Chronic Kidney Disease and Acute Renal Failure cause the kidneys to lose their ability to filter and remove waste and extra fluid from the body. Hemodialysis is a process that uses a man-made membrane (Dialyzer) to:
- Restore the proper balance of electrolytes in the blood.
- Eliminate extra fluid from the body.
- Remove wastes, such as urea, from the blood.
For hemodialysis, you are connected to a filter (Dialyzer) by tubes attached to your blood vessels. Your blood is slowly pumped from your body into the dialyzer, where waste products and extra fluid are removed. The filtered blood is then pumped back into your body.
Before treatments can begin, your doctor will need to create a site where the blood can flow in and out of your body during the dialysis sessions. This is called the dialysis access. The type of dialysis access you have will depend in part on how quickly you need to begin hemodialysis.
- Catheter: A tube, or catheter, may be used temporarily if you have not had time to get a permanent access. The catheter is usually placed in a vein in the neck, chest, or groin. Because it can clog and become infected, this type of catheter is not routinely used for permanent access. But if you need to start hemodialysis right away, a catheter may be used until your permanent access is ready.
- Fistula: A fistula is created by connecting one of the arteries to one of the veins in your lower arm. A fistula allows repeated access for each dialysis session. It may take several months for the fistula to form. A fistula may not clot as easily as other dialysis access methods. A fistula is the most effective dialysis access and the most durable. Complications include infection at the site of access and clot formation (Thrombosis).
- Graft: A vascular access that uses a synthetic tube implanted under the skin in your arm (Graft) may be used if you have very small veins. The tube becomes an artificial vein that can be used repeatedly for needle placement and blood access during hemodialysis. A graft does not need to develop as a fistula does, so a graft can sometimes be used as soon as 1 week after placement. Compared with fistulas, grafts tend to have more problems with clotting or infection and need to be replaced sooner. A polytetrafluoroethylene (PTFE or Gore-Tex) graft is the most common type used for hemodialysis.