic grafts (bovine heterografts) have higher reported rates of complications compared to PTFE grafts. Direct comparisons between PTFE and human umbilical cord vein grafts and other synthetic polymers have not been made.

Grafts using larger (ie, proximal) vessels have better flow and patency but can limit potential sites for future placement.14,18,43 A synthetic dialysis AV graft is expected to last 3 to 5 years43 (see Guideline 36: Cumulative Patency Rate of Dialysis AV Grafts). Grafts using smaller, more peripheral vessels can experience more frequent thromboses that require treatment. However, these grafts have the advantage of preserving more proximal sites for new grafts, should this become necessary in the future.13,14,18,68 Thus, the Work Group was unable to reach a consensus on a preferred location for AV grafts. The two preferred graft site types are the antecubital loop graft and the upper arm curved graft.

Potential sites for arterial inflow include: radial artery at the wrist, brachial artery in the antecubital fossa, brachial artery in the lower portion of the arm, brachial artery just below the axilla, axillary artery, and femoral artery. Potential sites for venous outflow include: median antecubital vein, proximal and distal cephalic vein, basilic vein at the level of the elbow, basilic vein at the level of the upper arm, axillary vein, jugular vein, and femoral vein.

GUIDELINE 5

Type and Location of Tunneled Cuffed Catheter Placement

A. Tunneled cuffed venous catheters are the method of choice for temporary access of longer than 3 weeks’ duration. (They also are acceptable for access of shorter duration.) In addition, some patients who have exhausted all other access options require permanent access via tunneled cuffed catheters. For patients who have a primary AV fistula maturing but need immediate hemodialysis, tunneled cuffed catheters are the access of choice. Catheters capable of rapid flow rates are preferred. (Evidence/Opinion)

B. The preferred insertion site for tunneled cuffed venous dialysis catheters is the right internal jugular vein. Other options include: the right external jugular vein, the left internal and external jugular veins, subclavian veins, femoral veins, or translumbar access to the inferior vena cava. Subclavian access should be used only when jugular options are not available. Tunneled cuffed catheters should not be placed on the same side as a maturing AV access, if possible. (Evidence)

C. Fluoroscopy is mandatory for insertion of all cuffed dialysis catheters. The catheter tip should be adjusted to the level of the caval atrial junction or into the right atrium to ensure optimal blood flow. (Atrial positioning is only recommended for catheters composed of soft compliant material, such as silicone.) (Opinion)

D. Real-time ultrasound-guided insertion is recommended to reduce insertion-related complications. (Evidence/Opinion)

E. There is currently no proven advantage of one cuffed catheter design over another. Catheters capable of a rapid blood flow rate are preferred. Catheter choice should be based on local experience, goals for use, and cost. (Evidence/Opinion)

Rationale Tunneled cuffed venous catheters have the following advantages for vascular access:

A. Universally applicable

B. Ability to insert into multiple sites

C. Maturation time not required

D. Venipuncture not required

E. No hemodynamic consequences

F. Ease and cost of catheter placement and replacement

G. Ability to provide access over a period of months–improving chances of AV fistula maturation in patients who require immediate hemodialysis36,69-77

H. Ease of correcting thrombotic complications69,78-80

Disadvantages of tunneled cuffed venous catheters relative to other access types include:

A. High morbidity due to:

1. Thrombosis70,78-80

2. Infection70,78,81

B. Risk of permanent central venous stenosis or occlusion20,22,70,82

C. Discomfort and cosmetic disadvantage of an external appliance

D. Shorter expected use-life than other access types36,37,78,83

E. Lower blood flow rates, which will require longer dialysis times84

Tunneled cuffed venous catheters should be placed preferentially in the right internal jugular vein because this site offers a more direct route to the caval atrial junction than the left-sided great veins. Catheter insertion and maintenance in the right internal jugular vein are associated with a lower risk of complications compared to other potential catheter insertion sites.85-87 Catheter placement in the left internal jugular vein potentially puts the left arm’s vasculature in jeopardy. Catheter placement in the left internal jugular vein is associated with poor blood flow rates and high rates of stenosis and thrombosis.72,85 Femoral and translumbar vein placement are associated with higher infection rates compared to other sites.88 Ultrasound insertion has been shown to limit insertion complications.89,90 Fluoroscopy allows ideal catheter tip placement to maximize blood flow.

Totally subcutaneous catheter based access systems are undergoing clinical trials and hold promise for minimizing catheter infection rates. These devices use a subcutaneous port attached to a dialysis catheter (Lifesite [Vasca Inc, Tewksbury MA] and Dialock [Biolink Inc, Boston, MA]).

GUIDELINE 6

Acute Hemodialysis Vascular Access–Noncuffed Catheters

A. Hemodialysis access of less than 3 weeks’ duration should be obtained using a noncuffed, or a cuffed, double-lumen percutaneously inserted catheter. (For cuffed catheters, see Guideline 5: Type and Location of Tunneled Cuffed Catheter Placement.) (Evidence/Opinion)

B. These catheters are suitable for immediate use and should not be inserted before needed. (Evidence)

C. Noncuffed catheters can be inserted at the bedside in the femoral, internal jugular, or subclavian position. (Evidence)

D. The subclavian insertion site should not be used in a patient who may need permanent vascular access. (Evidence)

E. Chest x-ray is mandatory after subclavian and internal jugular insertion prior to catheter use to confirm catheter tip position at the caval atrial junction or the superior vena cava and to exclude complications prior to starting hemodialysis. (Evidence/Opinion)

F. Where available, ultrasound should be used to direct insertion of these catheters into the internal jugular position to minimize insertion-related complications. (Evidence/Opinion)

G. Femoral catheters should be at least 19-cm long to minimize recirculation. Noncuffed femoral catheters should not be left in place longer than 5 days and should be left in place only in bed-bound patients. (Evidence/Opinion)

H. Nonfunctional noncuffed catheters can be exchanged over a guidewire or treated with urokinase as long as the exit site and tunnel are not infected. (See protocols in Table III-2.) (Evidence)

I. Exit site, tunnel tract, or systemic infections should prompt the removal of noncuffed catheters. Treatment guidelines for catheter infection are discussed in Guideline 15, Catheter Care and Accessing the Patient’s Circulation. (Evidence/Opinion)



1
Table III-2. Protocols for Urokinase Administration
NKF-KDOQI Protocol for Urokinase Administration

1. Attempt to aspirate the occluded catheter lumen to remove heparin.

2. Steadily inject urokinase (1 mL or volume sufficient to fill lumen) with 3 mL or other small syringe into the occluded catheter lumen (urokinase 5,000 U/mL).

3. If needed, fill remainder of the catheter lumen with saline in the same manner (eg, for a 1.3 mL catheter lumen use 1 mL urokinase and 0.3 mL saline).

4. Add 0.3 mL saline every 10 minutes x 2 to move active urokinase to distal catheter.

5. Aspirate catheter.

6. Repeat procedure if necessary.

Manufacturer’s Protocol for Urokinase Administration

1. Attempt to aspirate the occluded catheter lumen to remove heparin.

2. Steadily inject urokinase (1 mL or volume sufficient to fill lumen) with 3 mL or other small syringe into the occluded catheter lumen (urokinase 5,000 U/mL).

3. Fill entire catheter lumen (urokinase 5,000 U/mL).

4. After 30 minutes, aspirate catheter. May be repeated as needed.

Note: Numberous protocols for urokinase administration are in sue, There are two examples:

Rationale Noncuffed, double-lumen catheters are suitable for percutaneous bedside insertion and provide acceptable blood flow rates (250 mL/min) for temporary hemodialysis.22,36,69 These catheters are suitable for immediate use but have a finite use-life and therefore should not be inserted until they are needed.22,36,69 The rate of infection for internal jugular or subclavian noncuffed catheters suggests that they should be used for no more than 3 weeks.22,36,69,91 The infection and dislodgment rates for femoral catheters require that they be left in place for no more than 5 days and only in bed-bound patients with good exit-site care. To minimize recirculation, femoral catheters should be at least 19-cm long to reach the inferior vena cava.92 The Work Group believes that longer durations of hemodialysis are best served by tunneled cuffed catheters because they are associated with lower infection rates and higher blood flow rates.22,36,69- 71,73-75,77,91,93 Noncuffed catheters may be used for up to 3 weeks. {texp}Ultrasound-directed cannulation minimizes insertion complications94-96 and should be used where available. In addition, the use of a post-insertion chest x-ray after internal jugular or subclavian insertion confirms the position of the catheter tip in the superior vena cava and allows evaluation for pneumothorax and hemothorax.26,36,69,73,97-101

Thrombosed, noncuffed catheters can be exchanged over a guidewire or treated with urokinase.69,70 (See protocols in Table III-2.) Infection of any sort–exit site, tunnel tract, or systemic–requires removal of the catheter as well as antibiotic treatment as outlined in Guideline 15: Catheter Care and Accessing the Patient’s Circulation, for tunneled cuffed catheters. The absence of a cuff requires removal of the catheter to prevent bacteremia mediated by bacterial migration down the external surface of the catheter.

GUIDELINE 7

Preservation of Veins for AV Access

A. Arm veins suitable for placement of vascular access should be preserved, regardless of arm dominance. Arm veins, particularly the cephalic veins of the nondominant arm, should not be used for venipuncture or intravenous catheters. The dorsum of the hand should be used for intravenous lines in patients with chronic kidney disease. When venipuncture of the arm veins is necessary, sites should be rotated. (Opinion)

B. Instruct hospital staff, patients with progressive kidney disease (creatinine >3 mg/dL), and all patients with conditions likely to lead to ESRD to protect the arms from venipuncture and intravenous catheters. A Medic Alert bracelet should be worn to inform hospital staff to avoid IV cannulation of essential veins. (Opinion)

C. Subclavian vein catheterization should be avoided for temporary access in all patients with kidney failure due to the risk of central venous stenosis. (Evidence)

Rationale Venipuncture complications of veins potentially available for vascular access may render such vein sites unsuitable for construction of a primary AV fistula.

Patients and healthcare professionals should be educated about the need to preserve veins to avoid loss of potential access sites in the arms and to maximize chances for successful AV fistula placement and maturation. Subclavian vein catheterization is associated with central venous stenosis.20,26,102 Significant subclavian vein stenosis will generally preclude the use of the entire ipsilateral arm for vascular access. Thus, subclavian vein catheterization should be avoided for temporary access in patients with kidney failure.

GUIDELINE 8

Timing of Access Placement

A. Patients with chronic kidney disease should be referred for surgery to attempt construction of a primary AV fistula when their creatinine clearance is <25 mL/min, their serum creatinine level is >4 mg/dL, or within 1 year of an anticipated need for dialysis. The patient should be referred to a nephrologist prior to the need for access to facilitate kidney failure treatment and for counseling about modes of ESRD care, including hemodialysis, peritoneal dialysis, and renal transplantation. (Opinion)

B. A new primary fistula should be allowed to mature for at least 1 month, and ideally for 3 to 4 months, prior to cannulation. (Opinion)

C. Dialysis AV grafts should be placed at least 3 to 6 weeks prior to an anticipated need for hemodialysis in patients who are not candidates for primary AV fistulae. (Opinion)

D. Hemodialysis catheters should not be inserted until hemodialysis is needed. (Evidence/Opinion)

Rationale Both the size and anatomical qualities of venous and arterial components of primary AV fistulae can influence the fistulae maturation time. An aggressive policy of primary AV fistulae creation may result in failures in patients with marginal anatomy. However, timely attempts to create primary AV fistulae before the anticipated need for dialysis will allow adequate time for the fistulae to mature, and will allow sufficient time to perform another vascular access procedure if the first attempt fails, thus avoiding the need for temporary access. Early referral of the patient with chronic kidney disease to a nephrologist is needed to facilitate kidney failure therapy with medications and diets that preserve kidney function. In addition, counseling patients on ESRD treatment options is essential to plan for ideal access (ie, peritoneal, and hemodialysis access).

The Work Group’s consensus is that maturation of an AV graft access site–defined as reduction of surgically induced swelling and the graft’s adherence to its tunnel tissue–usually requires about 3 weeks. Thus, ideally, AV grafts should be placed 3 to 6 weeks prior to use.

Cuffed and noncuffed catheters are acceptable for short-term (<3 weeks) use. Tunneled cuffed catheters are the method of choice for temporary access of greater than 3 weeks’ duration.

Catheters are suitable for immediate use. To maximize their use-life, they should not be inserted until needed.

GUIDELINE 9

Access Maturation

A. A primary AV fistula is mature and suitable for use when the vein’s diameter is sufficient to allow successful cannulation, but not sooner than 1 month (and preferably 3 to 4 months after construction. (Opinion)

B. The following procedures may enhance maturation of AV fistulae:

1. Fistula hand-arm exercise (eg, squeezing a rubber ball with or without a lightly applied tourniquet) will increase blood flow and speed maturation of a new native AV fistula. (Opinion)

2. Selective obliteration of major venous side branches will speed maturation of a slowly maturing AV fistula. (Opinion)

3. When a new native AV fistula is infiltrated (ie, presence of hematoma with associated induration and edema), it should be rested until swelling is resolved. (Opinion)

C. PTFE dialysis AV grafts should not routinely be used until 14 days after placement. Cannulation of a new PTFE dialysis AV graft should not routinely be attempted, even 14 days or longer after placement, until swelling has gone down enough to allow palpation of the course of the graft. Ideally, 3 to 6 weeks should be allowed prior to cannulation of a new graft. (Opinion)

D. Patients with swelling that does not respond to arm elevation or that persists beyond 2 weeks after dialysis AV access placement should receive a venogram or other noncontrast study to evaluate central veins. (Opinion)

E. Cuffed and noncuffed hemodialysis catheters are suitable for immediate use and do not require maturation time. (Evidence)

Rationale A vein must be mature, both physically and functionally, prior to use for vascular access. The time required for fistula maturation varies among patients. The Work Group does not advise use of the fistula within the first month after construction because premature cannulation of a fistula may result in a higher incidence of infiltration with associated compression of the vessel by hematoma and permanent loss of the fistula. Allowing the fistula to mature for 3 to 4 months before use may be ideal; however, the Work Group did not reach consensus on this topic.

Although there are no definitive data in the literature, any intervention that increases blood flow to the extremity may improve the chances of successful fistula development. Therefore, regular hand-arm exercises, with or without a lightly applied tourniquet, are recommended until the fistula matures. Failure of a fistula to mature is occasionally due to venous side branches that drain critical flow from the primary vessel. Ligating these side branches may result in successful maturation; however, the Work Group was not unanimous on this topic.

Repetitive attempts to cannulate an infiltrated fistula carries a high risk of inaccurate cannulation, which may further exacerbate the existing swelling and possibly lead to permanent loss of the access. Rather, the Work Group recommends that infiltrated fistulae be rested, and if required, other access established (eg, temporary or cuffed catheter), until the swelling has subsided and the vessel is sufficiently mature to allow successful cannulation. In some instances, use of an AV fistula can begin with placement of the arterial needle only, with return flow accomplished by means of a catheter. The Work Group concluded that cannulation of a PTFE dialysis AV graft within 14 days after insertion should be avoided because adhesion of the subcutaneous tunnel and graft has not occurred; potential hematoma and bleeding into the graft tunnel may ruin the access site. Dialysis AV grafts may be considered mature when swelling of the access site has reduced to the point that its course is easily palpable, but not less than 14 days after placement. Attempting to cannulate a new PTFE dialysis AV graft in an edematous arm may lead to hematoma formation and graft laceration (graft wall damage) from inaccurate needle insertion. Some practitioners argue that grafts may be cannulated immediately if the tunnel is carefully constructed. The Work Group cannot recommend early cannulation until randomized trials of graft patency show similar long-term patency with immediate and delayed cannulation.

Swelling and edema of the extremity are expected following graft insertion due to changes in local hemodynamics and soft tissue injury secondary to tunnel creation. Edema of an extremity following AV graft insertion may also be an indication of an occult central venous stenosis or occlusion,103 if the edema does not resolve over time with arm elevation. Therefore, venography or other noncontrast studies should be performed if edema and swelling persist beyond 2 weeks after graft insertion. Erythema of a new dialysis AV graft should not prevent its use, as long as the redness is limited to the path of the graft. Erythema along the path of the graft suggests surgical inflammation rather than infection.

 

 

 

 

 

 

 

 

 

 

 

© 2001 National Kidney Foundation, Inc

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