Vascular Access for

Hemodialysis

I

f you will be starting hemodialysis

treatments in the next several

months, you will need to work with

your health care team to learn how the

treatments work and what you can

do to get the most from them. One

important step before starting regular

hemodialysis sessions is preparing a vascular access, which is the site on your

body where blood will be removed and

returned during dialysis. To maximize

the amount of blood cleansed during

hemodialysis, the vascular access should

provide high volumes of blood flow

continuously during treatments.

A vascular access should be prepared

weeks or months before you start dialysis. It will allow easier and more efficient removal and replacement of your

blood with fewer complications. There

are three basic kinds of vascular accesses

for hemodialysis: an arteriovenous

(AV) fistula, an AV graft, and a venous

catheter. The AV fistula is considered

the best long-term vascular access for

hemodialysis because it provides adequate blood flow for dialysis, lasts a

long time, and has a complication rate

lower than the other access types. If

an AV fistula cannot be created, an AV

graft or venous catheter may be needed.

Arteriovenous Fistula

An AV fistula requires advance planning

because a fistula takes a while after

surgery to develop (in rare cases, as 

long as 24 months). But a properly

formed fistula is less likely than other

kinds of vascular accesses to form clots

or become infected. Also, fistulas tend

to last many years, longer than any

other kind of vascular access.

A surgeon creates an AV fistula by

connecting an artery directly to a vein,

usually in the forearm. Connecting the

Forearm arteriovenous fistula.

From

dialysis

machine

To

dialysis

machine

National Institute of Diabetes and Digestive and Kidney Diseases

NATIONAL INSTITUTES OF HEALTH

U.S. Department of Health

and Human Services
artery to the vein causes more blood to flow

into the vein. As a result, the vein grows larger and stronger, making repeated insertions

for hemodialysis treatments easier. For the

surgery, you’ll be given a local anesthetic. In

most cases, the procedure can be performed

on an outpatient basis.

Arteriovenous Graft

If you have small veins that won’t develop

properly into a fistula, you can get a vascular

access that uses a synthetic tube implanted

under the skin in your arm. The tube becomes

an artificial vein that can be used repeatedly

for needle placement and blood access during

hemodialysis. A graft doesn’t need to develop

as a fistula does, so it can be used sooner after

placement, often within 2 or 3 weeks. 

Compared with fistulas, grafts tend to have

more problems with clotting or infection and

need replacement sooner, but a well-cared-for

graft can last for several years.

Venous Catheter for

Temporary Access

If your kidney disease has progressed quickly,

you may not have time to get a permanent

vascular access before you start hemodialysis

treatments. You may need to use a venous

catheter as a temporary access.

A catheter is a tube inserted into a vein in

either your neck, chest, or leg near the groin.

It has two chambers to allow two-way flow

of blood. Once a catheter is placed, needle

insertion is not necessary.

Catheters are not ideal for permanent access.

They can clog, become infected, or cause narrowing of the veins in which they are placed.

But if you need to start hemodialysis immediately, a catheter will suffice for several weeks or

months while your permanent access develops.

For some patients, fistula or graft surgery is

not successful, and long-term catheter access

must be used. Catheters that will be needed

for more than about 3 weeks are designed to

be tunneled under the skin to increase comfort

and reduce complications.

2

One kind of AV graft.

Venous catheter for temporary hemodialysis access.

Looped graft

Vein

Artery
What to Expect During Hemodialysis

With every hemodialysis session, needle insertion is required. Most dialysis centers use two

needles—one to carry blood to the dialyzer

and one to return the cleaned blood to your

body. Some specialized needles are designed

with two openings for two-way flow of blood,

but these needles are less efficient. For some

patients, use of this needle may mean longer

treatments.

Some people prefer to insert their own needles.

You’ll need training for this to learn how to

prevent infection and protect your vascular

access. You may also learn a “ladder” strategy

for needle placement in which you “climb”

up the entire length of the fistula session by

session so you won’t weaken an area with a

grouping of needle sticks. An alternative

approach is the “buttonhole” strategy in which

you use a limited number of sites but insert the

needle precisely into the same hole made by

the previous needle stick. Whether you insert

your own needles or not, you should know

about these techniques so you can understand

and ask questions about your treatments.

Possible Complications

All three types of vascular access—AV fistula,

AV graft, and venous catheter—can have

complications that require further treatment

or surgery. The most common complications

are access infection and low blood flow due

to blood clotting in the access.

Venous catheters are most likely to develop

infection and clotting problems that may

require medications and catheter removal

or replacement.

AV grafts may also develop low blood flows,

an indication of clotting or narrowing of the

access. In this situation, the AV graft may

require angioplasty, a procedure to widen

the small segment that is narrowed. Another

option is to perform surgery on the AV graft

and replace the narrow segment.

Infection and low blood flow are much less

common in AV fistulas than in AV grafts and

venous catheters. Still, having an AV fistula

is not a guarantee against complications.

Taking Care of Your Access

You can do several things to protect your

access.

■ Make sure your nurse or technician checks

your access before each treatment.

■ Keep your access clean at all times.

■ Use your access site only for dialysis.

■ Be careful not to bump or cut your access.

■ Don’t let anyone put a blood pressure cuff

on your access arm.

■ Don’t wear jewelry or tight clothes over

your access site.

■ Don’t sleep with your access arm under

your head or body.

■ Don’t lift heavy objects or put pressure on

your access arm.

■ Check the pulse in your access every day.

For More Information

Your health care team will help you learn more

about how to care for your access site. Also,

for a copy of the booklet Getting the Most

from Your Treatment: What You Need to

Know About Hemodialysis Access, contact

National Kidney Foundation

30 East 33rd Street

New York, NY 10016

Phone: 1–800–622–9010

Internet: www.kidney.org

3
National Kidney and Urologic

Diseases Information Clearinghouse

3 Information Way

Bethesda, MD 20892–3580

Phone: 1–800–891–5390 or (301) 654–4415

Fax: (301) 907–8906

Email: nkudic@info.niddk.nih.gov

Internet: www.kidney.niddk.nih.gov

This publication is not copyrighted. The

clearinghouse encourages users of this

fact sheet to duplicate and distribute as

many copies as desired.

This fact sheet is also available at www.

kidney.niddk.nih.gov.

U.S. DEPARTMENT OF HEALTH

AND HUMAN SERVICES

National Institutes of Health

NIH Publication No. 03–4554

April 2003

The National Kidney and Urologic Diseases

Information Clearinghouse (NKUDIC) is a

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The NIDDK is part of the National Institutes

of Health under the U.S. Department of

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urologic disorders and to their families,

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