(Cardiospasm; Esophageal Aperistalsis; Megaesophagus)
(See also Overview of Esophageal and Swallowing Disorders.)
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, 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 elderly 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 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.
If esophagoscopy is done, there is esophageal dilation but no obstructing lesion, and a classic "pop" is often felt when the esophagoscope passes into the stomach. Rarely, these findings can result from a tumor; endoscopic ultrasonography with biopsies can be considered to rule out cancer.
Achalasia must be differentiated from a distal stenosing carcinoma and a peptic stricture, particularly in patients with systemic sclerosis, in whom esophageal manometry may also show aperistalsis. Systemic sclerosis is usually accompanied by a history of Raynaud phenomenon and symptoms of gastroesophageal reflux disease (GERD) due to low or absent LES pressure.
Achalasia due to cancer at the gastroesophageal junction can be diagnosed by CT of the chest and abdomen or by endoscopic ultrasound with biopsy.
Pulmonary aspiration and the presence of cancer are the determining prognostic factors. Nocturnal regurgitation and coughing suggest aspiration. Pulmonary complications secondary to aspiration are difficult to manage. Incidence of esophageal cancer in patients with achalasia may be increased; this point is controversial.
No therapy restores peristalsis; treatment of achalasia is aimed at reducing the pressure at the LES.
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). 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 (2). Other current studies have shown peroral endoscopic myotomy to have good short-term and long-term outcomes (3). Thus, choice between these three procedures depends on the operator and the particular type of achalasia.
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, but results may last only 6 months to 1 year.
Reducing pressure at the LES can increase the occurrence of GERD. The incidence varies depending on which type of treatment is done. On average, it is estimated that about 20% of patients have postprocedural GERD.
Drugs such as nitrates (eg, isosorbide dinitrate 5 to 10 mg sublingually before meals) or calcium channel blockers (eg, nifedipine 10 to 30 mg orally 30 to 45 minutes before a meal) may be tried. These drugs are of limited effectiveness but may reduce LES pressure enough to prolong the time between dilations.
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. 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.
3. 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.