How is Dialysis Done?
Healthy kidneys filter water and waste products from the body. During kidney failure, an “artificial kidney” is needed. In hemodialysis, the dialysis machine components do the filtering. In peritoneal dialysis, the body’s own peritoneal membrane filters the blood. In either case, a “dialysis access” is needed to get the blood to dialysis solution so that excess fluid and waste products can be disposed of. Hemodialysis accesses can be a catheter, graft or fistula. Peritoneal access is done by a peritoneal catheter.
A Permacath is a hollow tube that is placed in a large vein in the neck or upper chest. It is most commonly used as a temporary access when someone needs dialysis immediately or when they are waiting for a fistula/graft to mature. It should not be used as a long-term access because of the high risk of infection.
A graft is a soft, synthetic tube that is surgically connected to an artery at one end and a vein at the other end. The tube acts like a natural vein, allowing blood to flow through it. It is already the size and strength it needs to be. A graft can be placed in the arm or the thigh.
A fistula is created by surgically joining a vein and an artery. Arteries carry blood at high speed and pressure and have strong walls to handle the blood flow. When an artery is joined to a vein, the fast blood flow from the artery causes the vein to enlarge and strengthen its walls. In time, the vein becomes strong like an artery and can be used for hemodialysis.
A peritoneal catheter is a plastic tube that is surgically inserted into the peritoneal cavity. The tube is about eight inches long and is about the width of a pencil. It takes several weeks for the wound to heal and the tube is left in permanently. Once the wound is healed, the peritoneal cavity can be filled with dialysate and dialysis can be started.