OC-009 SYNGENEIC VERSUS ALLOGENEIC NON-VASCULARIZED RECTUS FASCIA TRANSPLANTATION IN A RABBIT MODEL WITHOUT IMMUNOSUPPRESSION: SHORT TERM OUTCOME

Abstract

Abstract Background and aim Transplantation (Tx) of non-vascularized rectus fascia (NVRF) is a valid option in solid organ transplant recipients to avoid open abdomen after Tx. To extrapolate this technique for non-Tx patients, we investigated in a preclinical rabbit model the feasibility of transplanting NVRF in a syngeneic (Syn) versus allogeneic (Allo) strain without using immunosuppression (IS). Short-term outcome was evaluated after 4 weeks. Material and methods A validated rabbit model of NVRF Tx was used comparing 6 Syn New Zealand White (NZW) rabbits versus 6 Allo Mixed breed to NZW Tx without IS. Animals were macroscopically analyzed at harvesting after 4 weeks for graft integration, herniation, adhesions, seroma, hematoma, and surgical site infections. Histological and immunohistochemical analysis was performed to assess inflammatory cell reaction and neovascularization. Mechanical testing was performed to assess the thickness, stiffness and strength. Results Results showed similar sufficient macroscopic ingrowth of the NVRF in both groups. At the histological level, cell infiltration suggested a clearing reaction more than a rejection-based inflammation, which was more pronounced in the Allo group. No significant differences were seen concerning mechanical properties. Conclusions In a validated rabbit model of NVRF Tx, we showed that Tx was possible in an Allo strain without the need for IS, resulting in satisfying short term inflammatory and mechanical outcomes. Longer-term experiments are needed to evaluate the effect of graft integration and possible hernia development.