MESA/TESE -
microsurgical sperm retrieval from the epididymis or testicle 

Micro Epididymal Sperm Aspiration or MESA and Testicular sperm extraction or TESE are modern microsurgical techniques. Thanks to these procedures, we can obtain sperm for successful egg fertilisation in the case of very low sperm concentration and even if sperm are not present or not alive in a sample. Together with the ICSI injection method, these are revolutionary steps in assisted reproduction for couples with severe male factor infertility, for whom using donor sperm was previously the only way to conceive.

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What is MESA/TESE?

Modern MESA/TESE methods can obtain sperm capable of fertilisation even with unfavourable spermiogram results.

Male infertility is found in 20 – 50% of couples who experience difficulty in conceiving. In 90% of these cases, complications are related to the quality of the male reproductive cells — their quantity in the sample, motility, shape and their cellular DNA damage. Male infertility can be caused by a number of factors ranging from age and lifestyle to genetic and medical causes, such as infectious diseases, chemotherapy and injuries.

Contemporary medicine, specifically in andrology, has advanced significantly in the options it offers for couples with male infertility. In the case of low sperm concentrations in the sample, we often opt for hormonal treatment with testosterone. If sperm are completely absent in the ejaculate, known as azoospermia, the cause may be obstructive, from a mechanical disturbance in the ducts between the testis and urethra, or non-obstructive.

Obstructive azoospermia most often occurs after inflammation, a vasectomy, or a congenital defect in the development of the fallopian tubes. Non-obstructive azoospermia manifests as a defect or absence of germinal tissue in the testes and has various causes. Examples of these are genetic causes, conditions after chemotherapy, congenital disorders concerning testicular descent and hormonal insufficiency.

Identifying the cause or causes is the most important factor that will help us predict the prospects of obtaining usable sperm by MESA/TESE methods. In the case of obstructive causes of azoospermia, we achieve up to 95% success rate, while in non-obstructive methods cases, this rate is up to 50%. We always, however, assess each couple’s chances individually according to current hormonal results and the history of previous interventions and their success rates.


Analysis of sperm obtained by surgery by MESA/TESEPFC

What are the procedures like?

Both MESA and TESE are microsurgical, minimally invasive methods performed under optical magnification, and can provide sperm for fertilisation even in what were previously intractable cases of infertility. In the case of MESA (microsurgical epididymal sperm aspiration), we obtain sperm by suction directly from the ducts of the epididymis, where the sperm mature and from where they then travel to the testicles. Samples are immediately taken by the laboratory, analysed and if a low number of viable sperm is found, we can repeat the aspiration. If the MESA method does not yield sperm from the collected samples, we employ the TESE (testicular sperm extraction) method, where sperm is extracted directly from the testicular ducts from a small sample of collected tissue.

We freeze sperm and testicular tissue not used for fertilisation in several samples for possible future use. If the sperm we obtain surgically are not motile, then we test their viability using the LAISS method (laser-assisted sperm selection), which can distinguish non-mobile sperm from dead sperm.


Microsurgical methods of sperm retrieval for samples with low or no concentration are an extremely important tool for us to help even couples in difficult fertility circumstances. Through collaboration with an experienced urologist, we can tailor a personalised treatment for each couple.