Epididymal dysplasia

　　1. Etiology

　　By the sixth week of embryo development, the mesonephric duct and mesonephric ducts form, which tubes will differentiate into male and female reproductive tracts. When the embryonic reproductive glands differentiate into testes and produce testosterone, under the action of androgens, the mesonephric duct gradually differentiates into male reproductive ducts. The head part of the mesonephric duct becomes the epididymal appendage, and the epididymal duct derived from the mesonephric tubules, together with the epididymal duct formed by the elongated and tortuous winding of the mesonephric duct below, constitutes the head of the epididymis. The remaining epididymal ducts form the body and tail of the epididymis.

　　The etiology of congenital epididymal malformation is not yet clear. Since patients with cryptorchidism often have epididymal malformation, its occurrence may be related to endocrine dysfunction during embryonic development. Due to low testosterone levels, the mesonephric tubules and mesonephric duct do not develop or are underdeveloped, leading to various types of epididymal malformations. If the mesonephric duct does not develop at all, it can lead to congenital absence of the epididymis and vas deferens. If development stops at a certain location, it will form an atresia at that location. When there is a blockage in the coiling of the epididymal duct, it can result in the significant elongation of the epididymis and the formation of long-loop epididymal malformation.

　　Second, Pathogenesis

　　The epididymis is the excretory duct connecting the testis, with a thin, elongated, flat shape, located on the posterior and lateral side of the testis. 10-15 testicular efferent ducts curve into a conical shape, and their ends merge into a long epididymal duct that is 4-6 cm long and highly coiled. According to Turck's examination of 94 non-undescended testicles, such as hernia, hydrocele, varicocele, etc., the epididymal head and tail were found to be attached to the testis in 83.9% of cases, while there was a certain distance between the epididymal body and the testis, which could generally accommodate a finger tip. Only 12.5% of the epididymis and testis were in complete contact.

　　The malformation of the epididymis mainly manifests as developmental disorders of the epididymis and abnormal attachment to the testis. The former includes the absence of the epididymis, cystic transformation of the head, underdevelopment of the middle and tail, fibrous cord-like atresia, and the epididymis significantly elongated into a long-loop shape, etc. The absence of the epididymis can be further divided into:

　　1. The mesonephric duct does not develop at all, and the vas deferens, seminal vesicle, and ejaculatory duct are all absent.

　　2. The mesonephric duct is underdeveloped, and the body and tail of the epididymis are absent, accompanied by the absence of the vas deferens.

　　3. The mesonephric duct does not develop into the epididymal duct but directly differentiate into the vas deferens, seminal vesicle, and ejaculatory duct, and the efferent duct of the testis is connected with the vas deferens.

　　4. Without epididymis, the vas deferens does not connect with the testis, and its proximal end is blind. Abnormal attachment of the epididymis includes complete separation and partial separation of the epididymis from the testis, the latter referring to the head of the epididymis not connected with the testis, and the epididymis not attached to the inferior pole of the testis, etc.

　　Since Scorer and Farrington first classified epididymal malformation in 1971, many different classification methods have been reported. In 1990, Koff and Scaletscky made some modifications based on the Scorer classification method. The malformation of the epididymis is divided into 5 categories:

　　Type I: Long-loop epididymis: The epididymis is in the shape of a long loop, and it is significantly longer than the testis in size, and it is divided into 4 types: ①Twice as long as the testis; ②2-3 times; ③3-4 times; ④More than 4 times.

　　Type II: Separation of epididymis and testis: According to the site and degree of separation, this type can be divided into the following 3 situations: ①Only the tail is separated; ②Both the head and tail are separated from the testis, but are relatively close; ③Both the head and tail are separated from the testis, but are relatively far apart.

　　Type III: Angle between epididymis and testis. ①Simple angle; ②Accompanied by epididymal stenosis.

　　Type IV: Atresia of the epididymis or any part of the continuity between the epididymis and the sperm duct.

　　Type V: Longer testicular mesentery.

　　The above different types of epididymal anomalies can coexist in several types in the same patient. Koff's data shows that long-loop epididymal anomalies are the most common in cryptorchidism and ectopic testicles, accounting for about 79.3%, the separation of epididymis and testicle is 45.1%, the angular separation of epididymis and testicle is 8.5%, the atresia of epididymis or sperm duct is 3.7%, and the longer testicular mesentery is 1.2%. Koff's classification method cannot include all types of epididymal anomalies. Based on relevant data, various types of epididymal anomalies are summarized.

　　1, Seminal vesicle cyst:Benign cysts formed by the spermatozoa occurring in the testicle or epididymal location, the swelling and bulging mass is mostly as large as a piece of sugar cube, and people call it the third testicle, fortunately, this situation is very rare. If you insist on removing those lumps, the doctor can remove them for you. Avoid外伤 to the testicle and scrotum. Have regular sexual life and avoid long-term sexual excitement.

　　2, Scrotal hydrocele:Caused by excessive tissue water production between the thin membrane layers that enclose the testicle(s) or between one or two testicles. Sometimes it occurs after a single testicular injury or orchitis, but in most cases, no cause can be found. The scrotum appears swollen and bulging, and sometimes the cyst can even reach the size of a football, but it does not feel painful. Treatment by the doctor: The excess tissue water can be absorbed through a minor surgery under trivial anesthesia, and the doctor must also suture the small holes in the scrotum that leak fluid.

　　Patients with epididymal anomalies have no discomfort and are often diagnosed with cryptorchidism or male infertility in clinical practice.

　　Physical examination shows no obvious abnormal signs except for epididymal cysts, and most are diagnosed during surgical exploration for cryptorchidism or male infertility. Generally, there are no clinical symptoms, and they are often found during the investigation and treatment of male infertility and cryptorchidism surgery, often accompanied by sperm duct anomalies.

　　Parents of boys should carefully examine their children's scrotum. Generally, both sides of the scrotum can feel testicles the size of peanuts, with a sense of reality when touched. If the scrotum is empty and the testicles cannot be felt, or if there is only one, one should go to the hospital for treatment immediately. It is currently believed that epididymal surgery can be performed after the age of 2, but not later than 10 years old, otherwise it may affect sperm function.

　　Once a child is found to have cryptorchidism, it is necessary to go to a specialized department of a regular hospital for treatment immediately. The methods include drug and surgical treatment. However, regardless of the treatment method, it must be carried out within the child's second year of life. Because after the age of 2, the testicular tissue of the child will undergo pathological changes.

　　Ultrasound, CT, and other imaging examinations are not helpful for the diagnosis of epididymal anomalies.

　　Patients with cryptorchidism often come to the clinic due to the empty scrotum and the absence of testicles inside. There are also those who come to the clinic with the main complaint of 'hernia', or those who come for examination due to bilateral cryptorchidism or infertility after marriage. The diagnosis is generally not difficult. However, it should be emphasized that the differentiation between undescended testicles that cannot be felt and the absence of testicles should be given attention, as the latter does not require surgery.

　　If the patient's karyotype is XY, serum follicle-stimulating hormone (FSH) levels are elevated, and serum testosterone (T) levels are decreased, and the level of testosterone does not respond to chorionic gonadotropin (HCG) stimulation, it indicates bilateral absence of the testes, and no surgical exploration is needed.

　　For those with unilateral absence of the testis, it is difficult to make a preoperative diagnosis, and hormone tests are normal. Adrenal venography, laparoscopy, ultrasound, and CT scan may be helpful for diagnosis, and surgery may still be necessary if necessary.

　　1. Patients undergoing surgery should choose light foods and foods that help wound healing, such as eggs, crucian carp, and giant trevally.

　　2. Try to eat less spicy and刺激性 food. For example: onions, pepper, chili, Sichuan pepper, mustard greens, fennel.

　　First, Prevention

　　The etiology of the disease is not yet clear, and prevention is carried out according to congenital diseases.

　　Second, Surgical Treatment

　　If the epididymal malformation does not affect fertility, treatment is not necessary. Segmental epididymal atresia can be treated with epididymal duct vas deferens anastomosis. Under an operating microscope magnified 10-20 times, the Silber and Wagenknecht methods of epididymal duct vas deferens anastomosis are selected. The main difference between the two is that the Silber method uses expanded epididymal ducts for end-to-end anastomosis with the vas deferens, while the Wagenknecht method uses expanded epididymal ducts for end-to-side anastomosis with the vas deferens. After incising the expanded epididymal duct, the liquid flowing out of the epididymal duct is collected to find sperm, and after confirming the presence of sperm, the epididymal duct and the mucosa of the vas deferens are anastomosed using 11-0 atraumatic nylon suture, generally with 4-6 interrupted sutures, and then the epididymal capsule and the muscular layer of the vas deferens are anastomosed using 9-0 atraumatic nylon suture.

　　The treatment for epididymal head cysts can be performed by puncture, aspiration, and injection of sclerosing agent, but due to the high recurrence rate, it is less safe and reliable than surgical methods, and is now used less frequently. Those with absent epididymis cannot be treated and the main solution is to address fertility issues. If the patient's testicular spermatogenic function is normal, assisted reproductive treatment can be performed. For those with epididymal malformation and cryptorchidism, timely orchiopexy should be performed.