Human Epididymal and Testicular Sperm Cryopreservation

Cryopreservation of epididymal and testicular sperm is a valuable tool for azoospermic patients undergoing IVF and for cancer patients who wish to preserve their fertility. In cases of obstructive azoospermia, either frozen or fresh sperm may be used as fertilization and pregnancy rates are comparable, while in nonobstructive azoospermia, sperm quality may be further impaired after the freezing and thawing procedure. Spermatozoa from epididymal aspiration or testis biopsy can be cryopreserved with common protocols that are used for ejaculated sperm such as the conventional slow-freezing method. However, recently, alternative sperm freezing methods have been developed including cryoprotectant-free vitrification and single sperm freezing. In this chapter, we aim to describe the various protocols for epididymal and testicular sperm processing and freezing that currently exist and compare the advantages and disadvantages of each method.