Hi z.
Sorry to hear about your brothers condition. Radiation vascular disease can present this way. We tend to see a lot of coronary disease in Hodgkin's patients for example.
The best advice I can give to let an experienced reviewer look at these films and decide the feasablity of doing an intervention. This is not a slam dunk easy case. Dr. Jay Yadav here at the Cleveland Clinic is very good with carotid stents. If you are in this area, it may be worth hearing his opinion. You may even be able to send him your informatin for an e-consult over email.
It is possible that hypoperfusion is responsible for his passing out. There are also pressure receptors in his neck that may be compromised from the radiation and leading to these passing out episodes.
I hope this helps and thanks for posting.
Hey maybe you could look at my post under Tetracyclines and Calcification especially in my post to maryroe later on.
There has been some amazing results with this antibiotic family and i'm living proof.
If you are looking for alternatives to surgery this is definately something you could consider to discuss with your brother.
I wish him well he sounds like he's had some really tough times!