Testicular Sperm Aspiration (TESA)
In cases of severe male factor infertility, genetic abnormalities may be present in the male partner. Such abnormalities might be transferred to any male offspring. Antenatal genetic testing is recommended in these cases. If there is absolutely no sperm in the ejaculate we can perform TESA to remove the few non-moving sperm available. Testicular Sperm Aspiration is performed under local or general anesthesia and there is only brief, minimal discomfort following the procedure. All discomfort should be gone within a few hours. A very fine needle is passed through the skin into the testicles where sperm will be located. These sperm recovered through TESA can then be used to fertilize an egg with the ICSI procedure.
To achieve ICSI fertilization a single washed sperm is located and its tail is crushed so it will be immobilized and not damage the egg after it is injected. It is then picked up with an injection micropipette, a specially prepared ultra-fine, glass needle. A single mature egg is held in place by a holding micropipette and the egg is rotated so that its polar body is at the 12 o'clock position. This insures that the egg is in the proper position so no damage will occur during the injection process. The injection micropipette then punctures the outer zona pellucida of the egg at the 3 o'clock position. It continues inward toward the pliable inner membrane of the egg that is then broken by suction from the injection micropipette. The sperm and a small amount of the egg material are quickly injected back into the egg and the micropipette is removed. Fertilization has been achieved and normal cell division can now take place.
In men with obstructive azoospermia, (because of duct blockage or absence of the vas deferens) , sperm are usually recovered from the epididymis.
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.