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Congenital Diaphragmatic Hernia and Diaphragmatic Eventration 295

requiring a patch repair. Management is usually conservative, as these the incidence of pulmonary hypertension is low and the degree of
deformities tend to be mild. Operative intervention is reserved for those associated pulmonary hypoplasia is minimal. Thus, the presentation
with severe deformities. is less dramatic and usually somewhat delayed and the outcome is
9
Chronic lung disease is common in severely affected patients. A significantly better.
mild restrictive pattern of lung function is seen in most patients, but Demographics
is not necessarily associated with clinical symptoms. Alveolar growth Like CDH, eventration of the diaphragm is more common on the left.
continues up to 8 years of age, and children can outgrow any mild Bilateral lesions are rare. There is no gender or race predilection.
restrictions to exercise tolerance and susceptibility to chest infections. Aetiology/Pathophysiology
An increased incidence of asthma is seen. Those with severe neonatal
lung disease develop chronic lung disease. Continued pulmonary Eventration of the diaphragm is thought to result from failure of myo-
hypertension into infancy and childhood are associated with poor blastic transformation of the diaphragm or faulty ingrowth of muscle
outcome. There is a late mortality, due to chronic lung disease and into the dome during embryogenesis. The involved hemidiaphragm
associated or secondary cardiac dysfunction, which can be as late as 4 is therefore inactive and demonstrates paradoxical movement with
years of age. 16 respiration.
Neurodevelopmental delay and hearing loss are nonsurgical Although the elevated diaphragm can lead to lung compression and
complications that are consequences of poor oxygenation; they are hypoplasia with associated pulmonary vasculature hypertension, as
twice as common in children who receive ECMO support. 9,16 in CDH, this complication is uncommon or mild in eventration. The
incidence of other anomalies is low.
Prognosis and Outcomes Paralysis of the diaphragm due to phrenic nerve palsy or traumatic/
A summary of the major significant outcome measures and their main iatrogenic phrenic nerve damage can give a picture similar to eventration.
determinants (in parentheses) follows. The distinction is sometime difficult in those with a potential cause
• death (pulmonary hypertension, associated cardiac anomalies, chro- (birth trauma, cardiac/thoracic surgery). To some extent, the distinction
mosomal abnormalities, early severe disease); is not important because the treatment, in the symptomatic child, is
• neurological impairment and hearing loss (pulmonary hypertension, usually the same.
size of defect, early severe disease); Clinical Presentation
• chronic lung disease (pulmonary hypertension, size of defect, early History
severe disease); or Respiratory distress, tachypneoa, and cyanosis may be present in the
early neonatal period in severe cases of eventration of the diaphragm.
• recurrence (size of defect, need for patch repair).
Presentation is more often less dramatic and later than for those with
Thus, the main adverse determinants of outcome seem to be CDH. Due to the limited respiratory reserve, poor feeding or sucking,
associated chromosomal and cardiac anomalies, severity of the associated with tiring, is common. Failure to thrive may be the present-
pulmonary hypertension, and size of the defect.
ing complaint due to poor feeding. Vomiting may be the presenting
Prevention complaint. Failure to recover from a lower respiratory tract infection or
There are no known preventive measures for CDH. recurrent infections may prompt a chest x-ray that brings the diagnosis
Ethical Issues to light.
Two main ethical issues surround the management of CDH. Both are Physical
outside the scope of this text, but are discussed here briefly. The first The physical findings may be minimal. There may be signs of respira-
is the indication and benefit of any antenatal intervention in the foetus. tory distress. Decreased air entry may be present in both lungs but more
Antenatal plugging of the trachea is theoretically advantageous by marked on the affected side. The cardiac impulse may be shifted away
17
allowing increased foetal lung growth. The indications for interven- from the affected side.
tion are not clear from the research done to date. It is said that infants Investigations
with adverse features on antenatal scan could benefit from plugging.
A plain chest x-ray is suggestive of the diagnosis in most cases. Signs
Intervention is possibly too late to affect the developmental conse-
on the radiograph are that the right hemidiaphragm is more than two rib
quences at this stage, however; this may be borne out in the lack of spaces higher than the left (Figure 45.7), or the left is more than one rib
2
convincing benefit to date. The resources and personnel necessary to
space higher than the right (Figure 45.8).
run such a programme (or even research into it) are huge, and the debate
It is sometimes difficult to distinguish the radiological picture of
on cost versus benefit is likely to continue.
eventration of the diaphragm from that of CDH. Unlike the case with
Second, the use of ECMO as “rescue therapy” for infants with
CDH, however, there is usually a suggestion of a thin rim of diaphragm.
severe lung disease remains contentious. In one large trial in the United
16
Kingdom, the benefit of ECMO on survival in CDH could not be Fluoroscopy is diagnostic in most cases. Paradoxical movement of
the affected diaphragm is seen during screening. (This sign is lost in
established. A meta-analysis of randomised trials also failed to show
patients who are ventilated.)
a long-term benefit (late mortality was similar in ECMO and non-
18
ECMO CDH patients). Furthermore, the morbidity induced in those Ultrasound screening to demonstrate paradoxical movements can
also be used to make the diagnosis, but this process is less sensitive
that do survive (related complications included intracranial infarct or
16
bleed, major bleeding, seizures, and infection) is significantly high than fluoroscopy, mainly due to the inability to see both diaphragms
simultaneously.
and can be costly. Around one-fifth have severe neurodevelopmental
16
problems. The use of ECMO continues, and its advantages need to be Management
continually investigated to resolve this issue. Patients who are asymptomatic or patients who improve without
Eventration of the Diaphragm intervention may be treated conservatively. Conservative treatment for
asymptomatic cases suspected to be due to phrenic nerve injury can also
Eventration of the diaphragm is defined as an abnormal elevation of be advocated, with hope for recovery if possible. Operative manage-
an otherwise intact diaphragm due to poor or absent musculature. ment is the treatment of choice in symptomatic cases.
Although some of the mechanical effects are similar to those of CDH,