When people and machines work together, there has to be connection between them. It can be called the man-machine interface, a glib and sexist recognition that humans and devices are different, but naming a problem does not solve it. Most shortcomings of prostheses, implants, ventilators, and devices for circulatory assistance originate where machine meets person. Hemodialysis is not an exception. In the contrived symbiosis of dialysis patient and dialysis machine, the vascular access device is a major cause of complications and disability. There are only two basic ideas behind most methods for dialysis access. These are the external shunt and the internal fistula.
The first idea came from Quinton and Scribner. Their shunt made long-term hemodialysis possible; with modifications, it is still used. With this method vein and an artery are cannulated and tubing is led out through the skin and connected. Arteriovenous flow maintains shunt patency between dialysis treatments.