”My little baby’s scrotum suddenly bulged and screamed in pain, is it a hernia?” “My baby has a hernia, can it be cured by medicine? Will it be dangerous to have an operation or anesthesia?” “The baby is so small, should we wait until the baby is older before we operate?” These are questions that parents often ask in pediatric surgery clinics, and in this article, we will elaborate on pediatric hernia. The direct type is caused by a weak abdominal wall and is common in middle-aged and elderly people. More than 95% of pediatric hernias are of the indirect type, commonly known as prolapsed bowel or fallen bowel, and are the most common type of pediatric surgery, accounting for about 50% of all surgeries. It is formed when the fetus extends from the abdominal cavity down to the groin and then into the scrotum during maternal development, forming a duct that connects the abdominal cavity to the scrotum, commonly known as a hernia sac. In contrast, in female babies, the peritoneal sphincter extends from the abdominal cavity to the labia majora. In female babies, the hernia sac can travel along the round ligament, resulting in a hernia or edema, which in severe cases can be combined with the ovaries, fallopian tubes or even the uterus falling into the hernia sac. Most babies have this structure gradually close after birth, but some do not. If the contents of the abdominal cavity, such as the small intestine, enter the groin or even the scrotum through this structure, a hernia is formed. If this tectum is not closed but is very small, only ascites may flow in, forming a scrotal edema. Pain is the most common symptom In addition to this congenital unsealed peritoneal sphincter that should be closed, another condition necessary to constitute an inguinal hernia is an increase in abdominal pressure. The most common cause is an increase in abdominal pressure that develops when the child cries, coughs, defecates, or exercises, causing the intestines, omentum, ovaries, or ascites in the abdominal cavity to be pushed into the hernia pouch, producing a protruding mass in the inguinal region. At this point, older children will scream in pain, while smaller infants and toddlers will manifest with unexplained crying. Once the crying or movement stops, the intestinal fluid inside the hernia pouch will automatically reset and the mass will disappear due to a decrease in abdominal pressure. Disappearing masses Because masses sometimes appear and sometimes disappear, inexperienced parents do not always notice them at first, and they are often discovered in pediatric clinics during routine vaccinations, school health checks, or when the child is crying and upset and brought to the emergency room. The timing of the onset of symptoms depends on the size of the peritoneal sheath, which may occur shortly after birth in larger children, or when a connected scrotal fluid develops in smaller children or when the child is older. Therefore, the timing of hernia formation may occur in infants and children as well as in adolescents. Premature infants and cryptorchidism have a high incidence of hernia (about 30%). Premature infants also have a particularly high incidence of hernia (about 30%) because the peritoneal sphincter is under greater abdominal pressure before it closes or because the muscular membrane is softer. Children with cryptorchidism also have a high incidence of hernia (about 80%) because the testicles descend abnormally and the closure of the peritoneal sphincter is also abnormal. Examination methods When a baby is suspected of having a hernia during an outpatient examination, the child can be asked to stand or blow up a balloon to simulate an increase in abdominal pressure, and if a bulging mass is seen in the groin, a hernia may be present. If the infant is unable to cooperate, lie flat on the examination table and deliberately make the infant cry or push, then carefully touch the scrotum or inguinal area, and if a hernia sac is present, it will feel like a silk glove rubbing against each other. In the case of scrotal edema, a fixed sac can be palpated and if this edematous sac is illuminated with a flashlight, it is transparent. The vast majority of inguinal hernias are clear on palpation. For differential diagnosis with testicular tumors, varicose veins and enlarged inguinal lymph nodes, ultrasound can be arranged. In male babies, because the right testicle descends later during the embryonic period, the accompanying peritoneal sheath is more likely to be unclosed, so the incidence of either hernia or cryptorchidism is more on the right than on the left, with a ratio of right, left, and bilateral of about 6:3:1. The incidence of hernia in female babies is lower than in male babies, but the proportion of hernia occurring on both sides is higher than in male babies. Umbilical hernia Umbilical hernia is another form of abdominal wall defect that is second only to inguinal hernia. Because the umbilical ring is enlarged with only skin and subcutaneous tissue covering the belly button, the small intestine protrudes outward from the enlarged ring when the infant cries. This type of umbilical hernia rarely causes intestinal obstruction and necrosis, and most of them heal gradually at the age of 1 to 2 years, so there is no need for urgent surgical correction. Femoral hernia Femoral hernia is caused by a defect in the inguinal ligament and is rare in infants and toddlers, and is more common in girls than boys. It is more likely in girls than in boys and requires careful diagnosis and surgery because of the sequelae of small bowel necrosis. Who are the high risk groups? Babies born prematurely or with low birth weight, family history, fetal peritonitis, cirrhosis with ascites, hydranencephaly with ventriculoperitoneal drainage, genitourinary anomalies, cryptorchidism, hypospadias or epispadias, connective tissue disorders such as Van’s syndrome, etc. have a high incidence of herniation. Treatment Surgical repair is required, and the earlier the better. The reason a hernia needs surgery is to “prevent it before it happens”. If intestines or other abdominal contents get stuck in the hernia sac and cannot be returned, it can become lodged and cause pain. If it is stuck for too long or too tight, the blood circulation in the intestine will be blocked, resulting in intestinal obstruction and necrosis, vomiting, rapid heartbeat, fever, and even blood in the stool until it causes shock. At this point, surgery is necessary to avoid life-threatening sepsis. In the case of female babies, the ovaries and fallopian tubes may also be stuck for too long, causing necrosis and affecting future fertility. Moreover, the sheath of the peritoneum becomes larger and larger with age and increasing abdominal pressure, and the intestine often falls into the hernia sac causing flatulence and digestion and absorption problems. Post-operative care The wound does not need to be changed after surgery, and the body is cleaned by wiping for 5 days. 5 days later, a shower can be taken, and a follow-up visit after 1 week is sufficient. Due to the low infection rate of the hernia repair wound, only pain medication is needed for 1-2 days after surgery. Pediatric hernia wounds are small and shallow and usually not painful, and some small patients can get out of bed and play half a day after surgery. How to prevent recurrence Pediatric hernia is a common, time-consuming but delicate procedure. A recurrence is the reappearance of the hernia sac on the same side after a hernia repair. The recurrence rate after surgery is usually less than 1% and is usually caused by a large inguinal ring and high abdominal pressure. When performing surgery, the physician should consider posterior abdominal wall strengthening after the high ligation of the hernia sac, which will reduce the chance of recurrence. Children at high risk should avoid strenuous exercise and constipation for 1 month after surgery, and regular follow-up visits can reduce the recurrence rate. Early detection and early treatment Because of the fear of general anesthesia and surgery, parents are often afraid to let their babies undergo surgery. Nowadays, pediatric surgery is quite advanced, and all babies and children, no matter how small, can undergo surgery smoothly. Therefore, with early detection and treatment, pediatric hernia can usually be completely cured without any sequelae.