An AV graft is a small tube, usually made from synthetic material, that surgeons implant under your skin to connect an artery to a vein. It creates a reliable access point where dialysis needles can be inserted during hemodialysis treatments. The graft acts as a bridge between the two blood vessels, allowing high-volume blood flow that dialysis machines need to filter your blood effectively.
How an AV Graft Works
Normally, blood flows from arteries through tiny capillaries before reaching your veins. An AV graft bypasses those capillaries entirely, routing blood directly from an artery into a vein through the synthetic tube. This increases blood flow and pressure in the vein, making it possible to draw blood out, run it through the dialysis machine, and return it to your body at the flow rates hemodialysis requires.
Most grafts are made from a synthetic plastic called PTFE (polytetrafluoroethylene), the same material used in many medical implants. Biological options also exist, including grafts made from processed cow arteries, which may carry a lower infection risk and better compatibility with your body. Your surgeon will choose the material based on your anatomy and medical history.
Where Grafts Are Placed
The most common location is the forearm or upper arm, where the graft forms a loop or straight connection between a nearby artery and vein. When arm sites have been used up or aren’t suitable, surgeons can place grafts in the upper or mid-thigh, connecting the femoral artery to a leg vein. Thigh placements are more common in patients who have had multiple previous access surgeries, or whose arm vessels are too damaged or scarred to support another graft.
AV Graft vs. AV Fistula
A fistula is the other main type of dialysis access. Instead of using a synthetic tube, a surgeon directly connects your artery to your vein, and over weeks the vein gradually enlarges and strengthens. Fistulas are generally considered the preferred option because they last longer and need fewer maintenance procedures once they’re working well.
The trade-off is that fistulas take longer to mature and fail more often before they can even be used. About 50% of fistulas require some kind of procedure before they’re ready for dialysis, compared to roughly 18% of grafts. That means grafts are usable sooner and more predictably. Once both are working, fistulas typically outlast grafts and require fewer interventions per year to stay open. But fistulas that needed a procedure to mature lose much of that longevity advantage, performing similarly to grafts in terms of how long they stay functional.
Who Gets a Graft Instead of a Fistula
Grafts are typically recommended when your natural blood vessels aren’t large enough or healthy enough to form a fistula. A vein generally needs to be at least 2.5 mm in diameter for a fistula, but only needs to be wider than 4 mm at the connection point for a graft, since the synthetic tube itself provides the structural support. People with small or scarred veins, often from previous IVs, blood draws, or dialysis catheters, frequently end up with grafts.
Patients with a shorter life expectancy or significant other health conditions may also be better candidates for a graft, since it can be used weeks after placement rather than the months a fistula needs to mature. People with severe heart failure sometimes do better with a graft because the change in blood flow it creates is less dramatic than what a fistula produces, putting less strain on the heart.
How Long AV Grafts Last
A large meta-analysis of synthetic grafts found that about 41% are still working without any intervention at the one-year mark. With maintenance procedures to keep them open, that number rises to 70% at one year. By two years, about 28% are still functioning without any help, and 54% are still working with periodic interventions. These numbers reflect the reality that grafts often need tune-ups, but with proper monitoring and timely procedures, more than half continue to function past two years.
Common Complications
Grafts are more prone to problems than fistulas. The most frequent issue is clotting (thrombosis), which occurs at a rate of roughly 2.2 events per 1,000 patient days in grafts, compared to 0.24 for fistulas. When a graft clots, it stops working until the clot is cleared, usually through a procedure done by a vascular specialist.
Infection rates for grafts range from 11% to 20% per patient year, significantly higher than fistulas (which have very low infection rates) but lower than dialysis catheters (5% to 18% per patient year). Synthetic material is more vulnerable to bacteria than your own tissue, so keeping the area clean and watching for redness, warmth, or drainage matters.
Grafts also carry roughly double the risk of ischemic steal syndrome compared to fistulas. This happens when the graft diverts too much blood away from your hand or fingers, causing coldness, numbness, or pain. It’s uncommon but worth knowing about, especially if you notice your hand feeling cold or weak on the side where the graft is placed.
Monitoring Your Graft at Home
You can check your graft daily using a simple routine: look, listen, and feel. When you place your fingers gently over the graft, you should feel a vibration called a “thrill.” In a healthy graft, this thrill is only present at the point where the artery connects to the graft, and the pulse through the body of the graft should feel soft and easy to compress.
You can also listen to the graft by placing your ear close to it or using a stethoscope. A healthy graft produces a low-pitched, continuous swooshing sound called a “bruit” that you can hear during both heartbeats and the pauses between them. If that sound becomes high-pitched, short, or only audible during heartbeats, it may signal a narrowing inside the graft. Similarly, if you feel a thrill running through the entire body of the graft (not just at the connection point), or if the pulse feels hard and pounding rather than soft, those are signs that something needs attention.
Between dialysis sessions, watch for swelling, bruising, redness, drainage, or bleeding around the graft site. Check that the temperature and color of both hands (or both legs, if the graft is in your thigh) look and feel the same. Any sudden loss of the thrill or bruit means blood may have stopped flowing through the graft, and that needs prompt evaluation.