Achalasia Cardia

Definition

1. Impaired / absent lower esophageal sphincter (LES) relaxation with swallowing
2. Aperistalsis in the smooth muscle esophagus

Etiology and Pathophysiology

• Normal LES relaxation is mediated by inhibitory neurons secreting nitric oxide (NO) and vasoactive intestinal peptide (VIP)
• In achalasia, NO synthase activity is absent and VIP-staining neurons are markedly reduced
• The result: deglutitive inhibition fails - LES does not relax when swallowing occurs
• CCK paradox: Normally CCK stimulates inhibitory neurons to reduce LES pressure; in achalasia it increases LES pressure (pathognomonic finding)

• Type II (compression) → Type I (classic/dilated) → End-stage mega-esophagus
• Type III (spastic achalasia) has a distinct pathogenesis: myenteric inflammation and dysfunction without destruction

Chicago Classification of Achalasia Subtypes (HRM-Based)

Three subtypes of achalasia on high-resolution manometry - Harrison's Principles, 22nd Ed.

Clinical Features

• Dysphagia - universal; present for solids in all patients; most also have liquid dysphagia; gradual onset, fluctuates then plateaus
• Regurgitation - undigested food eaten hours or days earlier; nonbilious, nonacid, mixed with saliva
• Chest pain - ~2/3 of patients early in disease; may spontaneously resolve over time; responds less well to treatment than dysphagia
• Weight loss - progressive
• Heartburn - paradoxical complaint; actually caused by bacterial fermentation of retained food, NOT true acid reflux
• Hiccups, halitosis

• Bronchopulmonary complications - up to 10% of advanced cases (aspiration pneumonia, chronic cough)
• Airway compromise / stridor - rare; dilated esophagus compresses membranous trachea
• Squamous cell carcinoma - 17-fold increased risk vs. age-matched controls; 0.15% cumulative incidence; develops after many years in a dilated, stasis-inflamed esophagus

Diagnosis

1. Barium Swallow (Upper GI Series)

• Classic "bird's beak" or "rat-tail" appearance at the gastroesophageal junction
• Esophageal dilatation, stasis of contrast, "jet stream" sign

2. High-Resolution Manometry (Definitive)

• Gold standard - most sensitive, detects early disease before dilatation
• Mandatory findings: elevated integrated relaxation pressure (IRP) + absent peristalsis
• Enables Chicago Classification subtyping

3. Endoscopy (EGD)

• Typically shows dilated esophagus with retained food/secretions
• LES may feel tight on intubation ("pop" on passage)
• Required to rule out pseudoachalasia (carcinoma at EGJ mimicking achalasia)

4. Functional Luminal Imaging Probe (FLIP)

• Identifies a poorly distensible sphincter even when HRM shows adequate relaxation

Treatment

Pharmacologic (Temporizing Only)

Pneumatic (Balloon) Dilation

• Noncompliant cylindrical Rigiflex balloon (3.0, 3.5, or 4.0 cm) placed fluoroscopically across LES
• Inflated to disrupt circular muscle of sphincter
• Efficacy: 60-90%; ~100% for Type II achalasia
• Major complication: esophageal perforation ~1% (range 0.5-5%)
• Considered preferred initial therapy for Type II achalasia given its lower cost vs. surgery with equivalent outcomes

Laparoscopic Heller Myotomy (LHM)

• Surgical division of LES circular muscle
• Always combined with partial (Dor or Toupet) antireflux fundoplication to prevent post-myotomy GERD
• Success rate: 62-90%
• A landmark multicenter European RCT showed ~90% efficacy at 5 years for both LHM and pneumatic dilation
• Preferred for Type III achalasia (86% success vs. 40% for dilation)

Peroral Endoscopic Myotomy (POEM)

• Endoscopic procedure: mucosal incision → submucosal tunnel → circular muscle transection with electrocautery
• Particularly advantageous for Type III (spastic) achalasia due to ability to extend myotomy to distal esophageal body
• A RCT showed 92% remission at 1 year for POEM vs. 70% for pneumatic dilation (p<0.01)
• GERD is common after POEM (managed with PPIs); no antireflux procedure is created
• Advantages: endoscopic approach, shorter hospital stay, can tailor myotomy length

Temporary Self-Expanding Metal Stents (SEMS)

• Retrievable stents as a bridge/alternative when surgery is not possible
• Limited evidence; may be considered in patients unfit for definitive therapy

Esophagectomy (Last Resort)

• For refractory/end-stage achalasia: esophageal resection with gastric pull-up or colonic/small bowel interposition
• Indications: obstructive symptoms unresolvable by other means, malnutrition, chronic aspiration, perforation, cancer
• Mortality ~4%

Treatment Selection by Subtype

Type I or II Achalasia:
  → First choice: Pneumatic dilation (especially Type II) OR Laparoscopic Heller Myotomy
  → Type II: 100% response to dilation; equal to myotomy

Type III (Spastic) Achalasia:
  → First choice: POEM or Laparoscopic Heller Myotomy
  → Pneumatic dilation less effective (~40%)

Elderly/high surgical risk:
  → Botulinum toxin injection (repeated PRN)

Refractory/failed all above:
  → Esophagectomy

Cancer Surveillance

Key Points Summary