If you are preparing to start hemodialysis, you may hear your healthcare team talk about your dialysis access or vascular access.

Your dialysis access provides a way for blood to safely leave your body, travel through the dialysis machine for filtering, and return to your body.

There are three main types of vascular access used for hemodialysis:

• An arteriovenous (AV) fistula
• An arteriovenous (AV) graft
• A central venous catheter

Each has advantages, limitations, and situations in which it may be appropriate.

Understanding the difference between a fistula vs. graft vs. catheter can help you have a more informed conversation with your nephrologist and dialysis care team about which option may be right for you.

Why Is Dialysis Access So Important?

During hemodialysis, a dialysis machine filters waste products and excess fluid from your blood.

To accomplish this, the machine needs reliable access to your bloodstream so that enough blood can flow through the dialyzer and then return to your body.

Your vascular access is sometimes described as your dialysis “lifeline” because it makes your hemodialysis treatments possible.

Choosing and protecting your access is therefore an important part of dialysis care.

What Are the Three Main Types of Dialysis Access?

The three main types of vascular access for hemodialysis are an AV fistula, AV graft, and central venous catheter.

They work differently and have different advantages and risks.

Quick Comparison: Fistula vs. Graft vs. Catheter

Your individual circumstances determine which access is most appropriate.

What Is an AV Fistula?

An arteriovenous fistula, commonly called an AV fistula, is created surgically by connecting one of your arteries directly to a nearby vein.

It is commonly created in the arm.

Connecting the artery and vein causes more blood to flow through the vein. Over time, the vein becomes larger and stronger so that it can tolerate the repeated needle insertions needed for hemodialysis.

This process is known as maturation.

Why Is an AV Fistula Often Preferred?

When a patient has suitable blood vessels and enough time for the access to mature, an AV fistula is often considered the preferred type of long-term hemodialysis access.

Compared with other access types, a functioning fistula generally has advantages such as:

• Lower risk of infection
• Lower risk of certain access complications
• Good blood flow for dialysis
• Potential for long-term use

However, fistulas are not appropriate or possible for everyone.

What Are the Limitations of an AV Fistula?

A fistula cannot usually be used immediately after it is created.

It needs time to mature before it can reliably support dialysis. The amount of time required varies from person to person.

Some fistulas also fail to mature adequately.

For this reason, patients approaching kidney failure may benefit from discussing vascular access planning with their nephrologist well before dialysis is expected to begin.

What Is an AV Graft?

An arteriovenous graft, or AV graft, also creates a connection between an artery and a vein.

Instead of connecting the patient’s artery directly to the vein, however, a surgeon places a synthetic tube beneath the skin to connect them.

During dialysis, needles are inserted into the graft.

When Might an AV Graft Be Recommended?

An AV graft may be considered when a patient’s veins are not suitable for creating a successful fistula or when other clinical factors make a graft more appropriate.

One advantage is that grafts generally require less time before they can be used than traditional AV fistulas, although the exact timing depends on the type of graft and your healthcare team’s assessment.

What Are the Risks of an AV Graft?

Compared with AV fistulas, grafts can be more likely to develop problems such as:

• Infection
• Blood clots
• Narrowing of the blood vessels
• Access blockage
• Need for procedures to maintain blood flow

Regular monitoring can help identify access problems before they become more serious.

What Is a Dialysis Catheter?

A hemodialysis catheter, sometimes called a central venous catheter, is a flexible tube inserted into a large vein.

It is commonly placed in the neck area, although other locations may sometimes be used.

The portion outside the body contains connections that allow blood to travel to and from the dialysis machine.

Unlike a fistula or graft, dialysis needles generally do not need to be inserted into the access during each treatment.

Why Are Dialysis Catheters Used?

The major advantage of a catheter is that it can often be used immediately.

This makes catheters particularly useful when a patient needs dialysis urgently and does not yet have a functioning fistula or graft.

A catheter may also be necessary when other forms of vascular access are not currently possible.

What Are the Risks of a Dialysis Catheter?

The biggest concern with a dialysis catheter is infection.

Because the catheter provides a pathway into a large central vein and part of it remains outside the body, careful infection-prevention practices are essential.

Catheters can also experience problems with blood flow, clotting, or positioning.

For many patients, a catheter is therefore used as a temporary access while a fistula or graft is being prepared for long-term dialysis.

However, every patient’s situation is different, and some patients may need a catheter for longer periods.

Fistula vs. Graft vs. Catheter: Which Is Best?

There isn’t one dialysis access that is automatically best for every person.

Your healthcare team should consider your overall health, blood vessels, treatment needs, expected timing of dialysis, previous vascular access procedures, and personal circumstances.

For many patients with suitable blood vessels, an AV fistula may offer important long-term advantages.

An AV graft may be a good alternative when a fistula is not possible or is unlikely to mature successfully.

A catheter can provide immediate access when dialysis must begin before another access is ready.

The goal is to find the right access for the right patient at the right time.

How Do I Protect My AV Fistula or Graft?

Your fistula or graft requires daily attention.

One of the most important things you can do is learn how your access normally looks and feels.

Check for the “Thrill”

When you gently place your fingers over a functioning fistula or graft, you may feel a vibration or buzzing sensation.

This is known as the thrill.

Your dialysis team can teach you how and where to check it.

If the thrill becomes significantly different or you cannot feel it, contact your dialysis care team promptly. A change or absence of the thrill may indicate a problem with blood flow.

Protect Your Access Arm

Unless your healthcare team tells you otherwise, you may be advised to avoid:

• Having blood pressure taken on the access arm
• Having routine blood drawn from the access arm
• Wearing tight clothing or jewelry that compresses the access
• Sleeping with prolonged pressure on the access
• Carrying objects in a way that puts excessive pressure on the access

Follow the specific instructions provided by your dialysis team.

Keep the Access Clean

Wash your access area as instructed before dialysis.

Avoid scratching, picking, or irritating the skin around your fistula or graft.

After dialysis, follow your care team’s instructions for managing the needle sites and bandages.

How Do I Protect a Dialysis Catheter?

Catheter care is especially important because of the risk of infection.

Your dialysis team will provide detailed instructions.

In general:

• Keep the catheter dressing clean and dry.
• Do not remove or change the dressing unless you have been specifically trained and instructed to do so.
• Do not open the catheter caps or connections yourself.
• Avoid touching the catheter unnecessarily.
• Follow your dialysis team’s instructions about bathing, showering, and keeping the catheter dry.

Never use your dialysis catheter for purposes other than those directed by your healthcare team.

What Are Signs of Dialysis Access Infection?

Contact your dialysis team promptly if you notice possible signs of infection around your access, such as:

• Redness
• Warmth
• Swelling
• Increasing pain or tenderness
• Drainage or pus
• Fever
• Chills

Catheter-related bloodstream infections can become serious quickly.

If you develop fever, chills, weakness, confusion, shortness of breath, or feel severely unwell, seek medical attention according to your healthcare team’s emergency instructions.

What Other Dialysis Access Problems Should I Watch For?

Infection isn’t the only complication that can occur.

Tell your dialysis team if you notice:

• A missing or noticeably different thrill
• New swelling of the access arm or hand
• Increasing pain
• Unusual redness or discoloration
• Bleeding that takes longer than usual to stop after dialysis
• Changes in the appearance of the access
• Problems with blood flow during treatment

Early attention to access problems may help protect your access and prevent more serious complications.

Can I Shower or Swim With Dialysis Access?

The answer depends on which type of access you have.

People with a healed AV fistula or graft may have different bathing instructions from someone with a dialysis catheter.

A catheter generally requires much more protection from water because moisture around the catheter site can increase infection concerns.

Ask your dialysis team for specific instructions about showering, bathing, and swimming based on your access type.

When Should Dialysis Access Be Planned?

Whenever possible, vascular access planning should begin before hemodialysis is urgently needed.

Creating an AV fistula requires surgery and time for the fistula to mature. Planning early may therefore reduce the likelihood of needing to begin dialysis with a temporary catheter.

If your kidney function is declining and your nephrologist believes dialysis may be necessary in the future, ask:

“When should we start planning my dialysis access?”

Having the conversation early does not necessarily mean you will start dialysis immediately. It means your healthcare team can prepare for your future treatment needs.

Frequently Asked Questions About Dialysis Access

What is the best access for dialysis?

An AV fistula is often preferred for long-term hemodialysis when a patient has suitable blood vessels because it generally has good blood flow and lower infection risk. However, a fistula is not appropriate for everyone. The best access depends on your individual medical situation.

What is the difference between a fistula and a graft?

A fistula directly connects your own artery and vein. A graft uses a synthetic tube to connect an artery and vein.

A graft can generally be used sooner than a traditional fistula but may have a higher risk of infection and clotting.

Why would someone need a dialysis catheter?

A catheter may be necessary when dialysis must begin quickly and a fistula or graft is not ready. It may also be used when other types of vascular access are not currently possible.

How long does a dialysis fistula last?

There is no fixed lifespan for an AV fistula. Some functioning fistulas can be used for many years, while others may develop complications or require procedures to maintain adequate blood flow.

What happens if I can’t feel the thrill in my fistula?

Contact your dialysis center or healthcare team promptly. A missing thrill may indicate that blood flow through the access has decreased or stopped.

Do not wait until your next scheduled dialysis treatment to mention a significant change unless your healthcare team has specifically instructed you otherwise.

Your Dialysis Access Is an Important Part of Your Care

Whether you have an AV fistula, AV graft, or dialysis catheter, protecting your vascular access is an important part of successful hemodialysis.

Learn what your access normally looks and feels like, follow your dialysis team’s care instructions, and report changes promptly.

If you are approaching dialysis but haven’t had vascular access placed yet, talk with your nephrologist about your options.

Planning ahead can give you and your care team more time to select and prepare an access that fits your individual treatment needs.

Medical Disclaimer

This article is for general educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Vascular access recommendations vary based on a patient’s health, blood vessels, dialysis needs, and other clinical factors. Always follow the recommendations of your nephrologist, vascular access team, and dialysis care team.

References

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Vascular Access for Hemodialysis.

National Kidney Foundation. Hemodialysis Access.

Kidney Disease Outcomes Quality Initiative (KDOQI). Clinical Practice Guideline for Vascular Access.