Haemodialysis needs a blood vessel that can deliver a large flow, several times a week, for years. Joining an artery directly to a vein in the arm makes the vein enlarge and thicken until it can do exactly that.
An arteriovenous fistula is a surgical join between an artery and a vein, usually at the wrist or elbow, created so the vein enlarges under arterial pressure and becomes strong enough to be needled for haemodialysis. It takes six to twelve weeks to mature before it can be used. A fistula lasts longer and causes far fewer infections than a dialysis catheter or a synthetic graft.
Dialysis needs roughly 300 millilitres of blood a minute drawn out and returned. An ordinary vein cannot supply that: it is thin walled, low pressure, and would collapse.
Joining it to an artery changes it. Arterial pressure floods into the vein, and over the following weeks the vein responds by enlarging and thickening its wall. After six to twelve weeks it is big enough, strong enough and close enough to the surface to be needled three times a week without collapsing or tearing. That process is called maturation, and it is why a fistula must be created well before dialysis is needed.
The alternative, a tunnelled catheter in a neck vein, works immediately, which is its only advantage. It carries a much higher rate of bloodstream infection, it clots, and it gradually damages the central veins in a way that limits future access options. A synthetic graft sits between the two: usable sooner than a fistula, but more prone to clotting and infection.
Wherever possible the fistula is made as far down the arm as the vessels allow, usually starting at the wrist. That preserves the vessels higher up for future use, because most patients will eventually need a second or third access over a lifetime of dialysis.
Vessel quality decides this more than anything else, which is why the arm is scanned before a site is chosen.
The arm is examined and scanned to measure the artery and vein and choose the lowest workable site.
Usually local anaesthetic, or a regional block that numbs the whole arm. You stay awake.
A short incision exposes both vessels, most often the radial artery and cephalic vein at the wrist.
The vein is divided and sewn onto the side of the artery with fine sutures, creating the fistula.
A buzzing vibration should be felt over the vein immediately. Its absence means the join needs revisiting there and then.
The wound is closed and a light dressing applied. Nothing tight is placed around the arm.
Mild swelling and bruising. Keep the arm elevated when resting. The thrill should be present from day one and should be checked daily.
Wound healed. The vein begins to enlarge visibly. Hand exercises, such as squeezing a soft ball, encourage maturation.
The fistula is assessed for maturity, often with ultrasound. If large enough and superficial enough, needling can begin.
The fistula is in regular use. It is monitored at each dialysis session for flow, bleeding and signs of narrowing.
A well made fistula in good vessels can last many years and is the most reliable dialysis access available. Not all fistulas mature: a proportion fail to enlarge enough to use, more often in diabetic patients, in the elderly and where the veins have been damaged by repeated cannulation. Failure to mature is disappointing rather than dangerous, and another site is then chosen. The arm develops a visible, palpable, thrilling vein which some patients find unsightly, and a fistula can enlarge considerably over years.
Most are manageable, but steal syndrome and heart strain are the two that genuinely change decisions.
This arm becomes a lifeline. These rules apply from the day of surgery onward and are worth memorising.
A catheter is easier on day one and worse every day after. It infects the bloodstream far more often, clots, and damages the central veins, which limits access options for the rest of your life.
The wound heals in a fortnight; the vein needs six to twelve weeks to enlarge and thicken. Needling too early damages it and can lose it altogether.
Too much flow can steal blood from the hand and strain the heart. The aim is enough flow for dialysis, not the largest possible fistula.
A clotted fistula can sometimes be rescued within hours and rarely after a day or two. Losing time usually means losing the fistula.
Access is planned as a lifetime sequence rather than a single operation, starting as far down the arm as the vessels allow so that options remain for later. Microsurgical technique matters when the vessels are small.
Dialysis access creation is covered by health insurance and by government schemes including PM JAY in most circumstances, as part of the treatment of kidney failure. Cost depends on the site chosen and whether a graft is needed instead of a native fistula. A written estimate follows assessment.
The questions that come up before and after fistula surgery.
Ask your question →Usually six to twelve weeks. The wound heals long before that, but the vein needs time to enlarge and thicken. Using it too early is the commonest avoidable way to lose a fistula.
That vibration, called a thrill, is arterial blood rushing into the vein. It means the fistula is working. Checking it every day is the single most useful thing you can do, because its disappearance is the first sign of a clot.
Mild coolness can settle as the arm adjusts. A hand that is persistently cold, pale, painful or weak may be steal syndrome, where the fistula is diverting too much blood. Report it, because it can be corrected surgically.
A blood pressure cuff can clot the fistula. A cannula or blood test can damage the vein you depend on. It is worth being firm about this with any clinician, including in an emergency department.
It happens in a proportion of patients, particularly with diabetes or previously damaged veins. Another site is assessed, often higher in the same arm or on the other side, and a graft is considered if no suitable vein remains.
Yes. The vein becomes prominent and you can see it pulsating, and it enlarges over the years. Most patients accept this readily once dialysis is running well, but it is worth knowing beforehand.
Seeing patients from across the city and beyond: read about the practice on the plastic surgeon in Surat page, or check what a written estimate covers on the costs and insurance page.
