Fetal diaphragmatic hernia is a congenital defect that develops during the formation of
the diaphragm, the muscular shelf that separates the chest
cavity from the abdominal cavity. The diaphragm is the
muscle that helps us to breathe, so it is a critical
component of the
respiratory system. In a diaphragmatic
hernia, the diaphragm — which develops at about 8 to 10
weeks of pregnancy — does not completely form, and a gap is
created between the chest and the abdominal cavities.
The severity of this condition ranges from a small gap in
the diaphragm to no diaphragm on one side of their body.
Ninety percent of all defects are found on the left side of
the diaphragm. Depending on how large the hole is, the
intestines, spleen, liver and/or stomach may move up into
the chest cavity. In turn, this causes the lungs to develop
poorly, so that the baby is born with a smaller number of
air sacs,
blood vessels and airways. When this happens, breathing
can be difficult or impossible.
It is estimated that 1 in every 2,200 births is affected
by diaphragmatic hernia. Parents that have one child born
with a diaphragmatic hernia are at an increased risk of
having another child with this condition; their chance is
approximately 1 in every 50. Also, infants with this
condition are likely to have other birth defects. About 1 in
5 are born with heart defects, and 1 in 10 are born with
genetic abnormalities.
Diagnosis
Fetal diaphragmatic hernia can be diagnosed by
ultrasound (sonogram) examination prior to birth.
Evaluation of the chest and abdominal area is part of the
routine ultrasound examination done by many obstetricians as
part of their routine prenatal care around the 20th week of
pregnancy. Additionally, it is recommended that a baby
diagnosed with this condition be referred to a pediatric
cardiologist to undergo a fetal echocardiogram, which is an
ultrasound of the infant’s heart while still in the womb.
This is performed because many babies born with
diaphragmatic hernia also have congenital heart defects. The
echocardiogram provides a much more in-depth evaluation of
the heart. Sometimes
magnetic resonance imaging (MRI) is performed to better
view the area.
More here about fetal MRI.
Treatment
After fetal diaphragmatic hernia is diagnosed, the staff
at Children’s Memorial counsels the parents and prepares
them for what to expect when their baby is born. Plans are
made to assure that the baby is delivered in a hospital that
has a
neonatal intensive care unit (NICU) with a neonatologist
present at the delivery.
After birth, the baby is stabilized and then transferred
via ambulance to Children’s Memorial to begin treatment.
Often times the newborn is unable to breathe on his own
because of poor lung development. Most babies need help from
a breathing machine called a ventilator.
After stabilization (generally 1 to 2 weeks), the infant
has
surgery to repair the diaphragmatic hernia. This is done
either by closing the hole with stitches in cases of a small
defect; in larger defects, the surgeons may have to place a
sheet of mesh
graft into the baby’s chest to close the hole. In
carefully selected cases, these surgeries can be completed
using the ’minimally invasive surgery’ technique,
thus avoiding a large
incision.
More here about minimally invasive surgery.
If an infant cannot be stabilized while on the
ventilator, he may be temporarily placed on a heart/lung
bypass machine called
ECMO (extracorporeal membrane oxygenation). This machine
helps to pump blood and bring oxygen to the rest of the
body. Few babies need the assistance of ECMO because
neonatal care has significantly improved over the last 20
years. However, if a child does need to rely on it for a
short time, he will undergo an operation to attach the tubes
of the ECMO to his blood vessels. (see
more on ECMO )
Long-term outlook
The long term outlook for these children depends on the
the amout of functional lung tissue present, the size of the
hole in the diaphragm and whether or not they are born with
other birth defects or genetic problems. Some babies have
long-term problems and need regular follow-up care after
they return home. Some of the medical problems can include
hearing loss, chronic lung disease,
gastroesophageal reflux disease and other developmental
problems. Many of these problems can be treated with
medications and therapy — allowing the child to have a
better quality of life. Furthermore, diagnosing the problem
before birth increases their chances of survival and a
longer life expectancy since treatment can begin as soon as
they are born.
Unfortunately, the worst cases are sometimes not
compatible with life, despite the best treatments available
today.
