What is created in an AV fistula?

An AV fistula, or arteriovenous fistula, is created by surgically connecting an artery directly to a vein. This anastomosis allows for increased blood flow into the vein, which helps facilitate the process of hemodialysis for patients with kidney failure. The connection between the artery and vein is crucial as it enables the vein to handle the higher blood flow, ultimately enlarging the vein and making it more suitable for repeated needle insertions during dialysis treatments.

The other options do not accurately describe an AV fistula. A bypass around the heart refers to procedures such as coronary artery bypass grafting, which is unrelated to the creation of an AV fistula. A connection only in the veins would imply that there is no arterial involvement, which is not consistent with how an AV fistula operates. A synthetic graft typically involves using materials other than the patient's own tissue to create a connection, but in the case of an AV fistula, the connection is made using the patient's own artery and vein without the need for synthetic materials.