ARTERIOVENOUS SHUNT

Typical Number in Hospital:

Cost Bands:

References: 3,4

For haemodialysis blood must be removed from the body, passed through a dialyser and returned. Since it may be necessary to make and break these connections several times a week various methods have been developed for inserting tubes into blood vessels. The arteriovenous shunt consists of two PTFE (Teflon) and silicon rubber tube sets, one of which is connected into a tied-off artery and the other into a tied-off vein, usually at the wrist or lower leg. The silicon rubber tubes are brought out through the skin and are normally connected together, thereby forming a shunt between the artery and the vein. When haemodialysis is performed the connection is undone and blood from the artery will pass through the dialyser and back to the vein. These shunts are convenient to use but have proved relatively troublesome in terms of clotting, and infection at the site of passage through the skin.

Arteriovenous shunts have been largely supplanted by arteriovenous fistulae. In these cases an artery and a vein are tied off, each is slit for a few centimetres along each side and the two holes so created are sewn together, forming an internal shunt for the blood. The venous section bulges under the enlarged pressure providing a bulb of blood which is flowing rapidly, and can be easily penetrated by a wide bore needle or needles for haemodialysis. These fistulae have proved less troublesome than shunts.