Introduction In pig-to-baboon heart/artery patch transplantation models, adequate costimulation blockade prevents a T cell response. After heart transplantation, coagulation dysfunction (thrombocytopenia, reduced fibrinogen, increased D-dimer) and inflammation (increased C-reactive protein [CRP]) develop. We evaluated whether coagulation dysfunction and/or inflammation can be detected following pig artery patch transplantation. Methods Baboons received heart (n=8) or artery patch (n=16) transplants from genetically-engineered pigs, and a costimulation blockade-based regimen. Heart grafts functioned for 15–130d. Artery recipients were euthanized after 28–84d. Platelet counts, fibrinogen, D-dimer, and CRP were measured. Results Thrombocytopenia and reduced fibrinogen developed only in recipients of hearts not expressing a coagulation-regulatory protein (n=4), but not in other heart or patch recipients. However, in heart recipients (n=8), there were sustained increases in D-dimer (<0.5–1.9ug/mL [p<0.01]), and CRP (0.26–2.2mg/dL [p<0.01]). In recipients of artery patches, there were also sustained increases in D-dimer (<0.5–1.4ug/mL [p<0.01]), and CRP (0.26–1.5mg/dL [p<0.001]). An IL-6R antagonist suppressed the increase in CRP, but not D-dimer. Conclusion The pig artery patch model has proved valuable for determining immunosuppressive regimens that prevent sensitization to pig antigens. This model also provides information on the sustained systemic inflammation seen in xenograft recipients (SIXR). An IL-6R antagonist may help suppress this response.

Background ChatGPT is an artificial intelligence (AI) language model developed and released by OpenAI in late 2022. Objectives This study aims to evaluate the performance of ChatGPT on the Plastic Surgery In-Service examination and to compare it to residents’ performance nationally. Methods The Plastic Surgery In-Service examinations from 2018 to 2022 were used as a question source. For each question, the stem and all multiple-choice options were imported into ChatGPT. The 2022 examination was used to compare the performance of ChatGPT to plastic surgery residents nationally. Results 1129 questions were included in the final analysis and ChatGPT answered 630 (55.8%) of these correctly. ChatGPT scored the highest on the 2021 exam (60.1%) and on the comprehensive section (58.7%). There were no significant differences regarding questions answered correctly among exam years or among the different exam sections. ChatGPT answered 57% of questions correctly on the 2022 In-Service exam. When compared to the performance of plastic surgery residents in 2022, ChatGPT would rank in the 49th percentile for first-year integrated plastic surgery residents, 13th percentile for second-year residents, 5th percentile for 3rd and 4th year residents, and 0th percentile for 5th and 6th-year residents. Conclusions ChatGPT performs at the level of a first-year resident on the Plastic Surgery In-Service examination. However, it performed poorly when compared to residents in more advanced years of training. While ChatGPT has many undeniable benefits and potential uses in the field of healthcare and medical education, it will require additional research to assess its efficacy.

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BACKGROUND:There is a delicate balance between physiologic healing and formation of unfavorable scars. Homeostasis between extracellular matrix (ECM) deposition and remodeling is maintained by an array of interconnected signaling networks with situationally-dependent functions. We previously demonstrated that systemic mineralocorticoid receptor (MR) inhibition improves epithelialization and diminishes collagen deposition without eroding scar strength. MR-inhibition, however, has a range of offtarget effects when applied systemically. Consequently, herein we evaluated the role of local MR-inhibition in wound healing and hypothesize that signaling through the MR on macrophages contributes to a pro-fibrotic phenotype in wound healing.METHODS: Female C57Bl/6 mice sustained bilateral 6 mm full-thickness biopsies with stenting and were stratified into either a) vehicle control, b) 5% topical spironolactone, or c) systemic spironolactone. Systemic spironolactone was delivered intraperitoneally every three days, and topical cream formulations of spironolactone and vehicle control were reapplied every three days. Tegaderm was placed over the mice to allow topical cream to remain over wound. Mice were followed photographically for 6 weeks for time to re-epithelialization and terminal scar area. Wound biopsies were collected for gross architectural analysis and assess collagen, fibrin, and elastic fibers with Movat's pentachrome. RESULTS:By day 5, both spironolactone groups demonstrated epithelization with minimal contracture. Scar area was noted to be diminished in both the spironolactone

Introduction Complex burns are highly morbid injuries that can cause severe disfigurement and can be devastating to one’s quality of life and psychosocial well-being. Currently, there are no simple, single-stage procedures available for extensive or multifocal burns to address full-thickness trilaminar defects. Our team has previously demonstrated the viability of an adipose-first reconstruction to address hypodermal defects. In this study, we demonstrate the efficacy of a combined adipose plus finely minced skin to achieve a single-stage trilaminar skin reconstruction. Methods Full-thickness burns were created on female Yorkshire swine. After 48-hours, escharectomies were performed to the level of fascia. The wounds were layered with adipose harvested from female Yorkshire swine. In one group, autologous split-thickness skin grafts were cut into pixel size (0.3x0.3 mm) grafts and layered on top of the adipose. Pigs were maintained for 4-weeks with weekly photography, ultrasound, followed by endpoint histology and tension measurements. Results At the end of the 4-week period, adipose combined with pixel graft demonstrated improved epithelialization and less contracture (p&lt; 0.01). Thickness and mobility measurements were consistent in both groups. This findings were similar to our previous approaches using adipose following surgical debridement. Tissue pliability in the pixel grafting group was maintained to a high degree. Cross sections were performed which showed the persistence of fat graft at the base of the wounds. Conclusions Immediate, single-stage trilaminar reconstruction of full-thickness complex burns reduces contracture, mitigates adhesion, and restores normal soft-tissue thickness, therefore, presenting a paradigm changing approach in the current practice of burn injuries to the mobile surfaces. Applicability of Research to Practice Our results support the therapeutic potential of adipose-based soft-tissue reconstruction of burns to both enhance hypodermal augmentation and mitigate fibrotic complications including contracture and adhesions. Our data suggest that this approach is compatible with the standard of care skin grafting, and in fact provides improved epidermal thickness and pliability.