A hernia occurs when a portion of an organ within the abdomen, such as the intestines, protrudes through a weakness in the muscles of the abdomen. A soft bulge is seen underneath the skin where the hernia is located. A hernia that occurs in the groin area is called an inguinal hernia.
An inguinal hernia can occur at any age, but one-third of hernias in children appear in the first six months of life. Approximately 80% to 90% of inguinal hernias appear in boys. They are more common on the right side, but in about 10% of cases, they occur on both sides (bilaterally).
In just over 10% of cases, other members of the family may have had a hernia at birth or in infancy. In premature infants, the occurrence of inguinal hernia is increased by up to 30%.
Between 12 to 14 weeks of fetal development, the testicles or ovaries form in the abdomen near the kidneys. They gradually move down into the lower part of the abdomen as the baby continues to develop. As they move down, a portion of the peritoneum (a thin layer of tissue that lines the inside of the abdomen) that attaches to the testicle is drawn with it into the scrotum, forming a pouch or sac.
A similar process occurs in girls as the round ligament of the uterus descends into the groin at the labia. This sac is known as the processus vaginalis and normally closes shortly after birth. This eliminates any connection between the abdominal cavity and the scrotum or groin. When closure of the processus vaginalis is delayed or incomplete, it may stretch and eventually become a hernia. The stretching of the processus vaginalis creates an inguinal sac, allowing organs to extend from the abdomen and enter the sac. If fluid, rather than organs, builds up and remains in the sac, the child has a hydrocele.
Signs and symptoms of inguinal hernia include:
- Swelling or a bulge in the groin or scrotum may be seen during crying or straining, and it may get smaller or go away when the baby relaxes
- A smooth mass that is usually not tender
- Localized pain in the area of the hernia
If the bulge can be gently pressed back into the abdomen, the hernia is termed reducible. If it cannot be pressed back into the abdomen, the hernia is known as incarcerated (irreducible). When a hernia becomes incarcerated, infants or children will show signs of irritability and may vomit. They may also have loss of appetite, abnormal bowel patterns, and/or tenderness of the groin area and swelling of the abdomen.
With a prolonged period of incarceration, the blood supply to the intestine could be cut off, causing it to die. This is referred to as a strangulated hernia — a life-threatening situation that requires urgent surgical attention.
Inguinal hernias require an operation, and to avoid the risk of abdominal organs becoming incarcerated, this is generally done as soon as possible. In premature infants, who are only several months old, surgery may be postponed for two to three months to ensure that the lungs are functioning properly.
Surgery is carried out under general anesthesia. A small incision is made in the groin. The hernia sac is identified and repaired. The incision is closed with dissolving stitches. Tissue glue and steristrips (strong tape that sticks for seven to 10 days) are used to seal the surface of the incision. During the procedure, a generous amount of local anesthetic is injected around the incision to help control pain.
Most children who undergo hernia repairs go home the same day after a short stay in recovery; however, premature infants may require an overnight stay. Most children are able to return to normal activities, even sports, with no restrictions within a few days. The length of time sports activities are restricted depends on the age of the child and the sports activity.
In cases where a large inguinal hernia extends down into the scrotum, the scrotum may swell after surgery. It may appear as though the hernia has come back. This swelling is normal and will go away on its own within several weeks to months.
After surgery, the risk of the hernia returning is extremely low. However, the risk is known to be higher in premature infants and in children with hydrocephalus, connective tissue disorders, chronic lung disease and chronic renal failure.