Optimal perfusion of an intact ovary as a prerequisite for successful ovarian cryopreservation.

BACKGROUND: Cryopreservation and subsequent reimplantation of intact ovaries from cancer patients, offers potentially the best prognosis for restoring fertility after sterilizing cancer treatment. We used bovine ovaries as a model system to explore the perfusion procedure that is required for cryopreservation of intact ovaries. METHODS: The arteria ovarica was cannuled, and ovaries were flushed with Indian ink for 5 min. RESULTS: Successful perfusion of blood vessels was immediately visible macroscopically by a grey to black discoloration of the ovary and was confirmed microscopically, by examining tissue sections. There was no correlation between the time interval from removal of the ovary to the start of the perfusion, and success of perfusion. We determined the percentage of Indian ink-perfused vessels and scored blood vessels in four different size classes. The percentage of perfused vessels increased with an increase in vessel size. In a limited set of preliminary experiments with human ovaries, comparable results were obtained. CONCLUSIONS: Our results show that bovine ovaries are a suitable and adequate model system for optimizing the cryopreservation of human ovaries. As bovine are at least of comparable size to human ovaries, we expect that our results can be extrapolated to the human situation.