Achalasia Cardia - Essay Answer

Definition

Epidemiology

• Incidence: approximately 1 per 100,000 persons per year (Sabiston); prevalence 1.8-12.6 per 100,000 (Bailey)
• Occurs with equal frequency in males and females, and across racial groups
• Most commonly diagnosed between 30 and 60 years of age, with peaks at ~30 and ~60 years
• Prevalence appears to be increasing, likely due to improved diagnostic awareness

Aetiology and Pathophysiology

• Peristalsis of smooth muscle of the oesophageal body
• Relaxation of the LES

1. Mismatch in excitatory and inhibitory activity → failure of LOS relaxation + absent peristalsis
2. Oesophagus dilates progressively; contractions disappear
3. Oesophagus empties mainly by hydrostatic pressure of its contents (incomplete emptying)
4. The air-fluid level in the stomach (seen in normal erect X-rays) is absent - no bolus with air passes through the LOS
5. Progressive tortuous dilation = megaoesophagus
6. Persistent retention oesophagitis from food fermentation → increased risk of oesophageal carcinoma

Secondary / Associated Forms

Clinical Features

• Dysphagia for both solids AND liquids - ~95% of patients (most common symptom)
• Regurgitation of undigested food - ~70% (can cause aspiration, cough, hoarseness, pneumonia)
• Heartburn - 40-50% (NOT from gastric reflux; caused by stasis and fermentation of food)
• Chest pain - 40-50% (secondary to oesophageal distention)
• Weight loss - variable; some patients adapt diet
• Aspiration pneumonia, halitosis, regurgitation of previously eaten food

Eckardt Score

Chicago Classification (Manometric Types)

Investigations / Diagnostic Evaluation

1. Endoscopy (EGD)

• First test performed in dysphagia
• Findings: frothy saliva pooling, food residue, dilated tortuous oesophagus, tight/spastic OGJ that allows the scope to pass with gentle pressure
• ~30-40% of endoscopies are normal - a normal endoscopy does NOT exclude achalasia (Bailey)
• In ~40% of patients the test is normal; remainder show retained food, stasis oesophagitis, or Candida infection (Sabiston)
• Critical role: exclude pseudoachalasia (cancer of gastric cardia mimicking achalasia)

2. Barium Swallow (Contrast Study)

• Classic finding: "Bird's beak" sign - smooth tapering of the distal oesophagus at the OGJ
• Other findings (Sabiston): distal oesophageal narrowing, air-fluid level, slow emptying of contrast, tertiary contractions
• Provides anatomical information: axis (straight vs. sigmoid) and degree of dilation - important for treatment planning
• In early stages, can be normal in ~30% of patients

3. High-Resolution Manometry (HRM) - Gold Standard

• Gold standard for diagnosis of oesophageal motility disorders (Bailey)
• Demonstrates: elevated IRP (failure of LES relaxation), absent peristalsis, +/- pan-oesophageal pressurisation or spastic contractions depending on type
• Allows Chicago Classification typing

4. Ambulatory pH Monitoring

• Reserved for patients complaining of heartburn
• Differentiates acid reflux from fermentation-related stasis symptoms

Treatment

A. Medical (Pharmacological) Therapy

• Calcium channel blockers, nitrates, 5'-phosphodiesterase inhibitors
• Limited efficacy; used mainly for symptom relief in poor surgical candidates

B. Botulinum Toxin Injection

• Injected endoscopically at the LES; inhibits acetylcholine release from excitatory neurons
• Useful when the diagnosis is in doubt, or in elderly patients with comorbidities unfit for other procedures
• Repeated injection causes scarring, making subsequent treatments more difficult
• Should NOT be offered as first-line in patients suitable for myotomy or pneumatic dilation

C. Pneumatic Dilation (PD)

• Non-compliant balloons (polyethylene) of 30-40 mm diameter inserted over a guidewire to disrupt the sphincter muscle
• Graded serial dilation: 30 mm → 35 mm → 40 mm (Bailey)
• Efficacy: Serial PD has similar efficacy to surgical myotomy in selected patients
• Predictors of good response: age >45 years, female sex, undilated oesophagus, response to first dilation, Type II achalasia
• Complication: Perforation - averaged ~1.9% (0-16%); with 30 mm balloon, <0.5%; risk increases with larger balloons
• Requires experienced endoscopist and surgical backup
• Today, PD is largely reserved for recurrent dysphagia after LHM or POEM (Sabiston)

D. Laparoscopic Heller Myotomy (LHM) with Partial Fundoplication - Standard Surgical Treatment

• 4-5 trocars in upper abdomen
• Gastrohepatic ligament opened; right crus identified; peritoneum and phreno-oesophageal membrane transected
• Short gastric vessels divided (to allow fundoplication without tension)
• Myotomy ~8.5 cm total: 6 cm above GEJ + 2.5 cm onto gastric wall
• Muscle edges separated so mucosa is uncovered for ~140 degrees

• Without fundoplication, GORD occurs in up to 40% of patients post-myotomy
• Partial fundoplication is standard; 360° Nissen wrap is contraindicated (increases outflow resistance against aperistaltic oesophagus → dysphagia)
• Dor (anterior): Does not require posterior dissection; avoids risk to posterior vagus nerve
• Toupet (posterior): Requires posterior dissection; helps keep muscular edges separated, reducing recurrent dysphagia

• Padua group: 90% success in 407 patients at median 2.5 years; 87% asymptomatic at 5 years
• European multicenter study: 84% success at 5 years
• Swedish RCT: 92% excellent results at 5 years; 80% at 10 years

E. Peroral Endoscopic Myotomy (POEM)

• First described by Dr. Inoue in 2010
• Endoscopic submucosal tunnel technique

1. Mucosal opening created
2. Submucosal tunnel between mucosa and muscle layer created down to the stomach
3. Myotomy begins a short distance below the mucosal opening
4. Myotomy carried into the proximal stomach
5. Mucosal opening closed with endoclips

• Advantage for Type III achalasia: POEM allows a long myotomy extending into the oesophageal body - better suited than LHM for spastic type
• Short-term results are at least as good as LHM
• Main concern: Higher rate of post-procedure GORD compared to LHM with fundoplication (no antireflux wrap performed)

F. Oesophagectomy

• Reserved for end-stage achalasia with sigmoid/massively dilated megaoesophagus unresponsive to other treatments

Summary Box (Bailey & Love's 28th Ed., Summary Box 66.5)

• Achalasia is the most common oesophageal motility disorder
• A normal endoscopy does NOT exclude the diagnosis of achalasia
• Beware of pseudoachalasia (cancer mimicking achalasia)
• HRM is the gold standard for diagnosis
• Laparoscopic myotomy, pneumatic balloon dilation and POEM are all effective treatments
• Type III achalasia may be better treated with long myotomy by POEM

Comparison: LHM vs POEM vs PD

• Bailey and Love's Short Practice of Surgery, 28th Edition - Chapter 66 (Oesophagus), pp. 1143-1147
• Sabiston Textbook of Surgery - Chapter 83 (Oesophagus), pp. 1704-1708