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The introduction of Microinjection Technology into the in vitro fertilization laboratory has revolutionized our treatment of the infertile man. Intracytoplasmic sperm injection, or ICSI, is a new infertility treatment that uses micromanipulation technology for treating male infertility. What ICSI promises is the possibility for every man to father his own baby --- no matter what his medical problem!
What exactly is ICSI? As the name suggests, ICSI is a technique in which a single sperm is injected into the center of the cytoplasm of the egg, in order to achieve fertilization. While this may sound very crude, ICSI allows the IVF laboratory to achieve fertilization with very few sperm. The beauty of the technique is that since the sperm is being injected directly into the egg, all that is needed to achieve fertilization are live sperm - no matter how abnormal these may appear to be. With ICSI the equation "1 egg plus 1 sperm = 1 embryo" becomes possible!
ICSI is done in a super ovulated cycle during which fertility drugs (human menopausal gonadotropin - HMG- injections) are administered to the wife to aid in the production of multiple eggs, which are then removed under vaginal ultrasound guidance as is done for IVF. In normal circumstances, the egg is surrounded by a cluster of cells known as the cumulus corona cells, and this is called the oocyte cumulus corona complex. These cumulus cells are removed by repeated passage of the oocyte cumulus corona complex through fine pipettes, and by treating them with a chemical called hyaluronidase so that these cells are stripped off. The denuded eggs are examined, and only mature eggs (eggs in metaphase II, which have a polar body) are used for ICSI.
Sperm is collected from the man, usually through masturbation. For men with severe oligospermia, we have found it useful to use sequential ejaculates. Even though the first semen sample may not contain any sperm, we often find motile sperm in the second (or even the third sample, for men with enough stamina!) This may be because the later samples contain "fresher" sperm. Since these samples contain such few sperm, they need to be processed very carefully, so that all the sperm in the sample are recovered in the culture medium, and can be used for ICSI. For men with variable sperm counts, which vary from zero to a few thousand, it may be helpful to freeze a sample (which contains sperm) in advance. For patients with azoospermia, sperm harvesting techniques need to be used to retrieve the sperm. For men with obstructive azoopsermia, (because of duct blockage or absence of the vas deferens), the simplest 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. Occasionally, one may have to use microsurgery to find epididymal sperm, and this is called MESA (microepididymal sperm aspiration). 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 anesthesia. 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.
© Dr. Aniruddha Malpani and Dr. Anjali Malpani www.drmalpani.com
Credits: How to Have a Baby: Overcoming Infertility
