What is Epididymal Sperm Aspiration? Procedure & Techniques

By (gynecologist), (embryologist), (embryologist) and (invitra staff).
Last Update: 02/25/2021

Epididymal sperm aspiration is an option for couples who wish to conceive when no sperm is found in the male's ejaculate. However, this technique is only useful when the male does produce sperm even though it does not come out in the ejaculate.

The procedure consists of obtaining sperm directly from the epididymis, a duct of the male reproductive system where sperm are stored and complete their maturation until they are expelled with ejaculation.

How is done?

Epididymal sperm aspiration is a procedure that, as its name suggests, allows sperm to be obtained from the epididymis. In this way, this method offers an alternative to sperm donation in cases where there are no sperm present in the male ejaculate, provided that sperm production is not affected.

Besides, there is also the option of obtaining sperm directly from the testicle by aspiration or by testicular biopsy.

The type of technique used to obtain sperm from the epididymis will vary from case to case. There may even be a change of technique if no sperm is obtained in the epididymis. Because of this, the team that studies the particular circumstances that will lead to the choice of one method or another for the collection of spermatozoa acquires great importance.

Indications for sperm aspiration

Taking into account the characteristics we have discussed about this procedure, they can benefit from epididymal sperm aspiration:

  • Patients with obstructive azoospermia, i.e. patients with obstruction (due to infections or trauma) of the ducts through which the sperm must pass when ejaculating or males with congenital absence of vas deferens.
  • Patients who want to become fathers after a vasectomy and do not wish to undergo reversal surgery.

Therefore, it will be possible to obtain spermatozoa from the epididymis of these males for use in assisted reproduction techniques. This will allow them to be biological parents to their offspring and avoid resorting to a sperm donor.


A percutaneous technique (through the skin) or an open surgical approach can be used to obtain sperm from the epididymis.

Each of these methods for epididymal sperm aspiration is detailed below.


Percutaneous epididymal sperm aspiration, also known as PESA, involves the aspiration of epididymal contents with a needle. This method is performed under local anesthesia.

The needle is inserted through the upper part of the scrotum (the pouch covering the testicles) to reach the head of the epididymis and aspirate the sperm.

The obtained sample is quickly examined under a microscope in the laboratory to see if it contains motile sperm and what its concentration is.

This procedure can be repeated until an adequate number of motile sperm is recovered.

This is the least invasive method of obtaining sperm from the epididymis, but little sperm is recovered. It may even happen that no sperm are recovered and a testicular biopsy is necessary.

Therefore, it is common that PESA does not provide an adequate sample for cryopreservation, as some sperm will not survive the freeze-thaw process. Because of this, sperm obtained in this way are often used fresh in ICSI cycles. The advantage of this fertility treatment over others is that it only requires one sperm for each egg to be fertilized.


Another technique for obtaining sperm from the epididymis is microsurgical epididymal sperm aspiration or MESA. It involves making a 2-3 cm incision to expose the testicle and epididymis. This is done under general anesthesia, so the male will not feel pain.

Next, with a surgical microscope, the epididymis is evaluated and the surgeon obtains fluid from inside the epididymis. This is quickly taken to the laboratory, where the embryologist will look under the microscope to see if the sample contains motile sperm.

The microsurgical aspiration process can be repeated again in another area of the epididymis until a sufficient quantity of motile sperm is obtained. This technique allows the collection of a greater number of spermatozoa than PESA, so the sample obtained in this case can be cryopreserved for later use in ICSI.

However, the MESA technique has the disadvantage that it is a more invasive procedure and the recovery time is longer. In addition, it may also happen that no sperm are obtained after performing this technique. In this case, there is the possibility of performing a testicular biopsy.

FAQs from users

When is epididymal sperm aspiration used?

By Elena Santiago Romero M.D. (gynecologist).

This technique is recommended for those cases of infertility in which there is a very low concentration of sperm in the male ejaculate. Epididymal sperm aspiration is also recommended for those cases in which there is a complete absence of sperm in the sample (obstructive azoospermia) due to blockage or congenital absence of the vas deferens.

In addition, those men who have previously had a vasectomy, but wish to have children, can also have this procedure performed to obtain sperm.

Whenever sperm aspiration is performed, it must be complemented with ICSI (intracytoplasmic sperm injection) to try to fertilize the eggs.

What is the advantage of obtaining sperm from the epididymis versus a testicular biopsy?

By Silvia Azaña Gutiérrez B.Sc., M.Sc. (embryologist).

The main advantage of obtaining sperm from the epididymis is that they will be motile spermatozoa with a higher state of maturity than those obtained from the testicle, since the epididymis is the place where they accumulate and mature until they are expelled with ejaculation.

In addition, techniques such as PESA or MESA avoid direct intervention in the testicle.

However, obtaining sperm from the epididymis is only possible in cases of obstructive azoospermia (in which sperm production is not affected), so that in other types of azoospermia a testicular biopsy must be performed in search of foci of sperm production.

Similarly, in cases where it is not possible to recover sperm from the epididymis after PESA or MESA, a testicular biopsy can be performed. This would increase the possibility of finding spermatozoa since the testicle is the site where they are produced.

Suggested for you

If you are interested in reading more about obstructive azoospermia, you can visit the following article: Obstructive Azoospermia - Causes & Treatment Options.

Also, if you need more in-depth information about the testicular biopsy, we recommend you to click on this link: What Is a Testicular Biopsy? - Purpose & Procedure.

We make a great effort to provide you with the highest quality information.

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Bernie AM, Ramasamy R, Stember DS, Stahl PJ. Microsurgical epididymal sperm aspiration: indications, techniques and outcomes. Asian J Androl. 2013 Jan;15(1):40-3.

Coward RM, Mills JN. A step-by-step guide to office-based sperm retrieval for obstructive azoospermia. Transl Androl Urol. 2017 Aug;6(4):730-744.

Esteves SC, Miyaoka R, Agarwal A. Sperm retrieval techniques for assisted reproduction. Int Braz J Urol. 2011 Sep-Oct;37(5):570-83.

Gil Salóm M. Técnicas de recuperación espermática para inyección intracitoplasmática de espermatozoides (ICSI) en infertilidad masculina [Spermatic recovery techniques for intracytoplasmic spermatozoid injection (ICSI) in male infertility]. Arch Esp Urol. 2004 Nov;57(9):1035-46. Spanish. PMID: 15624403.

Gordon UD. Assisted conception in the azoospermic male. Hum Fertil (Camb). 2002 Feb;5(1 Suppl):S9-S14.

Popal W, Nagy ZP. Laboratory processing and intracytoplasmic sperm injection using epididymal and testicular spermatozoa: what can be done to improve outcomes? Clinics (Sao Paulo). 2013;68 Suppl 1(Suppl 1):125-30.

Van Peperstraten A, Proctor ML, Johnson NP, Philipson G. Techniques for surgical retrieval of sperm prior to intra-cytoplasmic sperm injection (ICSI) for azoospermia. Cochrane Database Syst Rev. 2008 Apr 16;2008(2):CD002807.

FAQs from users: 'When is epididymal sperm aspiration used?' and 'What is the advantage of obtaining sperm from the epididymis versus a testicular biopsy?'.

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Authors and contributors

 Elena Santiago Romero
Elena Santiago Romero
Bachelor's Degree in Medicine and Surgery from the Autonomous University of Madrid. Master's Degree in Human Reproduction from the King Juan Carlos University and the Valencian Infertility Institute (IVI). Several years of experience as a gynecologist specializing in Reproductive Medicine. More information about Elena Santiago Romero
License: 282864218
 Marta Barranquero Gómez
Marta Barranquero Gómez
B.Sc., M.Sc.
Graduated in Biochemistry and Biomedical Sciences by the University of Valencia (UV) and specialized in Assisted Reproduction by the University of Alcalá de Henares (UAH) in collaboration with Ginefiv and in Clinical Genetics by the University of Alcalá de Henares (UAH). More information about Marta Barranquero Gómez
License: 3316-CV
 Silvia Azaña Gutiérrez
Silvia Azaña Gutiérrez
B.Sc., M.Sc.
Graduate in Health Biology from the University of Alcalá and specialized in Clinical Genetics from the same university. Master in Assisted Reproduction by the University of Valencia in collaboration with IVI clinics. More information about Silvia Azaña Gutiérrez
License: 3435-CV
Adapted into english by:
 Romina Packan
Romina Packan
inviTRA Staff
Editor and translator for the English and German edition of inviTRA. More information about Romina Packan

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