An omphalocele is a congenital defect in which internal organs such as the liver, stomach, and intestines, are on the outside of the abdomen, at the umbilical cord, instead of being located inside the body. These abdominal cavity contents are enclosed in a thin, transparent, membranous sac that is actually formed inside the umbilical cord tissue. An omphalocele repair is a surgical procedure in which the organs are returned to the inside of the body, and the opening in the abdominal wall is closed. Whenever possible, a normal-looking belly button is created.
Purpose
The internal organs need to be enclosed inside the abdomen for protection against injury, and to ensure that the tissue remains properly hydrated. The omphalocele repair is necessary to return the tissue to the inside of the body.
Demographics
Omphaloceles usually occur in full-term infants, more frequently in boys than in girls. A recent study found that the ratio is two girls to three boys.
The presence of an omphalocele often occurs with other birth defects, including:
pentalogy of Cantrell, with malformations in the chest and abdominal area, including heart defects, and high mortality rate
To check for other congenital defects, x rays are usually taken of the heart, lungs, and diaphragm once the infant's condition has been stablized after birth.
Description
An omphalocele is a defect that can be viewed on sonogram during an ultrasound performed while the mother is pregnant. At about six to eight weeks of fetal development, the abdominal contents come out of the fetus's abdomen at the base of the umbilical cord. They return to the inside as development continues. If this process is interrupted in some way during the seventh to tenth week of fetal development, the contents remain on the outside, and an omphalocele develops. Because the abdominal contents are now on the outside of the body, the inside cavity may not develop properly. For this reason, a large omphalocele cannot simply be placed back inside because the cavity may be too small. The internal organs will need to be protected and kept hydrated while the inside is gradually stretched. Small amounts of the omphalocele are returned at any one time to allow the cavity to gradually stretch to accommodate them. If the sac surrounding the tissue has ruptured, or broken, there is a greater risk of infection, tissue damage, loss of body temperature, and dehydration.
The repair may be performed in stages. If the omphalocele is very small, it may be possible to return all of the contents to the inside, and surgically close the opening. If the omphalocele is too large to do this all at once, some contents will remain on the outside while a sterile pouch is created to protect the tissue that remains on the outside. To be sure that the tissue does not dry out, it will be covered with warm and moist sterile dressings. The infant can lose considerable body heat through the large amount of exposed surface area, so keeping him or her warm, and closely monitoring body temperature is a high priority. An antibacterial solution may be used to decrease the risk of infection. The infant will have a tube that goes in through the nose or mouth and down into the stomach, called a nasogastric tube. Suction is used to keep the stomach empty, avoiding the chance of vomiting, or of the fluid moving from the stomach up into the lungs. The contents of the sac will be carefully examined to make sure that none of the tissue is damaged or dead, and to check for signs of intestinal birth defects before being inserted into the body.
The omphalocele repair is a surgical procedure performed under general anesthesia. The infant will receive medication to relax his or her muscles, and to help the surgery move forward without causing any pain. A large omphalocele repair may be done in stages over several weeks. The contents of the sac are often swollen, which makes it impossible to return them into the small cavity all at once. The return of the sac contents into the abdominal cavity creates intra-abdominal pressure, which may cause the infant to have difficulty breathing. To help the infant breathe, a special breathing tube may be inserted. The tube is attached to a machine that regulates the length and frequency of the breaths. When the necessary surgeries have been completed, the suturing will be done in such a way as to leave, if possible, a somewhat normal-looking belly button. A large omphalocele repair can leave a large, unsightly scar. For cosmetic purposes, the scar may be operated on at a later date to make it less noticeable. Gastroesophageal reflux, which may require additional surgery, is common in patients with a repaired omphalocele.
Diagnosis/Preparation
The diagnosis of an omphalocele may take place during an ultrasound while the mother is still pregnant. A recent study found that 75% of omphaloceles were diagnosed by ultrasound, most commonly around week 18 of pregnancy. To avoid any injury to the omphalocele sac, a cesarean birth may be performed so that the infant does not travel through the birth canal. If the omphalocele has not been detected prior to birth, it is immediately noticeable upon birth.
Aftercare
The infant will need to spend some time after the surgery in the intensive care unit. Because infants are unable to properly regulate their temperature, they are placed in special beds that are kept warm. They will usually need oxygen and a breathing tube to help them breathe for a while. The breathing machine is referred to as mechanical ventilation, or a ventilator. This machine helps the baby breathe at the right depth and frequency for his or her age, allowing the infant to conserve energy for other functions. An infant that is struggling for air spends much energy on breathing, which slows the healing process.
Once the bowels are moving normally, feedings will be slowly started. Feedings are usually first done through a nasogastric tube so the infant does not need to use energy for sucking and swallowing. Sucking on a pacifier is avoided because this could cause the bowel to expand with air and slow down the healing process. Until the nasogastric tube is used, the infant will be fed intravenously. The intravenous line provides the infant with needed antibiotics, pain medication, and fluids.
Infants with an omphalocele may spend quite some time, perhaps several months, in the hospital before being discharged home. It may take them some time to learn to feed through normal infant sucking and swallowing. Their development may be delayed, and they may require help for months as they catch up to the physical and mental development that is normal for their age. If the parents do not live near the hospital, they should be encouraged to spend as much time with their infant as possible to ensure infant-parent bonding. When the repair is done in stages, it can be difficult for the parents to remain patient. The birth of a child with a birth defect can be quite emotionally difficult for the parents. Individuals trained to assist parents through this time should meet with them to provide information and support.
Risks
All surgery has risks, from the procedure itself as well as the anesthesia. Infection and bleeding are the two primary risks of surgery. Breathing problems and reactions to the anesthesics are the main risks from anesthesia. In addition to these standard surgical risks, an omphalocele repair has the associated risks of damage to the organs on the outside of the body, additional breathing problems from the added pressure inside the abdominal cavity when the contents are returned, infection of the abdominal cavity (peritonitis), and a slowing or paralysis of the bowels (paralytic ileus).
Normal results
The expected results depend on many factors, including:
Many omphaloceles can be completely corrected with excellent results.
Morbidity and mortality rates
An omphalocele occurs in about one in 5,000 live births. Other congenital defects are common. In one recent study, 50% of infants with omphalocele had other birth defects, primarily heart-related. On average, the infants spent three days on a ventilator, with about 45 total days spent in the hospital. The mortality rate was 8%, mostly due to heart problems.
Alternatives
There are no non-surgical alternatives to omphalocele repair. The abdominal contents need to be returned to the abdominal cavity, and the opening closed. While awaiting surgical repair, a sterile elastic bandage may be placed on the omphalocele to decrease edema (fluid accumulation).
BOOKS
Ashcraft, Keith W. Pediatric surgery. W. B. Saunders Company, 2000.
Pillitteri, Adele. Maternal & Child Nursing: Care of the childbearing & childrearing family. 3rd edition. Lippincott, 1999.
PERIODICALS
Barisic, I. et al. "Evaluation of Prenatal Ultrasound Diagnosis of Fetal Abdominal Wall Defects by 19 European Registries." Ultrasound Obstet Gynecol 18 (October 2001): 309–16.
Saxena, A. and G.H. Willital. "Omphalocele: Clinical Review and Surgical Experience Using Dura Patch Grafts." Hernia 6 (July 2002): 73–8
ORGANIZATIONS
National Library of Medicine: Medline Plus Health Information [cited July 7, 2003]. <http://www.nlm.nih.gov>
Esther Csapo Rastegari, R.N., B.S.N., Ed.M.
WHO PERFORMS THE PROCEDURE AND WHERE IS IT PERFORMED?
This procedure is performed by a surgeon, preferably board certified, who specializes in pediatric surgery and has experience with such conditions. The repair needs to be done in a hospital, preferably one with a neonatal intensive care unit, with specially-trained pediatric intensive care nurses and staff.
QUESTIONS TO ASK THE DOCTOR
In addition to the omphalocele, what other medical conditions does the child have?
What is the chance of surviving the procedures needed to correct these problems?
What quality of life can the child have if all the procedures are successfully performed?
How many of these procedures has the surgeon performed?
What outcomes has the surgeon's patients had?
How long will the child need to stay in the hospital?
