Diaphragmatic Hernias

by Allison Zwingenberger on April 18, 2007

What Are The Different Types Of Diaphragmatic Hernias?


Here is another great question from the sophomore class about the different types of diapragmatic hernias.
Hiatal hernia



A Hiatal hernia happens when the cardia and fundus of the stomach pass cranially though the esophageal hiatus in the diaphragm. The herniated stomach is in the caudal mediastinum, and the lower esophageal sphincter is located cranial to it. Sometimes an esophagram can highlight the area of the lower esophageal sphincter, and outline rugal folds within the caudal mediastinum.
Paraesophageal hernia



A paraesophageal hernia occurs when the stomach herniates through the diaphragm beside the esophagus. This can happen inside or outside of the mediastinum. A contrast study is necessary to outline the position of the stomach.
True diaphragmatic hernia



A true diaphragmatic hernia is a congenital defect in the diaphragm that is still covered by the peritoneum. These are very rare, and tend to look like an abnormal bulge or asymmetry of the diaphragmatic contour.
Peritoneal pericardial diaphragmatic hernia



One more type of hernia that you will hear about is a peritoneal-pericardial diaphragmatic hernia, or PPDH for short. These are also congenital, and result from a failure of some of the parts of the diaphragm during development. This leaves an opening between the peritoneum and the pericardial sac in the mediastinum, and abdominal contents such as the liver, intestines, omentum etc. can become trapped there. On radiographs, the heart has the same globoid shape as a pericardial effusion, and you may be able to see gas in some bowel loops. This anomaly occurs most often in cats, and they may also have fewer sternebrae than usual (normally , or an abnormally shaped sternum, because of the same developmental defect.
Traumatic diaphragmatic rupture



A traumatic diaphragmatic hernia is more properly known as a diaphragmatic rupture. The opening between the peritoneal and pleural surfaces is not a congenital opening, but an actual tear in the muscle. This is the type we see most often after animals are hit by a car, or suffer other trauma. The contour of the diaphragm is not visible, or is interrupted, and there is increased soft tissue opacity (+/- recognizable abdominal organs) in the pleural space. Pleural effusion often goes along with this injury, and the abdomen can appear empty.





How to tell what kind of hernia you are looking at: