Hiatal hernia is an anatomical defect wherein there is a weakening of the muscle of the diaphragm, causing some parts of the esophagus and/or stomach to pass through. The abnormal protrusion of the digestive organs within the said thoracic muscle causes a lot of symptoms that causes discomfort. There are three main types of hiatal hernia, namely; 1. Sliding hernia (most common) which accounts for nearly 90% of all cases, 2. Paraesophageal or rolling hernia, and 3. Mixed hernia. Sliding hernia is characterized by the slipping of both the stomach and gastroesophageal junction into the chest. Paraesophageal hernia on the other hand is the protrusion of the greater curvature of the stomach through the diaphragmatic defect. Mixed hernia resembles both the sliding and rolling hernia.
NORMAL ANTOMY AND PHYSIOLOGY
The esophagus is a 25 cm long collapsible tube that extends from the pharynx to the stomach. This digestive organ normally passes through the esophageal hiatus. On the lower end of the esophagus, there is a sphincter, a muscular structure which regulates the movement of masticated food to the stomach. It has an automatic response wherein it relaxes to allow the food to pass through and constricts after to prevent the backflow of gastric materials.
The stomach is a J-shaped pouch-like organ that is about 25-30 cm long. This hangs uner the diaphragm in the upper portion of the abdominal cavity. It can hold up to more than 1 liter of ingested materials. Its primary function is to mix masticated foods with gastric acids while it does the most of the digestive process.
Usually, hiatal hernia occurs with advanced age. This coincides with the wear-and-tear process, causing muscle weakness in almost all parts of the body, including the diaphragm. Congenital abnormality is also one of the leading causes of this problem. High abdominal pressure from pregnancy, constipation, ascites, and obesity also constitutes the development of hiatal hernia.