Allogeneic uterus transplantation in a rhesus model: A short-term graft viability study

Objective

This study examined the feasibility and safety of allogeneic uterus transplantation (UTx) from a living donor and assessed short-term graft viability in a rhesus model. This research is an important step towards further clinical application of UTx in humans.

Materials and methods

Four female rhesus monkeys with regular menstrual cycles were used in this study, the animals were either donors or recipients depending on ABO blood type compatibility. Retrieval surgery was performed to connect the uterus and uterine arteries together with the ovarian uterine vein from the living donor, and the vagina of the recipient was excised. After the back table had been prepared, bilateral uterine arteries were anastomosed end-to-side with the iliac externa arteries, and bilateral ovarian uterine veins were anastomosed end-to-side with the iliac externa vena. The transplanted uterus was evaluated based on the conditions of arterial blood, and flow was evaluated by transabdominal ultrasonography one month post operation. The conditions of the transplanted uterus were examined by secondary laparotomy. The reproductive function of rhesus monkeys was evaluated on the basis of the menstrual cycle.

Results

All 4 rhesus monkeys received the transplantation surgery without any surgical complications. No injury occurred in the other organs, and no vascular injury was observed in the allogeneic uterus. All recipients survived after the surgery with a 100% short-term survival rate. All recipients resumed normal menstruation within two months after surgery.

Conclusions

Our short follow-up shows that allogeneic UTx surgery is a safe and feasible technology in the rhesus model. The arterial conditions and blood flow of the grafted uterus can be monitored by ultrasonography examination.

Intra- and Postoperative Blood Flow Monitoring in a Sheep Model of Uterus Transplantation

BACKGROUND

The introduction of the opportunity to transplant a viable uterus into women for fulfilling their desire to have a child has awakened high expectations worldwide.

MATERIALS AND METHODS

A sheep model was used to evaluate tools for optimizing measurement of blood flow in uterine transplantation. Intraoperatively, blood flow was measured using unidirectional Doppler and indocyanine green (ICG) fluorescence imaging. Postoperatively, an implantable Doppler probe served as a tool for clinical monitoring the patency of anastomosed vessels.

RESULTS

ICG imaging showed complete vascularization of the uterus before and in short-term evaluation after surgery. The implantable Doppler probe proved to be highly suitable for assessing patency of vessels in a non-invasive way. Results of histology, and real-time polymerase chain reaction demonstrated viability of the transplanted uterus.

CONCLUSION

Different methods to monitor vasculature patency have proven to be advantageous in supporting both surgeons and researchers in ensuring successful implementation of uterine transplantation.

Laparoscopic uterine graft procurement and surgical autotransplantation in ovine model

Currently, uterus transplantation (UTx) is a clinical option for infertile women. Over the past three decades, treating benign or malignant gynecological diseases with minimally invasive gynecological surgery has improved, providing significant advantages over conventional open surgery. This study addresses the method used for laparoscopic live-donor ovariohysterectomy and graft harvest from a sheep model. Using a microsurgical practice, ten grafts were autotransplanted after uterine perfusion. End-to-end anastomosis techniques were used to approximate veins and arteries. Follow-ups were carried out 2-months after surgery and postoperative studies included ultrasound scan, diagnostic hysteroscopy, vascular angiography, and exploratory laparoscopy. All transplants were completed without complications. After vascular anastomosis, total reperfusion of the tissue was accomplished in all animals without confirmation of arterial or venous thrombosis. Angiographic explorations did not show any statistically significant dissimilarity in the arterial diameters between the different examination times. 3-months after uterine transplantation all animals underwent assisted reproduction techniques. Patent uterine arteries were observed 4, 8 and 12 months after the transplant. 6-months after transplantation, six sheep (60%) became pregnant with assisted reproduction practices. We noticed an increase in the degree of fibrosis of the cervix samples in non-pregnant animals of the transplant group. Laparoscopic surgery can be an advantageous approach for the uterus retrieval procedure during uterine transplantation. However, larger sample sized reports are needed in order to accomplish validation, standardization and wider use of this route.

Uterus Allo-Transplantation in a Swine Model: Long-Term Graft Survival and Reproductive Function

Background

The present study examined the feasibility and safety of allogeneic uterus transplantation (UTx) from a living donor and assessed long-term graft survival and the resumption of reproductive function in a swine model.

Material/Methods

Ten female miniature swine with regular menstrual cycles were used; the animals were either donors or recipients (n=5) depending on the sibling. Retrieval surgery included uterus and uterine arteries together with the anterior branches of the internal iliacs from the living donor; the vaginal canal was cut. After the back-table had been prepared, bilateral internal iliac arteries were anastomosed end-to-side with the external iliac arteries. The transplanted uterus was evaluated based on the arterial blood flow by transabdominal ultrasonography and observed by secondary laparotomy after surgery; estrus recovery was stimulated by mating with a male, and artificial embryo transfer was performed in healing swine.

Results

All 5 pigs revealed successful surgery without any surgical complications, injuries to other organs, or unanticipated vascular injury. All recipients survived for >3 months after the surgery, except pig 5, which died due to uterus necrosis 3 days post-surgery. A 100% surgical success rate and 80% long-term survival rate of the receptor were observed. Pig 2 had temporary estrus resumed, and the artificial embryo was transplanted 3 months after surgery; however, apparent gestation was not found by ultrasonography.

Conclusions

This study evaluated the safety and feasibility of the technology of allogeneic UTx, which was performed only by transplant uterine artery system from living-donor surgery in a swine model. Laboratory animals can show long-term survival and resumed estrous after UTx, which can be monitored by ultrasonography to assess the arterial blood flow of the grafted uterus.

Uterine transplantation: Review in human research

Uterine transplantation is the solution to treat absolute uterine fertility. In this review, we present the historical, medical, technical, psychological and ethical perspectives in human uterine transplantation research. We reviewed the PubMed database following PRISMA guidelines and added data presented by several research teams during the first international congress on uterine transplantation.

Use of biomedical photonics in gynecological surgery: a uterine transplantation model

Aim:

Uterine transplantation (UTx) has been proposed as a treatment for permanent absolute uterine factor infertility. The study aims were to compare pulse oximetry and multispectral imaging (MSI), for intraoperative tracking of uterine oxygen saturation in animal UTx models (rabbit and sheep).

Results/methodology:

Imaging results confirmed the re-establishment of adequate perfusion in the transplanted organ after surgery. Comparison of oxygen saturation values between the pre-UTx donor and post-UTx recipient, and pre-UTx and post-UTx recipient reveals a statistically significant decrease in saturation levels post-UTx.

Conclusion:

The use of MSI is the first case in gynecology and has demonstrated promise of possible future human use. MSI technique has advantages over pulse oximetry – it provides spatial information in a real-time, noncontact manner.

Transplanting wombs into women has been offered as a potential solution to treat women who have had them removed previously or who were born without one. Our aim here was to compare two techniques: pulse oximetry and multispectral imaging, for checking oxygen levels in the newly transplanted womb. The experiments were performed in two types of animals, rabbit and sheep. The use of multispectral imaging is the first case in gynecology and has demonstrated promise of possible future human use. It has advantages over pulse oximetry – it provides valuable information in a real-time, non-contact manner.

Uterus transplantation: Toward clinical application in Japan

Background

In recent years, uterus transplantation (UTx) has been applied as the treatment for patients with uterine factor infertility worldwide. Thus, the clinical application of UTx in Japan should be considered through both the history of UTx technology development in the world and future prospects.

Methods

Recent information on UTx was collected via a literature survey and the Internet.

Results

Basic research using various animals has been done mainly since 2000. In 2014, the world's first UTx baby was born in Sweden. In total, 24 UTx procedures have been performed at 10 institutes in nine countries and five births were obtained (as of May, 2017). In Japan, the "Project Team for Uterus Transplantation" initiated UTx experiments in 2008 and the "Japan Society for Uterus Transplantation" was organized in March, 2014. In the rest of the world, the "International Society for Uterus Transplantation" was established in January, 2016.

Conclusion

Uterus transplantation is still under development as a reproductive medicine tool and organ transplant procedure. A collaborative system that is not limited by facilities and specialties should strive to build an "all-Japan" team.

Uterus transplantation and beyond

Uterus transplantation is today the only available treatment for absolute uterine factor infertility which is caused by either congenital/surgical uterine absence or that a present uterus is non-functioning. Structured animal-based research, from rodents to nonhuman primates, was the scientific basis for a successful introduction of uterus transplantation as a clinical procedure. The patient groups for uterus transplantation, the preclinical research and data from the published human cases will be covered herein. During recent years the concept of bioengineering of organs and tissues has emerged. Creation of a bioengineered uterus is in the initial research state, with experiments performed in rodents. The research that has been performed to create a bioengineered uterus will be summarized. In conclusion, uterus transplantation is now a clinical experimental procedure for treatment of uterine factor infertility. In parallel to the establishment of this combined assisted reproduction technique and transplantation procedure as a routine clinical procedure, we predict that uterus bioengineering will develop further towards introduction within the human setting, but that this process will take several years.

Uterus Transplantation: Current State and Future Perspectives

Absolute uterine factor infertility (AUFI) has traditionally been regarded as untreatable. Gestational surrogacy (GS) is not permitted in most countries and societies in the world due to ethical, religious or legal reasons. The interest in uterus transplantation (UTx) as a treatment for AUFI started in the 1960s and, after some disappointing results, raised again in the new century, when our and other groups obtained live off-spring after UTx in the mouse, and here we review extensively the results of animal research. In September 2014, the first baby was born after human UTx and this proof-of-concept of UTx as an infertility treatment has been followed by several more births. All cases described in the literature are also reviewed.

The overall evidence suggests that the clinical introduction of UTx as the first available treatment for AUFI has been successful. However, UTx will stay at experimental stage for several years whilst optimizing the procedure and ensuring its safety from a medical and psychological perspective.

Use of nonhuman primates for the development of bioengineered female reproductive organs

Nonhuman primates (NHPs) have been widely used in reproductive biology, neuroscience, and drug development since a number of primate species are phylogenetically close to humans. In this review, we summarize the use of NHPs for nonclinical application in the reproductive system disorders including the loss or failure of an organ or tissue. Causes of infertility include congenital aplasia and acquired disorders of the reproductive organs. In addition, anti-cancer treatments can deplete ovarian follicles, leading to premature ovarian failure, infertility and long-term health risks. Along with a limited supply of human reproductive organs, anatomic/physiologic similarities to humans support the need for NHP models (New-World monkeys such as the common marmoset and Old-World monkeys such as cynomolgus and rhesus monkeys) to promote the advances in female infertility studies. For maintaining and executing animal studies using NHP, special protocols including animal care, anesthetic protocol, surgical technique, and immunosuppressive protocol are necessary. With a growing interest in the potential therapies such as endometrial tissue engineering, and ovary/follicle cryopreservation and grafting in Korea, this review can be useful in selecting appropriate animal models and can bridge between nonclinical studies and clinical applications by providing detailed information on the use of NHPs in the field of reproductive organ disorders.

Might uterus transplantation be an option for uterine factor infertility?

Current data on uterus allotransplantation research has been reviewed and summarized. Over the past 15 years, progress in uterus transplantation research has increased dramatically. As a consequence, the first pregnancy and delivery following uterus allotransplantation in rats have been reported. The technique has been better defined. Although clinical pregnancy and delivery following uterus allotransplantation has been reported in humans, there are still many questions to be answered before clinical application. Gestational surrogacy still remains an important option for being a genetic parent in selected cases with uterine factor infertility.

The need for laparoscopic ovarian transposition in young patients with cervical cancer undergoing radiotherapy

Maintaining the quality of life by preserving ovarian function in premenopausal patients with cervical cancer undergoing radiation is crucial. This can be accomplished with a simple and safe laparoscopic ovarian transposition procedure. This procedure aims to move the ovary out of the irradiation field, protecting it from direct radiation and irreversible damage and preserving its function. However, this procedure is often forgotten and seldom offered to patients. This review aims to lay stress on and reconsider the importance of laparoscopic ovarian transposition as a simple, safe, and extremely useful procedure. The biological effects of radiation are described briefly and several studies are evaluated, which reveal that this procedure has more benefits than risks.

Uterus transplantation: animal research and human possibilities

Uterus transplantation research has been conducted toward its introduction in the human as a treatment of absolute uterine-factor infertility, which is considered to be the last frontier to conquer for infertility research. In this review we describe the patient populations that may benefit from uterus transplantation. The animal research on uterus transplantation conducted during the past two decades is summarized, and we describe our views regarding a future research-based human attempt.