A hemodialysis or vascular access should be prepared weeks or months before you start dialysis. The early preparation of the vascular access will allow easier and more efficient removal and replacement of your blood with fewer complications.

The three basic kinds of vascular access for hemodialysis are an arteriovenous (AV) fistula, an AV graft, and a venous catheter. A fistula is an opening or connection between any two parts of the body that are usually separate—for example, a hole in the tissue that normally separates the bladder from the bowel. While most kinds of fistula are a problem, an AV fistula is useful because it causes the vein to grow larger and stronger for easy access to the blood system. The AV fistula is considered the best long-term vascular access for hemodialysis because it provides adequate blood flow, lasts a long time, and has a lower complication rate than other types of access. If an AV fistula cannot be created, an AV graft or venous catheter may be needed.

What is an AV (arteriovenous) fistula?

An AV fistula requires advance planning because a fistula takes a while after surgery to develop—in rare cases, as long as 24 months. But a properly formed fistula is less likely than other kinds of vascular access to form clots or become infected. Also, properly formed fistulas tend to last many years—longer than any other kind of vascular access.

A surgeon creates an AV fistula by connecting an artery directly to a vein, frequently in the forearm. Connecting the artery to the vein causes more blood to flow into the vein. As a result, the vein grows larger and stronger, making repeated needle insertions for hemodialysis treatments easier. For the surgery, you’ll be given a local anesthetic. In most cases, the procedure can be performed on an outpatient basis.