Before you can begin hemodialysis, you will need a vascular access. This is an area on your body where two needles will be inserted before each hemodialysis session to allow your blood to flow in and out of your body.
There are three common types of vascular access that for dialysis. The planning process will begin by first identifying which type of access you will need, to do this a specialized ultrasound or vein mapping will be done to see if you are a candidate for an arteriovenous fistula (AVF) or a arteriovenous graft (AVG). The vein mapping process helps identify which access will be placed, along with the location of the access.
The AVF is the safest and most reliable type of vascular access. An AV fistula is a connection between an artery (a large blood vessel that carries blood from your heart) and a vein (a blood vessel that carries blood to your heart). In order to make an AV fistula in your body, you will need to have a minor surgery to connect your artery to your vein. This is most often done in your non-dominant arm. For example, if you are right-handed, you would probably get your fistula in your left arm.
Once the artery and vein are connected, more blood is able to flow through the fistula. After two to three months, the fistula will be stronger than a normal artery or vein, and will be able to withstand having needles put in and taken out many times per week. Because the fistula needs time to heal and become strong, it is best to get an AV fistula two to three months before you need to start dialysis.
An AV fistula can be placed in an out-patient surgical area, or in a free standing interventional nephrology center.
An AV graft is the next best vascular access option. Instead of connecting your artery directly to your vein, an AV graft uses a plastic tube to connect the artery and vein inside your body. Like an AV fistula, the AV graft is made by a doctor during a minor surgery. An AV graft is usually ready to be used in just two to three weeks. However, AV grafts are more likely to have problems with infections and blood clots.
If you find out your kidneys are failing and you need to start dialysis right away, your nephrologist may recommend that you get a central venous catheter (CVC). This catheter may be used if you have acute kidney failure or if there is not enough time to get an AV fistula or AV graft before you need to start hemodialysis.