The human postmenopausal ovary as a tool for evaluation of cryopreservation protocols towards whole ovary cryopreservation

Abstract

Purpose Cryopreservation of a complete ovary may be a future method for fertility preservation in cancer patients. Difficulties exist in cryopreservation of the relatively large ovarian tissue mass. This study evaluates whether a human postmenopausal ovary can be used, as a complement to animal models, in studies of this research field. Methods Postmenopausal human ovaries (n=10) were isolated and flushed through ovarian arteries with either the cryoprotectant dimethylsulphoxide or Ringer-Acetate, followed by slow freezing. After thawing, production of androgens during in vitro perfusion and morphology (light/ electron microscopy) were assessed. ResultsThe dimethylsulphoxide-cryopreserved ovaries showed larger secretion of androgens during perfusion than Ringer Acetate-cryopreserved ovaries. Light microscopy showed well preserved morphology in both groups. Electron microscopy revealed normal appearance of stroma and vessels in the dimethylsulphoxide group. Conclusions The study demonstrates the potential to use the postmenopausal human ovary for further studies aiming at optimizing cryopreservation protocols, with special reference to ovarian vascularity and stroma.

Seven days ex vivo perfusion of whole ewe ovaries with follicular maturation and oocyte retrieval: towards the development of an alternative fertility preservation method

“…However, the relatively intact histomorphology of both the arterial and venous ovarian pedicles in both groups after the extended ovarian perfusion, together with the good cellular survival and minimal tissue damage is a significant achievement considering the long perfusion times explored. Our results are consistent with, and expand on, the previous short-time ovarian perfusion studies: 2 h of perfusion in ewes (Wallin et al 2009), 5 h in human (Abrahamsson et al 1990;Milenkovic et al 2011a), 12 h in rabbit (Lambertsen et al 1976;Hamada et al 1977Hamada et al , 1979Kobayashi et al 1981a) and 20 h in rat and mouse (Koos et al 1984;Sogn et al 1984;Brännström and Flaherty 1995). Our results support the findings of another study that used a complex perfusion medium supplemented with insulin, IGF-I and FSH that resulted in a successful 96-h long perfusion time (Maffei et al 2016).…”

“…This study demonstrated successful harvesting of oocytes and to our knowledge, this is the longest ex vivo perfusion time (7 days) described to date for ewe ovaries. A number of studies have been performed on ovarian tissue perfusion from rodents (Koos et al 1984;Sogn et al 1984;Brännström et al 1987;Brännström and Flaherty 1995), rabbit (Lambertsen et al 1976;Hamada et al 1977Hamada et al , 1979Kobayashi et al 1981a), sheep (Wallin et al 2009;Milenkovic et al 2011b;Maffei et al 2016) and also from human tissue (Stähler et al 1974;Abrahamsson et al 1990;Milenkovic et al 2011a;McLaughlin et al 2018). However, a complete follicular development in vitro with subsequent oocyte maturation and live offspring has only been successful in rodent models (Eppig and Schroeder 1989;O'Brien et al 2003).…”

“…Therefore, the addition of forskolin to the perfusate in future experiments could be beneficial using our ex vivo ovarian perfusion platform. Steroid hormones were also produced from perfused human postmenopausal ovaries in response to hCG during a 5-h perfusion period (Abrahamsson et al 1990;Milenkovic et al 2011a). Previous ovarian perfusion studies with rabbit, rodents and human models used shorter perfusion times than what is biologically required to retrieve fully mature oocytes (Stähler et al 1974;Lambertsen et al 1976;Hamada et al 1977Hamada et al , 1979Wallach et al 1978;Kobayashi et al 1981b;Koos et al 1984;Sogn et al 1984;Brännström et al 1987;Sogn et al 1987;Brännström and Flaherty 1995).…”

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

“…Finally, cryopreservation protocols must be adapted to human ovaries. Given their scant availability, initial studies could be conducted with postmenopausal ovaries, as proposed by Milenkovic et al [ 141 ].…”

“…The major issue when working with premenopausal whole human ovaries is their availability. In order to facilitate further research into development of an optimal freezing/thawing protocol, Milenkovic et al proposed using postmenopausal ovaries [ 141 ]. Indeed, this would initially allow us to establish and improve cryopreservation protocols respecting the vasculature and stromal architecture of the human ovary, since postmenopausal ovaries are free of follicles.…”