The black toes are probably gone but I really believe in maggot therapy for many reasons. They eat only dead tissue (they even take care of antibiotic resistant infections). Maggot therapy stimulates blood flow to the area and help healing. I do not know if your area does maggot therapy but it is saving many peoples fingers, hands, feet, and legs.
hi, you should consider your grandmom lucky that that they have scheduled an appointment to discuss treatment options in 4 days. in some countries..especially 3rd world country, it would takes weeks/months before they can be seen. Actually even here in the western countries, it takes a while too. if it is not life threatening, it generally takes approximately 1 week to months before the doctors/specialists can see them. Unfortunately, this is the nature of the health care.
If the antibotic works, then it would limit the spread of the wound. with wet gangrene, it is necessary to have debridement done (meaning that they need to cut away the dead tissues), so that it can limit spread of wound and clear the infection a bit. if that doesn't do it, and the infection is getting worst, amputation would be considered.
diabetic has a slower circulation therefore, it will be harder for their incision sites to heal. Even if they can clear the infection by surgery, the cut that they made with surgery might not heal well either, that's why they mean when they said surgery is risky.