Vascular access for dialysis

By Sue Lyon, Freelance Medical Writer & Editor

The 2017 Patient Reported Experience Measure (PREM) survey, coordinated by Kidney Care UK and the UK Renal Registry, had good and bad news for kidney units.

While most of the 11,027 kidney patients completing the survey highly rated their overall care, many haemodialysis (HD) patients were dissatisfied with their experience of needling—i.e. how often the kidney team inserted needles with as little pain as possible. Satisfaction with needling also varied widely between kidney units.

“This highlights that vascular access is one of the most important—and challenging—aspects of kidney care. Vascular access is a patient’s lifeline because good dialysis depends on it.

“Access must be ready for the start of dialysis, and then looked after to make sure that it’s functioning correctly,” says Alayne Gagen.

Alayne is the Renal Vascular Access Nurse Specialist for Manchester University NHS Foundation Trust (MFT), and recently became Co-Chair of the British Renal Society Vascular Access Special Interest Group (BRS VA).

Alayne recommends discussing vascular access as soon as possible — certainly when eGFR is declining towards 15 — and it should at least be broached in the pre-dialysis or low-clearance clinic. The prospect of dialysis can be unnerving, and Alayne believes that every patient deserves a great deal of empathy.

“Health professionals need to take a step back and understand each patient as an individual. Some people may not want to talk about access.

“This applies especially to those with acute kidney injury (AKI) or who have been diagnosed without warning with kidney failure and need to start dialysis immediately, as they have so much to absorb.

“And some patients do not feel ill even with very poor kidney function, while others see access as a step towards dialysis and feeling better. And every patient has lots of other concerns, such as the future of their family, job and other commitments,” she says.

Fistula first

There are four types of vascular access, but an arteriovenous fistula (AVF) is the gold standard. One reason is that it gives a good blood flow, which increases the effectiveness of dialysis, in turn improving health and wellbeing.

Alayne adds: “Since a fistula is made from your own blood vessels, you do not have a foreign body permanently inside you. Compared with other types of access, there is less risk of clotting and infection, so you are less likely to need hospital stays and antibiotics.

“A fistula also enables you to continue most of your daily activities. You can have a deep bath or a long, hot shower, and go swimming—none of which are advisable with a central venous catheter (CVC) or line.”

According to Alayne, the main drawback with a fistula is that it might not work or can stop working: the vein can become narrow (stenosis) or it can clot and become blocked.

It can also be difficult to balance the restrictions of a limited fluid allowance against maintaining the hydration needed for a good blood flow—a problem in very hot weather, or during any illness that causes diarrhoea or vomiting.

Some people also worry about the fistula’s appearance. “Patients tell me that they do not want ‘those lumps’ on their arm. The usual cause of lumps or aneurysms is area puncture—i.e. the fistula is needled or cannulated in the same place every time. ‘Rope laddering’ or the needling along the length of the fistula is recommended and will help to reduce the likelihood of aneurysms,” says Alayne.

Buttonholing is a newer method of needling that is less likely to cause aneurysms. Instead of sharp-pointed needles, blunt needles are inserted at the same two positions each time to create a tract or tunnel into the fistula—like the hole in the skin created by a piercing. It takes about six sessions to form buttonholes suitable for dialysis.

“At MFT, we train all our home HD patients to buttonhole. It can be difficult to use buttonholing in a dialysis centre unless the staff have received specific training. However, patients can learn the technique and do their own needling within the main unit—something we do encourage at MFT.

“This is because, in order to form the tracts, the same person must do the first six initial cannulations with the sharp needles, and we cannot always guarantee this in a busy dialysis unit,” explains Alayne.

Fistula surgery

When you are ready to go ahead with your access, the usual procedure is to be referred to a vascular surgeon for a consultation. At MFT the wait is four to six weeks.

"It can then take up to six months from being referred before you can needle your fistula. In the meantime, if you have to start dialysis you will need a line. This highlights why your fistula needs to be created in a timely fashion," says Alayne.

At the one-stop appointment with the surgeon, your veins are 'mapped' with ultrasound to see if they are suitable for a fistula, either at the wrist (radial fistula) or at one of two positions at the elbow (brachial fistula). One of the latter may involve a second operation called superficialisation, which should be discussed during the consultation.

At MFT, the fistula operation takes place three to four weeks after the one-stop appointment, lasts for 30 to 45 minutes and is usually done under local anaesthetic.

A general anaesthetic is possible if you cannot face being awake, but this means a longer wait for surgery because of the need for pre-operative assessment and possibly an overnight stay in hospital.

You can go home after the operation when the surgeon is happy with your recovery, usually after four to six hours with local anaesthetic. After your operation, you should not drive or lift heavy objects for two weeks. Your kidney unit should advise you when and how to start exercising your fistula arm to improve blood flow and help your fistula to develop.

From now on, check the appearance of your fistula and feel for the thrill (the buzzing sensation under the skin) every day. Contact your kidney unit at once if the thrill stops, or the fistula feels hot, looks red, or is painful.

"I strongly advocate that patients learn to be experts about their fistula. Sometimes I suggest that buying a cheap toy stethoscope so that you can get used to listening to sound of the thrill or bruit, " says Alayne.

Starting dialysis

At the follow-up appointment six to eight weeks after the operation, an ultrasound scan checks the depth, diameter and flow of blood of your fistula to see if it can be needled (called maturation). Should a superficialisation be needed, it will be booked after the follow-up appointment, and is generally done under a general anaesthetic.

Pre-operative checks should have already been done, but if not, an appointment will be sent before the operation date is given.

The early days of needling a fistula are often a worrying time for patients. According to Alayne: "We sometimes cannot avoid infiltration – when a needle goes into the fistula and out the other side, or nicks the vein wall.

“If the vessel wall is still fragile, the fistula may blow; i.e. the area will swell and pressure needs to be applied quickly, as it will cause bruising under the skin. It is the job of professionals to support patients through this experience".

Alayne stresses that pain should never be problem when needling a fistula or graft. "I always advocate that patients should have some form of local anaesthetic if they wish (at MFT we offer three types).

“Health professionals would not have dental treatment without anaesthetic and it is unacceptable to needle a fistula without offering pain relief, especially at the first of needling of the fistula," she says.

Unfortunately, fistula surgery sometimes fails and not everyone is suitable for a fistula or graft. Your artery walls may have become hardened due to deposits of calcium, while your vein can be too narrow. And sometimes blood vessels are too small or have been damaged due to other diseases like diabetes. This will be explained when you see the surgeon, who will then discuss your options for access.

According to Alayne, it is possible to dialyse long term with a line, providing it is well cared for and is checked carefully at every dialysis. She also sees no objection home haemodialysis with a line as long as you have been thoroughly trained to identify and cope with any problems.

Improving vascular access care

The BRS VA are working with colleagues to improve vascular access care across the UK. Initiatives include clinical practice recommendations to improve needling technique, tools to improve safety, and a national survey of the structure of vascular access services.

"By optimising vascular access services throughout the UK, our aim is to raise standards, which will in turn improve patients' wellbeing and the safety of their kidney care," concludes Alayne.

Janet's story

Janet Loftus is 59, lives in Manchester, and has been dialysing for five years. She dialyses at a hospital unit for four hours three times a week and has started to self-care. At present, she sets up her dialysis machine and dressings table and is hoping to start inserting her own fistula needles.

Three months after starting dialysis with a line, Janet underwent her fistula surgery at the one-stop vascular clinic in Manchester. She says: "I hated dialysing with a line and could not wait to have it out and use my fistula."

After her operation, Janet exercised with a squeeze ball to strengthen her fistula, and still uses one every day to maintain the blood flow. In the early days of dialysis, Janet's fistula blew a few times, but since then there have been no problems.

Janet says: "My fistula is amazing: it gives me a higher pump speed, so I feel much better than with a line. I can also do more.

“Before my kidneys failed, I used to go swimming with my granddaughter, and she was devastated when she found out I could not swim with a line. Now I have my fistula, she is happy that we are back in the pool.”