Basic principle: Pediatric cryptorchidism is a common disease, and the best time for cryptorchidism surgery should be around 1 year old and must be done before 2 years old. After the diagnosis of cryptorchidism is clear, treatment should be done as soon as possible to lower the testicles in abnormal position to normal scrotal position. To prevent infertility, surgery should be performed before the germ cells disappear, which rarely happens before 15 months of age. The American Academy of Pediatrics recommends treatment at around one year of age. Most scholars believe that the testes should be lowered to the scrotum within 12-18 months. Every effort should be made to lower the testicle at least to a position where it can be reached, otherwise that side of the testicle should be removed. Orchiectomy should also be considered in post-pubertal patients who are found to have a tendency for testicular degeneration or malignancy. The scrotum, because of its special structure, has good heat dissipation and the temperature is generally lower than the abdominal temperature by about 2°C. It is the most ideal site for testicular development. In addition to increasing the spermatogenic capacity after the testes descend to the scrotum, it can also relieve the children and parents of psychological stress and early detection of malignant testes. If the testicle has not descended by 6 months after birth, there is little chance for it to descend on its own. 6 months to 1 year old children can try hormone treatment, and those who do not succeed in hormone treatment should undergo testicular fixation surgery. 1.Hormone treatment. The cause of cryptorchidism, especially bilateral cryptorchidism, may be related to endocrine, so endocrine therapy can be given after 1 year of age, and the currently applied endocrines are: (1) chorionic gonadotropin (HCG) (2) luteinizing hormone releasing hormone (LH-RH) 2. Since the damage of cryptorchidism by high temperature is irreversible after 2 years of age, the surgery should be done before 2 years of age. The key of surgery is to free the spermatic cord sufficiently to facilitate the descent of the testis and make the testis tension-free when it is located in the scrotum; otherwise, the testis will retract after surgery and should be at least in a palpable position. The testicle is secured between the scrotal skin and the meatus so that it cannot retract. A hernia repair should be performed at the same time. Testicular fixation is the main method of treatment for cryptorchidism, and each child with cryptorchidism has a different testicular location. As long as the testicle can be pulled into the abdominal cavity, the minimally invasive technique can be used, and most children belong to this category. Zhou Fujin of the Department of Surgery of Shenyang Children’s Hospital suggests that minimally invasive surgery should be considered first. (1) External fixation of testicular meatus capsule using transverse inguinal incision has been widely used at home and abroad for low cryptorchidism beyond the palpable external inguinal ring mouth, and in recent years some scholars have adopted transcrotal incision for testicular fixation with better results. (2) Staged surgery: It is suitable for some high intra-abdominal cryptorchidism and those whose vas deferens is long and curved in the inguinal canal. That is, the first stage is to cut off the spermatic vessels and the second stage is to remove the testis. For long loop vas deferens with high cryptorchidism, if the separated spermatic cord is still not long enough, the Fowler-Stephens procedure can be applied. Recently, a modified method of this procedure is recommended, Fowler-Stephens staged surgery, which can try to clamp the internal spermatic cord artery, if the blood supply is good, this artery can be cut to lengthen the length of the spermatic cord and reduce the tension, that is, the initial surgery only cuts the spermatic cord vascular tip in high position In the second stage, after the establishment of abundant collateral circulation, the testis is fixed in the scrotum, which reduces the chance of testicular atrophy, but there is also the possibility of accidental injury to the spermatic cord vessels in the second operation. (3) Laparoscopic surgery for pediatric cryptorchidism Laparoscopic surgery can achieve both diagnostic and therapeutic purposes, and is especially suitable for patients with high cryptorchidism. With laparoscopy, the testicular vessels are first sought behind the peritoneum along the anatomical location of the testicular vessels, and the testicle can be found along the spermatic cord vessels at the intra-abdominal or inguinal ring. If the blind end of the vessels is seen along the spermatic cord vessels, the testicular defect can be identified, and if there is a nodule at the blind end, it should be removed and sent for pathological examination. If a high intra-abdominal cryptorchid and a long vas deferens are observed during the examination, Fowler-Stephen surgery can be performed if the spermatic cord cannot be free to pull down the testis, and staged testicular fixation is also possible. In the first stage of surgery, the spermatic cord is separated, clamped and severed, and the second stage of testicular fixation is reserved for later.