Achalasia

Achalasia

Yaiel G. Rodríguez-Avilés, MD

Table of Contents

Definition
Pathogenesis and Causes
Clinical Presentation
Diagnosis
Classification/Types
Treatment

See Also:
*See Esophageal Motility Disorders
*See Esophagogastric Junction Outflow Obstruction (EGJOO)
*See Esophageal Disorders of Peristalsis

Definition

Definition: Primary Esophageal Motility Disorder Characterized by Impaired Relaxation of the Esophagogastric Junction (EGJ) and Absent Peristalsis

Epidemiology

  • Incidence: Approximately 1.6 per 100,000 Annually
  • Most Commonly Diagnosed Between Ages 25-60
  • Affects Males and Females Equally

Pathogenesis and Causes

Pathogenesis

  • Selective Loss or Dysfunction of Inhibitory Myenteric (Auerbach) Plexus Neurons in the Distal Esophagus and Lower Esophageal Sphincter (LES)
    • Produces an Imbalance Between Excitatory and Inhibitory Input
    • Results in Failure of LES Relaxation and Loss of Esophageal Peristalsis
  • In Later Stages of the Disease, the Distal Obstruction and Retention of Food and Secretions Can Lead to Esophageal Dilation and Compensatory Remodeling of the Esophageal Wall

Causes

  • Primary Achalasia
    • Most Cases are Idiopathic
    • Proposed Mechanisms:
      • Genetic Susceptibility (e.g., Alstrom Syndrome, Down Syndrome)
      • Viral Trigger (e.g., HSV-1, HPV, Measles)
      • Immune-Mediated Destruction of Inhibitory Neurons
  • Secondary Achalasia/Achalasia-Like Disorders
    • Pseudoachalasia
      • Most Commonly Caused by Malignancy at the EGJ or Gastric Cardia
      • May Result from Direct Neural Invasion or Mechanical Obstruction
      • Suspected in Patients > 60 Years Old with New-Onset, Rapidly Progressive Dysphagia, and Weight-Loss of < 6 Months Evolution
    • Chagas Disease
      • Caused by Trypanosoma cruzi
      • Produces Destruction of Enteric Ganglion Cells
      • May Also Cause:
        • Megacolon
        • Cardiac Disease
    • Other associated disorders
      • Amyloidosis
      • Sarcoidosis
      • Neurofibromatosis
      • Multiple Endocrine Neoplasia Type 2B
  • Opioid-Associated Esophageal Dysfunction
    • Can Produce Type III Achalasia or Other Obstructive/Spastic Manometric Patterns
    • When Feasible, Perform Manometry After Withholding Opioids for an Appropriate Period

Clinical Presentation

Clinical Presentation

  • Dysphagia
    • Progressive Dysphagia to Both Liquids and Solids
  • Regurgitation
    • Regurgitation of Undigested Food and Saliva
    • Worse When Supine
    • Often Misinterpreted as Vomiting Which May Lead to Evaluation of Gastric Pathologies Rather than an Esophageal Disorder
  • Weight Loss
    • Usually Mild and Progressive in Primary Achalasia
    • Rapid and Severe Weight Loss Should Raise Concern for Pseudoachalasia
  • Substernal Chest Pain
  • Heartburn (Retrosternal Burning)
    • May Be Mistaken for Gastroesophageal Reflux Disease (GERD)
    • True GERD Can Also Develop, Particularly After Treatment
  • Difficulty Belching (Abelchia)
    • Paradoxical Increase in Upper Esophageal Sphincter (UES) Pressure Without a Belch
    • Associated Chest Pain and Distention May be Worsened by This “Trapped” Air

Additional Findings

  • Nocturnal Cough
  • Aspiration and Recurrent Pneumonia
  • Hiccups
  • Globus Sensation

Diagnosis

Diagnosis

  • High-Resolution Manometry (HRM) is the Diagnostic Gold Standard Test
  • Esophagogastroduodenoscopy (EGD) Should Be Performed in all Patients with Suspected Achalasia to Exclude Mechanical Obstruction, Malignancy, or Pseudoachalasia
  • Timed Barium Esophagram (TBE) is Complementary but Not Diagnostic Itself
  • Functional Lumen Imaging Probe (FLIP) if HRM is Inconclusive, Unable to Be Performed, or as Supportive Testing When the Diagnosis Remains Uncertain

High-Resolution Manometry (HRM)

  • The Gold Standard Diagnostic Test
  • Findings:
    • Elevated Median Integrated Relaxation Pressure (IRP)
    • Absence of Normal Peristalsis

Timed Barium Esophagram (TBE)

  • Classic Findings:
    • Dilated Esophagus
    • Impaired/Delayed Barium Emptying
    • Smooth Tapering at the EGJ
      • “Bird’s-Beak” Appearance
    • Other Findings:
      • Air-Fluid Level
      • Absence of a Gastric Air Bubble
      • Megaesophagus
      • Tortuous or Sigmoid-Shaped Esophagus
      • Epiphrenic (Pulsion) Diverticulum
    • Can Also Be Used to Objectively Assess Esophageal Emptying and Response to Treatment

Upper Endoscopy/Esophagogastroduodenoscopy (EGD)

  • Should Be Performed in All Patients with Suspected Achalasia
  • May Be Normal in Achalasia and is Not Diagnostic
  • Primary Purpose:
    • Exclude Malignancy
    • Exclude Stricture or Another Mechanical Obstruction
    • Evaluate for Pseudoachalasia
  • Findings that Support Achalasia:
    • Dilated Esophagus
    • Retained Saliva, Liquid, Pills, or Food
    • Puckered or Rosette-Like EGJ
    • Contracted LES that Can Usually Be Traversed with Gentle Pressure
  • Mucosal Biopsy Does Not Establish Achalasia Given that the Primary Abnormality is Within the Myenteric Plexus

Functional Lumen Imaging Probe (FLIP)

  • Generally Used When Achalasia is Suspected but HRM is Inconclusive or Unable to Be Performed
  • Uses Impedance Planimetry by Balloon Catheter to Measure Cross-Sectional Area and Intra-Luminal Pressure
    • The Ratio of the Two Measurements at the Level of the EGJ is Called the Distensibility Index (EGJ-DI)
  • Reduced EGJ-DI Supports EGJ Outflow Obstruction and is Consistent with Achalasia in the Appropriate Clinical Context

“Bird’s Beak” on Esophagram

Classification/Types

Type I Achalasia (Classic Achalasia)

  • Elevated Median Integrated Relaxation Pressure (IRP)
  • 100% Failed Peristalsis
  • Panesophageal Pressurization (PEP) in < 20% of Swallows

Type II Achalasia

  • Elevated Median Integrated Relaxation Pressure (IRP)
  • 100% Failed Peristalsis
  • Panesophageal Pressurization (PEP) in ≥ 20% of Swallows

Type III Achalasia (Spastic Achalasia)

  • Elevated Median Integrated Relaxation Pressure (IRP)
  • Absent Peristalsis
    • All Swallows are Either Failed or Premature/Spastic
  • Premature/Spastic Contractions in ≥ 20% of Swallows

Achalasia Type I: No Contractility with Incomplete LES Relaxation

Achalasia Type II: Penesophageal Pressurization (PEP) Bands – Vertical Green Columns

Achalasia Type III: Premature Spastic Contractions

Treatment

General Approach

  • Definitive Management:
    • Heller Myotomy (HM)
    • Peroral Endoscopic Myotomy (POEM)
    • Pneumatic Dilation (PD)
  • Options if Unable to Tolerate Definitive Therapy:
    • Endoscopic Botox Injection into the Lower Esophageal Sphincter (LES)
    • Pharmacologic Treatments

Heller Myotomy (HM)

  • Procedure: Complete Division of Both the Circular and Longitudinal Muscle Fibers of the Distal Esophagus and Proximal Stomach to Fully Disrupt the Non-Relaxing Lower Esophageal Sphincter (LES)
    • Preserves the Inner Submucosa and Mucosa
  • Myotomy Extent:
    • Proximal: 4-6 cm onto the Distal Esophagus
    • Distal: 2-3 cm onto the Gastric Cardia
  • Usually Combined with a Partial Fundoplication (Dor or Toupet)
    • Partial Fundoplication Reduces Postoperative GERD by Controlling Distal Esophageal Acid Exposure
    • Complete Nissen Fundoplication is Generally Avoided Because it May Recreate EGJ Obstruction

Peroral Endoscopic Myotomy (POEM) 

  • Procedure: Endoscopic Submucosal Tunneling Followed by Division of the LES Muscle
  • Advantages:
    • Often the Favored Option for Type III Achalasia in Which a Longer Myotomy Can Be Performed – Higher Rates of Clinical Success Compared to HM
    • Can Be Performed After Previous Dilation or Heller Myotomy
    • Avoids Abdominal or Thoracic Surgical Access
  • Disadvantages:
    • No Concomitant Fundoplication
    • Higher Risk of Postoperative GERD and Reflux Esophagitis

Pneumatic Dilation (PD) 

  • Procedure: Endoscopic Dilation of the LES Using a Graded Pneumatic Balloon
  • Usually Performed as Graded Dilations: 3.0 cm, 3.5 cm, 4.0 cm
  • Serial PD is an Effective Treatment Option for Achalasia for Both Short- and Long-Term Symptom Improvement
  • Major Complications:
    • Esophageal Perforation (Rate: 1-2%)
    • GERD

Botulinum Toxin Injection (Botox) 

  • Mechanism: Inhibits Acetylcholine Release at the LES
  • Provides Short-Term Symptom Improvement but Recurrence is Common and Repeated Injections are Frequently Required
  • Reserved Primarily for Patients Who:
    • Cannot Tolerate Definitive Therapy
    • Have Substantial Comorbidities
    • Have Limited Life Expectancy

Pharmacologic Therapy

  • Reserved for Patients Who Cannot Undergo Definitive Therapy or Botulinum Injections
  • Mechanism: Smooth Muscle Relaxation and Reduction of LES Pressure
  • Agents:
    • Nitrates
    • Calcium-Channel Blockers
    • Phosphodiesterase-5 (PDE-5) Inhibitors
  • Generally Less Effective and Less Durable Symptom Relief than Definitive Therapies

Esophagectomy

  • Salvage Treatment for Selected Surgically Fit Patients
  • Potential Indications:
    • End-Stage, Markedly Dilated Esophagus
    • Sigmoid-Shaped Esophagus
    • Failure of Dilation and/or Myotomy with Persistent Symptoms