(See also Overview of Esophageal and Swallowing Disorders Overview of Esophageal and Swallowing Disorders The swallowing apparatus consists of the pharynx, upper esophageal (cricopharyngeal) sphincter, the body of the esophagus, and the lower esophageal sphincter (LES). The upper third of the esophagus... read more .)
Achalasia is thought to be caused by a loss of ganglion cells in the myenteric plexus of the esophagus, resulting in denervation of esophageal muscle. Etiology of the denervation is unknown, but viral and autoimmune causes are suspected, and certain tumors may cause achalasia either by direct obstruction or as a paraneoplastic process. Chagas disease Chagas Disease Chagas disease is infection with Trypanosoma cruzi, transmitted by Triatominae bug bites or, less commonly, via ingestion of sugar cane juice or foods contaminated with infected Triatominae... read more , which causes destruction of autonomic ganglia, may result in achalasia.
Increased pressure at the lower esophageal sphincter (LES) causes obstruction with secondary dilation of the esophagus. Esophageal retention of undigested food and liquid is common.
Achalasia occurs at any age but usually begins between ages 20 and 60. Onset is insidious, and progression is gradual over months or years. Dysphagia for both solids and liquids is the major symptom. Nocturnal regurgitation of undigested food occurs in about 33% of patients and may cause cough and pulmonary aspiration. Chest pain is less common but may occur on swallowing or spontaneously. Mild to moderate weight loss occurs; when weight loss is pronounced, particularly in older patients whose symptoms of dysphagia developed rapidly, achalasia secondary to a tumor of the gastroesophageal junction should be considered.
(See also the American College of Gastroenterology’s practice guidelines on the diagnosis and management of achalasia.)
Esophageal manometry Manometry Manometry is measurement of pressure within various parts of the gastrointestinal tract. It is done by passing a catheter containing solid-state or liquid-filled pressure transducers through... read more is the preferred diagnostic test for achalasia. This test shows incomplete relaxation of the LES with a median integrated relaxation pressure ≥ 15, and 100% failed peristalsis.
Barium swallow is a complementary test that is often done during the initial phase of testing and that may show absence of progressive peristaltic contractions during swallowing. Typically, the esophagus is dilated, often enormously, but is narrowed and beaklike at the LES.
Esophagoscopy is often done. Findings include upstream esophageal dilation and chronic stasis changes in the mucosa but no obstructing lesion. A classic "pop" is often felt when the esophagoscope passes into the stomach.
Achalasia must be differentiated from a peptic stricture, particularly in patients with systemic sclerosis Systemic Sclerosis Systemic sclerosis is a rare chronic disease of unknown cause characterized by diffuse fibrosis and vascular abnormalities in the skin, joints, and internal organs (especially the esophagus... read more , in whom esophageal manometry may also show aperistalsis. Systemic sclerosis is usually accompanied by a history of Raynaud phenomenon Raynaud Syndrome Raynaud syndrome is vasospasm of parts of the hand in response to cold or emotional stress, causing reversible discomfort and color changes (pallor, cyanosis, erythema, or a combination) in... read more and symptoms of gastroesophageal reflux disease Gastroesophageal Reflux Disease (GERD) Incompetence of the lower esophageal sphincter allows reflux of gastric contents into the esophagus, causing burning pain. Prolonged reflux may lead to esophagitis, stricture, and rarely metaplasia... read more (GERD) due to low LES pressure.
Symptoms similar to those of achalasia (ie, pseudoachalasia) may be due to cancer at the gastroesophageal junction, which can be diagnosed by CT of the chest and abdomen or by endoscopic ultrasound with biopsy.
Esophageal dilation and tortuosity are poor prognostic indicators. Pulmonary aspiration is a late-stage complication. Nocturnal regurgitation and coughing suggest aspiration. Pulmonary complications secondary to aspiration are difficult to manage. Incidence of esophageal cancer in patients with achalasia is not currently thought to be increased.
No therapy restores peristalsis; treatment of achalasia is aimed at reducing the pressure at the LES.
Pneumatic balloon dilation of the LES and surgical or peroral endoscopic myotomy appear similarly effective. In 2016, a randomized, controlled trial involving achalasia patients found that at 5-year follow-up pneumatic balloon dilation had comparable efficacy to laparoscopic Heller myotomy (1 Treatment references Achalasia is a neurogenic esophageal motility disorder characterized by impaired esophageal peristalsis and a lack of lower esophageal sphincter relaxation during swallowing. Symptoms are slowly... read more ). A posthoc analysis of these data according to achalasia subtypes found better results with pneumatic balloon dilation for patients with type II achalasia (swallowing increases pressure in the entire esophagus) and better results with Heller myotomy for type III achalasia (spastic achalasia; swallowing often results in lumen-obliterating contractions). Both procedures produced similar outcomes in patients with type I achalasia (classic achalasia; swallowing results in no change in esophageal pressure) (1 Treatment references Achalasia is a neurogenic esophageal motility disorder characterized by impaired esophageal peristalsis and a lack of lower esophageal sphincter relaxation during swallowing. Symptoms are slowly... read more , 2 Treatment references Achalasia is a neurogenic esophageal motility disorder characterized by impaired esophageal peristalsis and a lack of lower esophageal sphincter relaxation during swallowing. Symptoms are slowly... read more ). The most concerning complication of these procedures is esophageal perforation. Perforation rates vary by center, ranging from 0 to 14% for pneumatic balloon dilation and 0 to 4.6% for laparoscopic Heller myotomy (3 Treatment references Achalasia is a neurogenic esophageal motility disorder characterized by impaired esophageal peristalsis and a lack of lower esophageal sphincter relaxation during swallowing. Symptoms are slowly... read more ). Other current studies have shown peroral endoscopic myotomy to have good short-term and long-term outcomes (4 Treatment references Achalasia is a neurogenic esophageal motility disorder characterized by impaired esophageal peristalsis and a lack of lower esophageal sphincter relaxation during swallowing. Symptoms are slowly... read more ). However, postprocedure gastroesophageal reflux disease rates are higher in patients who undergo peroral endoscopic myotomy than in those who undergo Heller myotomy. Thus, the ideal treatment option is based on achalasia subtype, procedure risk, and potential adverse effects.
In patients who are not candidates for these treatment options, chemical denervation of cholinergic nerves in the distal esophagus by direct endoscopic injection of botulinum toxin type A into the LES may be tried. Clinical improvement occurs in 70 to 80% of patients; results may last 6 months to over 1 year.
Drugs such as nitrates or calcium channel blockers have been used in the past but have not been shown to be effective.
1. Moonen A, Annese V, Belmans A, et al: Long-term results of the European achalasia trial: A multicentre randomised controlled trial comparing pneumatic dilation versus laparoscopic Heller myotomy. Gut 65(5):732–739, 2016. doi: 10.1136/gutjnl-2015-310602
2. Pandolfino JE, Kwiatek MA, Nealis T, et al: Achalasia: A new clinically relevant classification by high-resolution manometry. Gastroenterology 135(5):1526–1533, 2008. doi: 10.1053/j.gastro.2008.07.022
3. Lynch KL, Pandolfino JE, Howden CW, et al: Major complications of pneumatic dilation and Heller myotomy for achalasia: Single-center experience and systematic review of the literature. Am J Gastroenterol 107(12):1817–1825, 2012. doi: 10.1038/ajg.2012.332
4. Rentein DV, Fuchs K-H, Fockens P, et al: Peroral endoscopic myotomy for the treatment of achalasia: An international prospective multicenter study. Gastroenterology 145(2):272–273, 2013. doi: 10.1053/j.gastro.2013.04.057
A viral- or autoimmune-induced loss of ganglion cells in the myenteric plexus of the esophagus decreases esophageal peristalsis and impairs relaxation of the lower esophageal sphincter (LES).
Patients gradually develop dysphagia for both solids and liquids, and about one third regurgitate undigested food at night.
Esophageal manometry is the preferred test for achalasia and shows an elevated integrated relaxation pressure in conjunction with 100% failed peristalsis.
Barium swallow shows absence of progressive peristaltic contractions during swallowing and a markedly dilated esophagus with beaklike narrowing at the LES.
No therapy restores peristalsis; treatment aims to reduce the pressure (and thus the obstruction) at the LES.
Treatment is typically pneumatic balloon dilation or myotomy of the LES; patients who are not candidates for these treatments may be given botulinum toxin type A injections.
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
American College of Gastroenterology: Practice guidelines on the diagnosis and management of achalasia