Kevin Wu

Ex-Vivo Graft Presentation with Hydrogen Sulfide and Hydrogen Iodide for Suspended Animation of Non-Human Primate (Macaca mulatta) Upper Extremity Vascularized Composite Allotransplants

Abstract : Summary. H2S may play a role in mitigating onset of acute rejection in porcine VCA model in the absence of immunosuppression. Potential use for graft preservation strategies in a clinical setting that may require prolonged ischemic periods.

2602: GRAFT-implanted tacrolimus-eluting hydrogels prolong survival after vascularized composite allotransplantation

2602: GRAFT-implanted tacrolimus-eluting hydrogels prolong survival after vascularized composite allotransplantation Kevin Wu, M. R. Davis, V. S. Gorantla, S. D. Lawson, R. Cindass, J. Karp, P. Vemula, A. Dhayani, K. Slaughter, and N. Joshi RESTOR Program, 59 Medical Wing, JBSA Lackland AFB, TX, USA Background The shift to damage control resuscitation practice in forward combat hospitals and the many major advances over the years in combat gear has helped military troops to survive catastrophic extremity and maxillofacial trauma. Vascularized composite allotransplantation (VCA) is a superior restorative option compared to conventional reconstructive methods, however these patients require systemic multi-drug immunosuppression. We used a robust porcine preclinical VCA model to evaluate the efficacy of graftimplanted immunosuppression in preventing acute rejection (AR) and prolonging graft survival without systemic therapy. Methods Heterotopic gracilis myocutaneous flap VCA was performed between swine donor-recipient pairs with a single swine leukocyte antigen (SLA) mismatch. Group 1 (controls, n D 8) received no drug intervention. Group 2 (experimental, n D 3) and Group 3 (experimental, n D 3), a tacrolimus-eluting hydrogel injected subcutaneously into the donor flap at surgery with 28 mg/4cc and 49 mg/4cc, respectively. Serum and VCA tissues were collected for tacrolimus levels and grafts were clinically and histologically assessed for AR until the end point (23 days). Results All control animals developed Banff Grade 1 AR by post-operative day (POD) 7 and Grade 4 AR by POD 10. The tacrolimus-eluting hydrogel prolonged graft survival in both groups with an average of reaching Grade 4 AR by POD 20 and POD 28, respectively. Tissue and systemic tacrolimus levels showed no residual amount of the drug at time of euthanasia. Conclusion The use of injected tacrolimus-eluting hydrogel in VCA showed delaying of acute rejection and increasing graft survivability that is dose dependent. Donor graft tissue-specific immunomodulation with drugeluting compounds holds promise in VCA as a strategy to obviate need for systemic immunosuppression. Ultimately, propelling the field of reconstructive transplantation in the management of nonreconstructable

2595: A novel bioresorbable/biointegratable/biocompatible dressing for negative pressure wound therapy

2595: A novel bioresorbable/biointegratable/biocompatible dressing for negative pressure wound therapy Kevin Wu, R. Cindass, S. D. Lawson, V. S. Gorantla, and M. R. Davis RESTOR Program, 59 Medical Wing, JBSA Lackland AFB, TX, USA Aims Negative pressure wound therapy (NPWT) aims to improve healing by secondary intention of acute and/ or chronic wounds by dynamic vacuum assisted removal of wound exudate, promoting granulation The standard of care in NPWT uses a polyurethane sponge dressing (PUSD) applied to the wound as a filler to help facilitate vacuum suction The PUSD is non-biodegradable and needs removal every 2–3 days, causing repetitive trauma during wound healing We developed 2 novel bioresorbable/biointegratable/biocompatible sponge-dressing scaffolds (3B-SDS) and evaluated their feasibility and efficacy in optimizing wound healing and limiting need for dressing changes in a pre-clinical porcine NPWT wound model. Methods Ten full thickness wounds were created on 6 swine Four randomly chosen wounds served as controls undergoing wet-to-dry (WTD) dressing changes (2 wounds) and PUSD NPWT (2 wounds) The remaining 6 wounds underwent treatment with the novel 3B-SDSs All wounds were assessed every 3 d until creation of a skin graftable area or until the project end date of 2 months The primary outcome measure was time to skin graftable area Wound planimetry, colorimetry, tensiometry, and histology were secondary outcome metrics. Results This is an ongoing study and end point results will be presented at the meeting We anticipate that the 3BSDSs will achieve faster time to a skin graftable area without the need for repeated dressing changes compared to WTD dressing or the PUSD NPWT. Conclusions The use of 3B-SDSs is anticipated to be superior in terms of time to creation of a skin graftable area compared to PUSD NWPT and WTD dressings. CONTACT Kevin Wu kwu72md@gmail.com