Hello-
Your grandma is correct in not going through with surgery. I have read about many cases of people (especially war veterans) who cured gangrene back in the "early days" by using oral hydrogen peroxide. Look it up on the net and there is sooooo much information on how it cures all types of infections, viruses, etc...
There are also plenty (many many) of books out there that explain how taking hydrogen peroxide (not the peroxide sold at stores like Walmart), but the Food Grade and Technical Grade hydrogen peroxide can reverse infections. Doing this 3 times a day, along with changing the diet to NO sugar, little carbohydrates, and PLENTY of fruits and vegetables can reverse gangrene. Amputation does not have to be done. With alot of hard work and persistance, your grandma doesnt need surgery. (I dont check this site often...just passing thru, so I may not get your response if you respond. but I am really wishing your grandma well. Good luck.