Hi, I didn't have a bypass. I had massive blood clot several years ago. My TOS is because of a broken collarbone and hardware that was put in. They did put a stent in because the vein was so damaged but of course that broke. The arm is pretty functional. It gets tired quickly. I have massive pain often but that is from the nerves not the vein. I work at a desk. I even go to the gym but I use machines for weight training. The bloodflow is low in the area but the collaterals have taken over a lot. Not sure if this helps you but for me the vein isn't bothersome it is the nerve pain.