Uterus transplantation and beyond

3D printed gelatin/PTMC core/shell scaffolds with NIR laser-tuned drug/biomolecule release for cancer therapy and uterine regeneration

Surgical resection is an efficient treatment for cancerous tissues and uterine fibroids in the women uterus. However, the insufficiency of clinical interventions could result in tumor recurrence, and the defective tissues remained would cause intrauterine adhesions (IUAs) and further affect reproduction capacity. In this study, 3D printed hydrogel/poly(l-lactide-co-trimethylene carbonate) (PLLA-co-TMC, "PTMC" in short) core/shell scaffolds with NIR-tuned doxorubicin hydrochloride (DOX) and estradiol (E2) dual release were designed and fabricated for cancer therapy and uterine regeneration. Gelatin (Gel) and DOX were homogeneously mixed and then 3D printed to form Gel-DOX scaffolds. Gel-DOX scaffolds were then immersed in PTMC-PDA@E2 solution to fabricate Gel-DOX/PTMC-PDA@E2 core/shell scaffolds. Consequently, Gel-DOX/PTMC-PDA@E2 scaffolds could release DOX and E2 in a chronological manner, firstly delivering DOX assisted by phototherapy (PTT) to effectively kill Hela cells and then sustainably releasing E2 to promote uterine tissue regeneration. In vitro experiments showed that core/shell scaffolds exhibited excellent anticancer efficiency through the synergy of DOX release and hyperthermia ablation. Moreover, E2 could be sustainably released for over 28 days in vitro to promote the proliferation of bone marrow-derived mesenchymal stem cells (BMSCs). The novel Gel-DOX/PTMC-PDA@E2 core/shell scaffolds have therefore exhibited potential promise for the treatment of cancer therapy and uterine regeneration.

Uterus transplantation: A bibliometric review of six-decade study from 1960 to 2024

INTRODUCTION

Some women are unable to become pregnant because they do not have a functional uterus. Over the last decade, it has become possible for these women to get pregnant through uterus transplantation, which has been the subject of numerous research studies. Therefore, the purpose of this study is to review published articles in the uterus transplantation area.

MATERIAL AND METHODS

We conducted a cross-sectional bibliometric review to study the 100 highly cited papers in the Web of Science and Scopus databases from 1960 to 2024. Our research applied bibliometric analysis to these top 100 highly cited papers. Document citation and co-occurrence analysis were used for the data study. VOSviewer along with Bibliometrix® software was used to design the maps.

RESULTS

The trend of uterus transplantation publications increased exponentially after 2010. Sweden is the leading country, followed by the USA and Spain. Fertility and Sterility, Lancet, American Journal of Transplantation, and Human Reproduction were the highly cited journals. Collaboration among countries showed that the most collaboration took place between Sweden and Spain (18), Sweden and the USA (14), the USA and Spain (8), Sweden and Australia (6), and the USA and the United Kingdom (6). Furthermore, the results found that more than one-third of the highly cited papers were review papers (39%) and 27% were clinical trial studies.

CONCLUSIONS

This bibliometric review provides a valuable contribution to the literature on uterine transplantation by synthesizing and analyzing existing research findings. It offers insights into current trends, key themes, geographic distribution, and potential areas for future research within this rapidly evolving field.

Biomimicking trilayer scaffolds with controlled estradiol release for uterine tissue regeneration

Scaffold-based tissue engineering provides an efficient approach for repairing uterine tissue defects and restoring fertility. In the current study, a novel trilayer tissue engineering scaffold with high similarity to the uterine tissue in structure was designed and fabricated via 4D printing, electrospinning and 3D bioprinting for uterine regeneration. Highly stretchable poly(l-lactide-co-trimethylene carbonate) (PLLA-co-TMC, "PTMC" in short)/thermoplastic polyurethane (TPU) polymer blend scaffolds were firstly made via 4D printing. To improve the biocompatibility, porous poly(lactic acid-co-glycolic acid) (PLGA)/gelatin methacryloyl (GelMA) fibers incorporated with polydopamine (PDA) particles were produced on PTMC/TPU scaffolds via electrospinning. Importantly, estradiol (E2) was encapsulated in PDA particles. The bilayer scaffolds thus produced could provide controlled and sustained release of E2. Subsequently, bone marrow derived mesenchymal stem cells (BMSCs) were mixed with gelatin methacryloyl (GelMA)-based inks and the formulated bioinks were used to fabricate a cell-laden hydrogel layer on the bilayer scaffolds via 3D bioprinting, forming ultimately biomimicking trilayer scaffolds for uterine tissue regeneration. The trilayer tissue engineering scaffolds thus formed exhibited a shape morphing ability by transforming from the planar shape to tubular structures when immersed in the culture medium at 37°C. The trilayer tissue engineering scaffolds under development would provide new insights for uterine tissue regeneration.

A new bicornuate model of rat uterus transplantation

INTRODUCTION

Uterus transplantation has revolutionized reproductive medicine for women with absolute uterine factor infertility, resulting in more than 40 reported successful live births worldwide to date. Small animal models are pivotal to refine this surgical and immunological challenging procedure aiming to enhance safety for both the mother and the child.

MATERIAL AND METHODS

We established a syngeneic bicornuate uterus transplantation model in young female Lewis rats. All surgical procedures were conducted by an experienced and skilled microsurgeon who organized the learning process into multiple structured steps. Animals underwent meticulous preoperative preparation and postoperative care. Transplant success was monitored by sequential biopsies, monitoring graft viability and documenting histological changes long-term.

RESULTS

Bicornuate uterus transplantation were successfully established achieving an over 70% graft survival rate with the passage of time. The bicornuate model demonstrated safety and feasibility, yielding outcomes comparable to the unicornuate model in terms of ischemia times and complications. Longitudinal biopsies were well-tolerated, enabling comprehensive monitoring throughout the study.

CONCLUSIONS

Our novel bicornuate rat uterus transplantation model provides a distinctive opportunity for sequential biopsies at various intervals after transplantation and, therefore, comprehensive monitoring of graft health, viability, and identification of potential signs of rejection. Furthermore, this model allows for different interventions in each horn for comparative studies without interobserver differences contrary to the established unicornuate model. By closely replicating the clinical setting, this model stands as a valuable tool for ongoing research in the field of uterus transplantation, promoting further innovation and deeper insights into the intricacies of the uterus transplant procedure.

The artificial uterus: on the way to ectogenesis

The inability to support the growth and development of a mature fetus up to delivery results in significant human suffering. Current available solutions include adoption, surrogacy, and uterus transplantation. However, these options are subject to several ethical, religious, economic, social, and medical concerns. Ectogenesis is the process in which an embryo develops in an artificial uterus from implantation through to the delivery of a live infant. This current narrative review summarizes the state of recent research focused on human ectogenesis. First, a literature search was performed to identify published reports of previous experiments and devices used for embryo implantation in an extracorporeally perfused human uterus. Furthermore, studies fitting that aim were selected and critically evaluated. Results were synthesized, interpreted, and used to design a prospective strategy for future research. Therefore, this study suggests that full ectogenesis might be obtained using a computer-controlled system with extracorporeal blood perfusion provided by a digitally controlled heart-lung-kidney system. From a clinical perspective, patients who will derive significant benefits from this technology are mainly those women diagnosed with anatomical abnormalities of the uterus and those who have undergone previous hysterectomies, numerous abortions, and experienced premature birth. Ectogenesis is the complete development of an embryo in an artificial uterus. It represents the solutions for millions of women suffering from premature deliveries, and the inability to supply growth and development of embryos/fetuses in the womb. In the future, ectogenesis might replace uterine transplantation and surrogacy.

Who should provide the uterus? The ethics of live donor recruitment for uterus transplantation

Uterus transplantation (UTx) is an experimental surgery likely to face the issue of organ shortage. In my article, I explore how this issue might be addressed by changing the prevailing practices around live uterus donor recruitment. Currently, women with children - often the mothers of recipients - tend to be overrepresented as donors. Yet, other potentially eligible groups who may have an interest in providing their uterus - such as transgender men, or cisgender women who do not wish to gestate or to have children - tend to be excluded as potential donors. Moving forward, I recommend that donor inclusion criteria for UTx be broadened to be more inclusive of these latter groups.

Whole-organ decellularization of the human uterus and in vivo application of the bio-scaffolds in animal models

PURPOSE

The aim of this investigation was to design a perfusion-based decellularization protocol to provide whole human uterine bio-scaffolds with preserved structural and componential characteristics and to investigate the in vivo properties of the decellularized tissues.

METHODS

Eight human uteri, donated by brain-dead patients, were decellularized by perfusion of sodium dodecyl sulfate (SDS) through the uterine arteries using a peristaltic pump. The bio-scaffolds were evaluated and compared with native human uterus regarding histological, immunohistochemical, structural, and bio-mechanical properties, in addition to CT angiographies to examine the preservation of the vascular networks. Subsequently, we obtained acellular patches and implanted them on uterine defects of female Wistar rats to investigate the bio-compatibility and regenerative potential of the bio-scaffolds. Finally, we performed immunostaining to investigate the potential role of circulating stem cells in recellularization of the implanted bio-scaffolds.

RESULTS

The outcomes of this investigation confirmed the efficacy of the proposed protocol to provide whole human uterine scaffolds with characteristics and extra-cellular matrix components similar to the native human uterus. Subsequent in vivo studies demonstrated the bio-compatibility and the regenerative potential of the scaffolds and suggested a signaling pathway as an underlying mechanism for the regenerative process.

CONCLUSIONS

To the best of our knowledge, this investigation provides the first efficient perfusion-based decellularization protocol for the human uterus to obtain whole-organ scaffolds. The outcomes of this investigation could be employed in future human uterus tissue engineering studies which could ultimately result in the development of novel treatments for female infertile patients.

Endometrium as Control of Endometriosis in Experimental Research: Assessment of Sample Suitability

Endometriosis is a chronic gynecological disease that causes numerous severe symptoms in affected women. Revealing alterations of the molecular processes in ectopic endometrial tissue is the current policy for understanding the pathomechanisms and discovering potential novel therapeutic targets. Examining molecular processes of eutopic endometrium is likely to be a convenient method to compare it with the molecular alterations observed in ectopic tissues. The aim of the present study was to determine what proportion of the surgically resected eutopic endometrial samples is suitable for further experiments so that these can be comparable with endometriosis. Final hospital reports and histopathology reports of a 3-year-long period (1162 cases) were analysed. The application of a retrospective screening method promoted the categorization of these cases, and quantification of the categorized cases was accomplished. In addition, results obtained from cultured endometrium samples were also detailed. Only a small number of the harvested endometrial samples was suitable for further molecular analysis, while preoperative screening protocol could enlarge this fraction. Applying clinical and histopathological selection and exclusion criteria for tissue screening and histopathological examination of samples could ensure the comparability of healthy endometrium with endometriosis. The present study could be useful for researchers who intend to perform molecular experiments to compare endometriosis with the physiological processes of the endometrium.

The reproductive potential of uterus transplantation: future prospects

BACKGROUND AND AIM

Absolute uterine factor infertility (AUFI) is a form of infertility whereby conception and/or maintenance of pregnancy is impossible as a result of uterine absence or its completed dysfunction. It affects 1/500 women of reproductive age while the incidence is about 8% of infertile couples. Uterus transplantation (UTx) has been gaining ground as a viable option to enable women with AUFI to have biological children and as an alternative to surrogacy, a highly controversial practice still banned in many countries.

METHODS

The authors have set out to strike a reasonable balance between UTx benefits and the still numerous risks, whether clinical or ethical, associated with such an innovative form of transplant, which is not life-saving, requires immunosuppression throughout pregnancy and the organ to be removed right after childbirth.

RESULTS

While still far from achieving mainstream status, considerable strides have been made in UTx outcomes, with many live births already recorded. Procedures from living donor are reportedly more effective in terms of success rates. Organ tissue engineering has been explored and developed with promising results.

CONCLUSIONS

UTx entails various risks and ethical quandaries which have to do with reproductive autonomy and rights. New human attempts and clinical trials of UTx should be performed to further optimize the procedure in relation to safety and effectiveness. Techniques such as tissue engineering could lead in the medium-long term to a wholly bioengineered uterus to be used for transplantation, relying on scaffolds from decellularized organs or tissues that can be recellularized by several types of autologous somatic/stem cells. Such advances hold promise in terms of solving UTx-related complications and organ supply difficulties.

Adolescent Fertility Preservation: Where Do We Stand Now

Adolescence is a period of flux for many body systems. While fertility potential typically increases after menarche, there are diseases where the opposite occurs and fertility preservation options need to be considered early. In cases of cancer, options vary by pubertal status and can include ovarian tissue cryopreservation, oocyte cryopreservation, sperm cryopreservation, and testicular tissue cryopreservation. Much remains to be learned about fertility and preservation options in those with differences in sexual development (DSDs); however, depending on the form of DSD, fertility preservation may not be necessary. Similarly, traditional fertility counseling in children with galactosemia may need to be changed, as data suggest that fertility rates attributed to other causes of premature ovarian insufficiency may not be as applicable to this disease. Adolescents with Turner's syndrome are at high risk for premature ovarian failure; therefore, it is important to consider options as early as possible since ovarian reserves are depleted quickly. On the other hand, transgender and gender diverse adolescents may even be able to undergo fertility preservation after starting hormone therapy. In all cases, there are additional ethical components including technical/surgical risks in childhood, offering experimental therapies without creating false hope and evaluating children's consent and assent capabilities that must be considered.

Uterus transplantation in a sheep model: novel surgical technique with long-term survival and uterus vitality. First case series in Argentina

OBJECTIVE

To develop a sheep autologous uterus transplantation (UT) program with an innovative surgical technique and assess long term uterus vitality and animal survival.

METHODS

A novel surgical technique consisting of the procurement of the complete uterus and the two ovaries, back table vascular reconstruction, and subsequent implantation in the same animal, performing only two arterial and two venous anastomoses.

RESULTS

Four autologous transplantations were performed; anesthesia and surgery were well tolerated by all the animals without complications. Direct observation and Doppler US performed a week after UT and laparoscopy performed three months later confirmed uterus vitality. All animals were alive more than a year after transplantation.

CONCLUSIONS

Our study was the first to describe a novel surgical technique for sheep uterus autologous transplantation in Latin America, showing long-term survival and uterus vitality.

Uterine Tissue Engineering: Where We Stand and the Challenges Ahead

Tissue engineering is an innovative approach to develop allogeneic tissues and organs. The uterus is a very sensitive and complex organ, which requires refined techniques to properly regenerate and even, to rebuild itself. Many therapies were developed in 20th century to solve reproductive issues related to uterus failure and, more recently, tissue engineering techniques provided a significant evolution in this issue. Herein we aim to provide a broad overview and highlights of the general concepts involved in bioengineering to reconstruct the uterus and its tissues, focusing on strategies for tissue repair, production of uterine scaffolds, biomaterials and reproductive animal models, highlighting the most recent and effective tissue engineering protocols in literature and their application in regenerative medicine. In addition, we provide a discussion about what was achieved in uterine tissue engineering, the main limitations, the challenges to overcome and future perspectives in this research field.

New Advances in Transplants and Bioengineering Aid in Replacing the Womb

When Kayla Edwards turned 13, she began to wonder if she was different. It started as a seed of suspicion when her friends began their menstrual cycles, and hers never arrived. Her grandmother was late, she learned, but for Edwards, it still seemed odd. She had hit puberty's other benchmarks-the hormones, the breasts-just no cycle.

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.

Targeting connexins with Gap27 during cold storage of the human donor uterus protects against cell death

Uterus transplantation is an experimental infertility treatment for women with uterine factor infertility. During donor uterus retrieval and subsequent storage, ischemia and other stressors are likely to occur, resulting in the delayed restoration of organ function and increased graft rejection. The uterus expresses connexin-based hemichannels, the opening of which can promote ischemic cell death, as well as gap junctions that may expand cell death by bystander signaling. We investigated if connexin channel inhibition with connexin channel inhibitor Gap27 could protect the uterus against cell death during the storage period. The study involved 9 female patients undergoing gender-change surgery. Before uterus removal, it was exposed to in situ warm ischemia with or without reperfusion. Uterus biopsies were taken before, during, and after ischemia, with or without reperfusion, and were subsequently stored under cold (4ᵒC) or warm (37ᵒC) conditions. TUNEL cell death assay was done at various time points along the combined in vivo/ex vivo experimental timeline. We found that Gap27 protected against storage-related cell death under cold but not warm conditions when the uterus had experienced in situ ischemia/reperfusion. For in situ brief ischemia without reperfusion, Gap27 reduction of cell death was delayed and significantly less, suggesting that protection critically depends on processes initiated when the organ was still in the donor. Thus, the inclusion of the connexin channel inhibitor Gap27 during cold storage protects the uterus against cell death, and the degree of protection depends on the history of exposure to warm ischemia. Gap27 protection may be indicated for uteri from deceased donors, in which ischemia is likely because life-saving organs have retrieval priority.

First Successful Delivery after Uterus Transplantation in MHC-Defined Cynomolgus Macaques

Delivery following uterus transplantation (UTx)—an approach for treating uterine factor infertility—has not been reported in nonhuman primate models. Here, six female major histocompatibility complex (MHC)-defined cynomolgus macaques that underwent allogeneic UTx were evaluated. Antithymocyte globulin and rituximab were administered to induce immunosuppression and a triple maintenance regimen was used. Menstruation resumed in all animals with long-term survival, except one, which was euthanized due to infusion associated adverse reaction to antithymocyte globulin. Donor-specific antibodies (DSA) were detected in cases 2, 4, and 5, while humoral rejection occurred in cases 4 and 5. Post-transplant lymphoproliferative disorder (PTLD) developed in cases 2 and 3. Pregnancy was attempted in cases 1, 2, and 3 but was achieved only in case 2, which had haploidentical donor and recipient MHCs. Pregnancy was achieved in case 2 after recovery from graft rejection coincident with DSA and PTLD. A cesarean section was performed at full-term. This is the first report of a successful livebirth following allogeneic UTx in nonhuman primates, although the delivery was achieved via UTx between a pair carrying haploidentical MHCs. Experimental data from nonhuman primates may provide important scientific knowledge needed to resolve unsolved clinical issues in UTx.

Experimental techniques for the development of a uterus transplantation model in cynomolgus macaques

Uterus transplantation (UTx) is now a treatment for women with uterine factor infertility to have a child. However, UTx is still largely at the experimental stage, and many medical issues remain unsolved. Therefore, adequate studies in large animals including non-human primates are required for validation of these issues. UTx research, especially in non-human primates, can provide important information for its full establishment in humans due to the anatomical and physiological similarities between the two. We accumulated data from UTx studies using cynomolgus macaques since 2009 and established autologous and allogeneic UTx models which led to deliveries after performing the procedure. In this paper, we summarized key points to develop UTx models in cynomolgus macaques based on our experience. UTx models in non-human primates can surely contribute new and beneficial knowledge in this field and can be useful for the further development of UTx in humans.

Uterus Transplantation as a Therapy Method in Mayer-Rokitansky-Küster-Hauser Syndrome

The Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is the most common cause of uterine aplasia (underdevelopment or absence) at a frequency estimated to be worldwide of 1/4500 births of new-born female infants.

This is a literature review aiming to determine the sufficiency of the uterine transplantation (UTx) method as a therapeutic protocol for the MRKH syndrome.

Online searches were carried out in PubMed, Embase, CINAHL and Google scholar databases, during January and February 2019. The search included a combination of the various terms (see key words) as well as a combination of these terms in Greek and English so as to identify and display articles that would be as close as possible to the subject of research.

The online search yielded 95 articles. Eighty-five of these were considered as eligible and possible sources from the title and abstract presented but later were excluded, whereas 10 of them were selected to be included in the literature review. The literature review results showed that two therapeutic methods that are now successfully applied are the Vecchietti method and the Davydov method, which is the latest and less invasive technique but with equally if not improved immediate results. However, this treatment is not adequate to satisfy or provide a solution for the reproduction requirements of this patient group. The UTx proved sufficient.

Although uterus transplant could be considered the ideal solution for the management of infertility and the satisfaction of the reproductive and sexual needs of women with MRKH syndrome, since the first successful pregnancy after uterine transplantation is a reality in the recent years, it is early days to be considered as a safe mode of management.

Long-Term Outcome and Rejection After Allogeneic Uterus Transplantation in Cynomolgus Macaques

Uterus transplantation (UTx) is an option for women with uterine factor infertility to have a child, but is still in the experimental stage. Therefore, allogeneic animal models of UTx are required for resolution of clinical issues. In this study, long-term outcomes were evaluated in four recipients (cases 1-4) after allogeneic UTx in cynomolgus macaques. Immunosuppression with antithymocyte globulin induction and a triple maintenance regimen was used. Postoperative ultrasonography and biopsy of the transplanted uterus and immunoserological examinations were performed. All four recipients survived for >3 months after surgery, but continuous menstruation did not resume, although temporary menstruation occurred (cases 1 and 2). All animals were euthanized due to irreversible rejection and no uterine blood flow (cases 1, 2 and 4) and post-transplant lymphoproliferative disorder (case 3). Donor-specific antibodies against MHC class I and II were detected in cases 1, 2 and 4, but not in case 3. Peripheral lymphocyte counts tended to elevate for CD3⁺, CD20⁺ and NK cells in conjunction with uterine rejection, and all animals had elevated stimulation indexes of mixed lymphocyte reaction after surgery. Establishment of allogeneic UTx in cynomolgus macaque requires further exploration of immunosuppression, but the clinicopathological features of uterine rejection are useful for development of human UTx.

What will the future hold for artificial organs in the service of assisted reproduction: prospects and considerations

Assisted reproduction provides a wide spectrum of treatments and strategies addressing infertility. However, distinct groups of infertile patients with unexplained infertility, congenital disorders, and other complex cases pose a challenge in in vitro fertilization (IVF) practices. This special cohort of patients is associated with futile attempts, IVF overuse, and dead ends in management. Cutting edge research on animal models introduced this concept, along with the development of artificial organs with the aim to mimic the respective physiological functions in reproduction. Extrapolation on clinical application leads to the future use of infertility management in humans. To date, the successful clinical application of artificial reproductive organs in humans is not feasible because further animal model studies are required prior to clinical trials. The application of these artificial organs could provide a solution to infertility cases with no other options. This manuscript presents an overview on the current status, future prospects, and considerations on the potential clinical application of artificial ovary, uterus, and gametes in humans. This paper presents how the IVF practice landscape may be shaped and challenged in the future, along with the subsequent concerns in assisted reproductive treatments.

Development of an efficient perfusion-based protocol for whole-organ decellularization of the ovine uterus as a human-sized model and in vivo application of the bioscaffolds

PURPOSE

The main purpose of this investigation was to determine an efficient whole-organ decellularization protocol of a human-sized uterus and evaluate the in vivo properties of the bioscaffold.

METHODS

Twenty-four ovine uteri were included in this investigation and were decellularized by three different protocols (n 6). We performed histopathological and immunohistochemical evaluations, 4,6-diamidino-2-phenylindole (DAPI) staining, DNA quantification, MTT assay, scanning electron microscopy, biomechanical studies, and CT angiography to characterize the scaffolds. The optimized protocol was determined, and patches were grafted into the uterine horns of eight female Wistar rats. The grafts were extracted after 10 days; the opposite horns were harvested to be evaluated as controls.

RESULTS

Protocol III (perfusion with 0.25% and 0.5% SDS solution and preservation in 10% formalin) was determined as the optimized method with efficient removal of the cellular components while preserving the extracellular matrix. Also, the bioscaffolds demonstrated native-like biomechanical, structural, and vascular properties. Histological and immunohistochemical evaluations of the harvested grafts confirmed the biocompatibility and recellularization potential of bioscaffolds. Also, the grafts demonstrated higher positive reaction for CD31 and Ki67 markers compared with the control samples which indicated eminent angiogenesis properties and proliferative capacity of the implanted tissues.

CONCLUSIONS

This investigation introduces an optimized protocol for whole-organ decellularization of the human-sized uterus with native-like characteristics and a prominent potential for regeneration and angiogenesis which could be employed in in vitro and in vivo studies. To the best of our knowledge, this is the first study to report biomechanical properties and angiographic evaluations of a large animal uterine scaffold.

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.

Changes in the metabolic composition of storage solution with prolonged cold ischemia of the uterus

INTRODUCTION

The development of uterine transplantation (UTx) from deceased donors requires knowledge of the tolerance of the uterus to prolonged cold ischemia (CI). This can be evaluated through the use of biological parameters to assess degradation of the organ between its procurement and transplantation. The objective of this study was to analyze changes in the metabolic composition of the storage solution in cases of prolonged CI in uteri from ewes.

METHODS

Eighteen uterine auto-transplantations were performed in ewes. CI time was 1 h (T1) or 24 h (T24). Samples of Celsior® were taken when the explanted uterus was flushed (T0) and at the end of CI. A dual approach to metabolic analyses was followed: targeted biochemical analyses targeting several predefined metabolites and non-targeted metabolomics analyses based on nuclear magnetic resonance (NMR).

RESULTS

Metabolic analyses were performed on 16 explanted uteri. Metabolomic profiles differed significantly between T1 and T24 (p = 0.003). Hypoxia-associated degradation of the organ was demonstrated by the significantly higher lactate levels at T24 than at T1 (p < 0.05), accompanied by cell lysis, and significantly higher levels of creatine kinase activity in T24 than in T1 uteri (p < 0.05). Oxidative stress increased over time, with a significantly higher oxidized glutathione/glutathione ratio for T24 than for T1 uteri (p < 0.05).

CONCLUSION

The metabolic results indicate a significant degradation of the uterus during 24 h of CI. Metabolic analysis of the storage solution could be used as a non-invasive tool for evaluating uterine degradation during CI before transplantation.

Uterine Transplant: A Risk to Life or a Chance for Life?

Being inherently different from any other lifesaving organ transplant, uterine transplantation does not aim at saving lives but supporting the possibility to generate life. Unlike the kidneys or the liver, the uterus is not specifically a vital organ. Given the non-lifesaving nature of this procedure, questions have been raised about its feasibility. The ethical dilemma revolves around whether it is worth placing two lives at risk related to surgery and immunosuppression, amongst others, to enable a woman with absolute uterine factor infertility to experience the presence of an organ enabling childbirth. In the year 2000, the first uterine transplantation, albeit unsuccessful, was performed in Saudi Arabia from where it has spread to the rest of the world including Sweden, the United States and now recently India. The procedure is, however, still in the preclinical stages and several ethical, legal, social and religious concerns are yet to be addressed before it can be integrated into the clinical setting as standard of care for women with absolute uterine factor infertility.

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.

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.

Basic research on uterus transplantation in nonhuman primates in Japan

Uterus transplantation (UTx) is now a potential option for women with uterine factor infertility to have a child. However, UTx is still in an experimental stage and basic animal studies including in nonhuman primates are needed for accumulation of data that will provide important information for establishment of UTx in humans. Herein, we summarized our experiences using cynomolgus macaques, with the goal of promoting further development of UTx studies in nonhuman primates. Our basic studies using cynomolgus macaques were summarized, including the results of other teams in nonhuman primates. Our team in Japan launched UTx research in 2009 using cynomolgus macaques and has accumulated a large archive of results in the UTx research field, including examination of uterine blood flow, surgical procedures of autologous and allogeneic UTx, organ perfusion methods in deceased donor models, immunological response and rejection and ischemia/reperfusion injury. We achieved the first delivery after autologous UTx in primates and the first periodic recovery of menstruation after allogeneic UTx in nonhuman primate models. Results from animal studies, including those in nonhuman primates, provide the basis for clinical application of UTx. Therefore, our accumulated data since 2009 and our basic experience in cynomolgus macaque are meaningful for future UTx trials in Japan. In addition, more validation in nonhuman primate models is needed for resolution of medical issues and further development of UTx in humans, despite clinical application of UTx in several countries.

Allowable warm ischemic time and morphological and biochemical changes in uterine ischemia/reperfusion injury in cynomolgus macaque: a basic study for uterus transplantation

STUDY QUESTION

How long is the allowable warm ischemic time of the uterus and what morphological and biochemical changes are caused by uterine ischemia/reperfusion injury in cynomolgus macaques?

SUMMARY ANSWER

Warm ischemia in the uterus of cynomolgus macaques is tolerated for up to 4 h and reperfusion after uterine ischemia caused no further morphological and biochemical changes.

WHAT IS KNOWN ALREADY

Uterus transplantation is a potential option for women with uterine factor infertility. The allowable warm ischemic time and ischemia/reperfusion injury of the uterus in humans and non-human primates is unknown.

STUDY DESIGN, SIZE, DURATION

This experimental study included 18 female cynomolgus macaques with periodic menstruation.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Animals were divided into six groups of three monkeys each: a control group and groups with uterine ischemia for 0.5, 1, 2, 4 and 8 h. Biopsies of uterine tissues were performed before blood flow blockage, after each blockage time, and after reperfusion for 3 h. Blood sampling was performed after each blockage time, and after reperfusion for 5, 15 and 30 min for measurement of biochemical data. Resumption of menstruation was monitored after the surgical procedure. Morphological, physiological and biochemical changes after ischemia and reperfusion were evaluated.

MAIN RESULTS AND THE ROLE OF CHANCE

Mild muscle degeneration and zonal degeneration were observed in all animals subjected to warm ischemia for 4 or 8 h, but there were no marked differences in the appearance of specimens immediately after ischemia and after reperfusion for 3 h in animals subjected to 4 or 8 h of warm ischemia. There were no significant changes in any biochemical parameters at any time point in each group. Periodical menstruation resumed in all animals with warm ischemia up to 4 h, but did not recover in animals with warm ischemia for 8 h with atrophic uteri.

LIMITATIONS, REASON FOR CAUTION

Warm ischemia in actual transplantation was not exactly mimicked in this study because uteri were not perfused, cooled, transplanted or reanastomosed with vessels. Results in non-human primates cannot always be extrapolated to humans.

WIDER IMPLICATIONS OF THE FINDINGS

The findings suggest that the tolerable warm ischemia time in the uterus is expected to be longer than that in other vital organs.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI Grant Number 26713050. None of the authors has a conflict of interest to declare.

Laparoscopic-Assisted Uterus Retrieval From Live Organ Donors for Uterine Transplant: Our Experience of Two Patients

STUDY OBJECTIVE

To report the first ever laparoscopic-assisted live donor uterus retrieval in 2 patients for uterus transplant.

DESIGN

Case study (Canadian Task Force classification III).

SETTING

Galaxy CARE Laparoscopy Institute, Pune, India.

PATIENTS

Two patients with absolute uterine factor infertility with their mothers as donors.

INTERVENTIONS

In vitro fertilization and uterine transplant.

MEASUREMENTS AND MAIN RESULTS

A 12-member team was formed, and approval for transplant was obtained from the institutional review board. Pretransplant, in vitro fertilization for both patients was done. Two consecutive uterine transplants were done on 2 successive days. Vessels were harvested laparoscopically in both donors. Uterus and harvested vessels were retrieved by a small abdominal incision to prevent injury and infection. The uterus was transplanted in the recipients by end to side anastomosis of the harvested vessels to external iliac vessels, followed by anchoring of supports of the donor uterus to those of the recipients. Surgical intra- and postoperative parameters, postoperative investigations, and follow-up data of 6 months were measured. Operative time for laparoscopic donor surgery was 4 hours. Bench surgery took 45 minutes. Recipient surgery time was 4 hours. There were no intraoperative or immediate postoperative complications. Both the recipients started menstruating after 34 days and 48 days, respectively, and have had 6 cycles of menses at regular intervals. Uterine artery Doppler showed good flow in both patients. Hysteroscopy-guided cervical biopsies were used as a method of surveillance of graft rejection after uterine transplant. Office hysteroscopy was done after 2 months in both patients, and hysteroscopy-guided endometrial and cervical biopsies were taken. Minimal slough was seen on the endometrium in the patient with Mayer-Rokitansky-Küster-Hauser syndrome, which was removed. Repeat hysteroscopy after 10 days showed a healthy endometrium.

CONCLUSIONS

Laparoscopic-assisted uterus donor retrieval is feasible and affords all the advantages of a minimally invasive technique, thereby reducing the morbidity of the procedure. It helps in better dissection of the vessels, shortens the operative time, and helps to minimize tissue handling of the harvested uterus and vessels.

Uterus transplantation:robotic surgeon perspective

OBJECTIVE

To study the safety and feasibility of robotic dissection of deep pelvic vessels as applied to the robotic harvesting of a uterus from live transplant donor.

DESIGN

Surgical video.

SETTING

Gynecologic oncology practice of a tertiary community cancer center.

PATIENT(S)

Two patients undergoing robotic nerve-sparing radical hysterectomy for International Federation of Gynecology and Obstetrics (FIGO) stage Ib1 cervical cancer.

INTERVENTION(S)

Application of robotic platform to precise dissection of internal iliac artery and vein, their branches, including the superficial and deep uterine artery and vein. The robotic technique for deep pelvic dissection in gynecologic oncology demonstrated here provides superior outcomes compared with the open technique. In our settings, a typical robotic nerve-sparing radical hysterectomy takes 3 hours from completion of the pelvic lymphadenectomy to the moment when the patient leaves the operating room.

MAIN OUTCOME MEASURE(S)

Safety and adequacy of robotic dissection of deep pelvic vessels. The procedure's modification to the current technique demonstrated improved transplant blood supply and outflow. Demonstration of modification to current technique, that has potential to improve transplant blood supply and outflow.

RESULT(S)

Using the robotic technique for nerve-sparing radical hysterectomy, the pelvic vessels can be dissected with superior precision, hemostasis, efficiency, and clinical outcomes. Due to its difficulty, nerve-sparing radical hysterectomy is not even performed via a laparotomy approach in the United States. Robotic dissection allows for better exposure of the pelvic vessels, which may allow for harvesting intact uterine vessels with internal iliac artery and vein patches, thus facilitating wider vascular anastomosis and superior blood supply and outflow of the transplant.

CONCLUSION(S)

Uterine harvesting from a live donor is currently being performed via a laparotomy technique, resulting in long procedures associated with significant morbidity. Based on our gynecologic oncology experience, a robotic approach to deep pelvic dissection is superior to laparotomy. Robotic nerve-sparing radical hysterectomy is a difficult procedure that requires knowledge of deep pelvic vessels' anatomy, precise dissection techniques, and repetition. Robotic harvesting of the uterus for transplantation from a live donor may provide better results in terms of transplant survival and donor outcomes. This type of procedure should be attempted by a robotic team that has experience in working with deep and large pelvic vessels.