Azoospermia refers to the absence of sperm found in semen after semen analysis and accounts for approximately 10-15% of the entire male infertility population, and is a serious condition that causes absolute male infertility. There are two main types of azoospermia, namely obstructive azoospermia and non-obstructive azoospermia. The so-called obstructive azoospermia refers to a patient whose testicular sperm production function is normal and the reason for the absence of sperm is due to blockage of the vas deferens, such as the epididymis, vas deferens or ejaculatory ducts, which prevents the smooth discharge of sperm produced by the testes, so there is no sperm in the semen. For this type of patients, surgical investigation can be considered to find the obstruction and release it, so that the sperm can be discharged smoothly through the vas deferens, turning “no sperm” into “sperm” and solving the problem at root, so that the chance of natural conception can be restored; while For some patients who are unable to remove the obstruction (such as bilateral vasectomy) or who are unwilling to undergo surgery, they can also obtain sperm through the testes or epididymis and perform in vitro fertilization, or IVF, to obtain their own children. In a word, this group of patients has normal testicular spermatogenesis, and as long as there is sperm, we have the means to make the patient a real father. For the other type of azoospermia, non-obstructive azoospermia, also called testicular-derived azoospermia, as the name implies, the reason for the absence of sperm mainly originates from the testes, due to congenital or acquired lesions of the testes themselves that cause testicular spermatogenic dysfunction, and the testes cannot produce sperm normally; for this group of patients, treatment is much more difficult and a great challenge for the majority of professional male physicians. The cause of non-obstructive azoospermia is that the majority of spermatogenic tubules in the testis are unable to produce sperm due to testicular spermatogenic dysfunction, but it cannot be ruled out that there are very few spermatogenic tubules in the testicular tissue that are relatively well developed and can produce sperm, which is called “focal spermatogenesis”. Thanks to modern technology, we can inject a single sperm into the egg to form a fertilized egg and embryo, and eventually have a child of our own, as long as there is a mature sperm. Therefore, the core of our treatment for non-obstructive azoospermia patients is to identify the “spermatogenic foci” that are relatively well developed and have mature sperm. Currently, there is a very important technical tool for the treatment of non-obstructive azoospermia patients – testicular biopsy. A testicular biopsy can help us determine how well the testes are producing sperm internally; if the testicular biopsy easily reveals sperm, then we can obtain sperm directly this way and do IVF to have a child of our own. However, if no sperm is found on testicular biopsy, does that mean that the patient has no chance of having a child of his own? The answer is no. As we discussed earlier, in patients with non-obstructive azoospermia, the majority of the testes are spermatogenic, but there may be cases of “focal spermatogenesis”; testicular biopsy, however, only obtains a small amount of testicular tissue that is a little bit larger than a sesame seed, and analyzes the entire testis “point by point “In contrast, a testicular biopsy is performed to obtain a small amount of testicular tissue as large as a sesame seed to analyze the entire testicular spermatogenesis, but this does not fully represent the spermatogenesis of the testis. In order to better represent the spermatogenesis of the testis, and also to find the “spermatogenic foci” in the testis with a greater probability, a multi-point puncture biopsy can be considered, which means that during a single procedure, the surgeon will remove some tissue from different parts of the testis, hoping to obtain normal “local spermatogenic foci This means that during a single procedure, the surgeon will remove tissue from different parts of the testicle in the hope of obtaining a normal “localized spermatogenic focus. Nevertheless, we may miss the normal “local spermatogenic foci”; microscopic testicular dissection for sperm retrieval is a great improvement on the multi-point puncture biopsy technique, so as to help the surgeon find the normal “local spermatogenic foci” to obtain Sperm for in vitro fertilization. Microscopic testicular sperm extraction, as the name implies, involves cutting the testicle open from the equatorial plane under a microscope and searching for a relatively well-developed “localized spermatogenic focus”. The biggest advantage of this procedure is twofold: first, the testicle is cut open and fully exposed, so the entire testicle can be explored completely without missing any “local foci of spermatogenesis”; second, the magnifying effect of the microscope, which helps the surgeon to find those normal “foci of spermatogenesis” during the procedure. “The second is the magnification of the microscope. Therefore, microscopic testicular sperm extraction is particularly suitable for two types of patients, one is non-obstructive azoospermia patients who do not find sperm through routine testicular biopsy, and the other is non-obstructive azoospermia patients whose testicles are small in size and not suitable for testicular biopsy.