With the microvascular technique, the tiny blood vessels supplying the ovary are directly linked, and ischemia time, during which blood supply is restricted, is minimised. However, this is a very difficult operation not available in most reproductive centres. With the cortical grafting technique, ischemia time for revascularisation was always thought to be a limiting factor, not to mention the deleterious effect of freezing. However, very thin cortical slices not only allow the tissue to be frozen by vitrification, but also accelerate the speed of revascularisation of the ovarian graft.
"We believed that microvascular transplant would give us a longer duration of ovarian function," said Dr. Silber, "but our current research has proved us wrong. This is not only good news for surgeons, but also for patients who will be able to undergo a simpler procedure with equally successful results."
Out of the eight women who received cortical transplants, six have had one or more spontaneous pregnancies, resulting in the birth of seven healthy babies.
"We are in the middle of a massive global infertility epidemic, caused by the new structure of our society where women choose not to have children until they are older," said Dr. Silber. "As a result, many of them become infertile because of the ageing of their eggs and ovaries.
"This procedure is a solution to that social dilemma, allowing women to have children when they are older by preserving their ovaries when they are younger and transplanting them back at a later date. It can also be used to preserve the fertility of young women with cancer who are likely to be cured of their cancer, but who will become sterile as a result of the cancer treatment without such intervention," he said.
European Society for Human Reproduction and Embryology