Hypothermic machine perfusion in uterus transplantation in a porcine model: A proof of concept and the first results in graft preservation.

Introduction: Graft optimization is a necessity in order to develop uterus transplantation from brain-dead donors, as a complement to living donors, as these grafts are rare and the last organs retrieved in multiple organ donation. The aim of this study was to assess the feasibility and interest of hypothermic machine perfusion (HMP) in uterus transplantation using a porcine model; secondary outcomes were the evaluation of the graft's tolerance to a prolonged cold ischaemia time and to find new biomarkers of uterus viability.

Material And Methods: Fifteen uterus allotransplantations were performed in a porcine model, after 18 h of cold ischaemia, divided in three groups: Static cold storage in a HTK solution, HMP (with the VitaSmart (™) machine Bridge to Life Ltd.) with a UW-MP solution, and static cold storage in a UW solution. The main outcome was macroscopic: uterine arteries pulsatility, recoloration, and bleeding at the cut. Secondary outcomes were histological analyses (Zitkute and inflammation scores), caspase3 immunohistochemistry and plasmatic dosage of biomarkers.

Results: 14/15 allotransplantations were performed according to the protocol and met the criteria of macroscopic vitality. Grafts treated with HMP (MP did not show significantly more tissue) damage than the recipient's uterus, contrary to grafts in static cold storage, independently of the solution used. This difference disappeared one and 3 h after uterus transplantation. Plasma dosages before and after uterus transplantation did not allow to identify a new biomarker of uterus viability.

Conclusions: HMP is feasible in a porcine model, without inflicting damage on the grafts during cold ischaemia time. Grafts exposed to HMP seemed to better endure reperfusion phenomena, but this advantage did not last over time.