Daniel Finkelstein Oscar M. Laudanno

Regurgitation is the arrival of the esophageal or gastric contents in the mouth, without being preceded by nausea or vomiting. It differs from vomiting by the absence of previous nausea, by the relatively small amount of material expelled, and by the lack of participation of the muscles involved in vomiting.

Physiology and pathophysiology

During swallowing, a complex pressure-playing mechanism acts between the hypopharynx, the esophagus itself, and the sphincters (upper and lo esophageal sphincters), which, together with the esophageal peristaltic waves, advance food to the stomach due to differences in pressure gradients. preventing regurgitation.

Primary peristaltic waves drive the bolus down; they start with swallowing in the upper third of the esophagus and have a central origin (under control of the central nervous system). Secondary waves originate locally in the esophagus, immediately above the bolus, as a result of distention. Once the secondary contraction has started, it progresses downwards in a similar way to the primary contraction, giving rise to waves of less amplitude than the latter. They are propulsive waves; First of all, gastroesophageal reflux occurs systematically, cleaning the esophageal mucosa and acting as anti-reflux waves.

The function of both the upper and lower esophageal sphincters is equivalent to a pressure barrier at each end of the esophagus. The superior esophageal or cricopharyngeal sphincter is made up of striated muscle and innervated from the nuclei of the vagus and ambiguous, by nerves IX, X and XI. The pressure at rest is 15 to 30 cm of water. The inhibitory mechanism for its relaxation is produced by the afferent stimulus that originates in the pharynx during swallowing. The lower esophageal or esophagogastric sphincter is purely physiological (Fig. 30-1). It receives innervation from the vagus and the sympathetic, which control its relaxation, all in relation to the Auerbach's myeneric plexus. Control of the lower esophageal sphincter is neural and hormonal. It remains contracted in a tonic way (in a state of rest),Tertiary waves are seen more frequently in older ages, and in certain disease states such as esophagitis and esophageal cancer. These are contractions that occur irregularly and are located mainly in the lower esophagus, segmental, not propulsive; They are waves of the esophageal tone, which when exaggerated appear as segmental contractions.

The most important anatomical and physiological substrate of regurgitation is hypotonia of the lower esophageal sphincter, although there are organic causes that do not occur with the aforementioned alteration.

Regurgitation causes

The causes of regurgitation lie in different pathologies of the esophagus (esophageal regurgitation) and in hypotonia of the lower esophageal sphincter (gastroesophageal regurgitation), which conditions regurgitation of gastric cause.

1. Esophageal regurgitation:
   • Stenosing esophagitis
   • Acalasia
   • Zenker's diverticulum
   • Esophageal cancer
2. Gastroesophageal regurgitation
   • Hiatal hernia, with hypotonia of the lower esophageal sphincter
   • Hypotonia of the lower esophageal sphincter itself:
     • In the infant
     • For food (fats, whole milk, chocolate, mint, alcohol)
     • By hormones (estrogens and progesterone, corticosteroids.

The regurgitation of esophageal cause takes place as a consequence of the organic narrowing, typical of the evolution of diseases such as esophageal cancer, stenosing esophagitis and achalasia. In achalasia of the lower esophageal sphincter, there is an increase in pressure of said sphincter (cardio-spasm), and absence of the primary and secondary waves of the esophagus, with dilation of the esophagus (megaesophagus).

Regurgitation of gastroesophageal causes accompanies a very frequent pathology in gastroenterology, hiatal hernia, which by itself does not condition reflux, but is associated with hypotonia of the lower esophageal sphincter. Regurgitation of milk in the infant is frequent and normal until four months of age, and attributable to hypotonia of the lower esophageal sphincter.

It is proven that there are a series of causes (toxic, hormonal, medicinal, food, etc.) that act directly by decreasing the pressure of the mentioned sphincter (see Causes of regurgitation).

Study methodology

To evaluate regurgitation, the following can be performed: a) a serial esophageal-gastroduodenal radiograph, in a ventral position and increasing intra-abdominal pressure, to detect the existence of a sliding hiatal hernia and facilitate gastroesophageal reflux; b) a manometry that records the hypotonia of the lower esophageal sphincter; c) a determination of the pH: in the esophagus the pH is normally alkaline, while in reflux esophagitis it is acidic, and d) an endoscopy, which detects the inflammatory characteristics of the esophageal mucosa and the presence or absence of a sliding hiatal hernia. .