The most common treatment for kidney failure is Hemodialysis, also called dialysis. A dialysis machine is an artificial kidney which cleanses the blood. During dialysis, blood is drawn from the patient into the dialysis machine, circulated through the machine, and then returned to the patient. The purpose of vascular access is to provide reliable sites where the bloodstream can be easily accessed each time. The great majority of vascular accesses are created in the arm, but they can also be created in the leg.
An arteriovenous fistula is a connection between an artery (which carries blood away from the heart) and a vein (which carries blood back to the heart). This artificial connection allows the vein to become larger and for the walls of the vein to thicken, a process termed maturation. A mature fistula makes it easier for the vein to be punctured repeatedly for dialysis. Maturation typically takes one or 2 months, but in rare cases, can take up to 6 months or 1year. This makes advance planning for an arteriovenous fistula important.
An arteriovenous fistula is the preferred type of vascular access due to lower rate of infection and clot formation, resulting in greater longevity than other types of vascular access. However, not everyone is a good candidate for an arteriovenous fistula, particularly older patients and patients with small veins.
If a patient is not a good candidate for an arteriovenous fistula, an arteriovenous graft is considered. An arteriovenous graft is a piece of artificial tubing, generally made out of teflon or fabric, that is attached on one end to an artery, and on the other end to a vein. The tube is placed entirely under the skin and the tube itself is punctured during dialysis. An arteriovenous graft can in general be used two to three weeks after the operation.