Background: Commercially available human placental amnion/chorion tissue allografts have been successfully used as protective treatment barriers for wounds and diabetic ulcers. Burn and traumatic limb injuries with exposed bone or tendon generally require surgical flaps or amputations for healing. The purpose of this study was to determine if dehydrated human amnion/ chorion membrane allografts (dHACM) with decellularized human collagen matrix (dHCM) could be used to salvage injured human extremities. Methods and Materials: dHACM/dHCM was topically applied to the wounds after debridement. Negative Pressure Wound Therapy (NPWT) was concurrently initiated, primarily to bolster the tissue with moisture and contamination control. Approximately every seven days, wounds were re-evaluated for granulation tissue growth response. As needed, patients received dHACM/ dHCM and NPWT in the outpatient or home care settings after discharge. Results: Fifteen males and two females (26 extremities) were treated for fourteen burn and three Necrotizing Soft Tissue Infections (NSTI) injuries. Closure was observed in patients after two to five dHACM/dHCM applications. The dHACM/dHCM treatment was initiated: (median) 17-days after injury; NPWT for 17-days; autograft or primary closure after 21-days; discharge 25-days after the first application. Conclusion: Treatment with human placental-derived allografts provided a protective covering that enabled the healing cascade to generate granulation tissue formation in extremity wounds with exposed tendon and/or bone. In select limb salvage cases, dHACM/dHCM treatment may be a promising alternative to amputations, tissue rearrangements, free tissue flaps or other techniques for resolution of extremity wounds with bone and tendon exposure.
The most common interventions to heal burn and traumatic limb injuries with exposed bones and tendons include skin graft coverage, local or microvascular flaps, as well as amputations [
Placental amniotic membrane has been used as a wound dressing for more than 100 years [
In utero, native human amnion/chorion membranes contain an array of factors, which play critical roles in regulating tissue development and growth. Epidermal Growth Factor (EGF), basic fibroblast growth factor (bFGF), Keratinocyte Growth Factor (KGF), Transforming Growth Factor alpha and beta (TGF-α and TGF-β), Vascular Endothelial Growth Factor (VEGF) and Tissue Inhibitors of Metalloproteinases (TIMPs) are some of the regulatory proteins that have essential roles in physiological processes required for healthy tissue generation, such as cell migration, proliferation and recruitment [
This observational retrospective pilot study performed from January 2019 through October 2020 was approved by the Institutional Review Board for human studies. The inclusion criteria for treatment with dHACM/dHCM were: 1) exposed bone or tendon; 2) burn, trauma, or NSTI injuries; 3) failed split thickness skin graft (STSG) applications; 4) inadequate production of granulation tissue. The exclusion criteria were: 1) deep circumferential bone burn; 2) open joint; 3) continued tissue necrosis with tangential excisional debridement (TED) in the week after admission; 4) non-clearance of tissue infection with TED or antibiotics; 5) unstable lower limb ankle joint; 6) unrepairable peripheral vascular disease (no pulse or adequate arterial run-off to the feet).
The PURION® processed dHACM and dHCM are cleansed and dehydrated from donor-screened and tested elective caesarean section delivered placentas [
Prior to placental-derived tissue application, burn or NSTI wounds were debrided of dead or necrotic tissue with the water knife Versajet II Hydrosurgical System (Smith + Nephew, Andover, MA) [
Once the injured area was prepared, dHACM/dHCM were topically applied or packed (depending on wound depth), covered with either a nonadherent dressing, 3% bismuth tribromophenate petrolatum dressing, or a glycerol-hydroxyethy- lcellulose lubricant, and bolstered with NPWT at 50 - 100 mmHg (Figures 1-5). The wounds were re-evaluated every seven days for granulation tissue formation after removal of the NPWT device and underlying dressing. The wound bed was appropriately debrided and dHACM/dHCM were reapplied over or into the wound, if required. dHACM/dHCM treatment was continued until bone, tendon and muscle were covered with adequate granulation tissue to sustain a Split Thickness Skin Graft (STSG). Skin grafts were bolstered under a NPWT device to minimize shear effect and sub-graft fluid accumulation, which could potentially damage or lift the graft off the wound bed and disrupt the intracellular signals critical for successful graft incorporation [
was adopted in limb salvage protocols to fortify allografts such as dHACM and dHCM. To minimize disturbances to the protected wound healing environment, NPWT dressings were changed once a week instead of the usual wound care strategy of two-three times a week.
Statistical analysis was performed with Statistica® (StatSoft, Tulsa, OK): descriptive statistics, one way-ANOVA, with unequal N Tukey post-hoc comparisons, and Maximum Likelihood chi-squared tests. Comparisons were made between the patients with leg, foot, combined leg and foot, and upper extremity injuries. One-way ANOVA and Tukey statistics compared the following: age, percent total body surface (%TBSA), body mass index (BMI), operating room (OR) visits, extent of tangential debridement, autograft areas, length of stay (LOS), time to application of the dHACM/dHCM, time from application to autograft, time from first application to discharge, duration of NPWT use during treatment with these dressings, number of surgeries, and OR visits. Maximum Likelihood chi-squared compared ethnicity, gender, injury location, mechanism of injury, discharge location, comorbidities (diabetes, hypertension, cardiac, renal, etc.), alcohol/drug use, and infection. In all cases, a p < 0.05 value was considered significant.