Gastroesophageal Reflux Disease
Reflux disease is not caused by gastritis as commonly believed. The lower esophageal sphincter (LES) is the end of the esophagus at its junction with the stomach, but has no notable features anatomically, functionally, is responsible for maintaining the esophageal pressure at that level, greater than intragastric pressure, preventing passage of gastric contents in reverse.
GERD occurs when the LES does not close properly and stomach contents from leaking or refluxes, into the esophagus.
The burning and heartburn are common symptoms, but not necessarily signify the existence of GERD. Only when these symptoms are repetitive may be considered GERD. Anyone, including infants, children and pregnant women, may present it.
After a meal, the LES remains usually closed. When you relax, allowing acid particles and / or food reflux into the esophagus. In patients with GERD, experimentally induced gastric distension increases the number of transient LES relaxations, which are the main cause of reflux episodes. To the extent that the number of transient relaxations of the LES increases, the frequency of reflux episodes increased, so that the cumulative time of contact with the acidic material increases esophageal mucosa.
Another factor that increases the time of esophageal acid exposure in patients with GERD is ineffective esophageal peristalsis. Although peristalsis occurs, the wave generated is inefficient due to the decreased amplitude of secondary peristaltic waves.
Patients with reflux disease often experience many episodes of reflux of short duration and / or more prolonged episodes where the acid in the esophagus can stay for up to several hours.
Although the duration of esophageal acid exposure correlates with the frequency of symptoms and the extent and severity of mucosal injury of the esophagus, the degree of esophageal mucosal damage can increase markedly if the luminal pH is less than 2, or pepsin or conjugated bile salts are present in the reflux.
Histopathological lesions associated with GERD include erythema, erosions isolated confluent erosions, circumferential erosions, deep ulcers, the replacement of normal esophageal epithelium with intestinal epithelium (Barrett's esophagus).
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