Ivclinical Correlations

A. Esophageal hiatal hernia is a herniation of the stomach through the esophageal hiatus into the pleural cavity, caused by an abnormally large esophageal hiatus. Esopha-

Pleuroperitoneal Canal

""visceral" / Intraembryonic mesoderm Intraembryonic somatic coelom mesoderm

Amniotic

Spaces in lateral mesoderm gut tube

D Pleural cavity

Right common cardinal vein

Pericardial cavity

Heart

Lung

Lung

Pericardial cavity

Heart

Pleuroperitoneal Membrane

Phrenic nerve

Pleuropericardial membrane (fibrous pericardium)

Intraembryonic somatic mesoderm

Visceral pericardium

Phrenic nerve

Pleuroperitoneal membrane

Pleuropericardial membrane (fibrous pericardium)

Intraembryonic somatic mesoderm

Body wall

Pleuroperitoneal membrane

Formation Various Coeloms

Dorsal mesentery of esophagus

Intraembryonic coelom (pleuroperitoneal canal)

Visceral pericardium

Dorsal mesentery of esophagus

Intraembryonic coelom (pleuroperitoneal canal)

Septum transversum

Figure 15-1. Formation and partitioning of the intraembryonic coelom (IC). (A-C) Cross-sections show various stages of IC formation while the embryo undergoes lateral folding. (D) This cross-section shows two folds of intraembryonic somatic mesoderm carrying the phrenic nerves and common cardinal veins. The two folds fuse in the midline (arrows) to form the pleuropericardial membrane. This separates the pericardial cavity (shaded) from die pleural cavity (shaded). (E) A cross-section of an embryo at week 5 showing the four components that fuse (arrows) to form the diaphragm, which closes off the intraembryonic coelom between the pleural and peritoneal cavities. The portions of the intraembryonic coelom that connect the pleural and pericardial cavities in the embryo are called the pleuroperitoneal canals (shaded). A = aorta; E = esophagus; JVC = inferior vena cava. (Adapted from Dudek RW, Fix JD: BRS Embryology, 2nd ed. Baltimore, Williams & Wilkins, 1998, pp 237-239.)

geal hiatal hernia renders the esophagogastric sphincter incompetent so that stomach contents reflux into the esophagus. The clinical sign in the newborn is vomiting (frequently projectile) when the infant is laid on its back after feeding.

B. Congenital diaphragmatic hernia (Figure 15-2) is a herniation of abdominal contents into the pleural cavity, caused by a failure of the pleuroperitoneal membrane to develop or fuse with the other components of the diaphragm. Ir is found most commonly on the left posterolateral side. The hernia is usually life threatening, because abdominal contents compress the lung buds and cause pulmonary hypoplasia. Clinical signs in the newborn consist of an unusually flat abdomen, breathlessness, and cyanosis.

Flat Abdomen

Figure 15-2. (A) A congenital diaphragmatic hernia. Note the defect in the diaphragm, which allows loops of intestine and a portion of the liver to enter the pleural cavity. There is attendant pulmonary hypoplasia. (B) Radiograph of a congenital diaphragmatic hernia. Note the loops of intestine within the pleural cavity as indicated by the bowel gas above and below the diaphragm and the mediastinal shift to the right. (C) Radiograph after surgical repair of a congenital diaphragmatic hernia. Note the bowel gas present only below the diaphragm and the mediastinal shift back to the midline. (A, From Gilbert-Bamess E: Potter's Atlas of Fetal and Infant Pathology. Sr Louis, CV Mosby, 1998, p 172. B and C. from Aladjen S, Vidyasagar D: Atlas of Perinatology. Philadelphia, WB Saunders, 1982, pp 295, 375.)

Figure 15-2. (A) A congenital diaphragmatic hernia. Note the defect in the diaphragm, which allows loops of intestine and a portion of the liver to enter the pleural cavity. There is attendant pulmonary hypoplasia. (B) Radiograph of a congenital diaphragmatic hernia. Note the loops of intestine within the pleural cavity as indicated by the bowel gas above and below the diaphragm and the mediastinal shift to the right. (C) Radiograph after surgical repair of a congenital diaphragmatic hernia. Note the bowel gas present only below the diaphragm and the mediastinal shift back to the midline. (A, From Gilbert-Bamess E: Potter's Atlas of Fetal and Infant Pathology. Sr Louis, CV Mosby, 1998, p 172. B and C. from Aladjen S, Vidyasagar D: Atlas of Perinatology. Philadelphia, WB Saunders, 1982, pp 295, 375.)

100 Hair Growth Tips

100 Hair Growth Tips

100 Hair Growth Tips EVERY Balding Person Should Know. This Report

Get My Free Ebook


Post a comment