The kidneys are two bean-shaped organs, which are each about the size of your fist. They are located at the back of your abdomen, on either side of your spine. The kidneys work like a filter, getting ride of extra fluid and waste materials in the blood. When your kidneys lose the ability to filter and clean the blood, the fluid and waste can build up and poison the body. This is called kidney (renal) failure.
When the kidneys can no longer clean the blood, dialysis may be needed. The most common form of dialysis is called hemodialysis. In hemodialysis, blood from an artery in your arm flows through a thin plastic tube to a machine called a dialyzer. The dialyzer filters the blood, working like an artificial kidney, to remove the extra fluids and waste from the blood. The cleaned blood then flows out of the machine through another tube placed into a nearby vein in the same arm. Most people who need dialysis have three dialysis sessions each week. Each session lasts between three and four hours.
Vascular Access Site
Before you can begin hemodialysis, there needs to be a way to remove the blood from the body and then return it. Your arteries and veins are usually too small, so you will need surgery to create a vascular access site.
There are three kinds of vascular access sites:
- A fistula (also called an arteriovenous fistula or A-V fistula), which is made by joining an artery and a vein under the skin in your arm. When the artery and vein are joined, the pressure inside the vein increases, making the walls of the vein stronger. The stronger vein can then receive the needles used for hemodialysis. The fistula can be used for many years.
- A graft (also called an arteriovenous graft or A-V graft), which is made by joining an artery and vein in your arm with a plastic tube. The graft is usually ready to use about three weeks after the surgery. A-V grafts are usually not as long lasting as A-V fistulas, but a well-cared for graft can last multiple years.
- A catheter, which is inserted into a vein in the neck or below the collarbone is for short-term use until your AV fistula or A-V graft is healed and ready to use. A catheter is not used for permanent access.
What to Expect
Your surgeon will determine which vascular access site will work best for you. The operation to create the site in one of your arms will occur under anesthesia. The location of your access is based upon several factors--most importantly the quality of superficial veins available for creation of an AV fistula. The surgeon will try to create the access site in your non-dominant arm.
After Vascular Access Surgery
Patients should avoid heavy lifting. Any injury to your arm can cause bleeding. When you have a doctor’s appointment, do not let anyone take your blood pressure, start an IV, or take blood from the arm with the A-V fistula or graft.
If you have an A-V graft, you should avoid wearing anything tight around your wrists or arms. Clothing or jewelry that is tight can decrease the blood flow in the graft, which can lead to blood clots within the graft. Also, do not lie or sleep on top of your arm if possible.
For more information about vascular access for hemodialysis, call LifeBridge Health at 410-601-WELL (9355).