Establishing and maintaining hemodialysis access
Hemodialysis involves the use of a machine to clean or filter the blood when the kidneys are failing. Regular vascular access that provides high volumes of blood is required to perform this treatment. The access is often prepared weeks or months before dialysis is started. This allows easier and more efficient removal and replacement of cleansed blood with fewer complications. There are three main types of access used for hemodialysis. They include:
A fistula is a connection that is created between an artery and a vein, usually in the forearm. Called an AV fistula for short, this kind of access takes a while to develop after surgery. But, it is less likely to become infected even after years of use because it is made up of the patient's own tissue. Connecting the artery to the vein allows higher volumes of blood to flow through the vein. As a result, the vein grows stronger and larger, making repeated insertions for hemodialysis treatment easier. The creation of an AV fistula requires local anesthetic and is performed on an outpatient basis.
If a person's veins are unsuitable for AV fistula creation, a synthetic tube can be place under the arm and serve as an artificial vein that can be easily punctured repeatedly for hemodialysis treatment. A well cared for graft can last several years, but they are more prone to clotting and infection than a fistula.
If immediate dialysis is required, there may be no time for fistula creation and maturation. Instead, a venous catheter can provide temporary access. (See catheters and ports.)
All three types of vascular access used in hemodialysis risk complications of infection, clotting and reduced blood flow. The Vascular Center trains patients in the proper care of their access sites and monitors these closely for any signs of complications.