sperms 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 sperms to travel beyond the testicles to reach the penis for ejaculation, then sperms can be retrieved by two different methods: TESE (testicular sperms extraction) and PESA (percutaneous epididymal sperms aspiration).
PESA is a minimally invasive technique which is used to extract sperms from the epididymis under local anaesthesia with a fine needle. If sperms cannot be retrieved using this method then the patient may have to proceed to TESE which is also a minimally invasive procedure performed under local or general anaesthesia, and is used to extract sperms from the testicles.
Lack of sperms 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 areblocked by scarring from a previous infection, or if the man has undergone vasectomy in the past and reversal has failed.
sperms obtained from either the testicles or the epididymis will usually have poor motility. Therefore, in order to improve the chances of fertilization the sperms are usually microinjected into each egg by ICSI.