TESA, or testicular sperm aspiration (also known as TESE, or testicular sperm extraction) is one of the surgical sperm harvesting techniques used for retrieving sperm in patients with azoospermia. A number of surgical sperm retrieval or recovery methods have been devised to recover sperm from the male reproductive tract.
In men with obstructive azoospermia,(because of duct blockage or absence of the vas deferens) , sperm are usually recovered from the epididymis. The original technique was devised by a urologist, Dr Sherman Silber, who is a specialist in microsurgery. He used a method called MESA, or microepididymal sperm aspiration, in which the scrotum was opened, and an operating microscope used to identify the epididymal tubules which were distended with sperm. While this method was very successful, it was very complex , since it needed an operating microscope; and therefore very expensive as well. This is why a gynecologist from Dubai, Dr Pankaj Srivastav, developed a very simple and easy method to recover sperm from the blocked epidiymis. Since he could feel the turgid epididymis, swollen with sperm, he would blindly puncture the epididymis using a simple butterfly needle - a technique which was very similar to drawing blood from a blood vessel ! This simple technique is called PESA (percutaneous epididymal sperm aspiration), in which the sperm is sucked out from the epididymis by puncturing it with a fine needle.
This method is as effective as microsurgery to retrieve epididymal sperm ; is much easier for both the patient and the doctor; and much cheaper as well, since the infertility specialist can do it himself. It is also much less traumatic, since there is no need to cut the scrotum, with the result that there is no scar at all. This is why this is the preferred method of choice in most centers in India, UK and Belgium.
For patients with obstructive azoopsermia in whom sperm cannot be found in the epididymis, it is always possible to find sperm in the testis. The easiest way to retrieve this is through TESA or testicular sperm aspiration , in which the testicular tissue is sucked out through a fine needle, under local anaesthesia. The testicular tissue is placed in culture media and sent to the lab, where it is processed. The sperm are liberated from within the seminiferous tubules (where they are produced) and are then dissected free from the surrounding testicular tissue.
Using sperm from the epididymis and testis for ICSI in order to treat patients with obstructive azoospermia is logical, and thus conceptually easy to understand. However, surprisingly, it is possible to find sperm even in patients who have testicular failure (nonobstructive azoospermia) - even in those men with very small testes. The reason for this is that defects in sperm production are "patchy"- they do not affect the entire testis uniformly
Various methods have been devised to recover sperm from the testes, and a fashionable method prevalent in the US today was developed by Dr Schlegel from Cornell, in which he uses an operating microscope to try to identify healthy testicular tissue, in the hope that the chance of finding testicular sperm improve. However, a much easier, kinder and simpler method has been developed by Dr Rupin Shah of Bombay, India, where multiple needle biopsies are taken from both testes. While this is "blind", since it's possible to sample many more areas of the testes (we routinely perform over 10 microbiopsies using this technique, even from very tiny testes) this technique is at least as effective as Dr Schlegel's in recovering testicular sperm. Moreover, it's much less traumatic, since no blood vessels are touched, with the result that it causes much less pain; and it can easily be repeated in a few months if needed, because the testes are not damaged.
However, the tragedy is that many IVF clinics in the US continue using microsurgical techniques for sperm retrieval. They claim they are better, though actually they are not ! The sad truth is that the real reason is that they continue using these techniques is that it allows IVF clinics and the urologists attached to them to charge over US $ 3000 - 5000 for each sperm retrieval procedure ! By comparison, a PESA in our clinic costs US $ 400; and a TESA costs US $ 500 only !
There are 2 options for doing a TESA - diagnostic; or therapeutic. In a diagnostic TESE, the surgeon performs multiple diagnostic biopsies to determine if sperm are being produced in the testes or not. If no sperm are found , the diagnosis of complete testicular failure is confirmed; and treatment options then include adoption or donor insemination, since there is no treatment at present for this condition. If sperm are found, then these testicular sperm can be cryopreserved; and used for ICSI treatment in the future.
The advantage of doing a diagnostic TESE is that it is less expensive; and there is no need to give the wife expensive injections for superovulation.
Unfortunately, the results with testicular sperm cryopreservation are poor in most labs; which means most men will need a repeat TESE if they want to use their sperm for ICSI. This involves a second TESE, after a gap of about 6 months. There is also a 20% risk that no sperm may be found in the second biopsy, since the first biopsy may have removed all the areas of sperm production.
In our clinic, rather than do a diagnostic TESE, we recommend that patients do a therapeutic TESE-ICSI treatment cycle. If we do find sperm, then these can be used for ICSI immediately, maximising the chances of success. If we do not find sperm, and if patients agree, then we can use donor sperm to fertilise the retrieved eggs. The problem arises if we do not find testicular sperm and the patient is not willing to use donor sperm. In this situation, the ICSI treatment cannot proceed any further, and the treatment money is wasted. However, patients still have peace of mind that they did their best, and did not leave any stone unturned !
You can read a real-life success story of a man with testicular failure whom we treated in our clinic.
Why don't all clinics use this approach ? This is because they do not have a full-time andrologist, which is why they need to do the TESE first to suit the andrologist's convenience; and they then use these frozen sperm for ICSI later on. We feel this approach is suboptimal.