Obtaining the sperm

Sperm for ICSI can be obtained directly from the testis in a variety of ways, each with its own acronym.

 MESA (Micro-epididymal sperm aspiration) refers to an operation under general anaesthetic, in which the surgeon collects fluid from the epididymis with the help of an operating microscope. The operation is expensive, so this technique is usually only done if the man is having a vasectomy reversal (or a similar operation) at the same time.  The sperm from MESA is frozen for later use. The advantage of MESA is that a couple knows that there is definitely sperm before starting their ICSI cycle.

PESA (Percutaneous epididymal sperm aspiration) refers to passing a fine needle ‘blindly’ through the skin into the epididymis. Local anaesthetic is usually sufficient. PESA usually gives enough sperm for ICSI treatment, but often not enough to freeze. It is commonly done the day before the egg collection in the ICSI cycle.

TESA (Testicular sperm aspiration) or TESE (Testicular sperm extraction) can be used if there are no sperm on PESA, and for men whose testes make very few sperm. For TESA, a fine needle is used to take tissue from the testes, while in TESE a larger sample of tissue is taken through a cut in the skin. Both techniques are usually done under local anaesthesia, the day before or the day of the egg collection in the ICSI cycle.