What happens to the bypassed artery and associated nerves after a bypass operation?

Artery atrophies: Typically the bypassed artery has no blood flow (hence the need for a bypass) and simply atrophies / scars down. The nerves are preserved and should not be affected by a bypass. The nerves in the skin which are cut during the procedure and cause skin numbness may improve over a six month period. Any numbness after 6 months is unlikely to get any better.

Left behind: Left in place unless there is a damaged section of artery that needs to be removed during the procedure.