Objective: Uterine transplantation experiments have been performed in various animal species for future clinical applications of uterine transplantation for permanent uterine factor infertility in humans. The aim of this study was to confirm the feasibility of uterine auto-transplantation in cynomolgus monkeys by developing new surgical techniques.
Methods: Two female cynomolgus monkeys underwent surgery under general anesthesia. The uterus with vascular grafts and the vaginal wall was removed, and back-table preparation was performed using heparinized saline. The uterus with vascular grafts and the vaginal wall was anastomosed with the vaginal stump and blood vessels in the pelvis, respectively. The auto-transplant uterine function was evaluated by confirming engraftment of the uterus by laparotomy, endometrial proliferation by transabdominal ultrasonography and periodical menstruation.
Results: The first animal died due to acute renal failure 2 days after the operation. Second-look laparotomy in the second animal at 40 days after the operation indicated there was no congestion in the uterus, and the uterus showed the typical red color of a normal uterus. Thereafter, endometrial proliferation was observed by transabdominal ultrasonography and periodical menstruation was confirmed, indicating re-established uterine function.
Conclusion: This is the preliminary report of uterine auto-transplantation in cynomolgus monkeys. This study demonstrates the feasibility of uterine auto-transplantation by using new surgical technique in cynomolgus monkeys. Accumulation of basic experimental data in non-human primates is required prior to performing the procedure in humans.