PESA - PERCUTANEOUS EPIDYDIMAL SPERM ASPIRATION

How it is done

The PESA technique is extremely easy. In many cases, this procedure is done without any form of anesthesia. In most cases, the epidydim is turgid and easy to find, which facilitates the process even more.

The testicle is held between index, medium and thumb fingers and, with the other hand, the epidydim is palpado and its head identified. Then the auxiliar introduces directly into the epidydim a 13x4 needle connected to a 1 ml syringe, perpendicularly to the scrotal skin, creating negative pressure. If the needle point is correctly positioned, it will be observed that a small amount of fluid will enter the syringe immediately. At this moment the needle is removed and the material is taken to the laboratory.

NAt the laboratory, the fluid is deposited on a petri dish containing culture medium and the needle is washed 4 or 5 times with the same culture medium. ThenThen a small droplet from the material is examined, and the doctor is communicated about the presence or absence of mobile spermatozoa. Spermatozoon concentration is very high in the epidydimal fluid. Mininal fluid amounts may have 1 to 200 million spermatozoa. So, even if the aspired fluid amount is minimal, one must check carefully, because there may be enough mobile spermatozoa for ICSI.

At the end of the procedure, the patient is free to go and may go back to work immediately.

If there is exceeding material from the aspiration, the excess may be frozen to be used in future ICSI cycles, avoinding to have to puncture the same patient again. In case one doesn’t find any spermatozoa, a new aspiration must be done, in the same place or in the contralateral side, before one chooses to do another technique.

In the cases when PESA fails, the most indicated and effective procedures are testicular sperm aspiration (TESA) or a little testicular biopsy (TESE), which aims at obtaining sperm directly from the testicles.

TESA - TESTICULAR SPERM ASPIRATION

TESE - TESTICULAR SPERM EXTRACTION

The possibility to carry pregnancy to term, after intra cytoplasmic sperm injection obtained directly from the testicle, has significantly broadened the possibility of treatment for male infertility. Since then, even individuals carrying non obstructive azoospermy (diminished or absent sperm production) could generate their own children, as long as it is possible to obtain any viable spermatozoon in the interior of the testicular parenchima. Despite the fact that non obstructive azoospermy is the main and most important indication for for TESE/TESA, this technique can also be successfully employed under other conditions (see next table).

It is important to notice, however, that at this present moment there is no exam able to predict the presence or absence of sperm in the testicular parenchima, before TESE/TESA, in individuals affected by non obstructive azoospermy. FSH levels are not predictive indicators. Even in the cases in which most seminiferous tubes present the syndrome histological pattern: presence of only Sertoli cells, some tubes (about 10%) may show reduced spermatogenesis. On the other hand, an individual presenting normal FSH, normal size testicles, azoospermic, can have complete arrest of germ cell maturation, and there will be no way of obtaining any sperm through TESE/TESA.

Thus, it is extremely important to offer the couple na option: use donated semen, when there is no possibility to find spermatozoa through TESE/TESA.

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How it is done

There are two methods to obtain sperm from the testicle: sperm extraction via open biopsy (TESE – Testicular Sperm Extraction) and sperm aspiration from the testicle with a thin needle (TESA – Testicular Sperm Aspiration). Both can be performed under local anesthesia (sperm chord block) or light sedation.

In the case of open biopsy (TESE), a 1.0 cm incision is made in the scrotal skin and vaginal tunica. Following, a small incision in the tunica albuginea is made, avoiding the local veins and aiming at obtaining testicular tissue from the anterior-medial portion. Gentle pressure is exerted on testicle to extrude seminiferous tubes, and this fragment is excised with the help of microsurgical scissors. The testicle fragment i then deposited on a petri dish containing about 1 ml cultur medium (ex. HTF). In most cases, just one fragment is enough to provide spermatozoa for ICSI. However, in the cases of non obstructive azoospermy secondary to arrest of germ cell maturation, or the syndrome of presence of only Sertoli cells, 3 or more specimens may be necessary.

At the end of the biopsy, the tunica albuginea is sewn back with vycril or prolene stitches. The patient will be free to go within one hour, and may go back to work the next day. The material is sent to the laboratory where the tissue embedded in the culture medium supplemented with HEPES is then macerado, with the help of two 13 x 4 needles, under magnification. The effluent is then aspirated and transferred to a Falcon tube in order to proceed to centrifugation (300G for 5 minutes). The supernatant is removed and the resulting pellet is examined to verify the presence of free spermatozoa. It is common to observe the presence of very low motility spermatozoa, generally with no progression, which can, however, increase after incubation for about 12 hours. After ICSI, remaining sperm may be frozen for future use.

Testicular aspiration with a thin needle (TESA) is na extremely simple procedure. The testicle is held between the thumb, index and medium fingers. With the other hand a 21 or 23 G butterfly needle is introduced directly into the testicle, the needle is connected to a 20 ml syringe to facilitate the needle incursion in the interior of the testicular parenchima. The needle mut penetrate perpendicularly (at a right angle) with the scrotum skin, immediately creating a negative pressure. 4 to 6 needle incursions must be made into the testicle, in different directions. At the end of the procedure, the needle is removed and the material sent to the laboratory. In the laboratory, the fluid obtained, which is generally mixed with blood, is placed on a petri dish containing culture medium, and the needle is washed 4-5 times with the same medium. Following, a small droplet of the material is examined under the microscope, and the presence or absence of spermatozoa is communicated to the doctor. The spermatozoon number is low in the testicular fluid, especially in individuals affected by non-obstructive azoospermy. Therefore a careful analysis must be made. If there are too many red blood cells contaminting the smple, one can use a special medium to lyse them. In case no spermatozoon is found, another aspiration must be made, on the same side or on the contralateral side. In the cases when TESA fails, the method must be changed, proceeding to the sperm extraction directly from the testicle (TESE). The success of TESA to obtain spermatozoa for ICSI is more limited than the open biopsy, mainly in the cases of non obstructive azoospermy. Moreover, the number of spermatozoa obtained with TESA is much smaller that the number obtained with na open biopsy, and it is rare that exceeding material for freezing is left. The incidence of complications, like intra-testicular hematomas is small, but the risk exists and must not be underestimated. Although, due to the simplicity of the method, we consider TESA to be the first option to obtain spermatozoa from the testicle, going to TESE in the cases where the first one fails.