Examination of Tissue
Information regarding procedures under local or general anaesthetic. |
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Sometimes, the results of various tests contradict one another, in which case a small surgical procedure may be the only way to obtain a complete explanation for a particular problem. By means of a testicular biopsy or aspiration, surgeons hope to determine the number of healthy sperm cells there are in the testicles, where they are manufactured.
Anatomical explanation
Sperm is made in the testicles, inside tiny coiled tubules. The tubules are 30-150ml long and are made of two types of cells: sperm producing cells and feeding cells (Sertolice cells).
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The sperm production line. |
Quite obviously, the sperm producing cells are responsible for the making of sperm. Between the tubules, Leydig cells, together with two other cell sorts produce male hormones.
In adult men, the testicle consists of 32% sperm producing cells, 17% Sertolice cell and 3% Leydic cells. The rest is made of supporting tissue.
The Sertolice cells perform several important functions to do with the production and protection of sperm cells. They consist of a closed layer, whereby they form a protective barrier between the tubule and the surrounding environment. The layer contains nerve tissue, lymph nodes and blood vessels. It is important that sperm cells are not secreted into the blood. Sperm (which begins to be made at puberty) undergoes so many changes in its development, that it becomes 'alien' to the body. Thanks to the blood/testis barrier, the chances of them being rejected by the body are minimalized. Other functions of the sertolice cells include the support, protection and feeding of developing sperms. They produce a fluid which facilitates the sperms' passage to the epididymis. They also fullfil one other important function: the production of testosterone.
Causes of azospermia
Azospermia is the absence of sperm in the ejaculate. This can be due to an obstruction somewhere along the way to the outside, but can also be due to a problem in the testicle itself. A testicular biopsy (
see below) can show us what is happening in the testlicular tubules:
- in some men, the sperm producing cells are missing and only the sertolice cells are present (Sertoli cell only syndrome);
- in others, the sperm producing cells fail to complete the maturation process (maturation arrest);
- sometimes the whole process is carried out, but very few cells are produced (hypospermatogenesis);
- the whole tissue of the testicle can be damaged either by infection or trauma (sclerosis or atrophy).
As a result of all this, no sperm cells can be found in the sperm sample.
Luckily, sperm is present in the testicles of about 50% of these men, because there are sometimes normal tubules amongst the empty or damaged ones.
| | Left: normal spermatogenesis (normal tubules)
Right: Sertoli cell only syndrome |
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Testicular biopsy [Day case admission | ward and operating theatre] Under local or general anaesthetic, tiny amounts of testicular tissue are removed and sent for examination in the lab. The type of anaesthetic used depends on your personal choice and other medical factors. If it will be necessary to remove more biopsies, a general anaesthetic will be suggested.
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Looking for a needle in a haystack: two normal tubules amongst many empty ones. |
The biopsies will show whether the testicles have sufficient functional tubules. In azospermia, the operation will provide conclusive results as to whether the absence of sperm in the ejaculate is due to a blockage (post testicular - in which case the biopsy will contain sufficient amounts of sperm), or to a production fault in the testicles.
If during the operation healthy sperm are found (see
TESE), they can be retrieved for use in fertility treatment.