Differential Scanning Calorimetry, a Novel Method to Detect Uterine Ischemia-Reperfusion Injury During Autotransplantation in Experimental Sheep Model.

Background/Objectives: A novel treatment of absolute uterine factor infertility is uterus transplantation. In preparation for human surgery, autotransplantation was performed in a sheep model to assess ischemia-reperfusion injury of the uterine wall. Methods: Seven multiparous ewes underwent live-donor uterus autotransplantation; in six, the procedure was completed successfully. Tissue blocks of complete uterine wall, endometrium, and myometrium were obtained at four predefined time points: native (baseline), after 1 h of cold ischemia, after 30 min of warm ischemia, and after 30 min of reperfusion. Samples were analyzed by differential scanning calorimetry and routine hematoxylin-eosin histology. Results: Histology demonstrated preserved epithelial, glandular, and stromal structures, with only minimal, reversible changes that increased with the ischemic duration. Differential scanning calorimetry confirmed alterations in thermal stability: in the uterine wall and myometrium, the calorimetric enthalpy decreased from baseline (3.40 ± 0.53 J/g) to reperfusion (2.62 ± 0.22 J/g), indicating structural loosening; in contrast, the endometrium calorimetric enthalpy slightly increased, suggesting greater flexibility and less susceptibility to ischemia-reperfusion injury. Conclusions: In this preliminary study, differential scanning calorimetry proved to be an effective and sensitive method for detecting early structural alterations in the uterine wall that could negatively impact post-transplant function. Cold and warm ischemia did not cause irreversible damage within a two-hour time frame, supporting the feasibility of short-term preservation in uterus transplantation. The myometrium demonstrated more significant vulnerability than the endometrium, which highlights the necessity of protective strategies to preserve smooth muscle integrity during transplantation.