Gastroenterology · Esophageal Motility Disorders
The facts most likely to be tested
Press 1–5 to rate · ↑↓ to navigate
Achalasia is caused by the degeneration of inhibitory ganglion cells in the myenteric (Auerbach) plexus, leading to loss of peristalsis and impaired relaxation of the lower esophageal sphincter (LES).
The gold standard for diagnosis is esophageal manometry, which demonstrates aperistalsis in the distal esophagus and incomplete LES relaxation.
Barium swallow imaging classically reveals a bird’s beak appearance due to the tapering of the distal esophagus at the non-relaxing LES.
Patients typically present with progressive dysphagia to both solids and liquids and may report regurgitation of undigested food.
Chest X-ray may show an absent gastric bubble or a widened mediastinum with an air-fluid level in the esophagus.
Pneumatic dilation, Heller myotomy, and peroral endoscopic myotomy (POEM) are the primary definitive treatments for patients who are surgical candidates, with POEM preferred in type III (spastic) achalasia.
Achalasia is a pre-malignant condition that increases the long-term risk of developing esophageal squamous cell carcinoma.
Vignette unlocked
A 45-year-old male presents with a 6-month history of progressive dysphagia to both solids and liquids. He reports frequent regurgitation of undigested food and occasional nocturnal coughing. Physical examination is unremarkable, but a barium swallow study reveals a bird’s beak appearance of the distal esophagus. The patient has no history of tobacco or alcohol use.
What is the most accurate diagnostic test to confirm the suspected diagnosis?
Esophageal manometry
The clinical presentation and barium swallow findings are classic for achalasia; esophageal manometry is the gold standard diagnostic test to confirm the diagnosis by demonstrating aperistalsis and impaired LES relaxation.
Full handout
High yield triage
Etiology / Epidemiology
Idiopathic degeneration of Auerbach's plexus (myenteric plexus) leading to loss of inhibitory neurons.
Clinical Manifestations
Progressive dysphagia to solids AND liquids; bird's beak appearance on imaging.
Diagnosis
Esophageal manometry is the gold standard showing incomplete LES relaxation.
Treatment
Pneumatic dilation, Heller myotomy, or POEM; botulinum toxin for high-risk surgical candidates.
Prognosis
Increased risk of squamous cell carcinoma; however, the ACG guideline recommends against routine endoscopic surveillance, as it has not been shown to improve survival.
Full handout
Epidemiology & Etiology
Typically presents in adults aged 30-60 years. Primary achalasia results from autoimmune-mediated destruction of inhibitory ganglion cells. Secondary causes include Chagas disease (Trypanosoma cruzi) or pseudoachalasia from malignancy.
Pertinent Anatomy
The pathology centers on the lower esophageal sphincter (LES) and the esophageal body. Loss of inhibitory neurotransmitters (nitric oxide/VIP) prevents the LES from relaxing during swallowing.
Pathophysiology
Degeneration of the myenteric plexus results in aperistalsis of the esophageal body and failure of the LES to relax. This creates a functional obstruction, leading to proximal esophageal dilation and food stasis.
Clinical Manifestations
Patients report dysphagia to both solids and liquids simultaneously. Regurgitation of undigested food is common, often occurring at night. Weight loss and aspiration pneumonia are significant red flags. The classic bird's beak appearance is seen on barium swallow.
Diagnosis
Esophageal manometry is the gold standard, demonstrating aperistalsis and incomplete LES relaxation. Barium swallow shows the classic bird's beak tapering of the distal esophagus. Endoscopy is mandatory to rule out pseudoachalasia (malignancy).
Treatment
Definitive treatment is Heller myotomy, pneumatic dilation, or peroral endoscopic myotomy (POEM), which the ACG guideline considers comparable to pneumatic dilation and preferred for type III achalasia. Botulinum toxin injection is reserved for patients who are poor candidates for these definitive therapies. Pharmacotherapy with nitrates or calcium channel blockers is less effective and rarely used as first-line.
Prognosis
Patients have a significantly increased risk of squamous cell carcinoma of the esophagus. However, the ACG guideline recommends against routine endoscopic surveillance, as it has not been shown to improve survival; endoscopy is performed to evaluate new or recurrent symptoms.
Differential Diagnosis
GERD: usually presents with heartburn, not dysphagia to liquids
Esophageal cancer: presents with progressive dysphagia to solids first, then liquids
Diffuse esophageal spasm: presents with chest pain and 'corkscrew' esophagus
Scleroderma: LES pressure is low, not high
Pseudoachalasia: malignancy mimicking achalasia, usually in older patients with rapid weight loss