In response to the skyrocketing healthcare costs for dialysis patients, the National Kidney Foundation proposed the Dialysis Outcomes Quality Initiative (DOQI). The DOQI's purpose was to make recommendations for establishing clinical practice guidelines for managing patients with end-stage renal disease. Here, a brief summary of those vascular access guidelines pertinent to interventional radiologists is provided.
Dialysis access preservation
Mark B. Saker, MD; Howard B. Chrisman, MD; Alan H. Matsumoto,
are with the Division of Vascular and Interventional Radiology at
Northwestern University Medical School in Chicago, IL.
is Director of the Division of Angiography and Interventional
Radiology at University of Virginia Health Systems in
Charlottesville, VA. He is also a member of the editorial
advisory board of this journal.
Partly in response to the skyrocketing healthcare costs for
dialysis patients (estimated to be more than $1 billion for 1996),
the National Kidney Foundation proposed the Dialysis Outcomes
Quality Initiative (DOQI) in 1997. The purpose of this initiative
was to review the published literature and make recommendations for
establishing clinical practice guidelines for managing patients
with end-stage renal disease, with a goal of improving patient
outcomes and survival.
Practice guidelines addressed hemodialysis adequacy, peritoneal
dialysis adequacy, vascular access, and anemia. Specifically, the
guidelines for vascular access were established by a
multidisciplinary group that included five nephrologists, two
surgeons, two nurses, and one interventional radiologist. Of a
total of 114 clinical practice guidelines developed, 38 were
created to address the area of vascular access.
A brief summary of those vascular access guidelines pertinent to
interventional radiologists will be reviewed.
Guidelines regarding patient evaluation prior to access
Guideline 1: Patient history and physical examination
prior to permanent access selection
-Pertinent aspects of the history and physical examination that
will help to dictate the type and location of the vascular access
are emphasized. A detailed evaluation of the venous, arterial, and
cardiopulmonary systems is mandatory. Some of the most relevant
issues include previous central venous catheter and cardiac
pacemaker placement, and history of prior angio access for
hemodialysis. These have been associated with central venous
stenosis. Patients with conditions such as diabetes mellitus,
malignancy, and prior surgery or trauma to the chest area are at
higher risk for developing abnormalities in their venous system. On
physical examination, the presence of upper extremity edema or
collateral veins suggests a central venous stenosis.
Guideline 2: Diagnostic evaluation prior to permanent
-Preoperative venography is recommended if there is 1) edema or
size discrepancy in the target limb; 2) presence of collateral
veins; 3) a current or prior history of subclavian vein
catheterization; 4) a current or prior history of transvenous
pacemaker placement; 5) a previous history of surgery or trauma to
the chest, arm, or neck; or 6) prior access in the same limb.
Ultrasound and MRI evaluation can be used when venography is
contraindicated. Arteriography is also indicated if there are
diminished pulses in the target limb (figure 1).
A left upper extremity venogram was performed in this patient
with a history of multiple central catheter placements for
hemodialysis. The presence of collaterals and significant
narrowing preclude the creation of a native fistula or
implantation of a graft.
Guideline 3: Selection of a permanent vascular access and
order of preference for placement of arteriovenous (AV)
-The use of tunneled catheters for permanent access is discouraged;
the use of AV fistulae, preferably the radial-cephalic fistula, is
recommended. If the AV fistulae fail, an AV graft or transposed
brachial-basilic fistula should then be considered.
Guideline 4: Type and location of dialysis AV graft
-If a native fistula can not be created, the use of a synthetic AV
graft with polytetra-fluoroethylene (PTFE) is recommended. Graft
placement can be varied in configuration, and the type and location
can be determined by the patient's anatomy and access history.
Guideline 5: Type and location of tunneled cuffed
-Tunneled cuffed venous catheters are to be used when vascular
access is needed for more than 3 weeks or when all other options
are no longer available. These catheters can allow for the
maturation of native AV fistulae. Insertion via the right internal
jugular vein is preferred. Catheterization of the subclavian vein
should be avoided due to a 40 to 50% incidence of subclavian vein
stenosis following its use.
Additionally, fluoroscopic guidance is mandatory for line
placement, and ultrasound guidance for venous puncture is
desirable. There is no data to support the use of one catheter type
over another (figure 2).
Subclavian artery perforation is found during an attempt to place
a catheter without sonographic or fluoroscopic guidance.
Guideline 6: Acute hemodialysis vascular access:
-Vascular access for less than 3 weeks can be provided with cuffed
and non-cuffed venous catheters. Non-cuffed catheters can be
inserted at the bedside, and positioning should be confirmed with
an x-ray. Femoral vein catheters should be at least 19 cm in length
and should not be left in place for more than 5 days.
Guideline 7: Preservation of veins for AV access
-All upper extremity veins should be preserved in any patient with
a condition likely to lead to dialysis. Therefore, in patients such
as those with end-stage renal disease (creatinine > 3.0 md/dl)
and diabetes mellitus, vein puncture should be limted to the dorsum
of the hand and should be on a rotational basis. Subclavian vein
puncture should not be performed.
Guideline 8: Timing of access placement
-Patients should be referred for vascular access when creatinine
clearance is less than 25 ml/min, when serum creatinine is greater
than 4 mg/dl, or within one year of anticipated dialysis. AV
fistulae should be allowed to mature for at least one month and
preferably for 3 to 4 months. AV grafts should be placed 3 to 6
weeks prior to the anticipated need for dialysis. Central venous
catheters for dialysis should be avoided until they are absolutely
Guideline 9: Access maturation
&madsh;AV fistulae maturation may be improved by selective
obliteration/embolization of venous side branches. When a new
fistula is infiltrated (hematoma), it should be rested until the
swelling has resolved. Persistent arm swelling following the
creation of an AV fistula or graft should be evaluated with
Guideline 10: Monitoring dialysis AV grafts for
-Monitoring AV grafts for the development of a hemodynamically
significant stenosis is recommended. It has been shown that with
surveillance and preemptive intervention, graft thrombosis rates
can be reduced from 0.58-1.0 episodes per year to 0.19-0.28
episodes per year.
In addition, 6-month primary patency rates after graft declotting
range from 18 to 43%, as compared with 38 to 64% after percutaneous
angioplasty (PTA), without the need for declotting.
Therefore, AV grafts should be monitored on a weekly basis with
physical examination and an organized screening program that
includes one or more of the following: 1) dynamic venous pressure
measurements during dialysis, 2) static pressure measurements, and
3) intra-access flow using transonic methods.
A baseline dynamic pressure reading should be acquired when the
vascular access is first used, followed by repeat measurements at
least once a month. Three successive elevated pressure measurements
suggest an underlying problem with the AV graft and warrants
further evaluation with fistulography. Additional information can
be obtained with urea and non-urea recirculation methods, decreased
hemodialysis delivery (Kt/V), and elevated negative pre-pump
Duplex and color ultrasound also can be used for graft
surveillance but may not be cost-effective as a screening tool.
Criteria described as normal on ultrasound studies include peak
systolic velocities of 100 to 400 cm/sec and end-diastolic
velocities of 60 to 200 cm/sec. Stenoses of greater than 50% are
indicated by peak systolic velocity ratios of greater than 3.5.
The reported sensitivity of color Doppler is 84%, and it has a 60%
However, most patients with greater than 50% stenosis detected by
ultrasound surveillance are asymptomatic, and only 13 to 22% are
found to have increased venous pressures or urea recirculation
(figures 3A, 3B).
(A) A diagnostic fistulogram in a patient with elevated venous
pressures shows a high grade lesion at the venous anastomosis.
(B) This postangioplasty angiogram shows resolution of the lesion
with no retrograde venous flow.
Guideline 11: Monitoring primary AV fistulae for
-Flow rates during dialysis are the most accurate indicator of
dysfunction of a native AV fistula. Failing fistulae may manifest
by high in-flow pressures during dialysis, the inability to achieve
desired flow rates, elevated out flow pressures, or upper extremity
edema. If aspiration pressures during dialysis exceed 200 mm Hg, an
inflow lesion should be suspected. When out-flow pressures are
greater than 200 mm Hg, an outflow lesion usually is present. When
upper extremity edema develops, a stenosis or occlusion of an
essential central vein should be excluded.
Guideline 12: Recirculation methodology, limits,
evaluation, and follow-up
-The determination of urea circula tion is highly variable and
depends upon multiple factors (e.g., needle position, graft size,
dialysis pump speed, and central venous pressures). Generally, it
is considered to be abnormal when it is greater than 10%. However,
an elevated urea recirculation is an insensitive parameter, as many
fistulae fail despite the presence of "normal urea recirculation".
Guidelines addressing prevention of complications
Guidelines 13, 14, and 15
-These guidelines address how to prevent access infection,
adequately handle needle cannulation of grafts and fistulae, and
care for venous catheters. The patient and staff should be educated
in how to prevent graft or catheter infection. Infection rates
should be monitored, and cannulation of vascular access should
comply with OSHA regulations. Simple maneuvers such as the
application of a dry gauze dressing with povidone iodine can reduce
Guidelines on management of complications and when to
Guideline 16: Managing potential ischemia in a limb
bearing an AV access
-Diabetic patients and those with poor in-flow to the angio-access
site or poor run-off distal to the angio-access site are at greater
risk for developing limb ischemia. The symptoms can be seen acutely
or chronically. Treatment usually requires surgical intervention,
although endovascular therapy can be helpful.
Guideline 17: When to intervene on dialysis AV grafts for
venous stenosis, infection, graft degeneration, or pseudoaneurysm
-A stenosis greater than 50% accompanied by a clinical indicator of
access failure should undergo prophylactic intervention with either
PTA or surgery. Surgical intervention will be necessary for the
management of infection, degeneration, and pseudoaneurysm formation
Multiple pseudoaneurysm formation here requires surgical
Guideline 18: When to intervene on primary AV
-An intervention on primary AV fistulae is recommended when there
is inadequate flow to achieve the prescribed dialysis, a
hemodynamically significant stenosis is detected, or when a
clinically significant aneurysm is present.
Guidelines for optimizing treatment of failing dialysis
Guideline 19: Treatment of stenosis without thrombosis in
dialysis AV grafts and AV fistulae
-The expected outcome for the treatment of a stenosis without
thrombosis in an AV graft or primary AV fistulae are as follows:
primary patency at 6 months for PTA should be 50%, and the primary
patency of surgery at 12 months should be 50%. Surgery is held to a
higher standard due to its invasiveness and the loss of a usable
vein with each surgery. If PTA fails twice within 3 months,
surgical revision should be done, if possible. The use of stents is
reserved for PTA failures in non-surgical situations. However,
stents used for the treatment of peripheral venous stenoses in
association with ipsilateral dialysis fistulae have primary patency
rates reported to be as low as 33% at 12 months.
Guideline 20: Treatment of central vein stenoses
-Central vein stenoses should be treated with PTA. Stents should be
reserved for use when there is a recurrent stenosis within 3 months
of a PTA, or if there is immediate elastic recoil during the PTA
procedure. Stents in this setting are associated with 1-year
primary patency rates of 25 to 40% (figures 5, 6).
A previous central venous stent placed for failed angioplasty is
seen. Patency maintenance was achieved with repeated
Brachiocephalic vein reconstruction with the use of stents is
seen here, following failed angioplasty.
Guideline 21: Treatment of thrombosis and associated
stenoses in dialysis AV grafts
-The treatment of thrombosed AV grafts should be initiated
expeditiously, with no more than one femoral catheterization
performed for the purpose of temporary dialysis. Declotting is
performed with pharmacomechanical techniques, the use of
thrombectomy devices, or with surgery, and a post-procedure
fistulogram should always be done for evaluation. If an underlying
stenosis is detected, it can be corrected with either PTA or
surgery. Declotting of a graft should be done on an out-patient
basis, using local anesthesia. Clinical screening parameters should
return to normal following the procedure. There should be an
immediate technical success rate of 85% for all techniques.
Surgical intervention is associated with a 50% primary patency at
four months and 40% at 1 year. Percutaneous interventions are
associated with a 40% primary patency at 3 months.
Guideline 22: Treatment of primary AV fistulae
-Primary AV fistulae thromboses are difficult to treat. Selection
of procedure should be on an individual basis, according to local
expertise. Practitioners may consider surgery and mechanical and
Guideline 23: Treatment of poorly functioning tunneled
-Dysfunction of a dialysis catheter is defined as a failure to give
flow rates of at least 300 ml/min. The use of low-dose urokinase
(Opencath, Abbott Laboratories) is recommended for inital
management. If this fails, any of the following methods to
reestablish catheter function can be undertaken, depending upon the
expertise of those at your institution: fibrin sheath stripping,
urokinase infusion (i.e., 40,000 units/hour for 6 to 12 hours),
catheter exchange, or repositioning of a malpositioned
Guidelines 24 and 25: Treatment of infection of dialysis
AV grafts and primary AV fistulae
-Endovascular intervention in this clinical setting should be
avoided, due to the risk of bacteremia and sepsis.
Guideline 26: Treatment of infected tunneled
-Tunneled catheters with exit site or tunnel infections should be
managed with antibiotics. The catheter should be removed only if
antibiotic therapy is unsuccessful in managing the infection. In
the presence of bacteremia in an unstable patient or in a patient
with symptoms which last for more than 36 hours, the tunneled
catheter should be removed. If the patient is stable, the catheter
can be exchanged over a guidewire, but antibiotics should be
administered for at least 3 weeks. A new permanent tunneled
catheter should not be placed unless there have been negative blood
cultures for 48 hours.
Guidelines 27 and 28: Surgical management of AV graft
pseudoaneurysms and AV fistulae aneurysms
-During a fistulogram, direct puncture of these aneurysms and
pseudoaneurysms should be avoided.
Guidelines addressing quality of care standards
Guideline 29: Goals of access placement: maximizing
primary AV fistulae
-At least 50% of new patients electing hemodialysis should have
construction of an AV fistula. Approximately 15% of these patients
in the United States currently have native fistulae, though the
goal is to have at least 40% of the hemodialysis patients in the
United States with native AV fistulae. Each center should maintain
a database to track access types and complication rates.
Guideline 30: Goals of access placement: use of catheters
for chronic dialysis
-This guideline states that less than 10% of patients on chronic
hemodialysis should have chronic catheters (defined as those placed
for more than 3 months in the absence of a maturing access).
Guideline 31: Center-specific thrombosis rates
-AV dialysis graft thrombosis rates should not exceed 0.5 episodes
per patient year, though currently about 1.2 episodes of thrombosis
occur per patient year in the United States. Thrombosis rates for
an AV fistula, after adjusting for initial failures, should be less
than 0.25 episodes per patient year. Each institution should have
an ongoing quality assurance program to evaluate thrombosis rates
and their causes. Again, creating a screening program is the key to
achieving these goals.
Guideline 32: Infection rates
-Infection rates should not exceed 1% in native fistulae and 10% in
AV grafts, as calculated over the usable life of the access.
Tunneled catheters should have less than a 10% systemic infection
rate at three months, and less than 50% at one year.
Guideline 33: Primary access failure rates: AV
-The 30-day primary AV graft failure rates should not exceed 15%
for a straight forearm graft, 10% for a forearm loop graft, and 5%
for an upper arm graft. Again, each institution should create
monitoring programs to identify failures and problems with access
creation and use.
Guideline 34: Primary access failure rate: tunneled
-More than 90% of tunneled catheters should be able to exceed flow
rates of 300 ml/min during the initial dialysis session.
Significant complication rates (pneumothorax requiring a chest
tube, symptomatic air embolism, hemothorax, hemomediastinum, or
hematoma requiring evacuation) related to tunneled catheter
insertion should not exceed 2%.
Guideline 35: Primary access failure rate: AV
-No recommendations were made for primary native AV fistula
Guideline 36: Cumulative patency rates of dialysis AV
-The cumulative patency rates of newly created AV grafts should be
at least 70% at 1 year, 60% at 2 years, and 50% at 3 years.
Guideline 37: Cumulative patency rates of tunneled
-The chronic use of tunneled catheters is discouraged.
Guideline 38: Cumulative patency rates of native AV
-No recommendations were made.
Successful mechanical thrombolysis is achieved with the use of
the Castaneda-Cragg brush.