Final answer:
Incision and drainage of a subfascial soft tissue abscess involve the treatment of gangrenous inflammation and infection related to necrotizing fasciitis, requiring surgical intervention and antibiotics.
Step-by-step explanation:
With incision and drainage of a subfascial soft tissue abscess, the abscess was involved in gangrenous inflammation and infection. This medical procedure was undertaken as a treatment for a severe case of necrotizing fasciitis, a rapidly progressing infection that can occur due to bacteria such as Streptococcus pyogenes. Surgical intervention such as debridement or even amputation may be necessary to remove dead or infected tissue and stop the infection's spread, in combination with treatments like intravenous antibiotics and potentially hyperbaric oxygen therapy.