Infertility in some men may be due to non-obstructive azoospermia or an interruption of the sperm transport passages, as a result of either a previous male sterilisation operation (vasectomy), a birth abnormality (absence of the vas), or a spinal/pelvic injury or operation.
By using direct percutaneous needle aspiration, sperm can be retrieved from the epididymis (PESA). Alternatively, sperm can be collected from the testes by collecting multiple testicular biopsies (TESA). In certain cases, delicate open microsurgical aspiration of sperm may be performed
These techniques require a general anaesthetic and are performed on a day care basis. When timed with the female partner’s egg collection, the sperm can then be used for ICSI treatment that day, or frozen for future use.