I'm sorry to hear of your dad's struggle to cope with the pain associated with ischemia. I don't know what your father's overall condition is but unless he is free from other problems like with his heart, it is probably wise to hold off on the surgery. This is a very invasive surgery that would be hard on a otherwise healthy person. I'm sure your doctors have considered medications like Pletal or Trental to help with his circulation problems. If they haven't this should be considered. Pletal in particular can help tremendously with his pain issues. Your dad will be in my prayers.