Test of long-term uterine survival after allogeneic transplantation in rabbits.

AIM: To see if: (i) a large vessel aortocaval vascular patch technique may bring about long-term graft survival after allogeneic uterine transplantation (UTn) in a rabbit model; and (ii) fertility can be achieved following natural mating post-allogeneic UTn. METHODS: Allogeneic uterine cross transplantations were performed in New Zealand white rabbits using an aortocaval macrovascular patch harvested as part of the uterine allograft. Five rabbit recipients received a uterine graft from five unrelated donor rabbits. All female rabbits were unrelated and were of proven fertility with at least one previous litter each. Tacrolimus was administrated for immunosuppression post-transplant. Natural mating was attempted if long-term survival had been achieved. The main outcome measures were: (i) long-term recipient survival; (ii) long-term adequate uterine perfusion; and (iii) successful pregnancy post-UTn. RESULTS: All five recipient animals survived the surgery with satisfactory immediate postoperative recovery. Recipients 1, 2 and 4 died within the first 4 postoperative days. Both long-term survivors failed to conceive following introduction of a proven male breeder despite evidence of mating. Necropsy at 9 and 11 months showed a lack of patency of uterine cornua at the point of anastomosis, albeit a small uterus in recipient 3 and a reddish brown amorphous material at the site of the transplanted uterus in recipient 5. CONCLUSION: We have demonstrated the feasibility of uterine allotransplantation using a macrovascular patch technique, but could not demonstrate conception because of blocked cornua. To address this, we propose using embryo transfer techniques in order to achieve conception.

Uterine allotranspiantation in the rabbit model using a macrovascular patch technique.

The uterus and its blood supply en bloc were successfully harvested with an aortic-caval macrovascular patch in animal and human cadaveric models. The objective of this study was to assess the technical feasibility of uterine allotransplantation in the rabbit. Six uterine allotransplants were performed. This involved harvesting the uterine allograft with an aortic-caval vascular patch en bloc in the donor. After 1 hour of cold ischemic storage, the uterine allograft was transplanted to the recipient using an aortic-aortal cava-caval end to side anastomosis. Our 6 rabbit recipients surgically survived the procedure. After postmortem and histological analyses in the short term, all of the uteri appeared viable with no evidence of graft vessel thromboses. Postoperative complications included limb paraplegia, pulmonary emboli, and intraperitoneal hemorrhage. The feasibility of uterine allotransplantation using a macrovascular patch, in anatomical and surgical terms, has been proven. Further research will lead to a successful program of fertility restoration.