Indications and Limitations of Bilayer Wound Matrix–Based Lower Extremity Reconstruction: A Multidisciplinary Case-Control Study of 191 Wounds

Little is known about the efficacy of newer skin substitute scaffolds to reconstruct complex lower extremity wounds. The investigators present a multihospital experience of reconstructive surgeons utilizing collagen-GAG bilayer wound matrix in lower extremity soft-tissue reconstruction with the goals to (1) characterize a suitable patient population, (2) categorize failures to optimize patient selection, and (3) determine wound factors affecting success. METHODS: Subjects underwent collagen-GAG–based lower extremity wound reconstruction from May of 2010 to June of 2017. The primary outcome variable was 180-day graft success, defined as eventual split-thickness skin grafting after bilayer wound matrix application; failure was defined as inadequate wound bed for split-thickness skin grafting, requirement for vascularized tissue transfer, or eventual amputation. Eligible subjects had at least one lower extremity wound and were at least 18 years old. Exclusion criteria included third-degree burn wounds or failure to follow up for at least 60 days postoperatively. Predictor variables included demographics, medical comorbidities, perioperative characteristics, postoperative complications, and cost-related data for each hospitalization. RESULTS: There were 147 subjects with 191 wounds. Mean patient age was 60.1 years (range, 21.0 to 95.6 years), and mean body mass index was 30.5 kg/m(2) (range, 14.4 to 64.7 kg/m(2)). Average wound size was 73.1 ± 137.7 cm(2), with 49.0 percent of subjects receiving adjunct postoperative negative-pressure wound therapy. Seventy percent of wounds were successfully healed at 180 days. Most were localized between the knee and ankle (50.8 percent) or foot (46.1 percent). Tendon exposure (p < 0.05), bone exposure (p < 0.01), and bone excision (p < 0.04) were associated with reconstructive failure. CONCLUSIONS: The authors present the largest reported multihospital, multidisciplinary experience with collagen-GAG wound matrix for lower extremity reconstruction. Tendon and/or bone exposure and socioeconomic factors were associated with failure. CLINICAL QUESTION/LEVEL OF EVIDENCE: Risk, III.