ABSTRACT
Male infertility treatment has been revolutionalized twice: the first time by the introduction of intracytoplasmatic sperm injection (ICSI) in 1992 and the second time when ICSI allowed spermatozoa retrieved from the testis to fertilize an oocyte leading to viable embryos and healthy pregnancies. Azoospermia is defined as the absence of spermatozoa in the ejaculate after assessment of centrifuged semen on at least two occasions. Since obstructive azoospermia is the indication for epididymal aspiration, it is possible to obtain large numbers of spermatozoa with minimal contamination by red blood cells and non-germ cells. The aspirates are emptied into a tube containing a buffered medium containing heparin. Testicular samples contain large numbers of different cell types and debris, especially red blood cells. Additionally, the elongated spermatids, which are still attached within the seminiferous tubules, must be freed. A number of methods can be used to isolate the spermatozoa.
