ovarian tissue (at least 2 Â 2 Â 1 mm
3 ) should be initiated in
order to exclude malignant cells. This is essential for cryostorage and for subsequent therapeutic transplantation but should
be carried out by the surgical center that does removal of
ovarian tissue [3, 23].
4. Studies have shown that hypothermia of the biopsied ovarian
tissue sample can last for up to 24 h in different transport periods
without causing damage to the follicle reserve or without a loss
of success rates after transplantation [1, 3, 23, 33]. Centralized
ovarian tissue banking offers high-quality standardized processing, cryopreservation, and storage of cryopreserved ovarian
tissue. This is due to the professional expertise, which can be
only guaranteed if ovarian tissue is processed on a regular base.
5. The averaged results of the viability test from fresh and frozenthawed biopsies can then be summarized and correlated with the
patient’s age at the time of tissue removal, AMH value, and
AFC. This allows to determine the number of tissue pieces that
should be used for re-transplantation. As a rule of thumb, the
quantity of ovarian tissue to be transplanted should correspond
to approximately 15% of a whole ovary. Assuming 50% of the
ovary is taken from a patient, from which ten pieces with a size of
approximately 4 Â 8 Â 1 mm
3 were prepared and cryopreserved,
then three pieces should be thawed and transplanted in the first
treatment. In the case of a low follicle density and/or an
advanced age at the time of collection (approximately
>30 years), the number of pieces should be increased to
20–25%, which corresponds to a total of four to five pieces [34].
6. These examinations also ensure that the entire procedure chain
(removal of the tissue, handling, and transportation from surgery to the cryobank, subsequent processing, cryopreservation,
thawing) did not lead to any relevant damage, like loss of
follicles and oocytes [1, 23].
7. Further in vitro tests can also be performed. Such tests, like a
glucose uptake assay, may better reflect the overall tissue functionality, since only a completely intact ovarian cortex can
sufficiently supply the follicles and support their growth. The
tests include the measurement of the in vitro glucose consumption of standardized cortex biopsies before and after
cryopreservation [26].
References
1. Liebenthron J, Montag M, Reinsberg J,
Ko ¨ster M, Isachenko V, van der Ven K, van
der Ven H, Kru ¨ssel JS, von Wolff M (2019)
Overnight ovarian tissue transportation for
centralized cryobanking: a feasible option.
Reprod Biomed Online 38:740–749
2. Oktay K, Harvey BE, Partridge AH, Quinn
GP, Reinecke J, Taylor HS, Wallace WH,
Wang ET, Loren AW (2018) Fertility preservation in patients with cancer: ASCO clinical
practice guideline update. J Clin Oncol
36:1994–2001
Cryopreservation and Thawing of Human Ovarian Tissue
497
3 ) should be initiated in
order to exclude malignant cells. This is essential for cryostorage and for subsequent therapeutic transplantation but should
be carried out by the surgical center that does removal of
ovarian tissue [3, 23].
4. Studies have shown that hypothermia of the biopsied ovarian
tissue sample can last for up to 24 h in different transport periods
without causing damage to the follicle reserve or without a loss
of success rates after transplantation [1, 3, 23, 33]. Centralized
ovarian tissue banking offers high-quality standardized processing, cryopreservation, and storage of cryopreserved ovarian
tissue. This is due to the professional expertise, which can be
only guaranteed if ovarian tissue is processed on a regular base.
5. The averaged results of the viability test from fresh and frozenthawed biopsies can then be summarized and correlated with the
patient’s age at the time of tissue removal, AMH value, and
AFC. This allows to determine the number of tissue pieces that
should be used for re-transplantation. As a rule of thumb, the
quantity of ovarian tissue to be transplanted should correspond
to approximately 15% of a whole ovary. Assuming 50% of the
ovary is taken from a patient, from which ten pieces with a size of
approximately 4 Â 8 Â 1 mm
3 were prepared and cryopreserved,
then three pieces should be thawed and transplanted in the first
treatment. In the case of a low follicle density and/or an
advanced age at the time of collection (approximately
>30 years), the number of pieces should be increased to
20–25%, which corresponds to a total of four to five pieces [34].
6. These examinations also ensure that the entire procedure chain
(removal of the tissue, handling, and transportation from surgery to the cryobank, subsequent processing, cryopreservation,
thawing) did not lead to any relevant damage, like loss of
follicles and oocytes [1, 23].
7. Further in vitro tests can also be performed. Such tests, like a
glucose uptake assay, may better reflect the overall tissue functionality, since only a completely intact ovarian cortex can
sufficiently supply the follicles and support their growth. The
tests include the measurement of the in vitro glucose consumption of standardized cortex biopsies before and after
cryopreservation [26].
References
1. Liebenthron J, Montag M, Reinsberg J,
Ko ¨ster M, Isachenko V, van der Ven K, van
der Ven H, Kru ¨ssel JS, von Wolff M (2019)
Overnight ovarian tissue transportation for
centralized cryobanking: a feasible option.
Reprod Biomed Online 38:740–749
2. Oktay K, Harvey BE, Partridge AH, Quinn
GP, Reinecke J, Taylor HS, Wallace WH,
Wang ET, Loren AW (2018) Fertility preservation in patients with cancer: ASCO clinical
practice guideline update. J Clin Oncol
36:1994–2001
Cryopreservation and Thawing of Human Ovarian Tissue
497