My father is 82, very weak and barely walks. He just found out he has 90%of his arteries clogged in his neck... the 2 on the side.... he is getting a stressed test to see if can handle surgery. What do you think the chances are that he can have surgery, or not? And, whether it matters if he moves from sea level to 82,00 ft with this condition? He also has had a few minor strokes as a result.... thanks for any insight, anxious daughter.