In some situations, no sperm is found in the ejaculate. It could be because of an obstruction in ejaculation pathway or some non-obstruction causes. For obstructed cases, like vasectomy, sperm can be retrieved above the blockage region. The non-obstruct cases are mainly genetic issues. Congenital anomalies may be relatively uncommon in the general population but can occur in up to 2 percent of infertile men. Best known condition is congenital bilateral absence of the vas deferens (CBAVD) which occurs in almost all men with cystic fibrosis. Direct sperm extraction from seminiferous tubule seems to be the choice procedure for this kind of patient.
TESE is a microsurgical procedure done by an experienced Urologist. The sample could be used for an IVF cycle and also be preserved by freezing for future use or as a backup.