Neonatal inguinal hernia is a congenital disease, mostly caused by the failure to occlude the peritoneal sphincter during the descent of the testis during embryonic development, with an incidence of about 0.8% to 4.4%, more common in males, 2 to 3 times more on the right side than on the left side, and less common in bilateral cases, accounting for about 5% to 10%. 1. Failure of the peritoneal sheath (Nuck’s canal) to degenerate and attain atresia is the pathological basis of inguinal hernia; during embryonic development, the fetal testis is located below the retroperitoneal kidney, and its lower end is connected to the scrotum by the testicular lead, and as the fetus grows and develops, the testis gradually descends and enters the scrotum through the inguinal canal, and a diverticulum-like tubular protrusion is formed at the mouth of the inner ring with the descending peritoneum of the testis, called the sheath. Under normal circumstances, the distal end of the sphincter wraps around the testis to form the intrinsic sheath of the testis, and after the testis exits the mouth of the external ring, the sphincter is also pulled into the scrotum, and when the testis descends completely, the sphincter is atretic and degenerates, and if the sphincter is not completely closed, a hiatal hernia or syringomyelia can be formed, and intra-abdominal organs or tissues can easily protrude from the residual peritoneal sphincter through the inguinal canal to form a hiatal hernia. In girls, the inguinal canal contains round ligaments from the uterus to the labia majora, and there is also a peritoneal sheath, called Nuck’s canal, when it is equivalent to the male fetal testes descending; it closes at about 7 months of pregnancy and descends through the inguinal canal into the labia majora along the round ligaments, and the Nuck’s canal degenerates incompletely, forming a hiatal hernia or Nuck’s canal cyst. 2. Increased intra-abdominal pressure and weakness of the abdominal wall muscles are contributing factors to inguinal hernia. It has been reported that 80% to 90% of newborns are born with the peritoneal sheath not yet closed, and the time and mechanism of its closure are unclear. It is believed that the existence of the sheath is only the basis for the occurrence of inguinal hernia, and there are still other predisposing factors such as increased intra-abdominal pressure and weakness of abdominal wall muscles in premature infants that contribute to the emergence of inguinal hernia. The inguinal hernia may appear shortly after birth as a reducible mass with a stalk in the groin or scrotum, often appearing during crying or straining to defecate and disappearing during sleep or quietness. When the hiatal hernia is not incarcerated, the child has no special discomfort. The main sign is a reducible mass in the inguinal region. The mass varies in size, is smooth and soft; in smaller cases, it is mostly located in the inguinal canal or protrudes from the inguinal canal to the external ring, and is oval in shape; in larger cases, it may protrude into the scrotum, with no obvious boundary between the upper boundary and the inguinal canal and the internal inguinal ring, and appears to have a stalk leading into the abdominal cavity. The contents are mostly intestinal tubes, and the mass can be returned to the abdominal cavity by gently pushing upward with the hand. After the hernia contents are retracted, the outer ring can be enlarged and relaxed to the touch. When stimulating the child to cry, a sensation of impact can be felt by inserting a finger into the external ring. When the finger tip is pressed against the internal ring of the inguinal canal, the mass cannot be re-expanded and the swelling reappears after removal of the finger. In children with a history of a protruding inguinal mass that was not found on examination at the time of presentation, careful local examination reveals a fuller inguinal area on the affected side than on the contralateral side, and a larger scrotum on the affected side than on the contralateral side if the contents of the hernia can fall into the scrotum. In primary hernias with a small hernia neck or a narrow outer ring, a sudden rise in intra-abdominal pressure during violent crying and coughing can push more organs to expand the hernia ring and enter the hernia sac, and when the intra-abdominal pressure temporarily decreases, the hernia ring retracts elastically and the contents of the hernia cannot be retracted and become ingrown. The embedded hernia contents are mostly intestinal, and signs and symptoms of intestinal obstruction appear after the impaction. Due to local pain and intestinal colic, the child cries more and more, and the intra-abdominal pressure continues to increase, which, together with the local pain, can reflexively cause muscle spasm of the abdominal wall, aggravating the impaction and making it difficult to return. In addition, the time of onset of neonatal inguinal hernia is often poorly described at the time of consultation, and there is a significantly higher chance of intestinal strangulation and necrosis, which may manifest as scrotal redness and swelling with systemic toxic symptoms. Infarction may occur after prolonged compression of the spermatic cord and obstruction of testicular blood flow, with an incidence of 10% to 15%. In female children, the contents of the hernia may include the uterus, ovaries, and fallopian tubes, with a high incidence of ovarian impaction and necrosis. The broad ligament or the vascular tip of the ovary may enter the hernia sac and become part of the sliding hernia sac. In addition, inguinal hernia in preterm and very low birth weight infants has its own clinical characteristics: (1) high incidence and more prone to bilateral hernias: according to statistics, the incidence of inguinal hernia increases with decreasing birth weight, and the incidence of inguinal hernia in term neonates is only 1% to 5.0%, while the incidence in preterm infants can be as high as 6% to 30%, 16% in very low birth weight infants, and the incidence of hernia in those with birth weight less than 1000g. The incidence of bilateral inguinal hernias is also more common in full-term newborns than in full-term infants, with the literature reporting bilateral inguinal hernias in about 55% of low birth weight infants and 44% of preterm infants, while bilateral hernias in mature infants are only 8% to 10% of the total incidence. (2) High incidence of incarcerated hernia and complications: According to statistics, the incidence of incarcerated hernia in preterm infants is 2-5 times higher than that in older infants, and the incidence of testicular infarction of inguinal hernia in infants aged less than 3 months is 30%, which is significantly higher than the incidence of testicular infarction of irreducible inguinal hernia in general infants (7%-14%). In particular, inguinal hernia with cryptorchidism, where the undescended testicle is located just lateral to the internal inguinal ring, is more prone to testicular infarction. In some female infants, ischemic infarction of the ovaries or fallopian tubes may occur due to compression of the hernia sac or torsion of the reproductive organs themselves. (3) Intussusception and strangulation are the most serious complications: once intussusception occurs, systemic symptoms are severe. There may be bilious vomiting, obvious abdominal distension, and black or dark blue color of the herniated organ. The abdominal X-ray shows signs of small bowel obstruction. The disease progresses rapidly and severe cases may have toxic symptoms, such as tachycardia (pulse rate >160/min), white blood cell count >15×109/L, left shift of nucleus, and disturbance of water-electrolyte and acid-base balance. Treatment The treatment of neonatal incarcerated hernia is divided into conservative therapy and surgical therapy. The key lies in the selection of the timing of surgery and the perioperative management. 1.Conservative treatment: For good general condition, embedded time not more than 12h, no obvious redness, swelling and purple color of scrotal skin, no bloody stool and abdominal distension, manual repositioning can be tried by a specialist, but do not forcibly reposition. 2.Surgical treatment For children with long time of impaction or unknown time of impaction, trial repositioning is not recommended and immediate surgery should be performed. These children often have obvious redness or purple color of the scrotal skin, obvious abdominal distension, and even bloody stools. Testicular necrosis often precedes intestinal necrosis in neonatal hernias, and testicular necrosis is more common than intestinal necrosis. Therefore, early diagnosis and timely surgery are the most important methods to avoid testicular and intestinal necrosis in neonates with incarcerated hernia. (1) Timing of surgery: Theoretically, pediatric inguinal hernia has the possibility of self-healing, and a few cases of self-healing have been seen clinically, but the self-healing rate is low. In recent years, pediatric anesthesia techniques and surgical techniques have been greatly improved, and inguinal hernia surgery, including in premature infants, has become very safe. Therefore, age is no longer a major limiting factor for surgery. Analysis of a large amount of clinical data shows that the younger the child is, the higher the incidence of inguinal hernia incarceration and complications, with the incidence of inguinal hernia incarceration reaching 31% for those younger than 2 months, 34% for neonatal inguinal hernia and various intestinal complications, and 45% for intestinal necrosis. The incidence of various complications (including testicular atrophy and intestinal necrosis due to repeated impaction) is the lowest in those operated within 8 weeks after birth. Therefore, more and more scholars advocate early surgery as the most appropriate. There should be no age limit for recurrent impaction. For emergency surgery of an incarcerated hernia that has failed to be repositioned by manipulation or is not suitable for manipulation. Most doctors believe that hernia surgery should be performed immediately after diagnosis, which can greatly reduce the complications of hernia surgery. In our country, most scholars advocate surgery from 6 months to 1 year old, but surgery can be suspended for children with serious diseases such as cyanotic congenital heart disease, tuberculosis, malnutrition, infectious diseases, and weakness after illness. (2) Common surgical methods: ① High ligation of the hernia sac: A small incision is made at the projection of the body surface of the external ring on the affected side. The subcutaneous skin and fascia are incised, the levator muscle is separated, and the hernia sac is found in front of the spermatic cord; the hernia sac is cut open and explored, then transected, the proximal end is separated to the neck of the hernia sac, the “8” is ligated through, the excess hernia sac is removed, and after hemostasis, the incision is closed in layers and the external ring is reconstructed or narrowed. Laparoscopic inguinal hernia high ligation: laparoscopic surgery can directly close the inner ring opening through the abdomen without destroying the anatomical structure of the inguinal region, without destroying the levator muscle, without freeing the spermatic cord, and at the same time, the blood vessels and vas deferens around the inner ring opening and the inner ring opening are clearly visible under the laparoscope, which can avoid damage to blood vessels and nerves and lead to ischemic orchitis. In addition, it is possible to check and find out whether there is a hidden hernia on the other side at the same time, which is incomparable to conventional surgery. In recent years, some scholars have carried out research on mini-laparoscopic surgery or needle laparoscopic surgery for pediatric inguinal hernia.