A Quantitative Analysis of Microcirculation During Healing of Split-Thickness Skin Grafts in Standardized Full-Thickness Wounds

Background. Full-thickness skin defects often are managed with split-thickness skin grafting. The wound healing process, including formation of new vessels during the healing of skin grafts, is complex. Objective. To evaluate the microcirculatory changes in the treated tissue after skin grafting to analyze perfusion dynamics during the wound healing process. Materials and Methods. Fourteen full-thickness skin defects were created on the back of 14 adult male Lewis rats. All wounds were treated with autologous split-thickness skin grafts. The perfusion dynamics were assessed for 84 days with an O2C device that combines a laser light to determine blood flow and white light to determine postcapillary SO2 and the rHb. Results. Blood flow increased for 50 days after grafting. SO2 decreased in superficial skin layers (depth of 2 mm) and increased in deep skin layers (depth of 8 mm) during the entire observation period. The rHb increased until day 10 in superficial layers and until day 20 in deep tissue layers. Conclusion. The microcirculatory changes reflect the different phases of wound healing. Long after the skin transplants were macroscopically healed, alterations in microcirculation were still detected. These alterations were caused by the long-lasting changes in tissue metabolism due to the formation, conversion, and degradation of the dermal matrix and vessels during wound healing and scar formation.