Umbilical hernia in infants and young children

　　1. Etiology

　　After the umbilical cord detaches from the infant, the umbilical scar is a congenital weak point, and the anterior and posterior sheaths of the rectus abdominis at the umbilicus are not yet closed during infancy, leaving a defect, forming the condition for the occurrence of umbilical hernia. Various causes that increase intra-abdominal pressure, such as coughing, diarrhea, excessive crying, etc., can promote the occurrence of umbilical hernia.

　　2. Pathogenesis

　　The umbilicus is the last part of the abdomen to close, where the fetal umbilical cord is located. The umbilical vein is at the highest part of the umbilicus, passing through the abdominal wall and moving inward to the inferior margin of the falciform ligament. The segment of the umbilical vein near the umbilicus after birth becomes the round ligament of the liver. During fetal development, the two umbilical arteries are located between the transversalis fascia and the peritoneum, entering the umbilical cord on the lower side of the umbilicus. After birth, they regress into fibrous strands and are called the lateral umbilical ligament. The fetal urachus is located in the midline of the lower abdomen, between the abdominal wall and the peritoneum, and regresses into the median umbilical ligament after birth. The umbilical cord is tied and cut during birth, forming a scar at the断面. The above ligaments are filled with loose connective tissue, becoming the weakest part of the abdominal wall. The umbilical ring encircles the umbilicus and is quite tough, formed by the fusion of the anterior and posterior aponeuroses of the rectus abdominis and the transversus abdominis aponeurosis. At birth, the umbilical ring is large, which gradually shrinks during growth and finally disappears. When the umbilical ring is large, the gaps between the ligaments increase, and the abdominal viscera, with the peritoneum, pass through the gaps between the ligaments, protruding outside the umbilical ring, forming an umbilical hernia. Infants, especially premature infants, low-birth-weight infants, malnourished infants, and children with cerebral palsy, have poor or loose tissue development around the umbilicus, a larger umbilical ring, and a delayed contraction and closure of the umbilical ring, which are anatomical factors that make these children prone to umbilical hernia.

　　There are some people who conduct research on histology, where during the fetal stage, the elastic fibers within the umbilical artery wall continuously extend outward, reinforcing the lower part of the umbilicus, surrounding the umbilical artery and urachus, as if it were a sphincter. After the umbilical cord detaches, the umbilical ring closes, and the lower part of the umbilical ring is tightly closed. The surrounding area of the umbilical vein lacks this 'sphincter' structure, making the upper part of the umbilicus weaker than the lower part, hence the upper part is more prone to umbilical hernia.

　　1. Adhesion of hernial contents:Adhesions can cause pain at the umbilicus, especially when the omentum is adhered to the hernial sac, the pain is more obvious, and sometimes it can cause symptoms such as abdominal distension and vomiting.

　　2. Incarceration of umbilical hernia:The contents of umbilical hernia are mostly small intestine, omentum, etc., and incarceration occurs rarely. Once umbilical hernia incarceration occurs, various symptoms become more severe.

　　3. Rupture of umbilical hernia:The hernial sac and covering are thin, and they are prone to rupture when subjected to external force.

　　It often occurs a few days to a few weeks after the umbilical cord is cut off in infants. At this time, the incision site of the umbilical cord has formed an epithelium, so the surface of the hernia is covered with skin. The main manifestation is a bulge at the umbilicus, which increases in size during crying, the skin is very thin and slightly bluish, the mass shrinks and disappears when the baby is calm and lying down or sleeping, and there are loose wrinkles at the umbilicus. After the hernial contents are returned to the abdomen with the finger, a water-over-rock sound can often be heard, and the hard umbilical ring can be felt. By inserting the finger into the umbilical cavity, the diameter of the umbilical ring can be estimated. When the child coughs, cries, or strains, the finger can feel a shock.

　　Preventing an increase in abdominal pressure is an important measure to prevent the occurrence and development of umbilical hernia, such as strengthening the necessary care for infants, reducing the crying of infants; providing water, juice, or vegetable juice at regular intervals to promote smooth defecation; adjusting clothing and bedding as appropriate to prevent respiratory tract infections, etc. Maintain a healthy weight. Avoid pushing, lifting, or pulling heavy objects, drink plenty of water, eat high-fiber foods to promote smooth defecation, and prevent constipation.

　　1. The most important clinical manifestation is the reducible mass at the umbilicus, especially obvious during crying in infants. Generally, there are no other symptoms. A bulging, small, round mass can be seen at the umbilicus soon after birth, which is as small as a cherry and as large as a walnut. The small mass can become larger and tense when the baby is calm or lying down. If the mass is gently pressed back, a 'gurgling' sound can be heard, and a feeling of gas being squeezed back into the abdomen can be felt. Since the abdominal wall and hernial ring of infants are very soft, incarceration is rare.

　　2. Generally, it is only necessary to perform an abdominal X-ray to understand whether there are signs of intestinal obstruction.

　　Diet should be light. For the first few days after surgery, diet should be adjusted according to individual conditions, with a focus on liquid and semi-liquid foods. Eating foods rich in high protein is beneficial for wound healing. Supplementing a variety of vitamins, eating fresh vegetables and fruits. It is recommended to eat various lean meats, milk, eggs, and other protein-rich foods. Avoid overly greasy foods, and provide water, juice, or vegetable juice at regular intervals to promote smooth defecation.

　　1. Treatment

　　Under normal circumstances, the umbilical ring can continue to narrow within the first 18 months after birth, therefore, umbilical hernia in infants and young children has the possibility of self-healing, and most cases can heal spontaneously within 2 years without any treatment. Some statistics show that as age increases, the abdominal muscles become more developed, and the umbilical ring also gradually becomes smaller and closes. According to statistics, 90% close and heal within the first 6 months after birth, and 95% within a year.

　　1. Non-surgical therapy

　　Generally no treatment is needed. For individual children who like to cry and are prone to incarceration, it can be tried.

　　(1) Compression method: Use a 9-10cm wide elastic band of appropriate length, sewn into a circular shape; let the baby lie flat, return the umbilical hernia; align the convex surface of a cotton ball (the same size as the hernia) or half a ping pong ball with the umbilical hernia, and fix it with the elastic band.

　　(2) Adhesive tape method: You can wrap a coin, button, or round wooden piece slightly larger than the umbilical ring with gauze, press it on the umbilical ring, and then fix it with a wide adhesive tape. The width of the adhesive tape is 5cm, and the lumbar and back areas passed by the adhesive tape can be padded with gauze to avoid skin damage. The operation should first return the hernial contents to the abdominal cavity, so that the hernial sac is in a hollow state, avoiding the bulging of the hernial contents, which facilitates the closure of the umbilical orifice. It is generally changed once every 1-2 weeks, and it can be used continuously for 3-6 months. Local skin care should be paid attention to, and the umbilical orifice should be reduced each time to promote gradual healing.

　　2. Surgical treatment

　　During the normal development of infants and young children, umbilical hernia can disappear quickly, and only a few cases require surgical treatment, so there is no need to rush for surgery.

　　(1) Indications: Consider surgery for the following conditions:

　　① Large hernia with umbilical orifice diameter over 2cm;

　　② No cure after one year of conservative treatment, age over 2 years;

　　③ Incarcerated, with adhesion between the visceral organs and the hernial sac;

　　④ Abdominal pain, suggesting adhesion of the greater omentum.

　　(2) Surgical method: Make a semicircular skin incision below the umbilical hernia, separate the subcutaneous tissue, free the hernial sac, excise the hernial sac from under the umbilical skin, suture the peritoneum, and then suture the margins of the two sides of the rectus sheath with thick silk thread on the central line, suture the skin layer by layer. Cover the incision with sterile gauze and fix it with a wide adhesive bandage to eliminate the tension of the abdominal wall.

　　(3) Prevention and treatment of postoperative complications: Subcutaneous hematoma is a common postoperative complication, which is often caused by local bleeding after stripping the hernial sac, forming a hematoma and gradually expanding to the anterior abdominal wall. Improper treatment can lead to infection and the formation of an abscess. The way to avoid it is to stop bleeding carefully and thoroughly; a cotton ball of the same size as the umbilical fossa should be placed and compressed bandaged at the umbilical fossa after the operation. Small hematomas can be absorbed spontaneously, and large hematomas can be opened to remove the accumulated blood and clots, compressed bandaged, and systemic antibiotic treatment should be applied at the same time.

　　Second, Prognosis

　　The repair of umbilical hernia after surgery is effective, and it can retain a good appearance of the umbilicus, and there is rarely recurrence.