Practical Approach to the Pathologic Diagnosis of Mixed Filamentous Fungal Infections in Burn Wounds: A Case Series

Introduction/Objective Opportunistic infections by fungi are a major source of morbidity and mortality in patients suffering from extensive burn wounds. Here we review a series of cases of infections by multiple fungi in burn wounds as diagnosed by histopathology and outline the key features for the pathologist to include in the report. Methods/Case Report Biopsies from patients with more than one fungal species identified in the laboratory in a concurrent culture or by PCR were included in this study. Three cases are presented with multiple fungi identified. Each case had yeast and at least one different hyaline mold species present on pathology; two cases additionally had mucormycetes present, with angioinvasion in one case. All organisms requiried microbiologic cultures and variably required molecular testing for full identification. Results (if a Case Study enter NA) N/A Conclusion Pathologists should be aware of the possibility of infection by multiple fungal species in burn wounds. Fungal morphology in tissue sections should allow for detection and distinction of mucormyctes and other hyaline molds. Histopathologic correlation with culture and/or PCR results is essential to distinguish potential contaminants from true infection.

Skin grafts

Skin grafts are an option for closing skin defects that cannot be closed primarily. A skin graft consists of epidermis and a portion of the underlying dermis that is detached from its blood supply and transferred to another location, usually on the same individual (an autograft). Skin grafts can also be used from cadaver donors (allografts) in extensive burn injuries, but as the recipient’s immune system will eventually reject this foreign tissue, this is only a temporary measure.

124 Autologous Skin Cell Suspension Achieves Closure of Donor Site Wounds Facilitating Early Re-harvesting for Large TBSA burn Injuries

Introduction Management of extensive burn injuries is complicated often resulting in significant morbidity and mortality. Current standard of care includes use of split-thickness skin grafts (STSG) to obtain definitive closure; however, this treatment is often limited by donor site availability, which requires repeated re-harvesting of donor sites to obtain definitive closure in large total body surface area injuries. Additionally, this limitation often leads to increased risk of infection, hypertrophic scarring, and extended hospital length of stay. Autologous skin cell suspension (ASCS) prepared using the autologous cell harvesting device is an FDA approved point-of-care regenerative medicine technology that significantly reduces donor skin requirements to achieve definitive closure in acute thermal burn injuries across small and large burns. A prospective uncontrolled observational study (IDE 15945—NCT02992249) was conducted in which patients with life-threatening burn injuries were treated with ASCS. In this study, clinical outcomes were evaluated when ASCS was used in combination with wide meshed autografts for burn site treatment. Within the study, a subset of donor sites was also treated with ASCS and the purpose of the current work was to evaluate the clinical outcomes obtained to better understand impact on healing times and effect of re-harvesting in this compromised patient population. Methods ASCS was applied to the donor site after harvesting of split-thickness skin grafts. Clinical outcomes out to one year were evaluated, including the percentage of re-epithelialization, long-term cosmetic outcomes, and adverse events. Results Subjects (n=96) from 22 burn centers received ASCS as part of their donor site treatment regimen (n=528). Mean subject baseline demographics were: 30.2 years of age, 54.0 ± 17.4% TBSA injury, and 89.4 ± 32.9 Baux score with 37% of subjects having a score greater than 100. Percentage of donor sites healed, defined as >95% re-epithelialization, was 37.1% and 82.7% after week 1 and week 2, respectively. Approximately 20% of the donor sites treated with ASCS were re-harvested multiple times following initial healing (up to four times). Of these donor sites 39.3% (n=84), 81.0% (n=79), and 85.7% (n=77) were healed by week 1, week 2, and week 4, respectively. Scar assessments conducted on 427 donor sites after one year showed the majority had matched or mildly mismatched color, pigment, and texture. Safety analyses of adverse events (AEs) following ASCS treatment were unlikely or unrelated to the device. Conclusions This study demonstrates successful use of ASCS to achieve closure of donor site wounds in patients with extensive burn injuries.

Usage of intermingled skin allografts and autografts in a senior patient with major burn injury

Mortality rate in older adults following extensive burn injury is extremely high, and management of these patients is challenging. One of the main problems is that autologous split-thickness skin grafts are scarce and the wounds cannot be covered quickly and effectively. Intermingled skin grafting is a low-tech and economic method, which not only maximizes the use of precious autologous skin but also prevents the wounds from infection and consumption. Herein we present a case of extensive burn injury in a 68-year-old female successfully treated with intermingled skin grafting. The patient was accidentally burned by gas flame, resulting in a major burn injury covering 80% of her total body surface area. Early burn wound excision was performed and the wound was temporarily covered with irradiated porcine skin in the first week after injury. Autologous stamp-like skin grafts were applied to the wound bed 4 weeks after injury. In this operation, the results were not satisfactory. The take rate of the skin grafts is only about 50%. We covered the wounds with intermingled skin allografts and autografts 8 weeks after injury: autografts (0.5 cm × 0.5 cm) + fresh close relative’s allografts (1 cm × 1 cm) + cryopreserved allografts (2 cm × 2 cm).