TESE (testicular sperm extraction)
Sperm is produced in the testicles and carried to the penis through the tubes which are known as the epididymis and the vas deferens. When it is not possible for the sperm to travel beyond the testicles to reach the penis for ejaculation, then sperm can be retrieved by two different methods: TESE (testicular sperm extraction) and PESA (percutaneous epididymal).
PESA (percutaneous epididymal sperm aspiration) PESA is a minimally invasive technique which is used for sperm extraction from the epididymis under local anesthesia with a fine needle. If sperm cannot be retrieved using this method then the patient may have to precede to TESE (testicular sperm extraction) which is also a minimally invasive procedure performed under local or general anesthesia and is used to extract sperm from the testicles.
Lack of sperm in the ejaculate can occur as a result of various circumstances, for example, when a man is born without a vas deferens, if the ducts are blocked by scarring from a previous infection, or if the man has undergone vasectomy in the past and reversal has failed.
sperm extraction obtained from either the testicles or the epididymis will usually have poor motility. Therefore, in order to improve the chances of fertilization the sperm are usually microinjected into each egg by ICSI.