Hiatal hernia

Hiatal hernia is a condition in which elements of the abdominal cavity (most commonly the stomach) herniate through the esophageal hiatus into the mediastinum. Four types of hernias are described. Type I or sliding hernia is the most common. It consists of an anatomic disruption of the esophagogastric junction associated with a widening of the diaphragmatic hiatus and axial displacement separation of the lower esophageal sphincter and crural diaphragm. Type II, III and IV are ‘paraesophageal’ hernias resulting from a localized defect in the phrenoesophageal membrane. Age and obesity are factors associated with sliding hernia occurrence. A sliding hernia may be an intermittent phenomenon, especially when small, and may be an equivocal finding. Barium contrast radiography and endoscopy provide an anatomic description of the condition while high resolution esophageal manometry depicts a more physiological assessment. Thus, two high pressure zones are identified in sliding hiatal hernia: the lower esophageal sphincter and the crural diaphragm. Clinical presentation ranges from the absence of symptoms, to reflux, dysphagia, or chronic anemia.