In order to start hemodialysis, you will need what is called an “access” in order to pull out your blood to be filtered. There are many types of hemodialysis access. This article will focus on the AV Fistula, which stands for Arteriovenous Fistula.
An AV Fistula is the connection of a vein and an artery in your arm in order to allow the blood from your body to be pulled out into the dialysis machine and put back in at the same place. Your nephrologist (kidney doctor) may recommend you get an AV Fistula if he/she anticipates that you will need to start hemodialysis soon, or if you have recently started hemodialysis.
Why Is the AV Fistula Used?
There are many types of hemodialysis access that can be used to give a person dialysis. The AV Fistula is the preferred method to perform dialysis. Your own veins and arteries are being used to create access, so it is the least risky and longest lasting type of access. By connecting an artery and a vein together, it creates a large space for blood to flow. Your dialysis nurse will then use two needles: one to draw blood from your access, and the other to put the clean blood back in. It is necessary because you cannot take blood in while getting blood out from just an artery or a vein. By connecting an artery and a vein together, it creates a larger space where the blood can both enter and exit.
Assessment
Your nephrologist will start by assessing whether or not you need an AV Fistula. You will probably need an AV Fistula if you need to be on dialysis for a long period of time. If you are only going to be on dialysis short term, you likely will not need an AV Fistula, and will probably get a different form of access. It is also important that your veins and arteries are strong enough for the procedure. You will undergo a “venous mapping” procedure beforehand in order for the surgeon to find an area that is ideal for the AV Fistula. He/She will also decide whether or not your veins and arteries are strong enough to get an AV Fistula. If they are not, your surgeon and nephrologist will have to consider placing a different hemodialysis access such as an AV Graft, a VasCath, or a PermCath.
Surgery
Having an AV Fistula placed is not major surgery. It can usually be done fairly quickly, and usually is scheduled as an outpatient procedure unless you are in the hospital for another reason. Many times a nephrologist will schedule this surgery many months before he anticipates you will need to go on permanent hemodialysis. This is because an AV Fistula takes several months to “mature” and be ready for use. If you are already on hemodialysis, you will need another form of access until your AV Fistula matures.
Care
It is important to properly care for your access once it is placed. Your nurse needs to know which arm you have dialysis access in any time you get any type of care. She will likely listen to your AV Fistula to make sure it is working properly. If you are in the hospital for another reason, make sure you do not get an IV or a needle stick in this arm for any reason. You should also make sure any blood pressure cuff is used on the other arm. You need to make sure these things are done on your other arm to keep your AV Fistula intact. Make sure your access is kept clean before and after dialysis treatments. Try not to put pressure on this arm by sleeping on it, lifting heavy items, wearing tight clothes, or wearing heavy jewelry.
You should also be aware of where your nurse is accessing your AV Fistula each dialysis session. Usually your nurse will try to start at the bottom of your access and gradually move up each time so you don’t develop a lot of scar tissue in one spot. Eventually you may even be able to poke yourself to gain access to your AV Fistula if you would like in order to make sure this process is done correctly.
Infection
One of the main reasons an AV Fistula is the preferred route of hemodialysis treatments is the decreased risk of infection. There is always a risk of infection when getting surgery of any kind, but it is very low compared to the risk of continuing to do hemodialysis through another access. The AV Fistula actually has the lowest risk of infection for performing hemodialysis. Once your AV Fistula is matured, you will likely have less infections and will likely be able to get hemodialysis treatments problem free for many years.
Risks
There are some risks associated with having an AV Fistula which are common to dialysis accesses in general. There is the risk of it clotting or getting an infection. If your access clots, you will likely need to go to the hospital and get another form of access temporarily to receive dialysis until you can get your access declotted. This is another surgical procedure that is performed. It usually does not take very long and your AV Fistula can be used again right away. If your surgeon is unsuccessful in declotting your AV Fistula, you will need to get another AV Fistula created or another form of access. If it gets infected, you will need to go into the hospital to get antibiotics until the infection clears.