Ovarian Autograft After Cryopreservation. A Laparoscopic Approach in Ewes (original) (raw)
Techniques of Cryopreservation for Ovarian Tissue and Whole Ovary
Clinical medicine insights, 2019
Cryopreservation of ovarian tissue has been considered experimental for many years, but very recently the American Society of Reproductive Medicine is reviewing the process and perhaps soon will remove the label of "experimental" and recognize it as an established method for preserving female fertility when gonadotoxic treatments cannot be delayed or in patients before puberty or when there is desire to cryopreserve more than just few oocytes. This article discusses in detail the 3 methodologies used for cryopreservation: (a) slow freezing, (b) directional freezing, and (c) vitrification.
Methods for cryopreservation of human ovarian tissue
Reproductive BioMedicine Online, 2005
Human ovarian tissue can be successfully cryopreserved, with good survival and function after thawing. Experimental animal studies regarding ovarian tissue cryopreservation resulting in live-born offspring preceded the present freezing systems in humans. On the basis of current knowledge, the standard method for human ovarian cryopreservation is slow programmed freezing, using human serum albumin-containing medium, and propanediol, dimethylsulphoxide (DMSO) or ethylene glycol as a cryoprotectant, combined with sucrose. Vitrification is still at the experimental stage. Whole organ cryopreservation is an interesting experimental option. Transplantation of the frozen-thawed tissue is a feasible method to utilize the tissue in infertility treatment. Ovarian function has been restored in humans. Because one healthy child has already been born from cryopreserved tissue, tissue cryopreservation should perhaps be offered to all young girls and women who can be predicted to undergo premature ovarian failure due to cancer treatment or genetic causes. Maturation of follicles in vitro from frozen-thawed tissue is another option that is still under development.
OBJECTIVE: To determine the effect of storage duration on cryopreserved ovarian tissue using fresh and frozenthawed samples. METHODS: Seventeen fertile patients underwent an ovarian biopsy during elective laparoscopic tubal ligation. The tissue sample was divided into three parts: one part was processed fresh (FG), and two were slowly frozen, cryopreserved for 30 (G30) or 180 days (G180), thawed and analyzed. Follicular density, follicular viability, and steroidogenic capacity were assessed. RESULTS: We observed no differences between the groups in follicular density, which was assessed in hematoxylin and eosin–stained tissue sections. A heterogeneous follicular distribution was observed in the parenchyma, with a mean density of 361.3¡255.4, 454.9¡676.3, and 296.8¡269.0 follicles/mm3 for FG, G30 and G180, respectively (p = 0.46). Follicular viability was greater in FG (93.4%) when compared with the cryopreserved tissues (70.8% for G30 (p,0.001) and 78.4% for G180 (p,0.001)), with no difference in viability between the frozen samples (p.0.05). The steroidogenic capacity of the tissue was not significantly reduced following cryopreservation. CONCLUSION: The slow freezing procedures used for ovarian cryopreservation are capable of preserving follicular viability and maintaining the steroidogenic capacity of the tissue despite a roughly 30% decrease in follicular viability. Furthermore, short-term storage of ovarian tissue does not appear to compromise follicle integrity. KEYWORDS: Ovarian tissue; Cryopreservation; Tissue damage; Ovarian steroidogenesis; Tissue culture.
Ovarian cryopreservation strategies and the fine control of ovarian follicle development in vitro
Annals of the New York Academy of Sciences, 2011
Preserving the fertility of women whose reproductive tract function is threatened by disease or disease treatment is a challenge for the assisted reproduction clinic. In particular, the ovary is susceptible to damage by chemo-and radiotherapeutic treatments, as the reserve of primordial follicles is susceptible to damage and death. To overcome this challenge, experimental strategies are being developed where ovarian tissue or an entire ovary is removed and cryopreserved during the patient's treatment. After recovery, the tissue is thawed and reintroduced orthotopically to the patient, in hopes that ovarian function will recover. In complementary approaches, attempts are being made to foster ovarian follicle development in vitro so that mature eggs can be produced. Here, we consider the state of the art of these strategies, and consider the question of whether whole ovary freezing has a place in fertility preservation in the foreseeable future.
Cryopreservation of human ovarian tissue: Comparison of rapid and conventional freezing
Cryobiology, 2007
Cryopreservation, which is the most important procedure in ovarian tissue banking, can be divided into two methods: conventional freezing and rapid freezing. In previous study, the higher effectiveness of rapid freezing in comparison with the conventional freezing for human oocytes and embryos was shown. Data on comparison of these two methods for human ovarian tissue are limited. The aim of this study was to compare conventional freezing and rapid freezing for human ovarian tissue. Ovarian tissue fragments from 14 patients were transported to the laboratory within 22-25 h in a special, isolated transport box, which can maintain a stable temperature of between 5 and 8°C for 36 h. Small pieces of ovarian tissue (1 · 1-1.5 · 0.7-1 mm) were randomly distributed into four groups: Group 1: control, fresh pieces immediately after receiving transport box, Groups 2 and 3: experimental pieces after rapid freezing/warming, and Group 4: experimental pieces after conventional freezing/thawing. All pieces were cultured in vitro for 14 days. The viability of the tissue by in vitro production of hormones and development of follicles after culture was evaluated. The level of estradiol 17-b and progesterone was measured using heterogeneous competitive magnetic separation immunoassay. For histological analysis, the number of viable and damaged follicles was counted. After culture of fresh tissue pieces (Group 1), rapidly frozen/warmed pieces (Groups 2 and 3), and conventionally frozen/thawed pieces (Group 4), the supernatants showed estradiol 17-b concentrations of 358, 275, 331, and 345 pg/ml, respectively, and progesterone concentrations of 3.02, 1.77, 1.99, and 2.01 ng/ml, respectively. It was detected that 96%, 36%, 39%, and 84% follicles for Groups 1, 2, 3, and 4, respectively, were normal. For cryopreservation of human ovarian tissue, conventional freezing is more promising than rapid freezing.
Fertility and Sterility, 2008
Objective: To compare the effects of dimethyl sulfoxide (DMSO), 1,2-propanediol (PROH), sucrose, trehalose, concentration of cryoprotectants, equilibration method, and postseeding freezing rate on doe rabbit ovarian tissue preservation after freezing, using fractional experimental design. Design: Experimental prospective study. Setting: Research institute in veterinary and agronomic colleges. Animal(s): Californian doe rabbits. Intervention(s): Ovarian cortices were prepared from ovaries collected in slaughterhouse. Fractional experimental design was used to evaluate simultaneously five chemophysical factors influencing the cryopreservation of ovarian tissue. Main Outcome Measure(s): Follicle viability by Live/Dead Ò viability/cytotoxicity kit and histologic evaluation of the ovarian tissue. Result(s): Experimental design suggests that equilibration method and cryoprotectant concentration have no effect on the proportion of normal follicles. Penetrating and nonpenetrating cryoprotectants seems to influence the preservation of the follicles with advantage for PROH and trehalose. The follicular preservation seems to be highly influenced by the postseeding freezing rate. Freezing rate of 0.3 C/min seems to be less deleterious than 2 C/min. Morphologic preservation ratio reaches 85% using PROH and trehalose. Conclusion(s): Cryopreservation of doe rabbit ovarian tissue using conventional cryoprotectant and 0.3 C/min as freezing rate seems to be a promising technique and could be used as a model for women.
Comparative analysis of two cryopreservation systems of ovarian tissues in female Wistar rats
JBRA Assisted Reproduction, 2014
Objective: The aim of this study was to determine the most efficient protocol for cryopreservation of ovarian tissue using the automatic Freeze Control® system and to test two different cooling curves combined with two different cryoprotectants: dimethyl sulfoxide (DMSO) and ethylene glycol (EG). Methods: In this study, 20 female Wistar rats underwent bilateral oophorectomy. The ovaries were divided into two groups: one cryopreserved in 1.5M DMSO and the other in 1.5M EG. Two cooling curves, slow (1h 50min) and rapid (35min) were analyzed. Tissue samples were frozen, thawed, fixed, and stained with hematoxylin and eosin to analyze oocyte integrity. Follicular analysis was performed under optical microscopy (400x magnification) and preantral follicles were classified as primordial or primary according to developmental stage. ANOVA was performed, and Tukey's test was used for comparison between means, with P<0.05 defined as significant. Results: In cryopreserved tissue, the follicles with preserved integrity in each ovary were 79% primordial and 29% primary. In non-frozen (control) tissue, all follicular types were observed (primordial, primary, secondary, preantral, and antral). Reversible changes included cytoplasmic vacuolization and irregular cell outline. Irreversible changes included pyknosis. EG was more efficient than DMSO, preserving a greater number of viable primordial and primary follicles. Comparison of both cooling curves revealed no statistically significant differences between them. Conclusion: The EG is more effective as a cryoprotectant than DMSO for obtaining higher viable numbers of primordial and primary follicles from rat ovarian tissue. Further studies are needed to demonstrate ovarian functionality, such as detection of hormone levels.
Cryopreservation of human ovarian tissue: effect of spontaneous and initiated ice formation
Reproductive BioMedicine Online, 2008
This investigation compared conventional freezing of human ovarian tissue using either spontaneous or initiated ('seeded') ice formation. Biopsies of ovarian tissue were obtained from women with indications for chemotherapy or radiotherapy. Small pieces of experimental tissue were randomly distributed into three groups that were then subjected to different treatments prior to culture in vitro for 16 days: the control group, no treatment, cultured immediately after biopsy (group 1); cryopreservation/ thawing with spontaneous ice formation (group 2); and cryopreservation/thawing with initiated ice formation (group 3). Follicle viability and hormonal activity were then evaluated. There was no significant difference between groups regarding the concentration of oestradiol 17-β in the culture supernatant, whereas progesterone concentration was significantly (P < 0.05) higher in group 1 compared with group 2 or 3. There was a significant (P < 0.05) difference in primordial and primary follicle density between all of the groups (group 1 having the highest and group 2 having the lowest) and group 2 had significantly (P < 0.05) fewer normal grade follicles than the other two groups. For optimal cryopreservation of human ovarian tissue, the protocol of conventional freezing should therefore include a step of initiated ice formation.
Cryopreservation of oocytes from pre-antral follicles
Human Reproduction Update, 2003
Cryobiology is a very important tool in reproductive biology. Research in this area focuses on the possibility of restoring fertility in women with reproductive problems or after cancer treatments. Another goal is to establish a genetic resource bank for endangered or commercially important animal species. Cryopreservation of oocytes from pre-antral follicles has been studied during the past decade. Procedures can be divided between the cryopreservation of either ovarian tissue or isolated follicles. Most studies describe a slow freezing/rapid thawing protocol to cryopreserve ovarian fragments. Histology shows that the follicles maintain their morphological integrity, and transplantation of ovarian tissue demonstrates that the follicles can restart their growth and eventually ovulate. Some research groups have obtained offspring using this procedure in mice and sheep. With regard to the cryopreservation of isolated follicles, the few studies reported in this area used the same freezing protocol, and some of them described follicular growth using in-vitro culture. The best result was obtained in mice, with animal birth after follicular cryopreservation and culture. However, additional studies are necessary for a better understanding of the events during follicular cryopreservation and to establish a standard protocol for ovarian transplantation or follicle culture.
Cryopreservation of human ovarian tissue
European Journal of Obstetrics & Gynecology and Reproductive Biology, 2004
Approaches to the cryopreservation of human ovarian tissue are typically characterised by the use of slow freezing/rapid thawing methods using dimethyl sulfoxide or 1,2-propanediol (PROH) as cryoprotectants. This paper reviews current experience with these procedures.