Rationale:

• Interventionalist-radiologists can utilize diagnostic imaging to locate, biopsy, and aspirate deep collections or masses for diagnostic purposes as well as for therapeutic drainage without having to use a surgical incision. However, surgeons can macroscopically visualize an infected area and perform debridement as well as drainage.
• Early diagnosis and definitive treatment may save limbs and improve survival; however, a delay in diagnosis and treatment of necrotizing fasciitis increases mortality.
• Patients with necrotizing fasciitis or gas gangrene do not respond to antibiotics alone, and debridement of devitalized tissue is necessary.

Evidence:

• Interventionalist-radiologists can obtain diagnostic material from deep locations through a thin needle (55).
• Surgical inspection of the deep tissues through a small incision allows evaluation of the condition of the fascia and viability of underlying musculature (35). Tissue biopsy specimens can be obtained for Gram stain and culture.
• Diagnostic incisions can be extended to perform radical debridement should macroscopic evidence of a necrotizing infection be present (35).
• Frozen section for histopathology has been recommended in the past (39; 56). Surgical exploration of the infected area provides macroscopic evidence of necrotizing fasciitis without the need for a pathologist to examine the tissue microscopically. Macroscopic signs include a malodorous or “dishwater” drainage, with thrombosed vessels and a positive “finger test,” which refers to a lack of resistance to finger dissection in normally adherent tissues (35).

Comments:

• Diagnostic exploration determines the correct anatomic diagnosis, often yields an etiologic agent, and provides urgent treatment.
• Staphylococcal infections are frequently associated with abscesses. In one study, 73% of abscesses were caused by MRSA strains containing PVL, whereas 23% were caused by non-PVL-containing strains (57).