I. What is obstructive azoospermia? This is due to a blockage in any part of the sperm transport system, which will result in the sperm produced in the testes not being able to be removed from the body through ejaculation. The order of sperm transport is: testes – epididymis – vas deferens – seminal vesicles – ejaculatory ducts – urethra of the prostate – anterior urethra – outside the body 2. Why do most patients with obstructive azoospermia have semen but no sperm? Because semen is composed of several parts: epididymal fluid + seminal vesicle gland fluid + prostate gland fluid + urethral bulb gland fluid, etc. The most common obstruction site is located at the end of the epididymis, and the seminal vesicle gland, prostate gland and urethra are located after the obstruction site, so the semen is only without the part of epididymal fluid, and epididymal fluid accounts for a very small part of the total semen, so the amount of semen is generally not significantly reduced. Therefore, the semen component of epididymal site obstruction should include seminal vesicle gland fluid, prostate gland fluid, and urethral bulb gland fluid. Of course, the closer the obstruction site is to the urethra, the less the amount of semen may be. Also, as shown in Figure 1, if the obstruction site occurs in the ejaculatory duct after the seminal vesicle gland, the fluid of the seminal vesicle gland cannot come out with the ejaculate, which is the main component of the semen, except for the absence of sperm in the semen, the amount of semen in patients with ejaculatory duct obstruction will be significantly reduced. 3.What parts of the ejaculatory ducts are easily obstructed? In China as well as in our province, obstruction from the caudal part of the epididymis to the migrating part of the vas deferens is most common, which may be due to the pressure on the epididymal duct caused by acute and chronic epididymitis. The second obstruction is the ejaculatory duct. The opening of the ejaculatory duct is located in the posterior urethra, the urethral part of the prostate, and this part is easily affected by urethritis, prostate abscess, urethral intubation, etc., which causes the seminal fluid containing sperm, epididymal fluid, and seminal vesicle fluid to be unable to be eliminated from the body with ejaculation. Of course, the small tubes in the testes that carry sperm may also be blocked leading to obstructive azoospermia. However, this is rare and the cause is unknown. The lumen of the vas deferens may also be blocked, the most common cause being trauma, surgery such as inguinal hernia repair which may lead to narrowing and blockage of the lumen of the vas deferens. Second, can obstructive azoospermia be treated? How to treat it? First of all, it is clear that obstructive azoospermia can be treated. There are two options for treatment at present. (a) In vitro fertilization (IVF): This is a method in which a small amount of male sperm is removed by puncturing the testicles or epididymis, while the spouse’s eggs are removed and grown into a fertilized egg by injecting the sperm into the egg in vitro, and then implanted into the female uterine cavity. This method is most suitable for women suffering from tubal obstruction and other diseases at the same time. The disadvantages are: 1) The cost is high, about 30-40,000 RMB per cycle, 2) The success rate is about 30-40%. 3. Women need to have their eggs surgically retrieved, which is painful. 4. If there is a request for re-fertility, she can only start again. (B) Microseminal tract reconstruction surgery. This is a new technique carried out internationally and domestically in recent years, which is a boon to patients with obstructive azoospermia. It is mainly aimed at the most common group of patients with epididymal vas deferens obstruction in China. It mainly consists of two procedures: microscopic vas deferens epididymal anastomosis and microscopic vas deferens-vas deferens anastomosis. The method is to find the site of the obstructed epididymal duct during surgery and reattach the open vas deferens to the epididymal duct above the obstruction. In other words, the blocked part of the duct is left vacant and a smooth duct is rebuilt to achieve smooth passage of sperm. The advantages of this method: 1.Little surgical trauma, only a small incision of 3cm in the scrotum; 2.Fast recovery, usually only 5~7 days of hospitalization; 3.Low cost, about 10,000 yuan for all costs; 4.The exact efficacy rate of recanalization can reach 70~95%, 5.It can be cured permanently and achieve the arbitrary fertility. 6, the spouse does not need to bear any pain and risk.