Arteriovenous fistulas

Junior doctors and non-renal secondary care doctors are encountering patients with renal disease in greater numbers than before. Many of these patients will have arteriovenous fistulas for haemodialysis. Arteriovenous fistulas, in which a vein is joined to an artery, are created surgically. After the procedure there is a substantial increase in blood flow and blood pressure through the vein, which dilates, arterialises, and can then be cannulated with dialysis needles to facilitate haemodialysis. Fistulas can be created using native veins or a prosthetic graft. Prosthetic grafts are used when all native veins have been exhausted.

The rise in numbers of patients with renal failure is largely due to an ageing population with increasing rates of diabetes.12 In the United Kingdom, about 75% of patients with end stage renal failure will begin treatment with haemodialysis, and up to 40% will start treatment via central venous catheters.3 These catheters have disadvantages that include high rates of infection, high rates of dysfunction, and damage to the central veins due to stenosis and occlusion. A fistula has the advantage of being done as a day case procedure under local anaesthesia and with a low early complication rate. The National Kidney Foundation guidelines state that 80% of patients beginning haemodialysis should dialyse via a native arteriovenous fistula.45

Fistulas must be looked after carefully to ensure that patency is retained for as long as possible. This requires knowledge of common complications such as fistula thrombosis, steal syndrome, infection, and swelling of the arm. The aim of this article is to provide an overview of arteriovenous fistulas for medical students and junior doctors.