Dialysis Vascular Access: AV Fistulas, Grafts, and Catheters

If you receive hemodialysis — a treatment that filters your blood through a machine when your kidneys cannot do this job adequately — you need a reliable way for large amounts of blood to flow out of your body to the dialysis machine and back again. This requires a dialysis vascular access: a specially created or placed connection that can handle the high blood flow rates dialysis demands.

There are three types of dialysis access. Each requires different care and has different advantages, risks, and lifespans. This guide covers all three.

The Three Types of Dialysis Access

Type	What It Is	Typical Lifespan
AV Fistula	Your own artery and vein surgically connected	Years to decades (preferred)
AV Graft	Synthetic tube connecting artery to vein	2–5 years typically
Tunneled Dialysis Catheter (TDC)	Two-lumen catheter placed in a large vein	Months to years

Part 1: Arteriovenous (AV) Fistula

What is an AV fistula?

An AV fistula is created by a surgeon who joins one of your arteries (a high-pressure blood vessel) directly to a nearby vein (a lower-pressure vessel). This connection — usually made in the forearm or upper arm — causes arterial blood to flow into the vein under pressure. Over time, this pressure causes the vein to enlarge and its walls to thicken, creating a large, strong vessel capable of handling dialysis blood flow rates.

A mature fistula can be felt and heard: you will feel a continuous vibration called a thrill and, with a stethoscope, hear a swishing sound called a bruit. These are signs your fistula is working correctly. You will check for these every day.

Maturation: the waiting period

An AV fistula does not work immediately after surgery. It requires time — typically 6 weeks to several months — to “mature” (enlarge and strengthen) before it can be used for dialysis. Larger, deeper veins may take longer to mature, and some fistulas unfortunately never mature adequately and require revision or an alternative plan.

During maturation:

Your surgical site needs to heal
The fistula arm must be protected from compression and injury
Hand exercises may be recommended to promote fistula development (squeezing a soft ball)
Your vascular surgeon and dialysis team will monitor maturation with ultrasound assessments
Do not use the fistula arm for blood pressure measurements, blood draws, or IV insertion

Checking your fistula daily

This is one of the most important things you do as a dialysis patient. Every day, check your fistula for the thrill:

How to check:

Place two fingers gently over the fistula (the area of the enlarged vein you can feel in your arm).
You should feel a continuous, gentle buzzing or vibration — this is the thrill. It should be present 24 hours a day, 7 days a week.
You can also listen: place your ear or a stethoscope lightly over the fistula. You should hear a low, continuous swishing sound — the bruit.

If the thrill or bruit is absent, weak, or different than usual: This may mean a blood clot has formed in the fistula. This is an emergency — call your dialysis center immediately, even if it is outside normal hours. A clot in the fistula can sometimes be cleared with a procedure if caught quickly. Do not wait until your next scheduled dialysis session.

Protecting your fistula

Your fistula is your lifeline for dialysis. Protecting it is one of your most important health responsibilities.

Never allow on the fistula arm:

Blood pressure measurements — even once; the compression can damage the fistula or cause clotting
Blood draws or IV insertions — tell every healthcare provider: “I have a fistula in this arm. Please use my other arm.”
Tight clothing, watchbands, bracelets, or anything that compresses the arm over the fistula
Sleeping with your body weight on the fistula arm

Post-dialysis care: After each dialysis session, your dialysis nurse will remove the needles and apply firm pressure to the needle sites to stop bleeding. It may take 5–15 minutes (sometimes longer) to achieve hemostasis (bleeding stopped). Do not remove pressure early. Once the sites are fully healed, small bandages are applied.

Check the sites after you leave the center. If a site reopens and bleeds:

Apply firm, direct pressure with your other hand or a clean cloth.
Hold for 10–15 minutes without checking.
If bleeding does not stop after 20 minutes of firm pressure, go to the ER immediately.

Rotating needle sites: Your dialysis nurses should rotate the needle insertion sites (use a different location each time) to prevent scarring at a single spot, which can cause aneurysms (bulging of the vein). If you notice your nurse always using the same spot, ask about rotation. Over time, raised, lumpy areas at needle sites can indicate an aneurysm developing — report this to your nephrologist.

Signs that your fistula needs attention

Contact your dialysis center or go to the ER for:

Loss of thrill or bruit (possible clot) — urgent
Significant swelling of the entire arm (possible outflow obstruction)
Redness, warmth, and pus at needle sites (infection)
A rapidly enlarging bulge over the fistula (aneurysm growth) — especially if the skin over it looks thin, discolored, or shiny
Numbness, tingling, weakness, or cold hand (possible steal syndrome — the fistula “stealing” blood from the hand; can be serious)
Bleeding from a needle site that does not stop with 15–20 minutes of pressure

Part 2: Arteriovenous (AV) Graft

What is an AV graft?

When a patient’s own veins are not suitable for a fistula (too small, too deep, or too damaged), a surgeon creates an AV graft. A short tube made of synthetic material (usually polytetrafluoroethylene, or PTFE) is surgically implanted to connect an artery to a vein. Dialysis needles are inserted into this synthetic tube — not into your own vein — during each session.

Differences from a fistula

Maturation is faster: Grafts can often be used 2–6 weeks after placement (vs. months for a fistula) because the synthetic graft does not need to enlarge.
Shorter lifespan: Grafts typically last 2–5 years before complications (clotting, stenosis, infection) require intervention or replacement. Fistulas often last much longer.
Higher infection risk: The synthetic material is more prone to infection than your own tissue. Graft infections are serious and may require removal.
Higher clotting rate: Grafts clot more frequently than fistulas and may require angioplasty or thrombolysis procedures to restore function.

Checking your graft

Check for a thrill and bruit daily, exactly as described for fistulas. The feeling may be slightly different (sometimes described as more of a buzz than a vibration), but it should be consistently present. Loss of thrill = call immediately.

Protecting your graft

The same rules apply as for fistulas:

No blood pressure on the graft arm
No blood draws or IV insertions in the graft arm
No compression (tight clothing, watches, sleep position)
Report any redness, warmth, or swelling over the graft site promptly — graft infections can spread quickly

After dialysis

Apply firm pressure to needle sites until bleeding fully stops. Watch for late bleeding after you leave the center.

Part 3: Tunneled Dialysis Catheter (TDC)

What is a tunneled dialysis catheter?

A tunneled dialysis catheter (also called a tunneled hemodialysis catheter, or by brand names such as PermCath or Tesio) is a two-lumen central catheter placed in a large neck or chest vein (usually the internal jugular). Like other tunneled catheters, it passes under the skin before exiting the body, creating a tunnel that reduces infection risk.

TDCs are used when:

A patient needs to start dialysis urgently, before a fistula or graft can be placed and matured
A fistula or graft has failed and no immediate alternative access is available
A patient is not a candidate for surgical access creation

TDCs are considered the least preferred dialysis access option because they have the highest rates of infection, clotting, and catheter-related complications compared to fistulas and grafts. They are often described as a “bridge” access to be used while a fistula or graft is being prepared.

Exit site and dressing care

Your TDC exit site (where the catheter exits the skin on your chest or neck) requires regular professional dressing changes — typically at each dialysis session, performed by your dialysis nurse.

Between dialysis sessions:

Keep the exit site covered with a clean, dry dressing
Do not manipulate, touch, or pull on the catheter
Protect the site from water — shower with the area covered; no tub bathing or submersion
Wear a secure, snug-fitting dressing that will not slip when you move

Important: If the dressing becomes wet, loose, or soiled between sessions, contact your dialysis center for guidance. Do not remove a wet dressing without a clean replacement ready.

Lumen care

The two external lumens of your TDC (typically colored red for arterial and blue for venous) are capped with specialized dialysis connectors between sessions. These caps are changed at every dialysis session by your dialysis nurse.

Never open the caps yourself. The external lumens connect directly to the large central vein — opening them incorrectly can allow air to enter the bloodstream, cause serious bleeding, or introduce infection.

If a lumen cap falls off or is accidentally removed:

Do not panic, but act immediately.
Clamp the catheter lumen if a clamp is accessible.
Cover the open end with a clean cloth (do not let it dangle in the air).
Call your dialysis center or go to the ER immediately.

Warning signs with a TDC

Infection is the most serious and common TDC complication. Signs include:

Fever (≥38°C / 100.4°F), especially with shaking chills — go to the ER or call 911 immediately
Redness, warmth, swelling, or pus at the exit site
Redness or tenderness along the tunnel tract under the skin

Other warning signs:

Catheter blood flow becomes sluggish or the dialysis machine frequently alarms during sessions (possible clot — your dialysis team addresses this)
Catheter appears to have shifted position (longer or shorter than usual)
Any bleeding from the exit site that does not stop with gentle pressure

Working toward a permanent access

If you have a TDC, work with your nephrology and vascular surgery team to develop a plan for a permanent access (fistula or graft) as soon as possible. The goal is to use the TDC as a temporary bridge, not a long-term solution.

General Dialysis Access Principles

Medical alert identification

Consider wearing a medical alert bracelet or carrying a medical ID card that states: “DIALYSIS PATIENT — No BP or needles in [left/right] arm.” This is critical in emergencies when you may not be conscious to advocate for yourself.

Communicating with all healthcare providers

Every healthcare provider — emergency room physicians, dentists, surgeons performing procedures, imaging technicians — must know about your dialysis access before any intervention involving your arms or neck. Actively tell every provider:

“I have a [fistula / graft / dialysis catheter] in my [left/right] arm/chest.”
“Please do not use this arm for blood pressure, blood draws, or IVs.”

Do not assume the information is in your chart — always say it out loud.

Diet, fluids, and access protection

Your nephrologist will have specific dietary and fluid recommendations based on your kidney function and dialysis schedule. Managing your fluid intake between sessions protects both your heart and your vascular access — fluid overload increases blood pressure and venous pressure, which can stress your access.

This guide is for educational purposes. Dialysis access care requirements vary by access type, facility protocol, and individual patient factors. Always follow the specific instructions of your nephrology and dialysis care team.