Omphalocele: (audio pronunciation)
A birth defect in which part of the intestine, covered only by a thin transparent membrane, protrudes outside the abdomen at the umbilicus. The underlying error is a failure during embryonic development for a section of the intestines (the midgut) to return from outside the abdomen and reenter the abdomen, as it should. The opening in the abdominal wall cannot close because, to do so, would pinch off part of the intestines. An omphalolocele must be repaired by surgery.
click to enlargeWith an omphalocele, the part of the intestine that sticks out is covered by two thin transparent membranes called the amnion (the amniotic membrane) and peritoneum (the abdominal membrane). The liver and spleen may also be within the omphalocele.
An omphalocele is caused by an error in the normal embryonic development of the intestinal tract. During embryogenesis (the time during which the embryo forms), there are initially three distinct portions of the intestinal tract (the foregut, midgut and hindgut) that extend the length of the embryo. Much of the midgut is then herniated (protruded) outside the abdomen at the umbilicus (belly button). The midgut later reenters the abdomen (belly) and the opening in the abdominal wall closes. The error responsible for an omphalocele is a failure for the midgut to return and reenter the abdomen. The opening in the abdominal wall cannot close because to do so would pinch off part of the intestines.
About 1 in 5,000 babies is born with an omphalocele. The omphalocele can be an isolated birth defect (all by itself). Or it may occur in children who have additional malformations as for example a congenital heart defect. Omphalocele is a characteristic malformation in certain chromosome abnormalities as the trisomy 13 (Patau) syndrome and the trisomy 18 (Edwards) syndrome. It also is seen in some genetic disorders such the Beckwith-Wiedemann syndrome.
“Omphalo-” indicates a relationship to the umbilicus (the navel) and the suffix “-cele” refers to a hernia or rupture, so omphalocele literally = a hernia or rupture at the umbilicus.
Immediate care:
Because some or all of the abdominal organs are outside the body, infection is a concern, especially if the protective membrane around the organs breaks. Also, an organ may lose its blood supply if it becomes pinched or twisted. A loss of blood flow can damage the affected organ. Omphalocele can often be detected on fetal ultrasound in the second and third trimesters of pregnancy. A fetal echocardiogram (ultrasound of the heart) may also be done to check for heart abnormalities before the baby is born. After birth, the omphalocele can be noted by the physician during the physical examination. X-rays (diagnostic tests that use invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film) may also be done after birth to evaluate abnormalities of other organs or body parts.
Surgical Repair:
Specific treatment for an omphalocele will be determined by: the baby’s gestational age, overall health, and medical history extent of the condition the baby’s tolerance for specific medications, procedures, or therapies.
For a small omphalocele (only a portion of the intestine protruding outside the abdominal cavity), shortly after birth, an operation is done to return the organs to the abdomen and close the opening in the abdominal wall.
For a large omphalocele (most of the abdominal organs, including intestine, liver, and spleen, are present outside the abdominal cavity), the repair is done in stages and may include the following:
Initially, sterile, protective sheeting is placed over the abdominal organs.
Because the abdomen may be small and underdeveloped, it may not be able to hold all of the organs at once. Therefore, the exposed organs are gradually moved back into the abdomen over several days or weeks. The abdominal wall is closed surgically once the organs have been returned to the abdominal cavity.
Because the abdominal cavity may be small and underdeveloped and the organs may be swollen, a baby with an omphalocele may have breathing difficulties as the organs are returned to the abdomen. The baby may need help from mechanical ventilation while the swelling is decreasing and the size of the abdominal cavity is increasing.
Post-Operative Care:
The infant is cared for post-operatively in a neonatal intensive care unit. The baby is placed in an isolette (incubator) to keep warm and prevent infection. Oxygen is given and mechanical ventilation is often required. Intravenous fluids, antibiotics, and pain medications will be given. A nasogastric tube will be in place to keep the stomach emptied of gastric secretions. Feedings are started by nasogastric tube as soon as bowel function resumes. Feedings are started very slowly and often infants are reluctant to feed. These babies may need feeding therapy and lots of encouragement.
Prognosis:
Babies who have damage to the intestines or other abdominal organs may have long-term problems with digestion, elimination, and infection.
Greg Olson :: Ubiquity :: 303-962-8700 :: greg@ubiquitygroup.com
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