Abdominal Wall Defect Repair
Abdominal wall defect repair is a surgery performed to correct one of two birth defects of the abdominal wall: gastroschisis or omphalocele. Depending on the defect treated, the procedure is also known as omphalocele repair/closure or gastroschisis repair/closure.
For some unknown reason, while in utero, the abdominal wall muscles do not form correctly. And, when the abdominal wall is incompletely formed at birth, the internal organs of the infant can either protrude into the umbilical cord (omphalocele) or to the side of the navel (gastroschisis). The size of an omphalocele varies—some are very small, about the size of a ping pong ball, while others may be as big as a grapefruit. Omphalocele repair is performed to repair the omphalocele defect in which all or part of the bowel and other internal organs lie on the outside of the abdomen in a hernia (sac). Gastroschisis repair is performed to repair the other abdominal wall defect through which the bowel thrusts out with no protective sac present. Gastroschisis is a life-threatening condition that requires immediate medical intervention. Surgery for abdominal wall defects aims to return the abdominal organs back to the abdominal cavity, and to repair the defect if possible. It can also be performed to create a pouch to protect the intestines until they are inserted back into the abdomen.
Abdominal wall defects occurs in the United States at a rate of one case per 2,000 births, which means that
Abdominal wall defect surgery is performed soon after birth. The protruding organs are covered with dressings, and a tube is inserted into the stomach to prevent the baby from choking or breathing in the contents of the stomach into the lungs. The surgery is performed under general anesthesia so that the baby will not feel pain. First, the pediatric surgeon enlarges the hole in the abdominal wall in order to examine the bowel for damage or other birth defects. Damaged portions of the bowel are removed and the healthy bowel is reconnected with stitches. The exposed organs are replaced within the abdominal cavity, and the opening is closed. Sometimes closure of the opening is not possible, for example when the abdominal cavity is too small or when the organs are too large or swollen to close the skin. In such cases, the surgeon will place a plastic covering pouch, commonly called a silo because of its shape, over the abdominal organs on the outside of the infant to protect the organs. Gradually, the organs are squeezed through the pouch into the opening and returned to the body. This procedure can take up to a week, and final closure may be performed a few weeks later. More surgery may be required to repair the abdominal muscles at a later time.
Prenatal screening can detect approximately 85% of abdominal wall defects. Gastroschisis and omphalocele are usually diagnosed by ultrasound examinations before birth. These tests can determine the size of the abdominal wall defect and identify the affected organs. The surgery is performed immediately after delivery, as soon as the newborn is stable.
After surgery, the infant is transferred to an intensive care unit (ICU) and placed in an incubator to keep warm and prevent infection. Oxygen is provided. When organs are placed back into the abdominal cavity, this may increase pressure on the abdomen and make breathing difficult. In such cases, the infant is provided with a breathing tube and ventilator until the swelling of the abdominal organs has decreased. Intravenous fluids, antibiotics, and pain medication are also administered. A tube is also placed in the stomach to empty gastric secretions. Feedings are started very slowly, using a nasal tube as soon as bowel function starts. Babies born with omphaloceles can stay in the hospital from one week to one month after surgery, depending on the size of the defect. Babies are discharged from the hospital when they are taking all their feedings by mouth and gaining weight.
The risks of abdominal wall repair surgery include peritonitis and temporary paralysis of the small bowel. If a large segment of the small intestine is damaged, the baby may develop short bowel syndrome and have digestive problems.
In most cases, the defect can be corrected with surgery. The outcome depends on the amount of damage to the bowel.
Morbidity and mortality rates
The size of the abdominal wall defect, the extent to which organs protrude out of the abdomen, and the presence of other birth defects influence the outcome of the surgery. The occurrence of other birth defects is uncommon in infants with gastroschisis, and 85% survive. Approximately half of the babies diagnosed with omphalocele have heart defects or other birth defects, and approximately 60% survive to age one.
Gastroschisis is a life-threatening condition requiring immediate surgical intervention. There is no alternative to surgery for both gastroschisis and omphalocele.
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American Academy of Pediatrics. 141 Northwest Point Boulevard, Elk Grove Village, IL 60007-1098. (847) 434-4000. <http://www.aap.org>.
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Monique Laberge, Ph.D.
WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?
Abdominal wall defect surgery is performed by a pediatric surgeon. A pediatric surgeon is specialized in the surgical care of children. He or she must have graduated from medical school, and completed five years of postgraduate general surgery training in an accredited training program. A pediatric surgeon must complete an additional accredited two-year fellowship program in pediatric surgery and be board-eligible or board-certified in general surgery. (Board certification is granted when a fully trained surgeon has taken and passed first a written, then an oral examination.) Once the general surgery boards are passed, a fellowship-trained pediatric surgeon becomes eligible to take the Pediatric Surgery examination. Other credentials may include membership in the American College of Surgeons, the American Pediatric Surgical Association, and/or the American Academy of Pediatrics. Each of these organizations require that fellows meet well-established standards of training, clinical knowledge, and professional conduct.