Heterotopic autotransplantation of the ovary with microvascular anastomosis: a novel surgical technique

Effects of resveratrol on HIF-1α/VEGF pathway and apoptosis in vitrified duck ovary transplantation

Preservation of ovarian tissues is an effective way to ensure genetic diversity of susceptible natural bird populations that are in danger of extinction. We examined whether the addition of the plant phenol resveratrol to vitrification solutions ameliorates the damaging effects of tissue hypoxia and reperfusion injury when the tissues are transplanted. Duck ovary tissues were frozen in the presence of varying concentrations of resveratrol in cryopreservation solutions and then transplanted under the renal capsules of 2-day-old Shelducks. Samples of the transplanted tissues were examined on days 3- and 9- post transplantation for activation of hypoxia-, antioxidant- and apoptosis-related gene expression and apoptosis. Resveratrol significantly increased expression of VEGF, HIF-1α, Nrf2, CAT and Bcl-2 mRNA and decreased BAX and Caspase-3 mRNA and reduced numbers of TUNEL-positive cells after vitrification and heterotopic ovarian transplantation. Resveratrol improved the antioxidant capacity, reduced apoptosis and activated the HIF-1α/VEGF pathway to promote angiogenesis 3- and 9-days following transplantation. These results indicated that the addition of resveratrol to vitrification solutions intended for long-term cryopreservation of ovary tissues improves survival in storage and the grafts following transplantation. This study provides a theoretical basis for the successful transplantation of avian ovarian tissue after vitrification.

Biological Graft as an Innovative Biomaterial for Complex Skin Wound Treatment in Dogs: A Preliminary Report

Complex wounds in dogs are a recurrent problem in veterinary clinical application and can compromise skin healing; in this sense, tissue bioengineering focused on regenerative medicine can be a great ally. Decellularized and recellularized skin scaffolds are produced to be applied in different and complex canine dermal wounds in the present investigation. Dog skin fragments are immersed in a 0.5% sodium dodecyl sulfate (SDS) solution at room temperature and overnight at 4 °C for 12 days. Decellularized samples are evaluated by histological analysis, scanning electron microscopy (SEM) and gDNA quantification. Some fragments are also recellularized using mesenchymal stem cells (MSCs). Eight adult dogs are divided into three groups for the application of the decellularized (Group I, n = 3) and recellularized scaffolds (Group II, n = 3) on injured areas, and a control group (Group III, n = 2). Wounds are evaluated and measured during healing, and comparisons among the three groups are described. In 30- and 60-day post-grafting, the histopathological analysis of patients from Groups I and II shows similar patterns, tissue architecture preservation, epithelial hyperplasia, hyperkeratosis, edema, and mononuclear inflammatory infiltrate. Perfect integration between scaffolds and wounds, without rejection or contamination, are observed in both treated groups. According to these results, decellularized skin grafts may constitute a potential innovative and functional tool to be adopted as a promising dog cutaneous wound treatment. This is the first study that applies decellularized and recellularized biological skin grafts to improve the healing process in several complex wounds in dogs, demonstrating great potential for regenerative veterinary medicine progress.

Two-Decade Experience of Royan Institute in Obtaining Mature Oocyte from Cryopreserved Ovarian Tissue: In Vitro and In Vivo Approaches

Ovarian tissue cryopreservation (OTC) holds promise for preservation of fertility among women who have lost their fertility due to diseases such as cancer. OTC has significantly assisted such cases by helping them maintain normal hormonal levels and menstrual cycles. Appropriate strategies to develop and extract mature oocytes from OTC could overcome a range of complications that are associated with ovarian dysfunction, caused by aging, and primary or secondary ovarian insufficiency. Scientists from different departments at The Royan Institute (Tehran, Iran) have been conducting studies to find the best way to extract mature oocytes from animal and human cryopreserved ovarian tissues. The various studies conducted in this area in the past 20 years, by researchers of the Royan Institute, are collated and provided in this review, in order to provide an idea of where we are now in the area of fertility preservation.

Whole Ovary Cryopreservation and Transplantation: A Systematic Review of Challenges and Research Developments in Animal Experiments and Humans

Ovarian tissue cryopreservation and transplantation is the only fertility preservation option that enables both restoration of fertility and resumption of ovarian endocrine function, avoiding the morbidity associated with premature menopause. It is also the only technique available to prepubertal patients and those whose treatment cannot be delayed for life-threatening reasons. Ovarian tissue cryopreservation can be carried out in two different ways, either as ovarian cortical fragments or as a whole organ with its vascular pedicle. Although use of cortical strips is the only procedure that has been approved by the American Society for Reproductive Medicine, it is fraught with drawbacks, the major one being serious follicle loss occurring after avascular transplantation due to prolonged warm ischemia. Whole ovary cryopreservation involves vascular transplantation, which could theoretically counteract the latter phenomenon and markedly improve follicle survival. In theory, this technique should maintain endocrine and reproductive functions much longer than grafting of ovarian cortical fragments. However, this procedure includes a number of critical steps related to (A) the level of surgical expertise required to accomplish retrieval of a whole ovary with its vascular pedicle, (B) the choice of cryopreservation technique for freezing of the intact organ, and (C) successful execution of functional vascular reanastomosis upon thawing. The aim of this systematic review is to shed light on these challenges and summarize solutions that have been proposed so far in animal experiments and humans in the field of whole ovary cryopreservation and transplantation.

Expression of angiogenic factors in cryopreserved mouse ovaries after heterotopic autotransplantation

Objective

Revascularization is critical for successful ovarian tissue transplantation. Vascular endothelial growth factor (VEGF) and angiopoietin-2 (angpt-2) are the principal mediators of neovascularization. This study was designed to assess VEGF and angpt-2 levels in cryopreserved ovarian tissue after heterotopic autotransplantation.

Methods

Ovarian tissues harvested from ICR mice at 5 to 6 weeks of age were stratified as follows: no cryopreservation (controls, group I); vitrification in VFS-40 (vitrification, group II); and gradual freezing in dimethyl sulfoxide (slow-freezing, group III). Frozen specimens were thawed at room temperature, assaying VEGF and angpt-2 levels 1 week after cryopreservation and 2 weeks after autotransplantation.

Results

VEGF and angpt-2 protein levels were significantly lower in cryopreserved ovaries of groups II and III than in controls (group I, P<0.05), whereas groups II and III did not differ significantly in this regard. After autotransplantation of cryopreserved ovarian tissue, VEGF and angpt-2 protein levels did not differ significantly by technique but tended to be lower than corresponding levels in controls.

Conclusion

Expression of angiogenic factors in ovarian tissue is thought to vary by method of cryopreservation. Our findings indicate that levels of angiogenic factors expressed in cryopreserved ovarian tissue after autotransplantation do not differ appreciably from control levels, regardless of cryopreservation technique.

A combination of simvastatin and methylprednisolone improves the quality of vitrified-warmed ovarian tissue after auto-transplantation

STUDY QUESTION

Does the preoperative administration of simvastatin and methylprednisolone enhance mouse ovarian quality after auto-transplantation of vitrified-warmed ovarian tissue (OT)?

SUMMARY ANSWER

Treatment with combined simvastatin and methylprednisolone enhances the quality of transplanted mouse OTs.

WHAT IS KNOWN ALREADY

The prevention of ischemic injury after transplantation of OT is critical for preserving the ovarian follicles. Preoperative administration of simvastatin (a cholesterol-lowering drug) has beneficial effects on various organ transplantations. Moreover, donor treatment with simvastatin and methylprednisolone (main effects are on immune response) prevents ischemia-reperfusion injury and has a beneficial effect on allograft survival in rat cardiac allografts.

STUDY DESIGN, SIZE, DURATION

A total of 232 6-week-old B6D2F1 mice were randomly distributed into fresh control, vitrified-warmed control and experimental groups (n = 10-17 per group). The experimental groups were as follows: sham control, simvastatin, methylprednisolone and co-treatment groups. In the experimental groups, the mice were administered simvastatin (5 mg/kg, orally), methylprednisolone (15 mg/kg, i.v.) or a combination of simvastatin and methylprednisolone 2 h before ovariectomy, whereas the sham control mice received normal saline.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Whole ovaries were removed from the mice and vitrified by two-step vitrification procedures. The vitrified ovaries were warmed 1 week later and auto-transplanted under the bilateral kidney capsules. The ovaries and blood samples were collected 2, 7 and 21 days (D) after transplantation for histological analysis, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, immunohistochemistry for CD31 and serum anti-Mullerian hormone (AMH) level estimation. Embryonic development was evaluated after IVF of oocytes obtained from the transplanted ovary.

MAIN RESULTS AND THE ROLE OF CHANCE

The group that received simvastatin and methylprednisolone showed a significantly improved intact (Grade 1) follicle ratio (D2: P < 0.001, D7: P < 0.05 and D21: P < 0.001), apoptotic follicle ratio (D21: P < 0.05), CD31-positive area (D7: P < 0.05 and D21: P < 0.05) and serum AMH level (D7: P < 0.001) after transplantation when compared with the sham control. However, no difference was noted in the fertilization and blastocyst formation rates, number of total and apoptotic blastomeres per blastocyst and inner cell mass/trophectoderm ratio among the four transplantation groups.

LIMITATIONS, REASONS FOR CAUTION

Although we evaluated the beneficial effects of simvastatin and methylprednisolone in the present study, we did not unravel the corresponding protective mechanisms.

WIDER IMPLICATIONS OF THE FINDINGS

Our results suggest that a combination of simvastatin and methylprednisolone has beneficial effects on the quality and functioning of transplanted OT. This combined treatment can potentially be applied clinically to humans and domestic animals subject to further studies.

Preliminary observations on whole-ovary xenotransplantation as an experimental model for fertility preservation

Ovarian tissue preservation and retransplantation is a promising strategy to restore fertility in cancer survivors. Ischaemia accompanying ovarian tissue grafting, however, can lead to significant follicle loss. Transplantation of the whole ovary by vascular anastomosis has been considered as an alternative to prevent widespread ischaemic damage. In this study, the feasibility and function of transplanting whole ovary with intact vasculature were evaluated, with the goal of developing a xenograft model for studies using donated human ovaries. Whole-swine ovaries with vascular pedicles were perfused and transplanted as intact ovaries by anastomosis into irradiated ovariectomized nude rats (n = 10). The observation period was between 1 and 4 weeks. Fresh swine ovaries served as controls (n = 10). Ovarian stroma and follicle populations were assessed through histological examination in both transplanted and control ovaries. Most of the transplanted whole ovaries (n = 6) maintained stromal quality and all preantral follicle classes were represented, although follicle numbers decreased compared with fresh control. Four transplanted ovaries were fibrotic after 1-4 weeks within the nude rat. Our results demonstrate transplantation of whole-pig ovary into nude rats is possible and support development of this xenograft model system for human studies.

Effect of necrostatin on mouse ovarian cryopreservation and transplantation

OBJECTIVE

To investigate the effects of necrostatin-1 (Nec-1) supplementation on vitrification, warming and transplantation of ovarian tissue.

STUDY DESIGN

Ovaries from 4-week-old ICR mice were vitrified using a two-step procedure; ovaries were suspended in equilibration solution for 10min, and then mixed with vitrification solution for 5min. Ovaries were divided at random into three groups and 0 (control), 25 or 100μM Nec-1 was added to the vitrification solution. After warming, follicular morphology and apoptosis were assessed. For each group, a sample of vitrified, warmed ovaries was autotransplanted. The same dose of Nec-1 that was added to the vitrification solution was added to each warming solution and injected intraperitoneally. Follicular morphology and apoptosis of transplanted ovaries were assessed after 2 weeks.

RESULTS

After vitrification and warming, morphological analysis revealed that the intact follicle ratio was significantly higher in the Nec-1-treated groups compared with the control group (control, 45.1%; 25μM Nec-1, 51.7%; 100μM Nec-1, 57.9%). The rate of apoptosis was lower in the Nec-1 treated groups compared with the control group (control, 11.2%; 25μM Nec-1, 8.5%; 100μM Nec-1, 7.2%). After transplantation of the vitrified, warmed ovaries, morphological analysis revealed that the intact follicle ratio was significantly higher in the Nec-1 treated groups compared with the control group (control, 43.1%; 25μM Nec-1, 60.6%; 100μM Nec-1, 70.7%). The rate of apoptosis was lower in the Nec-1 treated groups compared with the control group (control, 5.3%; 25μM Nec-1, 2.5%; 100μM Nec-1, 2.0%).

CONCLUSIONS

Nec-1 supplementation during vitrification, warming and transplantation has beneficial effects on the survival of ovarian tissue. These results can help to improve ovarian tissue vitrification and transplantation protocols for fertility preservation.

Fertility preservation and minimizing reproductive damage in cancer survivors

Recent advances in oncology have helped in the survival and cure of increasing numbers of childhood cancer patients and those during their reproductive age period. This has increased the need to improve existing technology, and prompted the search for new technologies, to minimize the gonadotoxic effects of cancer treatment and preserve human fertility. Conservative surgical approaches for cancer treatment have been widely accepted following progress in early detection of cancer and accumulating long-term outcome safety data. Gonadal suppression to increase resistance to cancer treatment by gonadotropin analogues and sex hormones has been suggested. However, while this is unlikely to be effective in males, there is no general consensus on its success in the female. Fertility preservation options for both male and female patients include cryopreservation of embryos, gametes and gonads. While embryo cryopreservation is a well-established and successful technique, there are several obvious limitations. Gamete cryopreservation is very successful in males (sperm freezing) while still experimental in females (oocyte freezing), with growing evidence suggesting its potential success. Gonadal cryopreservation is still in its early stages of experimental development, both in males (testicular tissue cryopreservation and in vitro spermatogenesis) and female (ovarian tissue cryopreservation and in vitro follicular maturation).

Effect of Human Endothelial Progenitor Cell (EPC)- or Mouse Vascular Endothelial Growth Factor-Derived Vessel Formation on the Survival of Vitrified/Warmed Mouse Ovarian Grafts

The aim of this study was to evaluate the effectiveness of improving angiogenesis at graft sites on the survival of follicles in transplanted ovarian tissue. Matrigel containing 5 × 10⁵ of cord blood-derived endothelial progenitor cells (EPCs) or 200 ng of mouse vascular endothelial growth factor (VEGF) was injected subcutaneously into BALB/c-Nu mice. After 1 week, vitrified/warmed ovaries from female B6D2F1 mice were subcutaneously transplanted into the injection sites. After 1, 2, and 4 weeks posttransplantation, the ovaries were recovered and subjected to histological analysis. Oocytes were collected from the transplanted ovaries, and their fertilization, embryonic development, and delivery were also observed. Vitrified/warmed ovaries transplanted into EPC- or VEGF-treated sites developed more blood vessels and showed better follicle survival than those transplanted into sham-injected sites. Normal embryonic development and consequent live births were obtained using oocytes recovered from cryopreserved/transplanted ovaries. Treatment with EPCs or VEGF could prevent the ischemic damage during the early revascularization stage of ovarian transplantation.

Direct comparative analysis of conventional and directional freezing for the cryopreservation of whole ovaries

OBJECTIVE

To compare conventional slow equilibrium cooling and directional freezing for cryopreservation of whole ovaries.

DESIGN

Experimental animal study.

SETTING

Academic research environment.

ANIMAL(S)

Adult ewes.

INTERVENTION(S)

Eighty-one ovaries were randomly assigned to fresh control, conventional freezing (CF), and directional freezing (DF) group. Ovaries of CF and DF groups were perfused via the ovarian artery with Leibovitz L-15 medium, 10% fetal bovine serum, and 1.5 M dimethyl sulfoxide for 5 minutes. Each ovary was inserted into a glass test tube containing 10 mL of the same solution and cooled to -100°C or -70°C, respectively. Ovaries were stored in liquid nitrogen for a minimum of 2 weeks.

MAIN OUTCOME MEASURE(S)

Structural integrity of cortical and medulla regions, vascular integrity, follicle in vitro development, cell proliferation, and DNA damage and repair.

RESULT(S)

All examined parameters indicate that the structure of DF ovaries remains largely intact and comparable to fresh controls, whereas significant damages were observed in CF ovaries.

CONCLUSION(S)

Directional freezing allows good preservation of whole ovaries, with most of the parameters taken into consideration almost identical to those recorded in fresh control samples. This encourages a reconsideration of the possible use of whole-ovary cryopreservation as a viable alternative to cortical fragments.

Ovarian tissue and follicle transplantation as an option for fertility preservation

OBJECTIVE

To review and summarize data from the scientific literature on ovarian tissue and follicle transplantation as an option for fertility preservation.

DESIGN

Review of pertinent literature.

SETTING

University hospital.

PATIENT(S)

Women having undergone ovarian tissue transplantation.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Review of the literature.

RESULT(S)

Over the last decade, the field of ovarian transplantation and cryopreservation has significantly progressed, becoming applicable in humans. Indeed, fresh and frozen cortical ovarian tissue transplantations have been successfully reported worldwide, resulting in around 28 healthy babies. Although ovarian-tissue harvesting seems to be safe, the risk of reimplantation of cancer from ovarian cortical transplants cannot be estimated at this time. As a consequence, auto-transplantation of ovarian tissue in women having suffered from systemic hematological malignancies is not recommended. In these situations, reimplantation of isolated ovarian follicles might represent an interesting option in the future.

CONCLUSION(S)

Although the clinical experience is limited, the robust results obtained open new perspectives for the management of premature ovarian failure resulting or not from gonadotoxic treatments.

Follicle growth and oocyte development after ovary transplantation into back muscle of immune-intact adult castrated male mice

Ovary grafting is not only a method of investigating follicle and oocyte development, but also a useful model to explore the possibility of the re-establishment of the reproductive axis in male-to-female sexual reversal. This study investigated ovary survival and follicle development after mouse ovaries were transplanted into immune-intact castrated male mice. Ten-day-old mouse ovaries were transplanted into the back muscle of adult outbred castrated male mice treated with immunosuppressants. Twenty-two days later, the ovary structure and the number of follicles present was examined by hematoxylin and eosin staining. The oocytes were harvested, and then used for in vitro maturation (IVM) and IVF. The results showed that primordial and antral follicles were mainly found in the grafts, and there were obvious differences compared with 32-day-old fresh ovaries (P<0.05). Embryos were derived from collected oocytes after IVM and IVF with a 72.4% cleavage rate and 7.9% blastocyst rate; 12 live pups were generated by embryo transfer. The hormone assay showed that plasma concentrations of both estrogen and progesterone increased after ovarian transplantation (P<0.01). In conclusion, immune-intact adult castrated male mice can support ovary survival and further development of follicles with endocrine function after ovarian transplantation.

Current achievements and future research directions in ovarian tissue culture, in vitro follicle development and transplantation: implications for fertility preservation

BACKGROUND Female cancer patients are offered 'banking' of gametes before starting fertility-threatening cancer therapy. Transplants of fresh and frozen ovarian tissue between healthy fertile and infertile women have demonstrated the utility of the tissue banked for restoration of endocrine and fertility function. Additional methods, like follicle culture and isolated follicle transplantation, are in development. METHODS Specialist reproductive medicine scientists and clinicians with complementary expertise in ovarian tissue culture and transplantation presented relevant published literature in their field of expertise and also unpublished promising data for discussion. As the major aims were to identify the current gaps prohibiting advancement, to share technical experience and to orient new research, contributors were allowed to provide their opinioned expert views on future research. RESULTS Normal healthy children have been born in cancer survivors after orthotopic transplantation of their cryopreserved ovarian tissue. Longevity of the graft might be optimized by using new vitrification techniques and by promoting rapid revascularization of the graft. For the in vitro culture of follicles, a successive battery of culture methods including the use of defined media, growth factors and three-dimensional extracellular matrix support might overcome growth arrest of the follicles. Molecular methods and immunoassay can evaluate stage of maturation and guide adequate differentiation. Large animals, including non-human primates, are essential working models. CONCLUSIONS Experiments on ovarian tissue from non-human primate models and from consenting fertile and infertile patients benefit from a multidisciplinary approach. The new discipline of oncofertility requires professionalization, multidisciplinarity and mobilization of funding for basic and translational research.

Orthotopic and heterotopic ovarian tissue transplantation

BACKGROUND

Transplantation of ovarian tissue is, at present, the only clinical option available to restore fertility using cryopreserved ovarian tissue. More than 30 transplantations of cryopreserved tissue have been reported, and six babies have been born, worldwide, following this procedure. Despite these encouraging results, it is essential to optimize the procedure by improving the follicular survival, confirming safety and developing alternatives. Here, we review the different factors affecting follicular survival and growth after grafting.

METHODS

Relevant studies were identified by searching Pubmed up to January 2009 with English language limitation. The following key words were used: (ovarian tissue or whole ovary) AND (transplantation) AND (cryopreservation or pregnancy). Using the literature and personal experience, we examined relevant data on the different exogenous and clinical factors affecting follicular development after grafting.

RESULTS

Clinical factors such as the patient's age and the transplantation sites influenced the lifespan of the graft. A heterotopic transplantation site is not optimal but offers some advantages and it may also promote the hormonal environment after a combined heterotopic and orthotopic transplantation. Exogenous factors such as antioxidants, growth factors or hormones were tested to improve follicular survival; however, their efficiency regarding further follicular development and fertility potential remains to be established.

CONCLUSION

Additional evidence is required to define optimal conditions for ovarian tissue transplantation. Alternatives such as whole ovary or isolated follicles transplantations require further investigation but are likely to be successful in humans in the future.

Fertility preservation for women with malignancies: current developments of cryopreservation

The preservation of fertility in female cancer survivors has become an important health issue. The different cryopreservation options available for fertility preservation are embryo, oocyte, and ovarian tissue cryopreservation. Oocyte cryopreservation is available for women without partners, but there is a limited experience with this technique and the pregnancy rate is still low. In spite of recent reports of successful birth after autotransplantation of cryopreserved-thawed human ovarian cortical tissues, clinical experience is also limited and this technique remains still experimental. Whole ovary cryopreservation itself poses several challenges. Further researches for establishing optimal cryopreservation and thawing protocols and increasing post-thawing survival, pregnancy, and delivery rates are necessary. In this article, the strategies for fertility preservation in cancer survivors are discussed. The different options and their results are discussed, as well as their indications, efficacy and ethical issues.

Difficulties improving ovarian functional recovery by microvascular transplantation and whole ovary vitrification

OBJECTIVE

To evaluate recovery of endocrine function and fertility after transplantation and vitrification of whole ovaries.

DESIGN

Animal study.

SETTING

Lyon Veterinary School, France.

ANIMAL(S)

Ewes.

INTERVENTION(S)

In group 1 (n = 5), the left ovary was removed with its vascular pedicle and was transplanted onto the contralateral pedicle. In group 2 (n = 5), the left ovary with its pedicle was cryopreserved after a vitrification procedure. After thawing, transplantation was performed by microvascular anastomosis to the contralateral ovarian pedicle.

MAIN OUTCOME MEASURE(S)

Median ischemia time, progesterone levels, histologic examination.

RESULT(S)

Successful microsurgical transplantation was performed in both groups. The median ischemia time was statistically significantly longer in group 2 (287 minutes, range: 226 to 349] versus 129 minutes [range: 125 to 130]) in group 1. In group 1, four sheep recovered spontaneous ovarian endocrine function about 2.5 (range: 2.00 to 3.75) months after transplantation. Two ewes gave healthy live births at 12 and 25 months, respectively, after transplantation. In group 2, one ewe recovered ovarian endocrine function 6 months after transplantation. However, histologic evaluation showed a follicular survival rate of 6% in group 1, and total follicle loss in group 2.

CONCLUSION(S)

Autograft of whole sheep ovaries with microvascular anastomosis seems technically feasible but resulted in a very poor follicle survival rate (6%), in spite of endocrine function recovery and birth of two lambs. Attempts at cryopreservation with vitrification resulted in no follicle survival at all.

Morphology and function of cryopreserved whole ovine ovaries after heterotopic autotransplantation

BACKGROUND

The objective of this study was to perform complex characterization of cryopreserved and then autotransplanted ovaries including determination of the ability to respond to in vivo follicle stimulating hormone (FSH)-treatment, fertilizability of retrieved oocytes, and morphology, vascularization, cellular proliferation and apoptosis in sheep.

METHODS

Mature crossbred ewes were divided into two groups; an intact (control) group (n = 4), and autotransplanted group (n = 4) in which oophorectomy was performed laparoscopically and ovaries with intact vascular pedicles frozen, thawed and transplanted back into the same animal at a different site. Approximately five months after autotransplantation, estrus was synchronized, ewes were treated with FSH, and ovaries were collected. For all ovaries, number of visible follicles was determined, and collected cumulus oocyte complexes (COC) were matured and fertilized in vitro. Remaining ovarian tissues were fixed for evaluation of morphology, expression of factor VIII (marker of endothelial cells), vascular endothelial growth factor (VEGF; expressed by pericytes and smooth muscle cells), and smooth muscle cell actin (SMCA; marker of pericytes and smooth muscle cells), and cellular proliferation and apoptosis. Two fully functional ovaries were collected from each control ewe (total 8 ovaries).

RESULTS

Out of eight autotransplanted ovaries, a total of two ovaries with developing follicles were found. Control ewes had 10.6 +/- 2.7 follicles/ovary, oocytes were in vitro fertilized and developed to the blastocyst stage. One autotransplanted ewe had 4 visible follicles from which 3 COC were collected, but none of them was fertilized. The morphology of autotransplanted and control ovaries was similar. In control and autotransplanted ovaries, primordial, primary, secondary, antral and preovulatory follicles were found along with fully functional vascularization which was manifested by expression of factor VIII, VEGF and SMCA. Proliferating cells were detected in follicles, and the rate of apoptosis was minimal in ovaries of control and autotransplanted ovaries.

CONCLUSION

These data demonstrate successful autotransplantation of a portion of frozen/thawed ovaries manifested by restoration of selected ovarian function including in vitro maturation of collected oocytes, presence of follicles from several stages of folliculogenesis and blood vessels expressing specific markers of vascularization, and proliferation and apoptosis of ovarian cells. Thus, heterotopic autotransplantation of a whole frozen/thawed ovary allows for development of preovulatory follicles, oocyte growth, and for restoration of vascularization and cellular function. However, additional improvements are required to enhance the efficiency of autotransplantation of frozen/thawed ovaries to produce more oocytes.

Laparoscopic ovariectomy for whole human ovary cryopreservation: technical aspects

OBJECTIVE

To describe the technique of laparoscopic ovariectomy with a view to cryopreservation of a whole ovary with its vascular pedicle.

DESIGN

Descriptive study.

SETTING

Gynecology research unit in a department of gynecology in a university hospital.

PATIENT(S)

Women with indications for chemotherapy or radiotherapy who are at high risk of premature ovarian failure.

INTERVENTION(S)

Laparoscopic ovariectomy for whole ovary cryopreservation in nine patients.

MAIN OUTCOME MEASURE(S)

Feasibility of laparoscopic ovariectomy for whole ovary cryopreservation and later autotransplantation without delaying chemotherapy.

RESULT(S)

The whole ovary was successfully removed by laparoscopy and cryopreserved by arterial catheterization in all nine patients.

CONCLUSION(S)

Ovariectomy with a view to whole ovary cryopreservation for future transplantation may be performed by laparoscopy. Great care must be taken to remove the ovary, together with a large part (> or =5 cm) of the infundibulopelvic ligament, allowing dissection of the ovarian vessels, perfusion with a cryoprotective medium, and cryopreservation for subsequent autografting of the whole ovary. The period of ischemia between ligation of the ovarian pedicle and ovarian cryopreservation must be as short as possible.

Ovarian tissue preservation, present and clinical perspectives

Ovarian tissue preservation and transplantation are intended for women undergoing aggressive regimens of chemical and/or radiological therapy, bone marrow transplantation or stem cell transplantation. Main indications for the procedure are neoplastic diseases and autoimmune disorders. The first live human birth after ovarian tissue autotransplantation was successfully done in 2002. Cryopreserved ovarian tissue can be autografted either orthotopically or heterotopically. Neovascularization of the implanted tissue is essential for the procedure. Vascular transplantation seems to be the best approach for avoiding follicular loss and extending the lifespan of the ovarian grafts. The procedure, regardless of whether ortho- or heterotopic, is connected with a risk of reimplantation of neoplastic cells. This can be minimized by multiple ovary biopsies, thorough histological examination and molecular genetic techniques. Introducing ovarian tissue transplantation into clinical practice requires many problems to be solved. Standardization of the freeze-thaw protocol is one of the most important issues. Solving the problem of transient graft ischemia is also essential. Eventually, the future safety of the method requires the development of efficient tests to detect the presence of neoplastic cells in the transplanted tissue.

Apoptosis and ultrastructural assessment after cryopreservation of whole human ovaries with their vascular pedicle

OBJECTIVE

To investigate possible damage caused by freeze-thawing whole human ovaries.

DESIGN

Prospective experimental study.

SETTING

Academic gynecology research unit in a university hospital.

PATIENT(S)

Ovaries were obtained from three women (aged 29-36 years).

INTERVENTION(S)

Ovaries were perfused and bathed in cryoprotective solution, and slow freezing was performed. Rapid thawing was achieved by perfusion and bathing with a decreased sucrose gradient.

MAIN OUTCOME MEASURE(S)

Apoptosis was assessed by the terminal deoxynucleotidyl transferase-mediated biotinylated deoxyuridine triphosphates nick end-labeling (TUNEL) method and by immunohistochemistry for active caspase-3 in fresh ovaries, after cryoprotectant exposure, and after thawing. Morphometric analysis of TUNEL-positive surface area was performed. Ultrastructure was assessed by transmission electron microscopy (TEM) in the thawed tissue.

RESULT(S)

No primordial or primary follicles were found to be positive for either TUNEL or active caspase-3. No statistically significant difference in mean TUNEL-positive surface area values was found between the three groups: fresh, 0.05% +/- 0.03%, with 134 high-power fields (HPFs); cryoperfused, 0.02% +/- 0.01%, with 130 HPFs; and thawed, 0.09% +/- 0.03%, with 622 HPFs. By means of TEM, follicles and vessels showed a well-preserved ultrastructure, with 96.7% (29/30) healthy-looking primordial and primary follicles, and 96.3% (180/187) healthy-looking endothelial cells.

CONCLUSION(S)

Cryopreservation of intact human ovary with its vascular pedicle, according to the freeze-thawing protocol described here, is not associated with any signs of apoptosis or ultrastructural alterations in any cell types. Whole-organ vascular transplantation may thus be a viable option in the future.

Harvesting and autotransplantation of vascularized ovarian grafts: approaches and techniques

The objective of this study was to describe the different surgical approaches involved in harvesting and heterotopic autotransplantation of intact ovaries with microvascular anastomosis. Twenty-one synchronized Merino sheep underwent harvesting of their intact ovaries with vascular pedicles. Autotransplantation was performed with fresh (n = 6) and cryopreserved-thawed (C-T; n = 15) ovaries. The ovarian vessels were anastomosed to the deep inferior epigastric vessels using end-to-end (n = 8), end-to-side (n = 6) and fish-mouth modification (n = 7) techniques. Patency of the anastomosis, ischaemia time, hormonal functions and histology were evaluated. In addition, ovarian harvesting techniques in two human subjects were described. Possible autotransplantation sites in humans were suggested. In all, 33.3% (7/21) of all fresh and C-T transplants showed patency after 10 days of follow-up. Patency was observed in 5/8, 2/6 and 0/7 animals using end-to-end, end-to-side and fish-mouth modification for completion of the microvascular anastomosis respectively. Use of the fish mouth modification technique was associated with significantly higher ischaemia time compared with end-to-end (P < 0.01) and end-to-side (P = 0.05) anastomosis. A laparoscopic approach appears to be convenient for ovarian harvesting in humans. The inferior epigastric vessel is probably the most suitable heterotopic vascularizing vessel. End-to-end anastomosis yields the highest patency rate of vascularized grafts.

Cryopreservation of intact human ovary with its vascular pedicle

BACKGROUND

The aim of this study was to assess the immediate post-thawing injury to the human ovary that was cryopreserved either as a whole with its vascular pedicle or as ovarian cortical strips.

MATERIALS AND METHODS

Bilateral oophorectomy was performed in two women (46 and 44 years old) undergoing vaginal hysterectomy and laparoscopic hysterectomy, respectively. Both women agreed to donate their ovaries for experimental research. In both patients, one of the harvested ovaries was sectioned and cryopreserved (by slow freezing) as ovarian cortical strips of 1.0 x 1.0 x 5.0 mm(3) each. The other ovary was cryopreserved intact with its vascular pedicle. After thawing 7 days later, follicular viability, histology, terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-digoxigenin nick-end labelling (TUNEL) assay (to detect apoptosis) and immunoperoxidase staining (to define Bcl-2 and p53 protein expression profiles) of the ovarian tissue were performed. Tissues from non-cryopreserved ovaries served as control specimens (two cases).

RESULTS

The overall viability of the primordial follicles was 75 and 78% in intact cryopreserved-thawed (C-T) ovaries and 81 and 83% in ovarian cortical strips in the 46- and 44-year-old patients, respectively. Comparable primordial follicle counts, absence of features of necrosis, mean values of apoptosis and weak Bcl-2 and p53 protein expressions were observed both in the intact C-T ovary and in the C-T ovarian cortical strips.

CONCLUSIONS

Cryoperfusion and cryopreservation of entire human ovary can be achieved with the maintenance of excellent viability of the superficial and the deeper tissues using a slow-freezing protocol. Cryopreservation injury is associated neither with significant alteration in the expression pattern of Bcl-2 and p53 proteins in the ovarian tissues nor with significant follicular damage.

Ovarian tissue cryopreservation and transplantation: a review

The review covers current options for ovarian tissue cryopreservation and transplantation and provides a systematic review of the existing literature from the last 10 years, taking into account all previously published reviews on the subject. The different cryopreservation options available for fertility preservation in cancer patients are embryo cryopreservation, oocyte cryopreservation and ovarian tissue cryopreservation. The choice depends on various parameters: the type and timing of chemotherapy, the type of cancer, the patient's age and the partner status. The different options and their results are discussed, as well as their putative indications and efficacy. The review concludes that advances in reproductive technology have made fertility preservation techniques a real possibility for patients whose gonadal function is threatened by premature menopause, or by treatments such as radiotherapy, chemotherapy or surgical castration.

Fertility preservation in cancer patients

Fertility preservation is an important but often neglected need of cancer patients. There are several options available but many are considered experimental or are unproven. Most require interventions that can postpone the initiation of cancer treatment. The options include surgical procedures to move the ovaries out of the path of a radiation field, prophylactic medical therapy with gonadotropin-releasing hormone agonists and storage of gametes, embryos or gonadal tissue. Embryo freezing after conventional in vitro fertilization has a high success rate. Experimental fertility preservation procedures such as oocyte freezing and ovarian tissue cryopreservation/transplantation should be offered to cancer patients only under institutional review board oversight. Laparoscopic ovarian transposition is a viable option if radiotherapy is to be used alone. Oncologists, reproductive endocrinologists and other healthcare professionals should be part of a multidisciplinary team that offers cancer patients options to preserve their reproductive potential if they desire to do so.

Orthotopic microvascular reanastomosis of whole cryopreserved ovine ovaries resulting in pregnancy and live birth

OBJECTIVE

To evaluate the feasibility of contralateral autotransplantation of cryopreserved whole ovaries with microanastomosis of the ovarian vascular pedicle.

DESIGN

Animal study.

SETTING

Department of Biomedical Sciences, General Hospital of Vienna, Austria.

ANIMAL(S)

Nine ewes, six month of age.

INTERVENTION(S)

Laparotomic unilateral oophorectomy was performed. Ovaries were frozen using a controlled-rate freezing system. After frozen storage, contralateral laparotomic oophorectomy was performed, and the thawed ovaries were returned to the contralateral orthotopic site with microsurgical vascular anastomosis.

MAIN OUTCOME MEASURE(S)

Histologic examination and serum follicle-stimulating hormone and progesterone levels.

RESULT(S)

Four sheep showed postoperative luteal function. One sheep conceived after spontaneous intercourse and delivered a healthy lamb 545 days after transplantation. Histologic examination of the ovaries 18-19 months after transplantation showed that the structural integrity of the ovarian stroma had largely been retained in six out of nine animals. Follicular survival rate in the grafted ovaries was 1.7%-7.6%.

CONCLUSION(S)

Microvascular anastomosis of whole ovaries and orthotopic transplantation after cryopreservation is technically feasible and a promising procedure in ovarian tissue banking.

Normal gestations and live births after orthotopic autograft of vitrified–warmed hemi-ovaries into ewes

BACKGROUND

The aim of this study was to evaluate the long-term outcome of autotransplantation of vitrified warmed hemi-ovaries into ewes.

METHODS

Six hemi-ovaries from six ewes aged 6 to 12 months were vitrified. After dissection of the medulla, the hemi-ovarian cortex was stored at -196 degrees C in liquid nitrogen. Four to six weeks after the first laparotomy, the left ovary was removed and the vitrified-warmed hemi-ovary was sutured.

RESULTS

Plasma progesterone concentration increased in a regular manner in all ewes. Three pregnancies occurred, from which four lambs were born. The first delivery of a normal lamb occurred in February 2003. The second delivery of two normal lambs occurred in March 2003 (a 2.5 kg male and a 2.8 kg female). The last lamb had a normal delivery but had a malformation of the left leg and the oesophagus. This lamb died two months after delivery from pneumariae. Histological examination of the grafted vitrified ovaries showed few primordial and antral follicles.

CONCLUSIONS

These three pregnancies in a ewe model may indicate that ovarian vitrification gives results as good as those from a slow cooling protocol in autograft. It is impossible to establish a link between the vitrification procedure and the malformation of the last lamb, and further studies are needed to evaluate the feasibility of ovarian vitrification.

Fertility preservation options for female patients with malignancies

PURPOSE OF REVIEW

Preservation of fertility in female patients diagnosed with cancer has recently been an area of intensive investigation. This review summarizes available options and discusses recently published data concerning experimental methods. Specific strategies for fertility preservation in women with gynecologic malignancies are also presented.

RECENT FINDINGS

Success with ovarian stimulation protocols using tamoxifen or aromatase inhibitors has recently been reported for women with breast cancer who attempt embryo cryopreservation prior to chemotherapy. The first embryo transfer using oocytes retrieved from cryopreserved ovarian tissue implanted at a heterotopic location, the first pregnancy following orthotopic transplantation of cryopreserved ovarian tissue, and increasing success with oocyte cryopreservation were also reported.

SUMMARY

Fertility preservation in female patients with cancer has become an important health issue due to increasing survival rates and delayed childbearing especially in Western countries. Radical vaginal trachelectomy for cervical cancer, conservative surgery for ovarian tumors, and progestin treatment in endometrial cancers may be considered at early stages in order to preserve fertility. Embryo cryopreservation is an established technique that is available for fertility preservation, providing a delay in the initiation of chemotherapy or radiotherapy is acceptable, and a partner or donor sperm is available. Additional techniques that could be offered after counseling the patient about their experimental nature include oocyte cryopreservation, ovarian cryopreservation, and gonadotropin-releasing hormone agonist co-treatment with chemotherapy. Improvement of these techniques as well as better characterization of their success rates and risks await further investigation.

Reducing blood loss at open myomectomy using triple tourniquets: A randomised controlled trial

OBJECTIVES

To evaluate triple tourniquets in controlled conditions and for the first time to investigate the hypothesis that leaving a semi-permanent tourniquet around the uterine artery reduces post-operative bleeding from the uterine incisions.

DESIGN

A randomised controlled trial.

SETTING

Two University teaching hospitals.

POPULATION

Twenty-eight patients with symptomatic fibroids and uterine sizes ranging from 14 to 24 weeks of gestation undergoing open myomectomy.

METHODS

A number 1 polyglactin suture was tied around the cervix to occlude the uterine arteries, and polythene tourniquets were tied around the infundibulopelvic ligament to obstruct the ovarian vessels. At the end of the procedure, the ovarian ties were released but the uterine artery suture remained in situ.

MAIN OUTCOME MEASURES

Intra-operative blood loss, post-operative blood loss, blood transfusion rates, operative morbidity, uterine blood flow and ovarian function.

RESULTS

There was significantly less blood lost in the tourniquet group than in the control group (difference between means 1870 mL, 95% CI 1159-2580 mL, P < 0.0001; transfusion rates of 7% and 79%, P= 0.0003). The volume in the pelvic drain 20 min post-operatively and after 48 hours failed to reach statistical significance between the two groups (P= 0.10 and P= 0.165). There were no differences in uterine artery Doppler resistance indices at five days (P= 0.54), six weeks (P= 0.47), three months (P= 0.49) and at six months (P= 0.18). Day two serum FSH concentrations after surgery were unchanged (P= 0.45), compared with baseline values.

CONCLUSIONS

Triple tourniquets are effective in reducing bleeding and transfusion rates. There appears no obvious adverse effect on uterine perfusion or ovarian function.

Fertility preservation and pregnancy outcome after malignancy

PURPOSE OF REVIEW

The overall survival and cure rates of patients with childhood and adult malignancies have improved dramatically, but cancer treatment can be associated with diminished reproductive potential. However, research on the preservation of fertility in these patients has given patients new options. This article discusses the mechanisms of reproductive failure after cancer therapy and the currently available fertility preservation strategies.

RECENT FINDINGS

Ovarian transposition is still a viable option if radiotherapy is to be used alone. Modifications in assisted reproductive technology that decrease peak estradiol levels are ideal for breast cancer survivors. Embryo freezing technology offers excellent pregnancy rates. Oocyte freezing is available for women without a partner, but there is more limited experience with this technique. Understanding the concepts of graft function after the autotransplantation of frozen-thawed ovarian tissue has resulted in great strides in the technical requirements for success.

SUMMARY

Gonadotropin-releasing hormone analogues are the only available medical protection means for gonadotoxic chemotherapy. Assisted reproductive technology offers excellent results, but the protocols require a delay in implementing chemotherapy. Despite recent reports of embryo development after the transplantation of cryopreserved-thawed ovarian tissue, clinical experience is limited and the technique remains experimental.

Freeze-thawing intact human ovary with its vascular pedicle with a passive cooling device

OBJECTIVE

To test the feasibility of freezing intact human ovary using a passive cooling device.

DESIGN

Prospective experimental study.

SETTING

Academic research unit of the department of gynecology in a university hospital.

PATIENT(S)

Ovaries were obtained from three women who were between 29 and 36 years of age.

INTERVENTION(S)

Ovarian perfusion with cryoprotective solution and slow freezing with a cryofreezing container (5100 Cryo 1 degrees C Freezing Container; Nalgene, VWR, Belgium). Rapid thawing of ovaries by perfusion and bathing with decreased sucrose gradient.

MAIN OUTCOME MEASURE(S)

Viability of follicles, stromal cells, and vascular components was assessed with live-dead stains in freshly removed ovary, after cryoprotectant exposure before freezing, and after thawing. Histological morphology was assessed at these three different times.

RESULT(S)

The percentage of live follicles was 99.4% in fresh tissue, 98.1% after cryoprotectant exposure, and 75.1% after thawing. Viability assessment showed live stromal cells and small vessels after thawing. On histological evaluation, the morphology of follicles and cortical and medullar tissue was similar in all three groups.

CONCLUSION(S)

We described the cryopreservation, using an accessible protocol, of intact human ovary with its vascular pedicle and proved high survival rates of follicles, small vessels, and stromal cells and a normal histological structure in all the ovarian components after thawing using our protocol.