Preservation of Rat Cremaster Muscle Microcirculation after Prolonged Cold Storage and Transplantation

Microvascular surgery for the reconstruction of complex defects involves an ischemic period, which may cause flap failure as the result of ischemia/reperfusion injury. We assessed the microvascular consequences of rat cremaster muscle transplantation after prolonged periods of cold storage in HTK-Bretschneider solution (HTK). Cremaster muscle transplantations were performed immediately or after 8 or 24 h of cold storage (4°C) in HTK or saline. Intravital microscopy was used to quantify capillary perfusion and venular leukocyte-endothelium interactions following transplantation. The transplantation procedure itself resulted in 50–65 min of ischemia. After direct transplantation, capillary perfusion was 90% of control. Transplantation after 8 h of cold storage in either HTK or saline did not deteriorate capillary perfusion. When the tissue was stored for 24 h, HTK was superior to saline in preserving capillary perfusion (HTK: 76–83% of control, saline: 30%). Immediate transplantation induced a small increase in leukocyte adhesion. Prolonged cold storage in either fluid resulted in reduced flow velocities (qualitative observations) and edema formation, which hampered quantification of leukocyte-endothelium interactions. Even after 8 or 24 h of cold storage in HTK, transplantation of rat cremaster muscle was successful with good capillary perfusion. Capillary perfusion was better preserved in HTK than in saline.