This observation has revolutionized an old concept that the testicle produced sperm in a uniform fashion and has lead to the new concept of "focal spermatogenesis". Sperm production has been found in up to 70% of men who have FSH (follicle stimulating hormone) levels greater than three times normal or who had no sperm production on a past biopsy.
Our challenge is to locate the areas of sperm production within the testicle and retrieve the sperm for use with ICSI. Because the testicular tubules are microscopic structures, they can not be discerned to the naked eye. By using an operating microscope to examine the tubules at the time of testicular biopsy, the better or more normal appearing tubules can be selectively removed. There is a higher chance of sperm being found in “fuller”, more normal tubules than in scarred or fibrotic tubules. Once the specimens are removed, the tubules are opened in a Petri dish containing sperm wash media and the search for sperm begins by examining the minced specimens under the microscope. It can take up to 4-5 hours to search for sperm in the specimens and is a very involved and tedious process but very thorough. Once found, the sperm are then either incubated and injected into awaiting eggs or frozen for future injection.
This technique allows us to direct the biopsy to the best areas and increase the chance of finding sperm while removing smaller amounts of tissue then a random biopsy, causing less damage. One recent study compared the microsurgical TESE to the regular TESE in the same men. They used one method on the right testicle and the other on the left side. The results were remarkable. Twenty percent of men who had no sperm found with the random biopsy had sperm found using the microsurgical approach. Micro TESE is currently recognized as the best way of finding sperm in men with non-obstructive azoospermia. Very few surgeons are able to perform this technique so it is unfortunately not widely available. Random biopsies are not adequate to truly and accurately asses sperm production. We have performed Micro-TESE on men who had prior biopsies with no sperm found. Our results show than sperm were found in roughly 20% of men who had a prior biopsy that showed Germ Cell Aplasia (Sertoli-Only Syndrome) and in 40-50% of men with maturation arrest on prior biopsy. The combination of using the operating microscope, dissecting the testicular tubules and having trained personnel available to search for sperm can make the difference between success and failure for many couples.
Micro TESE can be performed as a diagnostic procedure and if usable sperm are found then they can be frozen and the couple is recommended to proceed with ICSI. It can also be performed timed with an egg retrieval/IVF cycle and the sperm are injected into the eggs without freezing. Freezing the sperm from men with sperm production problems can be difficult since these sperm are usually few in number and don’t thaw well. Therefore the best chance of pregnancy is to use fresh sperm obtained just prior to IVF.
Please contact Dr. Werthman if you have questions regarding Micro-TESE.
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