Common Terms


Artery A vessel that carries blood away from your heart to your other organs, muscles and tissues.
Arteriovenous fistula (AVF) A vascular access created by a surgeon connecting an artery and a vein.
Arteriovenous graft (AVG) A vascular access created by a surgeon using an artificial blood vessel to connect an artery and a vein.
Cap A sterile, plastic piece that has a threaded fitting connector with a locking mechanism for the hub to seal in your blood and seal out air and infection.
Catheter A thin plastic tube that is inserted into a blood vessel and used for dialysis, intravenous drugs, fluids and/or nutrition.
Clamp A small, plastic, notched device that is fitted over each catheter tail as a backup safety device to the cap. The clamp should always be “on” when the catheter is not in use. Only the dialysis staff should place it in the “off” position when opening your catheter for hemodialysis.
Cuff A small fibrous band around the catheter just inside the tunnel (from the exit site) that holds the catheter in place.
Exit site The opening in your skin for the catheter. It is always covered with a sterile dressing.
Hemodialysis Healthy kidneys filter out waste products from the blood, and eliminate them in the form of urine. When a person’s kidneys fail, these waste products stay in the body. Hemodialysis removes these waste products. For all the blood to be properly cleaned during a treatment, it is rapidly and continuously transferred to and from the hemodialysis machine. Only a small amount of blood is outside the body at any time, and then only for 30 to 60 seconds.
Hub The end piece on each catheter tail that has a screw-on connector and a locking mechanism for the cap, the dialysis tubing or a syringe.
Lumen The inside part of your catheter. Most hemodialysis catheters have two lumens.
Right atrium The portion of your heart where the catheter tips will be placed.
Tail The portion of the catheter outside your body.
Tip The end of the catheter inside your body.
Tunnel The passage that was made under your skin for the catheter to pass through, to keep the catheter secure.
Vein A vessel that carries blood back to your heart.