What is an inguinal hernia?An inguinal hernia is a bulge that occurs in the groin area. In children, almost all inguinal hernias are congenital. This means that the defect was present from the time the patient was born. 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 in the womb. As they move down in a male, 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, this is called a hydrocele. In both boys and girls, these areas are supposed to seal off prior to the baby being born. If they fail to close before birth, then the child is at risk of having an inguinal hernia. Given this, it is not surprising that inguinal hernias are more common in premature infants.
Approximately 80 percent to 90 percent of inguinal hernias appear in boys. They are more common on the right side, but in about 10 percent of cases, they occur on both sides (bilaterally). An inguinal hernia can occur at any age, but one-third of hernias in children appear in the first 6 months of life. Sometimes parents worry that their child lifted something too heavy or strained too hard to cause a hernia to develop, but in almost all cases this is not true. The hernia defect or hole was likely always there since birth. It was only the straining that pushed something through the hole to make it become noticeable.
How are inguinal hernias treated?The diagnosis of a hernia is best made by a careful physical exam by the pediatric surgeon. Inguinal hernias appear as a bulge or swelling in the groin or scrotum. The swelling may be more noticeable when the baby cries or strains, and may get smaller or go away when the baby relaxes. Your child will be examined to determine if the hernia is reducible (can be pushed back into the abdominal cavity) or not. If your doctor pushes gently on this bulge when the child is calm and lying down, it will usually get smaller or go back into the abdomen. In select cases where the history or physical exam is less certain your doctor may choose to obtain an ultrasound to provide added information.
Occasionally, the loop of intestine that protrudes through a hernia may become stuck, and is no longer reducible. This is termed an “incarcerated hernia.” When this happens, that section of intestine may lose its blood supply. A good blood supply is necessary for the intestine to be healthy and function properly. The following are the most common symptoms that indicate this has occurred: A full, round abdomen, vomiting, pain, fussiness, redness, discoloration or fever. 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.
An inguinal hernia repair is necessary to close the defect, as they do not resolve on their own. In contrast, a hydrocele can be observed until age 1 or 2 as it may self resolve. The hernia will be surgically repaired fairly soon after it is discovered, since the intestine can become stuck in the inguinal canal. The main reason that hernias are repaired is to prevent the problems that can arise from incarceration or strangulation of the hernia.
What will happen in the hospital?The operation is done under general anesthesia. Occasionally the operation may be performed with a spinal anesthesia in a premature infant. A small incision is made in the groin at the area of the hernia. The surgeon gently pushes any bulging tissue back into the belly. The goal of the operation is to sew closed the opening between the abdomen and the scrotum. The hernia sac is also usually removed in this process.
If your child has hernias on both sides or if the surgeon suspects your child might have hernias on both sides, the surgeon may discuss options for evaluation and treatment with laparoscopic exploration of the opposite side.; The surgery is done the same except that before closing the hernia hole, a small camera (about 3 mm in diameter) is passed into the abdomen to examine the opposite groin from the inside. The surgeon may recommend this laparoscopic exploration in certain circumstances to rule out a potential hernia on the opposite side. If a hernia is detected, a matching incision is made on the opposite side to allow repair of the second hernia. In contrast to adult hernias that are usually secondary to weakness in the abdominal wall muscles, during the repair of pediatric congenital hernias, a piece of mesh is generally not used.
The primary risks of hernia surgery include bleeding and infection (rare). In boys, there is a low (1-2%) chance of injury to the vas deferens or spermatic vessels as they lie adjacent to the hernia sac. The risks of hernia recurrence are 1-2% but are slightly increased in operations in premature babies.