- Release date: September 6 2022
Mıcro TESE (Mıcrodıssectıon Testıcular Sperm Extractıon)
Sperm (male reproductive cells) pass through 3 different stages of formation to become mature spermatozoa. It takes between 42 and 76 days for the sperm to become mature and ready for ejaculation. Sperm develop in the testicles in areas called seminiferous tubules, in the cavity of Sertoli cells. Leydig cells secrete testosterone (male hormone), which enables sperm development.
A conventional (standard) semen analysis is the diagnostic test for male factor infertility. It shows sperm production in the testicles, whether the ducts of the reproductive system are intact and whether the glands are functioning. Male infertility can be defined as the absence of pregnancy despite regular unprotected sexual intercourse. The most common cause of male infertility is inability of the testes.
Among male infertility factors, azoospermia (no sperm in the ejaculate fluid) is the most serious condition. It occurs in about 1% of men and 10% of male factor infertility is due to azoospermia. Azoospermic patients are generally divided into two groups: obstructive (due to obstruction) and non-obstructive (not due to obstruction). This distinction is important because it affects both the clinical approach and treatment outcomes.
Approximately 10% of men diagnosed with infertility have non-obstructive azoospermia and 60% of patients diagnosed with azoospermia have non-obstructive causes. In obstructive, sperm production is preserved and azoospermia is due to a mechanical blockage anywhere in the reproductive system. In other words, in obstructive azoospermia, satisfactory pregnancy rates can be achieved by removing the obstruction or by sperm collection techniques. Non-obstructive azoospermia can be caused by a wide variety of causes that can disrupt sperm production in the testicles. The causes include genetic or congenital anomalies, hormonal irregularities, exposure to toxic substances (such as radiotherapy, chemotherapy) and trauma to the testicles. These causes should be listed in more detail:
Congenital: Klinefelter syndrome, Male XX syndrome, Robertsonian translocations/inversions, Y chromosome microdeletions, Cystic fibrosis, New monogenic mutations, Immotile cilia / Kartagener syndrome, Congenital cryptoorchidism. Acquired Causes: Infections (mumps orchitis, Echovirus, Gonorrhea, Chlamydia, Tuberculosis, Testicular torsion or trauma, Cancers, Chemotherapy, Pelvic radiation or Surgery, Large varicocele, Medications. Idiopathic: Conditions of unknown cause.
Environmental Factors/ systemic diseases: Obesity, Drugs that disrupt the hormone system. Reproductive system anomalies: Disorders in sperm transport: Obstructions, congenital deficiency of the vas deferens, infections, vasectomy.
Others : Problems in ejaculation.
The differential diagnosis of azoospermia with or without obstruction is made using clinical or laboratory parameters. These are the patient's history, physical examination and hormone tests. Non-obstructive azoospermia is not a treatable condition. This does not mean that the patient will never have children. Sperm is present in 30-60% of these patients. The sperm must be removed from the testicles and placed into the egg by ICSI. The ICSI procedure has been used in IVF treatments since 1992. The ICSI procedure has significantly increased the success of IVF with surgically collected sperm. Sperm can be used fresh or frozen after surgical collection (Micro TESE).
Techniques for sperm collection in non-obstructive cases are TESA (testicular sperm aspiration), c TESE - one or more conventional (open) sperm extraction and Micro TESE. The chances of finding sperm with these techniques depend on the technique used. The one with a higher chance of success is c TESE or Micro TESE. The aim of all retrieval techniques is to take samples from the tissues where sperm are produced and to find and extract the sperm in these tissues under a microscope. Since the areas of sperm production are not completely clear, the most appropriate surgical approach is to find these areas with Micro TESE.
In non-obstructive azoospermia, the first approach is to try to collect sperm from the area called epididymis. If this is unsuccessful, the sperm extraction (TESE) procedure is initiated. TESE is the most appropriate approach in cases of non-obstructive azoospermia. Simple lifestyle changes such as smoking cessation can increase pregnancy success in male infertility. In cases where hormone secretion from the brain is insufficient (hypogonadotropic-hypogonadism), medication can increase the success of sperm extraction.
Clomiphene citrate, aromatase inhibitors and hcg can be used in hormonal treatment. In Klinefelter syndrome, testosterone levels are low and can be increased above 250 ng/dL with medication, thus increasing the chance of finding sperm in micro TESE. If hypospermatogenesis (insufficient sperm production) is diagnosed in non-obstructive azoospermic men and the first micro-TESE is unsuccessful, the use of gonadotropins before the next TESE may increase the chance of success. Surgically, the testicle consists of 200-400 wedge-shaped compartments. These compartments are called testicular lobes. These lobes are composed of compartments of fibrous tissue of the tunica albuginea. Each lobe contains 3 to 10 seminiferous tubules.
An operating microscope allows the seminiferous tubules that are most likely to contain sperm to be visualized. This means that less tissue needs to be removed to find sperm. In c TESE without a microscope, more intact testicular tissue must be removed to find the same amount of sperm.
The difference is about 70 times greater. The procedure starts from the larger testicle or, if both are the same size, from the right side. Care is taken not to damage the blood vessels during the procedure. Microdissection should continue until sperm is found or until all areas of the testicle are evaluated. If no sperm is found in the first testicle, the next one is started. When sperm is found, small bleeding is stopped and the incision in the testicle is closed with sutures.
After the tissues are given to the laboratory, they are cut open. Sperm are tried to be found with the wet method. If found, the search process is terminated. If not, the enzymatic process is started. The chance of finding sperm in the enzymatic process varies between 7-25%.
Bleeding, infection, blood clot formation, hardening due to healing tissue (fibrous) may occur after TESE. In cases where no sperm is found despite TESE, sperm donation can be used for pregnancy as a last resort.