In medical terms, is a laparoscopy with fragments extraction of ovarian tissue to insert it after anticancerous treatment.

The intention of this procedure is to have ovarian tissue available to be used after its thawing. The ovarian tissue freezing is thinking like the best alternative to preserve the reproductive potential given that more than 90 % of the oocytes can be protect in this way. The ova in the fundamental follicles are less differentiated so more cryopreservation-resistant. Moreover, the ovarian tissue cryopreservation is with frequently the only option of future fertility available to preteenager woman with ovarian damage risk (for example, treatment in large doses of chemotherapy or radiotherapy).

It could be a satisfactory option too in women with cancer who haven´t the enough time to realize the ovarian stimulation cycles and the catchment of the required ova in the cryopreservation process of gametes or embryonic death.

Until the appropriate development of the culture technology and maturation in the follicles and immature oocytes laboratory is achieved, it seems that the best way to use the cryopreserved ovarian tissue for reproductive purposes is the autotransplantation.

This organ transplantation can be done in the remaining ovary (orthotopic transplantation) or in alternative areas, like the forearm or anterior rectus sheath abdomen (heterotopic transplantation). In this last case, it’s necessary to catch ovules (easier than in the conventional in vitro fertilization because there are more accessible areas) and an in vitro fertilization to get a pregnancy.

It’s necessary to control, depends the cancer type, reproductive degree of cancer cells to realize the ovarian tissue autotransplantation. Therefore it’s essential to make a pathological study of a piece of a sample to freeze. Then, after its thawing and before the transplantation, it will repeat a new pathological study on another piece of the sample.

This technique has another control like not all follicles will survive the freezing-thawing process.

Another consideration to take into account in this technique is not always 100% of the follicles survive the freezing-thawing process.

To obtain ovarian tissue for later maintenance it’s necessary to make a laparoscopy. Using this technique, we access to the patients ovaries. We remove a piece of both, which isolate the cortex. This tissue is full of oocytes before starting their maturation process.

The final tissue is cut into slices less than one centimeter wide and a millimeter thick, which allows the liquid cryopreserved (DMSO) will spread to all cells. It’s preserved at 196 Celsius degrees below zero and it can keep frozen indefinitely for more than 20 years, without losing its effectiveness.

Later, when the patient wants to use their ovarian tissue, some of these pieces will thaw and placed via laparoscopy, in windows that are made in the cortex of the ovary remaining.

It’s evaluated in the first time the reappearance of ovarian function. They put it again between 3 and 5 months later. Then, we must wait to a spontaneous pregnancy.

Another advantage of this technique is the permanence of the normal ovarian function with a lot of benefits for these women, who in many cases, have lost because the treatments.

Dr. Donnez's group in Belgium was the first documented in 2004, a pregnancy after transplantation of cryopreserved ovarian tissue before cancer treatment. Then, the groups of Dr. Meirow in 2005 and Dr. Demeestere in 2006 presented new gestations.

In cases of Donnez and Demeestere pregnancy was spontaneous after the placement of the ovarian tissue in their usual area. In the last case, also they had placed a piece of ovarian tissue in the abdominal subcutaneous area. Meirow’s case needs the in vitro fertilization use, although they only waited 3 months before starting the treatment.

Currently, Dr. Otkly’s group of the Cornell Institute (USA) presents the best statistics at the global level in these techniques.