Your kidneys play a vital role in purifying and maintaining the chemical balance of your blood. However, they can eventually lose their ability to function due to conditions like chronic kidney disease or acute kidney injury.
In such cases, unless you can have a kidney transplant, you'll need to undergo dialysis to filter and clean your blood. To receive this treatment, you'll first need to undergo dialysis access surgery to establish a connection between your bloodstream and the dialysis machine.
There are many types of access for dialysis. Based on your health condition and how urgently you need the treatment, your doctor will suggest the most suitable vascular access that'll give you the best result.
What is dialysis access surgery?
A dialysis machine can replace your kidney function by filtering out toxins and removing excess water from your blood.
To get your blood filtered, you can get hemodialysis. Dialysis is then done by connecting the blood vessels in your arms or legs with a dialysis machine. Alternatively, you can undergo peritoneal dialysis, in which your blood is purified by moving a cleaning solution through the blood vessels lining your abdomen.
However, arteries and veins are generally so small that it's not possible to insert an artificial object into them. For this reason, doctors carry out a minor operation called dialysis access surgery. During this surgery, they create a small opening in your body called vascular access through which they insert a needle in case of hemodialysis or a catheter in case of peritoneal dialysis.
Vascular access allows huge volumes (almost a pint) of blood to flow continuously through the dialysis machine every minute.
What are the types of access for dialysis?
These are the most common types of access for dialysis recommended for people with acute kidney problems:
AV fistula. Also called an arteriovenous fistula, this is considered the best kind of vascular access since it has the least risk of infection and can be used safely for many years. To make it, surgeons sew together a piece of vein and its nearby artery, present under the skin of your arm or leg. By doing so, the pressure inside the sewn-in vein rises, which makes it larger, thicker, and strong enough to receive the hemodialysis needle.
AV graft. When the veins are not big enough for an AV fistula, doctors install an arteriovenous graft via an AV graft bypass surgery. To make this graft, usually, a U-shaped plastic tube is sewn between your radial artery and a vein near your elbow.
Hemodialysis catheter. If you have an immediate need for hemodialysis, your doctor may suggest using a dialysis catheter until your AV graft or AV fistula has healed.
Such catheters are usually considered temporary vascular access since they have a high risk of infection.
Peritoneal dialysis catheter. To carry out peritoneal dialysis, surgeons use a long, thin, and flexible silicone-based tube, which is known as the Tenckhoff catheter. A small cut is made on your stomach through which this catheter is inserted deep into the inner lining of your lower abdomen.
What steps should be taken while preparing for dialysis access surgery?
Make sure that your dialysis access surgery is scheduled weeks or months before the first dialysis session. If your vascular access doesn't heal properly, it could lead to problems like blood clots, narrow veins, and reduced blood flow.
To prepare for the surgery, your doctor may ask you to "preserve your veins." This means you shouldn't get blood drawn from the veins in your chosen arm or leg. You may also be asked to not have any food or drink for at least 8 hours before the operation.
There are some exercises that can grow your blood vessels larger and make it easier for you to receive a hemodialysis needle. During your initial consultation, ask your doctor if they can tell you more about these exercises.
Are there any risks of dialysis access surgeries?
The most common problem that you may face after getting vascular access for dialysis is bleeding.
Additionally, since vascular access redirects some of your blood, you may notice a slight coolness in the selected arm or leg. However, severe coldness or numbness could be a sign of a serious issue and should be given urgent medical attention.
After having an AV graft bypass surgery, you could feel some redness or swelling where the graft is inserted. This is a normal problem that can be resolved by keeping your elbow straight and propping your arm on pillows. Still, you should call your doctor if you notice severe swelling and redness or a saturated dressing.
Over time, your AV graft could become narrow or cause blood clots, which could affect the blood flow in your arm or leg. In such a case, you may require a small surgery to replace or widen the narrow part.
A hemodialysis catheter has a high risk of developing a scarred vein, an infection, or blood clots, which could all lead to the narrowing of your vein. If this happens, your doctor may prescribe antibiotics to fight the infection or a blood thinner like warfarin to prevent blood clotting.
In some cases, a peritoneal dialysis catheter causes bleeding, as well as injuries to the abdominal blood vessels or the small or large intestines. In such situations, a minor surgery is needed to correct the position of the catheter.
How to take care of vascular access for dialysis
These are a few steps that you could take to reduce the risk of injury and infection in your vascular access site:
- Avoid heavy lifting or doing something that could put pressure on your access site.
- While your AV fistula can get wet 1 to 2 days after the surgery, make sure your hemodialysis catheter never gets wet.
- When you visit a doctor, see that no one starts an IV, draws blood, or takes a blood pressure reading using your access arm.
- Try not to wear jewelry or tight clothes on the arm containing the AV graft, as this could reduce your blood flow and cause blood clotting.
- Avoid lying on top of your access arm.
- If you place your fingers on the access site, you should be able to feel a slight vibration caused by the high-pressure flow of blood through the graft or fistula. Call your doctor if the vibration stops or feels different, as that could mean that your vascular access has become narrow.