@hotrodbob01 I am pretty sure they can be redone....by the right vascular surgeon..., but it may mean longer bypasses and taking more veins from other parts of your body. Well outside my area of expertise. An angioplasty might work for the most robust grafts, but they tend to have to be repeated after a couple of years or more. But to me, the non-expert, why can't they just slide a 'soda straw' of some kind into a slit and lift apart the collapsed area(s). It's not like it's now dead/scarred tissue.....do you think? I would consult with a vascular surgeon willing to take a look at your case.