Fusarium infection-induced partial failure of free anterolateral thigh musculocutaneous flap: Case report

Abstract

Fusarium species, a soil-borne fungi, causes disease in animals and humans, particularly in immunocompromized patients. A 62-year-old male presented with type II diabetes mellitus, diagnosed 4 years ago. He had a motorcycle accident-caused open tibiofibular fracture of the left lower extremity (Gustilo grade IIIb). With open reduction and internal fixation, an anterolateral thigh musculocutaneous flap was harvested for coverage of exposed bone and defect reconstruction. Partial failure of the flap occurred 9 days following reconstruction, and histological examination revealed Fusarium spp. After treatment with antifungal drugs and debridement, we performed a split-thickness skin graft. At 2-year follow-up, the flap was viable with adequate bone union. This is the first reported case of partial flap failure due to a Fusarium spp. infection. Possibility of fungal infections in patients with late-onset flap failure should be noted. Prompt diagnosis and treatment are needed to prevent repeated free-tissue transfer and/or devastating outcomes.

Keywords: Fusarium infection; anterolateral thigh flap; open tibiofibular fracture.

Figure 1.

(a) Left tibiofibular shaft open fracture (Gustilo grade IIIb). (b) Left lower leg open fracture contaminated by roadside soil. (c) The orthopedic surgeon performed open reduction and internal fixation of the tibiofibular fracture. (d) We performed an ALT musculocutaneous flap, harvested from the ipsilateral leg, for defect reconstruction. Recipient vessels were the anterior tibial artery and its concomitant veins. (e) The patient’s postoperative course was uneventful. However, the proximal part of the flap started to show mild bluish changes 9 days following reconstruction. (f) The size of the affected area gradually increased day by day, and dry gangrenous changes ultimately developed over the proximal one-third of the by 35 days following reconstruction.

Figure 2.

(a) Orange cottony colonies grew on the Sabouraud dextrose agar. (b) White-cottony colonies grew on the brain heart infusion agar. (c) Cover slide under a light microscope showed septated hyphae with acute branching (lactophenol cotton blue stain, ×1000). (d) Cone-shaped microconidia, the characteristic of Fusarium (lactophenol cotton blue stain, ×1000). (e) Debridement of the gangrenous flap was performed on 35 days following reconstruction. (f) The periodic acid Schiff stain demonstrates septated, acute angled fungal hyphae, and spores in the tissues from the left lower leg (×1000).

Figure 3.

At 2-year follow-up, the flap was viable with adequate bone union.