Critical Ischemia Times and The Effect of Novel Preservation Solutions HTK-N and TiPROTEC on Tissues of a Vascularized Tissue Isograft.

Background: We herein investigate critical ischemia times and the effect of novel preservation solutions HTK-N and TiProtec on the individual tissues of a rat limb isograft. Methods: Orthotopic hind-limb transplantations were performed in male Lewis rats following 2h, 6h or 10h of cold ischemia. Limbs were flushed and stored in either HTK-N, TiProtec, HTK or saline solution. Muscle, nerve, vessel, skin and bone samples were procured on day 10 for histology, immunohistochemistry, confocal and electron microscopy and RTqPCR analysis. Results: Histomorphology of the muscle showed a mainly perivascular inflammatory infiltrate, fibrotic degeneration and neovascularization after 6h and 10h of cold ischemia. However, centrally aligned nuclei observed in muscle fibers suggest for muscle regeneration in these samples. In addition to Wallerian degeneration, nerve injury was significantly (p=0.032) aggravated after prolonged cold ischemia. Proinflammatory and regulatory cytokines were most significantly upregulated after 2h cold ischemia. Our data suggest no superiority of novel perfusates HTK-N and TiProtec in terms of tissue preservation, compared to HTK and saline. Conclusions: Limiting cold ischemia time below 6h is the most significant factor to reduce tissue damage in vascularized tissue transplantation. Signs of muscle regeneration give rise that ischemic muscle damage in limb transplantation might be reversible to a certain extent. Copyright (C) 2017 Wolters Kluwer Health, Inc. All rights reserved.

http://ift.tt/2sTkCQ1