The procedure of ovarian tissue cryopreservation permits retention of hundreds of immature oocytes kept within the protective environment of the original ovarian tissue. An important advantage of this technique is the lack of unnecessary delays in providing anticancer treatment. Additionally, because the primordial follicles are small and structurally simple, they are much more tolerant to manipulation and to the freeze-thaw procedure compared with the large growing follicles that readily undergo atretic degeneration and granulosa cell apoptosis.
In most cases, ovarian tissue can be collected using laparoscopic ovariectomy or multiple ovarian biopsy. Even though autotransplantation (transplanting the ovarian tissue back into the patient) seems to be the natural choice for preservation of fertility, the potential risk of retransferring cancer cells along with the grafts is a major drawback of this option. Shaw et al. reported that ovarian tissue from a mouse donor with lymphoma transferred the malignancy to recipient mice. However, none of the mice that were grafted with ovarian tissue taken from human lymphoma patients developed the disease. Ovarian tissue xenotransplantation (transplantation between different species) can serve both as a model/research system and as a safer clinical option by which the risk of malignant cancer cell transmission is reduced. In addition to the benefit to human patients who suffer from premature ovarian failure, this approach can also serve for preservation of endangered animal species. actos tablets