Hiatal / Paraesophageal Hernia
Hiatal hernias occur due to a loss of tension at the point where the esophagus enters the abdomen and becomes the stomach (phrenoesophageal membrane). This allows the gastroesophageal junction (GEJ) to migrate superiorly into the chest. Hiatal hernias occur in four types: Type I (sliding hernia; most common), Type II (GEJ remains in abdomen but top segment of stomach herniates into the chest), Type III (contains both GEJ and stomach in the chest) and Type IV (other abdominal organs herniating into the chest). Hiatal hernia types II through IV are also referred to as paraesophageal hernias.