Congelacion de tejido ovárico. Método lento

A number of options are currently available to preserve fertility in cancer patients: embryo cryopreservation, oocyte cryopreservation or ovarian tissue cryopreservation. The choice if the most suitable strategy for preserving fertility depends on different parameters: the type and timing of chemotherapy, the type of cancer, the patient=s age and the partner status. The cryopreservation of ovarian tissue is the only option for prepubertal girls, and for women who cannot delay the start of chemotherapy. Ovarian tissue can be frozen in three different forms: as fragments of ovarian cortex, as the entire ovary with its vascular pedicle or as isolated follicles. Human ovarian tissue can be successfully cryopreserved, by slow programmed freezing methods, with good survival and function after thawing. Ovarian cryopreservation and transplantation procedures have so far been almost exclusively limited to avascular cortical fragments, in both experimental and clinical studies, and, for now, this is the only procedure that has yielded five live births in humans after autologous transplantation. The main drawback of this method is that the graft is completely dependent on the establishment of neovascularisation and, as a result, a significant proportion of follicles are lost due to ischemic damage by the time neovascularisation is achieved. Therefore, reducing the ischemic interval between transplantation and revascularisation is essential to maintaining the viability and function of the graft. Cryopreservation and transplantation of intact ovary with vascular anastomosis would allow immediate revascularisation of the transplant