Vascular access: fistula, graft or catheter

Why an access is needed at all

Haemodialysis works by taking blood out of you, cleaning it and giving it back, at a speed that ordinary veins simply cannot supply. A vein in the back of your hand can give you a blood test. It cannot give a dialysis machine several hundred millilitres of blood a minute, three times a week, for years, without collapsing.

So an access has to be built. That is all an access is: a piece of engineering that makes a vein strong enough and fast enough to do a job it was never designed for.

The three options

Fistula first, and why that slogan was softened

For years the message was simple: everyone should have a fistula. The case for it is genuinely strong. A fistula stays open longer, gets infected far less, needs fewer procedures, gives better blood flow, and is associated with better outcomes.

But the 2019 KDOQI vascular access guideline deliberately moved away from a rigid hierarchy. It introduced the idea of an ESKD Life-Plan: an individual, written, annually reviewed map of your whole dialysis life, covering which treatments you expect to use and which accesses will serve them, including a contingency plan for when one fails. The principle it states is "the right access, in the right patient, at the right time".

The reason is honest and worth understanding: a fistula is the wrong answer for someone whose life expectancy is short, or whose vessels are poor, or who is likely to spend months waiting for a fistula to mature, fail, and end up catheter-dependent anyway. Forcing a fistula on that person buys them surgery and disappointment.

What to take from this: a fistula is still first choice for most people who will need long-term haemodialysis. But if your team recommends something else, that is not necessarily a second-rate decision, and you are entitled to ask them to explain the plan, including what happens if it fails.

Maturing: why a fistula takes so long

When the surgeon joins the artery to the vein, the vein is suddenly exposed to arterial pressure. Over weeks and months it responds by thickening its wall and enlarging, until it can take two large needles and give up blood at high speed. That process is called maturation, and it cannot be hurried.

The traditional yardstick is the Rule of 6s, from the 2006 KDOQI guideline: by six weeks after the operation, a fistula should have a blood flow of at least 600 mL/min, a diameter of at least 6 mm, a depth of no more than 6 mm below the skin, and at least 6 cm of straight, usable segment to put needles into.

It is a guide, not a verdict, and this is worth knowing if your fistula is being discussed as a borderline case. A 2022 analysis in the Journal of Vascular Surgery found that while the rules do predict maturation, many fistulas that fail the Rule of 6s will still support dialysis perfectly well, and that flow and depth together predict maturation about as well as all three criteria, with the vein's diameter mattering less than people assume.

Fistulas fail to mature reasonably often. That is not something you did wrong. It is a known, expected outcome, it is why the guideline asks for a contingency plan from the start, and it is why creating the access early rather than late matters so much.

Looking after your access: the daily habits

These come from the National Kidney Foundation's patient guidance, and they are as close to universal as anything in dialysis gets. They are also the difference between an access that lasts years and one that does not.

Every day

• Feel for the thrill. Several times a day, place your fingers over the access and feel the buzz. Learn what your normal feels like, because you are the person best placed to notice when it changes. If it stops, ring the unit immediately, whatever the time.
• Wash the access with antibacterial soap every day, and always before dialysis.
• Look at it. Redness, swelling, a growing bulge, or skin that is becoming thin and shiny all need reporting.

Never, on the access arm

• No blood pressure cuff.
• No blood tests, no drips, no cannulas.
• No tight clothing, no tight sleeves, no bracelets or watches.
• Nothing heavy carried on that arm, and no pressure on the access.
• Do not sleep with your head on it, and do not lie on it.

This is worth being firm about with people who do not know you. Tell every nurse, every doctor and every paramedic which arm carries your access, before they touch you. Many people wear an alert bracelet or carry a card for exactly this reason, because you will not always be conscious or in a position to argue.

Around the needles

• Needle sites should be rotated, or the buttonhole technique used if your unit teaches it, to avoid wearing out one spot and forming an aneurysm there.
• Do not scratch or pick the scabs over needle sites.
• Keep gauze or a clamp with you, always, in case of bleeding.
• Bleeding that takes more than 30 minutes to stop after needles are removed should be reported.

Most normal activity is fine and encouraged. Exercise is good for you, and the fistula is not made of glass. Protect the arm from direct injury, and otherwise use it.

How your access is monitored, and a change worth knowing about

This is a genuinely counterintuitive shift, and it explains something patients often find confusing.

The 2019 KDOQI guideline states that clinical monitoring is primary and surveillance is supplementary. In plain terms: what the staff feel, hear and see, and what the machine does during your session, matters more than routine scanning. It specifically does not recommend pre-emptively ballooning a narrowing found on a scan when there are no clinical signs to go with it. Intervention should need both: a clinical problem and imaging that confirms it.

The same guideline sets a performance goal it calls the "1-2-3 rule": no more than two procedures to get an access usable in the first place, and no more than three a year to keep it working. If your access is taking considerably more than that, it is fair to ask whether it is the right access for you, and what the contingency plan is.

What this means in practice

• Protect your veins now, before anyone needs them. If kidney failure is a possibility in your future, the veins of your non-dominant arm are a resource. Ask that blood tests and drips be taken from elsewhere.
• Have the access conversation early. A fistula created in good time is a fistula that is ready when you want it. Creating one is not a commitment to start dialysis.
• Ask for your plan, including the contingency. Which access, which arm, what happens if it does not mature, and what is next after this one.
• Learn the thrill. It takes five seconds a day and it is the single highest-value habit on this page.

Once your access is ready, the next question is what actually happens in the chair. We have described a first session, step by step.