Achalasia is defined by the following important elements:
- Hypertonic lower esophageal sphincter;
- Absence of lower esophageal sphincter relaxation to swallowing;
- Absence of peristaltic waves in two thirds of the lower esophagus.
In conclusion, the lower esophageal sphincter relaxation dose not occur during swallowing.
Etiopathogenesis is not well known. It incriminate genetic factors, such as the existence of a genetic predisposition, environmental factors, such as infection with certain viruses, the role of emotions and stress in triggering the disease.
Pathological studies have shown an impairment of the nervous control of motility of the esophagus, and esophageal muscles.
The hypothesis of involvement of a virus that secrete a neurotoxin that affects vague nerve is supported by the existence of secondary achalasia in Chagas disease (infestation with Tripanosoma Cruzi), the parasite produces nerve damage that causes the appearance of mega-esophagus.
The clinical picture is dominated by dysphagia or odynophagia (pain on swallowing). Sometimes swallowing may be paradoxical, difficulty in swallowing liquids, but with good tolerance of solid food. Hiccups may occur late when is an important esophageal dilatation.
Regurgitation of food and saliva is quite common, occurring in several hours after fasting, but over time, by dilation of the esophagus, regurgitation will diminish. At night, regurgitation can cause coughing and dyspnea.
In advanced stages, patients typically take a position (position of Valsalva), which increases their intrathoracic pressure and ease the transition of the bowel towards to the stomach.
Suspected clinical diagnosis will be confirmed by endoscopy and radiology.
Endoscopy will show a dilated esophagus with food debris and abundant saliva, but without mucosal injury.
Barium-swallow examination of the esophagus is useful and valuable because it shows a more dilated esophagus, which narrows in the lower portion symmetrically, with an aspect of radish. Tracking swallowing, will reveal a absence of esophageal peristaltic and lack of esophageal sphincter relaxation.
Treatment is often difficult and consists of three alternatives:
- Drugs that decrease lower esophageal sphincter pressure, such as nitrates, calcium channel blockers, miofilin, theophylline, anticholinergics. It is administered one or two drugs a day, in the first stages of the disease can be effective;
- Endoscopic. Consist in expansion technique of the lower esophageal sphincter with inflatable balloon under floroscopic control. It can be used endoscopic injection in the lower esophageal sphincter of botulinum inactivated toxoid, which makes a temporary paralysis of the sphincter. The effect is for several months and after that, the injection can be repeated;
- Surgery. It is rarely indicated in cases where other techniques have failed and consists of Heller cardiomyotomy of the lower esophageal sphincter (longitudinal section of the circular fibers). Ultimately predispose to gastroesophageal reflux disease.