Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) is a defect in prenatal growth, thought to occur around the transition from embryologic to fetal stages of human development. It is identified in approximately 1 in 4000 live births. The mature diaphragm is a summation of five component parts, including the anterior septum transversum, a right and left pleuroperitoneal fold located posteriorly, the midline esophageal mesentery (which also contains IVC and aorta), and the body wall serving as peripheral boundary. Normal cranio-caudal folding in embryologic development results in pleuroperitoneal canals along either side of the esophageal mesentery, which under expected conditions will close around 8 weeks of gestation. Animal studies have revealed that CDH most frequently results from some abnormal increase in intraperitoneal pressure, such as premature return of the midgut from the umbilical stalk back into the abdomen. While CDH can technically occur at any of the junctional points between the five component diaphragmatic parts, most occur as intraperitoneal contents are forced up through still-open pleuroperitoneal canals.