after endarterectomy, now scar tissue what can I do?

I had an endarterctomy on my right carotid artery, I developed a keloid on my neck. I had six months ago a test and everything was perfect, and yesterday, after six months I have a blockage of 90% bigger than the one I had before (85%). The doctor told me that this time is scar tissue. I'm super confuse...what to do. My options are another endarterectomy or stent. Also the doctor is telling me that I can develop again scar tissue. What can I do, and the most important thing, which one could be the best choice for someone with my scar tissue problem.
Let me tell you that my original blockage was 85% at age 50, very rare as you now, and now also, according to the doctor, very rare to develop scar tissue in six months creating a blockage of 90%.
I read an article that mentions that "often a patch is use to widen the artery as part of the procedure. Is a patch same as stent? If I have a patch can I still develop scar tissue? Please help me, thank you.