diaphragmatocele

diaphragmatic hernia protrusion of some of the contents of the abdomen through an opening in the diaphragm and into the chest cavity. The condition may be congenital or acquired.

Congenital diaphragmatic hernia in newborns is due to failure of the embryonic diaphragm to fuse. The opening in the diaphragm can be large enough to permit filling of the thoracic cavity with abdominal contents, thus interfering with normal expansion of the lungs. This produces respiratory distress, which is the outstanding feature of neonatal diaphragmatic hernia. hypoxia results from persistent fetal circulation that produces a right-to-left shunting via the foramen ovale and patent ductus arteriosus. The severity of symptoms and age of onset depend on the extent of hypoplasia of the lungs and the degree of interference with ventilation. The condition constitutes a surgical emergency. Without immediate and successful intervention the neonate is likely to succumb to rapid and progressive respiratory failure.

At the moment of birth the neonate with this condition will show some degree of respiratory distress. The abdomen may appear sunken and the anterior-posterior chest diameter enlarged. Because the position of the heart can be shifted by the herniating organs, heart sounds are often heard on the side opposite the hernia, and bowel sounds may be heard in the chest cavity. A simple x-ray of the chest and abdomen will demonstrate loops of bowel in the chest, with the mediastinum shifted toward the contralateral side.

Surgical repair of the hernia and restoration of internal organs to their rightful place should be done as soon as possible. Before surgery the neonate is stabilized without delay. Nasogastric decompression is begun; intubation and assisted ventilation with supplemental oxygen may be necessary.

Postoperatively, the infant may remain extremely critical; at times extracorporeal membrane oxygenation will be necessary until the persistent fetal circulation resolves. It has been found that the survival rate for these neonates is greatly improved if they are cared for in an environment that is quiet, soothing, and as nonstressful as possible considering the intensive monitoring and care they must have.

Diaphragmatic hernia in the adult usually is a sliding type of hiatal hernia; that is, a part of the stomach slides upward into the thoracic cavity, following the normal path of the esophagus through an enlarged hiatal opening in the diaphragm. Causes include congenital weakness of the structures, trauma, relaxation of ligaments and skeletal muscles, or increased upward pressure from the abdomen. It is most often found in persons of middle age or older.

Small sliding hiatal hernias are found in the majority of persons undergoing an upper gastrointestinal series. Most are asymptomatic and do not require treatment. Those causing symptoms do so because of inflammation of the esophageal lining resulting from gastroesophageal reflux. Typically, the symptoms occur after a full meal and include heartburn and indigestion. Large sliding hernias can cause intermittent abdominal and chest pain, difficult breathing, and cardiovascular symptoms. If the herniated portion of the stomach becomes incarcerated or is perforated, there is sudden sharp pain under the sternum and symptoms of obstruction. Although this rarely occurs, it is a surgical emergency.

The preferred treatment consists of small meals of bland, easily digested food, moderate exercise, and sleeping with the upper part of the body in a raised position. Surgical repair involves invasion of the abdominal and thoracic cavities and is reserved for severe cases that cannot be managed medically.

Bochdalek's hernia congenital posterolateral diaphragmatic hernia, with extrusion of bowel and other abdominal viscera into the thorax; due to failure of closure of the pleuroperitoneal hiatus.

cerebral hernia (hernia ce´rebri) protrusion of brain substance through a defect in the skull.

crural hernia femoral hernia.

diaphragmatic hernia see diaphragmatic hernia.

fat hernia hernial protrusion of peritoneal fat through the abdominal wall.

femoral hernia protrusion of a loop of intestine into the femoral canal, a tubular passageway that carries nerves and blood vessels to the thigh; this type occurs more often in women than in men. Called also crural hernia and femorocele.

hiatal hernia (hiatus hernia) protrusion of a structure, often a portion of the stomach, through the esophageal hiatus of the diaphragm; see diaphragmatic hernia.

Holthouse's hernia an inguinal hernia that has turned outward into the groin.

incarcerated hernia a hernia so occluded that it cannot be returned by manipulation; it may or may not become strangulated. Called also irreducible hernia.

incisional hernia hernia after operation at the site of the surgical incision, owing to improper healing or to excessive strain on the healing tissue; such strain may be caused by excessive muscular effort, such as that involved in lifting or severe coughing, or by obesity, which creates additional pressure on the weakened area.

inguinal hernia hernia occurring in the groin, or inguen, where the abdominal folds of flesh meet the thighs. It is often the result of increased pressure within the abdomen, whether due to lifting, coughing, straining, or accident. Inguinal hernia accounts for about 75 per cent of all hernias.

A sac formed from the peritoneum and containing a portion of the intestine or omentum, or both, pushes either directly outward through the weakest point in the abdominal wall (direct hernia) or downward at an angle into the inguinal canal (indirect hernia). Indirect inguinal hernia (the common form) occurs more often in males because it follows the tract that develops when the testes descend into the scrotum before birth, and the hernia itself may descend into the scrotum. In the female, the hernia follows the course of the round ligament of the uterus.

Inguinal hernia begins usually as a small breakthrough. It may be hardly noticeable, appearing as a soft lump under the skin, no larger than a marble, and there may be little pain. As time passes, the pressure of the contents of the abdomen against the weak abdominal wall may increase the size of the opening and, accordingly, the size of the lump formed by the hernia. In the early stages, an inguinal hernia is usually reducible—it can be pushed gently back into its normal place. Inguinal hernia usually requires herniorrhaphy.

intra-abdominal hernia (intraperitoneal hernia) a congenital anomaly of intestinal positioning, occurring within the abdomen, in which a portion of bowel protrudes through a defect in the peritoneum or, as a result of abnormal rotation of the intestine during embryonic development, becomes trapped in a sac of peritoneum.

irreducible hernia incarcerated hernia.

mesocolic hernia an intra-abdominal hernia in which the small intestine rotates incompletely during development and becomes trapped within the mesentery of the colon.

Morgagni's hernia congenital retrosternal diaphragmatic hernia, with extrusion of tissue into the thorax through the foramen of Morgagni.

paraesophageal hernia hiatal hernia in which part or almost all of the stomach protrudes through the hiatus into the thorax to the left of the esophagus, with the gastroesophageal junction remaining in place.

posterior vaginal hernia downward protrusion of the pouch of Douglas, with its intestinal contents, between the posterior vaginal wall and the rectum; called also enterocele. See illustration.

reducible hernia one that can be returned by manipulation.

Richter's hernia incarcerated or strangulated hernia in which only a portion of the circumference of the bowel wall is involved.

rolling hernia paraesophageal hernia.

scrotal hernia an inguinal hernia that has passed into the scrotum.

sliding hernia hernia of the cecum (on the right) or the sigmoid colon (on the left) in which the wall of the viscus forms a portion of the hernial sac, the remainder of the sac being formed by the parietal peritoneum.

sliding hiatal hernia the most common type of diaphragmatic hernia; a hiatal hernia in which the upper stomach and the cardioesophageal junction protrude upward into the posterior mediastinum. The protrusion, which may be fixed or intermittent, is partially covered by a peritoneal sac.

slip hernia (slipped hernia) sliding hernia.

strangulated hernia one that is tightly constricted. As any hernia progresses and bulges out through the weak point in its containing wall, the opening in the wall tends to close behind it, forming a narrow neck. If the neck becomes pinched tight enough to cut off the blood supply, the hernia will quickly swell and become strangulated. This is a very dangerous condition that can appear suddenly and requires immediate surgical attention. Unless the blood supply is restored promptly, gangrene can set in and may cause death. If a hernia suddenly grows larger, becomes tense, and will not go back into place, and there is pain and nausea, it is strangulated. Occasionally, especially in the elderly, hernia strangulation may occur without pain or tenderness.

umbilical hernia see umbilical hernia.

vaginal hernia hernia into the vagina; called also colpocele.