Hemodialysis Access

About Hemodialysis Access

Dialysis access surgery creates a reliable route to the bloodstream for hemodialysis in people with kidney failure. The arteriovenous fistula, a direct surgical connection between an artery and a vein, is generally the preferred long term access. Common sites are the radiocephalic fistula at the wrist, first described by Brescia, Cimino and colleagues in 1966, and the brachiocephalic fistula at the elbow. After creation, the vein enlarges and its wall thickens over a period of weeks, a process called maturation, until it can withstand repeated needle insertion. Fistulas tend to last longest and have the lowest infection rates of the access types, although some fail to mature. An arteriovenous graft, which uses a synthetic tube usually made of PTFE to connect an artery and a vein, is used when the veins are unsuitable; it can be used sooner but is more prone to narrowing, clotting and infection. Tunneled central venous catheters provide immediate access and are used as a bridge or when other options are exhausted, but carry the highest risk of infection. Ultrasound mapping of the arteries and veins before surgery helps choose the best site, and preserving arm veins in people with chronic kidney disease is considered important for future access. Complications include steal syndrome, in which blood is diverted away from the hand causing pain or ischemia, aneurysm formation at needle sites, narrowing that reduces flow, clotting, infection and, with large fistulas, strain on the heart. Narrowings are often treated with balloon angioplasty.