The following are definitions of words and terms commonly heard by patients or family members of those undergoing dialysis treatments.
A
Anastomosis: In an arteriovenous fistula (AVF), the point where a vein and an artery are connected. In an arteriovenous graft (AVG), the locations where the graft is connected to the patient’s vein and artery. An AVG has 2 anastomoses and an AVF has 1 anastomosis.
Aneurysm: A weak spot in the wall of the AVF or AVG which results in an excessive localized enlargement of the AVF or AVG. The aneurysm may expand and, if untreated, may eventually burst.
Angioplasty: A procedure used to widen vessels narrowed by stenoses or occlusions.
Arteriovenous (AV): A connection between an artery and a vein.
Arteriogram: An X-ray of the arteries taken with the use of contrast dye; sometimes called angiography.
Artery: Blood vessels that carry blood away from the heart.
AV Fistula (AVF): A surgically created vascular access where a vein and an artery are connected to each other resulting in the flow of blood from an artery directly into a vein. Ideally, AV Fistula creation is done several months before hemodialysis is needed, since it needs time to develop, or mature.
AV Graft (AVG): A surgically created vascular access using a synthetic material to connect an artery to a vein. AV graft placement is usually done a few weeks prior to use, and takes several days to several weeks before it is usable for hemodialysis.
B
Bruit: A buzzing sound, or swooshing caused by the high-pressure flow of blood through the patient’s AV fistula or graft. Can be heard through a stethoscope at the anastomosis, and for some distance along the access
C
Central Venous Catheter (CVC): A soft, flexible tube that is inserted into a large vein in the neck, chest, or leg to provide vascular access for hemodialysis
Chronic kidney disease (CKD): Progressive loss of kidney function over a period or months or years.
D
Dialysis: The process of removing wastes and excess fluid from the blood artificially as a substitute for the normal function of the kidneys
E
End-stage renal disease (ESRD): The progression of chronic kidney disease to the point where dialysis or transplantation is necessary to sustain life.
F
Fistulogram: The study of a hemodialysis access to evaluate patency and/or identify stenosis. Performed by injecting contrast through a catheter placed directly into the fistula
G
Graft: In hemodialysis, a vascular access surgically created using a synthetic tube to connect an artery to a vein.
H
Hemodialysis: The process of purifying the blood of a person whose kidneys are not working normally.
Hematoma: Excessive bleeding between the access and surrounding tissue – a bruise.
Heparin: Medication used to prevent blood from clotting while outside of the body.
Hyperplasia: Faster growth of tissue than normal.
Hypertension: High blood pressure.
Hypotension: Low blood pressure.
K
Kidney: One of two bean-shaped organs that filter wastes from the blood.
Kidney failure: Loss of kidney function.
O
Occlusion: Blockage. May occur in fistulas or grafts.
P
Pseudoaneurysm: Similar to an aneurysm but doesn’t involve the entire thickness of the vessel wall. Often occurs from repeated needle sticking of one site
R
Recirculation: Already dialyzed blood returning to the patient through the venous needle mixes with un-dialyzed blood entering the arterial needle
S
Shunt: The original permanent vascular access for hemodialysis patients, extended plastic tubes which were connected to an artery and to a nearby vein; this was called a Scribner Shunt. The tubes extend outside of the body, and when not in use are connected together, externally. This type of access is rarely used in dialysis treatment today due to a high rate of infection and bleeding. Many people continue to refer to arteriovenous grafts and fistulas as “shunts” since blood is shunted through these passageways
Steal Syndrome: A condition that occurs when the AVF or AVG“steals” blood flow from the lower part of the limb that it is located in; the reduced blood flow causes the hand or foot to feel unusually cold.
Stenosis: an abnormal narrowing of an opening, such as in a blood vessel.
Stent: A mesh-like device that is placed into a stenotic or narrowed area of a blood vessel to keep it open.
T
Thrill: The turbulence resulting from the passage of blood from the high-pressure arterial system to the low–resistance venous system. Can be palpated (felt) with the fingers.
Thrombosis: The formation of a blood clot in a blood vessel.
Thrombectomy: The removal of a clot from a graft or fistula.
V
Vascular access: A natural or artificial blood vessel used to move blood to and from the body and the hemodialysis filter.
Vein: A blood vessel that carries blood toward the heart.
Vessel Mapping: A procedure to evaluate the size and depth of the arteries and veins to determine if they can be used for the creation of an arteriovenous dialysis access.
