Dialysis Access & AV Fistula

An arteriovenous fistula is a direct join, made surgically, between an artery and a vein just under the skin of the arm. High pressure from the artery then flows into the vein, and over the following weeks that vein widens and its wall thickens until it can take large needles repeatedly and carry a high flow. A vein on its own is too small and too delicate for that; the fistula is what turns it into something durable.

The waiting is intrinsic to it. The join is made in an hour and the vein takes six weeks to three months to become usable, so the operation is arranged well before access is actually needed.

Your surgeon chooses the site carefully, usually in the non-dominant arm and as far down the arm as the vessels allow, starting at the wrist and moving to the elbow only when the wrist is unsuitable. Working from the bottom up preserves the sites above for the future. An ultrasound map of the arteries and veins is taken beforehand to find the best vessels. Where the veins are too small or too damaged, a synthetic graft between artery and vein is the alternative; it can be used sooner and has a shorter working life.

The operation is done as a day procedure under local anaesthetic, sometimes with a block that numbs the whole arm, and you go home the same day. You are awake and there is no pain once the area is numb.

Your surgeon makes a cut of a few centimetres over the chosen site, separates the artery and the vein from the surrounding tissue, and checks that both are suitable. The vein is divided and its end is stitched to a small opening in the side of the artery with very fine sutures, under magnification.

When the clamps come off, your surgeon feels the join for a thrill, a continuous buzzing vibration that shows blood is flowing from artery to vein, and listens for the accompanying sound. That thrill is the sign the fistula is working, and you will be taught to feel for it yourself before you leave.

The wound is closed with sutures and a light dressing and never a tight one, because pressure over the join can stop a new fistula working. The whole procedure takes roughly 60 to 90 minutes, and you are observed for a short while before going home.

The arm is sore and a little swollen for about a week. Keep it raised on a pillow when sitting or lying, keep the dressing dry, and take ordinary painkillers as needed. Sutures come out at 10 to 14 days, and desk work is usually possible within a few days.

Avoid lifting anything heavy with that arm for two weeks. Once the wound has healed, your team will usually ask you to exercise the arm, commonly by squeezing a soft ball, to encourage the vein to develop.

The fistula cannot be used straight away. It needs a minimum of six weeks and often two to three months to mature, and your surgeon or the dialysis nurse will examine it at intervals and decide when it is ready. Using it too early damages it.

Two habits start now and are permanent. Feel for the thrill every day, morning and evening. And protect the arm for life: no blood pressure cuff, no drip, no blood sample and no injection in it, no tight sleeves or watch straps, and no sleeping with your weight on it.