hello concerned friend,thanks for writing to HCM.
I have read the history given in the query and understand the query.
it would have been helpful if you could put in details like:
age of the patient,site of origin of gangrene and how it started(whether it started as a raw ulcer or following a bite or wound inflicted by thorn etc),whether he has diabetes,
hypertension,coronary artery disease,high
cholestrol or any other systemic diseases and what other drugs he is on.
coming to your query,
first we need to know whether this was caused by impaired blood supply or bacterial infections as in cases of gas gangrene caused by clostridium perfringes which can be lethal
if he was my patient,
first debridement would be tried,if debridement fails,then
amputation would be the
next choice to prevent further spread and limit infection and then a prosthetic limb to be used to maintain functionality to an extent.
another necessary measure is to give him strong antibiotic coverage preferably using intravenous antibiotics, give him iv fluids and blood transfusions if needed.
if blood supply impairment is causing the problems,then bypass surgeries or relieving block of artery by
angioplasty can be done.
hyperbaric oxygen therapy is effective in some cases,but efficacy is limited and reconstructive
plastic surgery using skin grafts can be done.
life expectancy depends on extent of gangrene,his nutritional and immune system status,his age etc.if infection is aggressively managed and amputation is a viable option,7-10years is an optimistic call.As i said ,lack of details,wouldnt help in giving a better call.
Hope it helps and hope for the best..hope he recovers soon.
Clarify if any doubts are there.good day.