What is esophageal motility?
Esophageal motility refers to contractions occurring in the esophagus, which propel the food bolus forward toward the stomach. When contractions in the esophagus become irregular, unsynchronized or absent, the patient is said to have esophageal dysmotility. The areas of dysfunction in the esophagus may be in the upper esophageal sphincter (UES), the body of the esophagus or the lower esophageal sphincter (LES).
Oropharyngeal and UES dysfunction may be caused by neurologic and neuromuscular diseases or may be of unknown cause. Oropharyngeal dysfunction may result from certain surgeries, such as tracheostomy, laryngectomy or cervical dissection.
There are primary idiopathic motor disorders that include achalasia, diffuse esophageal spasm, nutcracker esophagus, hypertensive LES and nonspecific esophageal motility disorders.
Reflux disease is associated with an LES that is not sufficiently tight allowing gastric acid to wash back into the esophagus. The contractions of the esophagus in patients with reflux are generally not abnormal, but with long-standing reflux disease, they may decrease in amplitude.
What are the causes of swallowing disorders?
There are a large number of disorders that cause swallowing problems. Among the more common are neurological or neuromuscular disorders that cause weakness of the pharynx, benign or malignant strictures, esophageal motor disorders including achalasia (in which the lower esophageal sphincter does not relax) and esophageal spasm (in which esophageal contractions become uncoordinated). Treatment depends on the type of disorder and its underlying cause.
How are swallowing disorders evaluated?
Evaluation usually begins with a barium study, either a barium esophagram or video study of both the pharynx and the esophagus. When symptoms are localized to the chest, a barium esophagram is sufficient and is usually performed as part of an upper gastrointestinal (UGI) series (a barium X-ray of the esophagus, stomach and beginning of the small intestine). When there is a question of pharyngeal dysfunction, a video study of both the pharynx and esophagus should be performed. Further evaluation depends on specific symptoms and radiographic findings. Direct visualization of the pharynx (pharyngoscopy), usually performed by an otolaryngologist, is appropriate when pharyngeal structural or motor dysfunction is found or suspected. Upper endoscopy, usually performed by gastroenterologists, is a procedure during which the esophagus is examined by a flexible telescope. It should be considered whenever there is a question of structural or inflammatory disorder of the esophagus. Esophageal manometry, during which a thin flexible catheter is passed either through the nose or mouth into the esophagus, is used to measure the strength and coordination of muscle function in the esophagus. A continuous pH monitor study (referred to as a 24-hour pH probe study) utilizes a thin acid sensitive catheter positioned in the esophagus to confirm the possibility of gastroesophageal reflux disease (GERD).
How is esophageal spasm treated?
Primary esophageal spasm is rarely life threatening, and the most important element in treatment is often reassurance. However when dysphagia or chest pain is frequent or severe, drugs that decrease smooth muscle contractility are often used. Unfortunately, in addition to lowering pressure in the esophagus, these medications also lower blood pressure. Recently it has been recognized that patients with chest pain presumed to be of esophageal origin are often unusually sensitive to esophageal stimulation. In this case, tricyclic antidepressant drugs have been effective in some patients. The effect of these drugs occurs at low doses and does not appear to relate to the presence or absence of depression. This suggests that the drugs may act on pain recognition rather than mood alteration.
How are esophageal strictures treated?
There are a variety of conditions that narrow the esophagus. Among the most common are webs and rings, which are thin bands of tissue that form a shelf-like constriction of the esophagus. Inflammatory strictures are a product of esophageal wall thickening resulting from a combination of active inflammation and subsequent scarring. Strictures may also result from malignant tumors involving the esophagus.
Strictures may cause difficulty in swallowing solid foods. Tougher cuts of meat, stringy vegetables and doughy foods such as breads or pasta may increase the severity of symptoms. To best manage symptoms, it is important to cut food into small pieces, adequately chew before swallowing and eat slowly. A varied menu should be sought when dining out. Appropriate food selection and careful attention to cutting and chewing will decrease the frequency and severity of symptoms.
Simple dilation (stretching), performed during upper endoscopy, provides prompt and often sustained relief of symptoms from rings or webs. Recurrent symptoms generally respond to repeat dilations or placement of an esophageal stent. Strictures also respond to dilation but are likely to recur fairly rapidly unless the cause of inflammation is controlled. Re-stricturing may continue even after the underlying process is recognized and removed due to ongoing scar formation. However, over time, the rate of re-stricturing and the accompanying need for dilation should decrease. Malignant strictures are best managed surgically. When this is not possible, radiation therapy, laser therapy and stent placement (a rigid tube that holds the channel open) are among the therapeutic approaches.
What is achalasia and how is it treated?
Achalasia is a condition in which the nerves in the esophageal wall have been damaged. The cause of this injury is unknown, but its effects are well recognized. With this condition, the esophagus is unable to contract in a coordinated manner and the lower esophageal sphincter does not relax with swallowing. This results in food remaining in the esophagus above a closed sphincter segment. Treatment is directed toward weakening the sphincter muscle, after which food will empty by gravity. Routine dilation, such as that used for strictures (see above) is usually ineffective. Effective treatments include dilation with a large size balloon dilator, botulinum toxin (Botox) injection in the lower esophageal sphincter or surgical myotomy (a procedure in which the LES is cut). The best approach depends upon the situation, local expertise and the patient's personal preference. The choice should be made after a consultation in which these factors can be considered and discussed.
What is the treatment for esophageal dysmotility?
Achalasia may be treated with drugs that relax smooth muscle and prevent spasm, such as isosorbide dinitrate or nifedipine. Pneumatic dilation is a procedure that dilates the LES with a high-pressure balloon. This is usually undertaken in conjunction with endoscopy under fluoroscopy. The surgical procedure that is performed for this is called a myotomy with or without the anti-reflux procedure. During the surgery, the LES is incised and the anti-reflux procedure wraps the top portion of the stomach around the bottom of the esophagus to tighten it enough so that gastric content cannot reflux. Botulinum toxin (Botox) is a new treatment modality being used for achalasia. Very small doses of this poison are injected into the LES, which causes the muscle to relax. Ongoing studies are being conducted to determine its efficacy.
Diffuse esophageal spasm is treated with smooth muscle relaxants or surgically with a long myotomy with or without the anti-reflux procedure.
Patients with nonspecific esophageal motility disorders are usually evaluated for severe gastroesophageal reflux and treatment for gastroesophageal reflux disease (GERD) is instituted.