A 60-year-old man with past medical history significant for diabetes presented with a several-week history of a left-foot wound. The patient stated that a small ulcer developed on the plantar surface of his foot, which gradually progressed to erythema with tracking streaks to above the ankle. Despite having baseline mild neuropathy, he described significant pain across the forefoot and noticed increasing dark discoloration across the forefoot and plantar surface. The patient also admitted to subjective fevers and chills.
On examination the patient's temperature was 101.9°F, pulse 110, and blood pressure was normal. He had proximal and pedal pulses in both lower extremities. The left foot was malodorous, edematous, and erythematous, with dark gangrenous changes along the third to fifth toes and plantar surface (Figures 6-1,6-2, and 6-3). Subcutaneous crepitance could also be appreciated along the forefoot extending to just below the ankle.
Left-foot gangrene with extensive necrosis of the plantar surface and the first toe. Tracking cellulitis, outlined with pen markings, extends above the medial malleolus.
Magnified view of left-foot gangrene showing plantar extension. The tissue was boggy with subcutaneous crepitance indicating gas-forming necrotizing infection.
Left-foot gangrene depicting extent of cellulitis. Despite appearing localized externally, all fascial planes of the foot and ankle were extensively necrotic.
Given these findings, a necrotizing diabetic foot infection was suspected. The patient was started on broad-spectrum intravenous antibiotics with coverage for clostridium and group B streptococcal species.
The patient was subsequently taken for operative wound exploration with finding of extensive tracking necrotizing infection along all fascial planes. A guillotine amputation above the ankle was performed with the wound left open.
After 3 days of antibiotics the patient was subsequently taken for conversion to a planned below-knee amputation.
Diabetes and peripheral arterial disease (PAD) account for the vast majority of amputations worldwide.1
Patients with diabetes have a 10-fold higher risk of amputation than nondiabetic patients, secondary to the higher incidence of PAD in diabetic patients.2
Treatment of critical limb ischemia (CLI) differs significantly among regions due to surgeon specialty training, experience, and case volume, with low volume centers having higher amputation rates.1
Regional, socioeconomic, racial, and ethnic disparities have been shown to affect amputation rates.3
Earlier endovascular and open bypass procedures have decreased the national amputation rate to approximately 15%.4,5
INDICATIONS FOR AMPUTATION
CLI with failed revascularization
Extensive pedal gangrene
Nonreconstructible arterial anatomy
Overwhelming pedal sepsis
Excessive surgical risk