My husband has 70% blockage in his carotid arteries and he is 78 years old. Would you recommend an operation. He had an ultrasound and a cat scan. His cat scan showed he had something on his lung. Yesterday he had another cat scan of his lung. In May of 2014 he had an aortic valve replacement (animal skin) He has had a balance problem ever since the operation and can t walk very fast. He has fallen several times. He was in very good physical health before his aortic valve replacement.