Allograft as an Adjunct for Free Omental Flaps for Lower Extremity Coverage of a Mangled Lower Extremity

The utility of allograft for temporary coverage of soft tissue defects is well-established, most notably in the burn literature. Its utility as an adjunct to free tissue transfer for soft tissue defects has been described, but literature on the effectiveness of this hybrid approach for lower extremity salvage is limited. We present a series of two patients who underwent lower extremity salvage using an omental free flap and allograft followed by staged split-thickness skin grafting at our institution. Patient characteristics analyzed included age, smoking status, comorbidities, mechanism of injury, wound class, and wound surface area. Endpoints included partial or complete flap loss, number of days from allograft to autograft, postoperative infection, unplanned reoperation, and successful, functional extremity salvage.  Both patients were male, ages 50 and 35, with a BMI of 31 and 19.2 kg/m², respectively. Both were active smokers and had contaminated Gustilo IIIB wounds with areas of over 300 cm². Both flaps had partial necrosis, averaging 6cm², that was debrided at the planned second stage. Neither had an unplanned return to surgery, and both patients returned to ambulation.  Allograft skin as a practical and effective adjunct to omental free flap for post-traumatic lower extremity reconstruction. It can facilitate the resolution of edema and prevent flap desiccation, allowing time demarcation of partial flap necrosis and confirmation of flap viability prior to definitive skin autograft. This is particularly useful for large surface area contaminated highly irregular traumatic lower extremity wounds.