Page8/Case 03/01
CDH Etiology
Failure
of closure of the pleuro-peritoneal canal
(8-10 weeks)
Development
of the diaphragmatic primordium (3-4 weeks).
At
the end of this phase the primitive diaphragm is composed of two parts:
1.
Ventral transverse septum
2.
Dorsal diaphragmatic mesentery
Development
of the pleural cavity and closure of the pleuro-peritoneal canals
(4 to 8 weeks)
The
diaphragm is formed from the septum transversum and the dorsal mesentery,
which separate the thoracic system from the abdominal organs. The poster-olateral
areas are the last to close and the left side closure occurs later than
the right.
Different
concept of development (Iritani, 1984)
Primitive
diaphragm consisted of 3 parts:
1.
Transverse septum ventrally
2.
Pleuroperitoneal canals caudally
3.
Posthepatic mesenchymal plate (interposed), leads to the closure of the
canals.
Pathophysiology
(dynamic lesion)
–
Migration
of intraperitoneal structures in the hemithorax leads to compression and
secondary pulmonary hypoplasia.
–
V/Q
mismatch
–
Pulmonary
hypertension
–
Relative
left ventricular hypoplasia
–
Right
to left shunt through foramen ovale or ductus arteriosus
–
Surfactant
deficiency
