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 $ 300;
and a TESA costs US $ 500 only !
Unfortunately, it's the poor infertile couples who
have to bear the added burden.
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