PESA (percutaneous epidydimal sperm aspiration) and TESA (testicular sperm aspiration) are procedures that are performed to obtain sperm in certain cases of male infertility. PESA or TESA can be performed on men that have zero sperm counts due to either a sperm production problem or a blockage in their reproductive tract, such as the result of a vasectomy, congenital absence of vas deferens, or infection. With PESA, a small needle is placed into the epidydimis, which is a reservoir of sperm that sits atop each testicle, using local anaesthesia. During TESA, sperm is obtained by means of a biopsy of the testicle. The sperm obtained from these procedures can only be used for ICSI.
The technique known as TESA can salvage a few sperm cells from a tiny biopsy of testicular tissue, which are still able to fertilize an egg and thereby help men who are even unable to produce their own sperm.
Results from TESA and other sperm retrieval techniques (such as PESA and MESA, which both retrieve sperm) from the epididymis) have been most encouraging suggests that men who for various reasons are unable to ejaculate or generate sperm are now able to supply the sperm to fertilize their partner’s egg and thereby further therein own children.
Infertile couples who are recruited to ICSI programmes will usually be carefully selected (severe sperm defects for example) and will sometimes have been unsuccessful in previous IVF cycles, because there is a small risk that the male partner’s infertility is the result of an inherited condition which may be transmitted to a male child. Counselling and genetic screening may be required. Most centers also require followup during and after pregnancy.
The female partner of course must undergo the routine procedure of ovarian stimulation with fertility drugs and egg collection, while the male partner must produce a sperm sample (unless sperms are being removed from a biopsy).
Crucial to the success of ICSI is the preparation and selection of sperm cells, which is done by a process of washing and grading, sperm preparation allows just a few viable sperms to be salvaged from an otherwise unusable sample.