Found the following on DaVita.com
Dear Annie,
Can you explain the buttonhole technique?
Connie
Dear Connie,
The buttonhole technique, or constant-site cannulation, is a way for care partners or patients to cannulate an arteriovenous (AV) fistula by inserting a dialysis needle into the same spot for each dialysis treatment, with little or no pain. A fistula is cannulated in exactly the same location for 6-8 treatments until a tract (think of an earring hole) is developed. Once this tract is established, a blunt needle is used for cannulation thereby decreasing the need for sharp needles. When cannulating buttonholes, great care must be taken to protect against infections, as micro-organisms can be easily carried through the tract into the patient's bloodstream.
Annie
Can you explain the buttonhole technique?
Connie
Dear Connie,
The buttonhole technique, or constant-site cannulation, is a way for care partners or patients to cannulate an arteriovenous (AV) fistula by inserting a dialysis needle into the same spot for each dialysis treatment, with little or no pain. A fistula is cannulated in exactly the same location for 6-8 treatments until a tract (think of an earring hole) is developed. Once this tract is established, a blunt needle is used for cannulation thereby decreasing the need for sharp needles. When cannulating buttonholes, great care must be taken to protect against infections, as micro-organisms can be easily carried through the tract into the patient's bloodstream.
Annie