To be able to carry out the in vitro fertilization treatment which is an option for the couples who cannot have baby naturally, firstly father and mother must have the reproductive cells. In other words, if egg or sperm cells cannot be obtained, it will not be possible to perform the IVF treatment because IVF procedure make use of the reproductive cells received from the mother and father to achieve pregnancy. In the in vitro fertilization procedure, oocytes received from mom and the sperm cells received from dad are taken out of the body and fertilization occurs in a laboratory setting. Afterwards, 1-2 embryos-the healthiest of all generated embryos-are transferred into uterus. In case of azoospermia (no sperm count) which is one of the causes of infertility in men; surgical methods are applied to collect sperm(s) to be used in IVF. Tese, Tesa, Pesa and Mesa are the techniques/procedures used for sperm retrieval for men whose semen contains no sperm. IVF specialist and urologist together decide the technique to be used for sperm retrieval. Micro-TESE (microsurgical testicular sperm extraction) may be mentioned as the most successful method in today’s medical technology used for obtaining sperm from men with azoospermia.
What is TESE and how is it performed?
Testicular sperm extraction (TESE) is the process of removing a small portion of tissue from the testicles of men with no sperm in semen under local anesthesia and extracting the few sperm cells with biopsy. Azoospermia is generally divided into two categories: obstructive azoospermia (OA) and non- obstructive azoospermia (NOA). Nearly in all OA cases, it is possible to extract sperm from the testicles through TESE. However, the rate of successful sperm retrieval is about 50% in NOA cases. If TESE method provides more than needed sperm cells, only necessary cells are used and others can be frozen to be used for microinjection later.
What is TESA and how is it performed?
In those subjects whose sperm production is normal but sperm cannot be found in semen, the reason underlying the problem is either obstruction or absence of a sperm duct. In such cases, all methods of MESA (surgical), TESA or PESA (sperm retrieval with a needle) and in case of the testicular disorder TESE (testis biopsy and sperm retrieval method) are used. Any sperm obtained through any of these methods can be used for fertilization. These procedures performed under local anesthesia do not damage either general health or sexual function of a man. However, it is necessary to underline that the most modern and non-problematic technique applied currently for azoospermia is micro-TESE.
What is MESA and how is it performed?
The epididymis is a tightly coiled mass of thin and microscopic tubes that carries sperm from the testes to the ductus deferens in the male reproductive system. Sperm matures as it passes through the epididymis and gain movement ability. In MESA-a method used to retrieve sperm in case of no sperm count in semen- the epididymis is surgically entered and sperm is tried to be collected with cells taken from epididymis.
What is PESA and how is it performed?
In PESA, the epididymis (sperm matures as it passes through the epididymis) is entered with a needle to obtain sperm cells.
It can be argued that the micro-TESE procedure is the most successful of the biopsy methods that have been present for a long time. With a specially designed microscope set-up, sperm production centers can be precisely identified and sperm can be obtained even from men in whom other biopsy procedures could not be successful. Furthermore, as less tissue is removed and the vessels feeding the testicles are less damaged in the micro-TESE method, the patient can recover more rapidly. In men with obstructed sperm channels, it is not possible to find sperm as it cannot go down into the testicles. In such cases, the sperm channels or the testicle tissue is accessed with a very thin needle and samples are taken. The likelihood of finding sperm in these parts is very high. The micro-TESE method may be the most logical method if obstruction of sperm channels-the reason of azoospermia- is not present and there is no or insufficient sperm production because it is not very healthy to take tissue or parts from the whole testicle in case of no or insufficient sperm production. There are thousands of mini-tubes in the testicle tissue and the sperm production varies between the tubes. In other words, while sperm is produced in some tubes on the day of the procedure, there may be no production in other tubes. If sperm is sought with surgical procedures, many cells/parts will be damaged. However, the micro-TESE method enables the detection of sperm-producing tubes with the surgical microscope and sperm retrieval starts accordingly. In the micro-TESE procedure, the ovaries are examined under general anesthesia, the sperm-producing areas are identified and the sperm cells, if any, are extracted from the tissue.