Achalasia
Summary
Achalasia is a primary oesophageal motility disorder characterised by failure of Lower Oesophageal Sphincter (LOS) relaxation combined with aperistalsis of the oesophageal body. The underlying pathology involves degeneration of inhibitory neurons (nitric oxide and VIP-releasing) in the myenteric plexus. It affects approximately 1 per 100,000 population annually and presents classically with dysphagia to both solids AND liquids from onset, distinguishing it from mechanical obstruction. Diagnosis is confirmed by high-resolution manometry, and treatment focuses on reducing LOS pressure via endoscopic or surgical myotomy.
Key Facts
- Definition: Primary oesophageal motility disorder with absent LOS relaxation and aperistalsis
- Prevalence: 1 in 100,000 per year, equal male-to-female ratio
- Mortality/Morbidity: Low mortality but significant quality of life impact; increased oesophageal cancer risk (squamous cell carcinoma 3-5%)
- Key Management: Heller's myotomy or POEM for definitive treatment; pneumatic dilatation as alternative
- Critical Finding: Dysphagia to BOTH solids AND liquids from onset (vs. mechanical = solids first)
- Key Investigation: High-resolution oesophageal manometry (Gold Standard)
Clinical Pearls
"Solid AND Liquid" Rule: Unlike mechanical obstruction (where solids precede liquids), achalasia causes equal difficulty with both from the start due to failed peristalsis.
Pseudoachalasia Alert: Malignancy at the gastro-oesophageal junction can mimic achalasia. Suspect if: age >55, rapid symptom onset (<6 months), >6kg weight loss, or difficulty passing endoscope.
Bird's Beak Sign: Classic barium swallow appearance showing smooth tapering at the GOJ with proximal oesophageal dilatation — pathognomonic for achalasia.
Why This Matters Clinically
Untreated achalasia leads to progressive oesophageal dilatation, food retention, aspiration pneumonia, and malnutrition. Early diagnosis prevents irreversible megaoesophagus. Additionally, there is a 25-fold increased risk of developing oesophageal squamous cell carcinoma requiring surveillance consideration.
Incidence & Prevalence
- Incidence: 1.0-1.6 per 100,000 per year
- Prevalence: 10 per 100,000 population
- Trend: Stable; increased detection due to better diagnostics
Demographics
| Factor | Details |
|---|---|
| Age | Typically 25-60 years; can occur at any age; bimodal peaks (30-40 and 60-70) |
| Sex | Male = Female (1:1 ratio) |
| Ethnicity | No significant variation; equal across all groups |
| Geography | Similar incidence worldwide; no geographic predilection |
Risk Factors
Non-Modifiable:
- Genetic factors (rare familial cases, HLA-DQw1 association)
- Age (peak 30-60 years)
- Possible viral triggers (HSV-1, varicella-zoster implicated in some studies)
Modifiable:
| Risk Factor | Relative Risk |
|---|---|
| None well-established | N/A |
| (Achalasia is considered idiopathic in most cases) | — |
Conditions Associated with Secondary Achalasia (Pseudoachalasia):
| Cause | Notes |
|---|---|
| Malignancy at GOJ | Adenocarcinoma, squamous cell carcinoma |
| Chagas disease | Endemic in South America (Trypanosoma cruzi) |
| Amyloidosis | Rare |
| Sarcoidosis | Very rare |
| Post-fundoplication | Tight wrap causing obstruction |
Mechanism
Step 1: Loss of Inhibitory Neurons
- Selective destruction of inhibitory neurons in the myenteric (Auerbach's) plexus
- These neurons normally release nitric oxide (NO) and vasoactive intestinal peptide (VIP)
- Loss is selective for inhibitory neurons; excitatory cholinergic neurons initially preserved
- Cause unknown — possible autoimmune, infective (viral), or inflammatory trigger
Step 2: Imbalance of Oesophageal Tone
- Loss of inhibitory input leads to unopposed excitatory (cholinergic) activity
- Results in:
- Failure of LOS relaxation (tonic contraction)
- Aperistalsis (no coordinated propulsion)
- Elevated resting LOS pressure in some cases
Step 3: Clinical Consequences
- Food bolus cannot pass through non-relaxing LOS
- Oesophageal body cannot propel food due to absent peristalsis
- Progressive oesophageal dilatation (megaoesophagus over years)
- Food stasis → regurgitation, aspiration, weight loss, malnutrition
- Chronic inflammation → increased squamous cell carcinoma risk (3-5%)
Classification
| Type (Chicago v4.0) | Manometric Definition | Clinical Features | Treatment Response |
|---|---|---|---|
| Type I (Classic) | Failed LOS relaxation (IRP ≥15 mmHg) + 100% failed peristalsis with minimal pressurisation | Most common; dysphagia, regurgitation | Good response to all treatments |
| Type II (with pressurisation) | Failed LOS relaxation + pan-oesophageal pressurisation (>0 mmHg) in ≥20% swallows | Similar symptoms; may have chest pain | BEST treatment outcomes (>0% with myotomy) |
| Type III (Spastic) | Failed LOS relaxation + premature (spastic) contractions with DL <4.5s in ≥20% swallows | Chest pain more prominent; dysphagia | Worst response; POEM may be better than Heller's |
Anatomical/Physiological Considerations
The lower oesophageal sphincter is a 3-4 cm high-pressure zone located at the gastro-oesophageal junction. Normal swallowing triggers a coordinated peristaltic wave down the oesophageal body with reflex LOS relaxation mediated by inhibitory neurons. In achalasia, the LOS remains contracted and the oesophageal body has no effective peristalsis, creating a functional obstruction. Over time, the oesophagus proximal to the LOS dilates progressively, eventually forming a sigmoid-shaped "megaoesophagus" in late-stage disease.
Symptoms
Typical Presentation:
Atypical Presentations:
Signs
Red Flags
[!CAUTION] Red Flags — Urgent investigation for Pseudoachalasia (malignancy) if:
- Age >55 years at symptom onset
- Symptom duration <6 months (rapid onset)
- Weight loss >6 kg
- Cannot pass endoscope through LOS (high resistance)
- CT evidence of mass at GOJ or mediastinal lymphadenopathy
- Dysphagia progressing despite treatment
Structured Approach
General:
- Assess nutritional status (BMI, cachexia, muscle wasting)
- Vital signs (fever may suggest aspiration pneumonia)
- Hydration status
Specific System Examination:
- ENT: Oral hygiene, halitosis
- Respiratory: Auscultate for crackles (aspiration)
- Abdominal: Usually normal; no specific findings
- Neck: No masses (rule out extrinsic compression)
Special Tests
| Test | Technique | Positive Finding | Sensitivity/Specificity |
|---|---|---|---|
| Water swallow test | Give water, observe for regurgitation or delay | Immediate regurgitation, coughing, prolonged swallowing time | Low sensitivity; screening only |
| Timed barium swallow | Measure oesophageal emptying at 1, 2, 5 minutes | Retained barium at 5 minutes, "Bird's Beak" appearance | ~90% sensitive for achalasia |
| High-resolution manometry | Measures LOS pressure and peristalsis | IRP ≥15 mmHg, absent peristalsis | 98%/96% (Gold Standard) |
First-Line (Bedside)
- Basic observations — exclude aspiration (fever, tachycardia)
- CXR — may show air-fluid level behind heart, dilated oesophagus, aspiration changes
Laboratory Tests
| Test | Expected Finding | Purpose |
|---|---|---|
| FBC | May show anaemia (chronic malnutrition) | Assess nutritional impact |
| U&Es, LFTs | Usually normal | Baseline; dehydration assessment |
| Albumin | May be low in malnutrition | Nutritional status |
| CRP | Elevated if aspiration pneumonia | Infection marker |
| Chagas serology | Positive in endemic areas | Rule out secondary achalasia (Chagas) |
Imaging
| Modality | Findings | Indication |
|---|---|---|
| Barium swallow | "Bird's Beak" sign (smooth tapering at GOJ); Dilated, aperistaltic oesophagus; Delayed contrast passage | Initial investigation; screening |
| OGD (Mandatory) | Dilated oesophagus with retained food; Resistance at LOS (but passable); Rules out malignancy | Exclude pseudoachalasia; biopsy if suspicious |
| CT chest/abdomen | Dilated oesophagus; May detect GOJ mass in pseudoachalasia | If pseudoachalasia suspected |
| High-resolution manometry | IRP ≥15 mmHg; Type I/II/III classification | GOLD STANDARD for diagnosis |
| Endoscopic ultrasound (EUS) | Excludes submucosa/extrinsic mass | If pseudoachalasia suspected |
Diagnostic Criteria
Chicago Classification v4.0 Diagnostic Criteria for Achalasia:
| Criterion | Requirement |
|---|---|
| Integrated Relaxation Pressure (IRP) | ≥15 mmHg (abnormal relaxation) |
| Peristalsis | 100% failed or premature contractions |
| OGD | No mechanical obstruction |
Subtype Classification:
- Type I: No oesophageal pressurisation
- Type II: Pan-oesophageal pressurisation ≥30 mmHg in ≥20% swallows
- Type III: Premature contractions (DL <4.5s) in ≥20% swallows
Management Algorithm
Acute/Emergency Management (if applicable)
Immediate Actions (for severe aspiration or dehydration):
- NBM if aspiration risk
- IV fluids for dehydration/electrolyte replacement
- Treat aspiration pneumonia (antibiotics covering oral flora)
- NGT insertion if severe food impaction (rare)
Conservative Management
- Dietary modification: Soft diet, small meals, upright position during and after eating
- Avoid eating within 3 hours of bedtime
- Elevate head of bed (reduce nocturnal regurgitation)
- Adequate hydration with meals
Medical Management
| Drug Class | Drug | Dose | Duration |
|---|---|---|---|
| Calcium Channel Blockers | Nifedipine | 10-30 mg sublingual/PO 30 minutes before meals | Short-term; primary role is symptom relief pre-definitive therapy |
| Nitrates | Isosorbide Dinitrate | 5 mg sublingual pre-meals | Short-term; limited efficacy |
| PDE5 Inhibitors | Sildenafil | 50 mg before meals | Limited evidence; rarely used |
Note: Pharmacological therapy has limited long-term efficacy (<50% symptom relief) and is reserved for patients unfit for endoscopic/surgical intervention.
Endoscopic/Interventional Management
| Intervention | Technique | Efficacy | Risks |
|---|---|---|---|
| Botulinum toxin injection | 100 units injected into LOS during OGD | 70-80% initial relief; 50% relapse at 1 year | Low risk; temporary; fibrosis may complicate later myotomy |
| Pneumatic dilation (PD) | Graded balloon (30-40mm) dilation of LOS | 70-90% initial; 30-40% need repeat at 5 years | Perforation 1-3%; GORD |
| POEM (Per-Oral Endoscopic Myotomy) | Endoscopic submucosal tunnel + myotomy | >0% success at 2 years | Reflux post-POEM higher than Heller's; preferred for Type III |
Surgical Management
Indications:
- Failed or inadequate response to endoscopic therapy
- Patient preference for definitive treatment
- Type III achalasia (POEM or extended myotomy)
- Young patients (preferring single definitive procedure)
Procedure:
- Laparoscopic Heller's Myotomy + Partial Fundoplication (Dor or Toupet):
- Myotomy: 6-8 cm on oesophagus + 2-3 cm onto stomach
- Fundoplication (anterior Dor or posterior Toupet) to prevent GORD
- >90% long-term symptom relief
- Reflux rates ~10-15% with fundoplication
Disposition
- Admit if: Severe dehydration, aspiration pneumonia, malnutrition, emergency endoscopy needed
- Discharge if: Stable, able to maintain oral intake, planned outpatient workup/treatment
- Follow-up: Post-procedure review at 4-6 weeks; long-term surveillance considering cancer risk (OGD every 3-5 years in long-standing disease)
Immediate (Minutes-Hours)
| Complication | Incidence | Presentation | Management |
|---|---|---|---|
| Oesophageal perforation (post-dilatation/POEM) | 1-3% (PD); <1% (POEM) | Chest pain, subcutaneous emphysema, fever | CT; conservative if contained; surgery if large |
| Aspiration | Variable | Cough, desaturation during procedure | Suction; supportive care |
| Bleeding | <1% | Haematemesis, melaena | Endoscopic haemostasis |
Early (Days)
- Dysphagia recurrence: Inadequate myotomy or fibrosis (repeat therapy may be needed)
- Infection: Rare; mucosal breach
- Reflux symptoms: Especially post-POEM (no anti-reflux procedure)
Late (Weeks-Months)
- Gastro-oesophageal reflux disease (GORD): 20-40% post-POEM; 10-15% post-Heller's with fundoplication
- Treatment failure/recurrence: 10-20% at 5 years
- Megaoesophagus: End-stage with sigmoid deformity (may require oesophagectomy)
- Oesophageal squamous cell carcinoma: 3-5% lifetime risk (25x general population); surveillance recommended
Natural History
Untreated achalasia leads to progressive oesophageal dilatation over years. Patients develop worsening dysphagia, malnutrition, weight loss, and recurrent aspiration. Eventually, the oesophagus becomes massively dilated and sigmoid-shaped (end-stage megaoesophagus), at which point myotomy is less effective and oesophagectomy may be the only option. Untreated patients have significantly impaired quality of life.
Outcomes with Treatment
| Variable | Outcome |
|---|---|
| Mortality | Low (<0.5% procedure-related); disease rarely directly fatal |
| Morbidity | Significant if untreated; moderate post-treatment (reflux, recurrence) |
| Recurrence | 10-20% at 5 years; Type II has best outcomes |
| Long-term symptom relief | POEM/Heller's: >0% at 2 years; PD: 70-80% at 2 years |
Prognostic Factors
Good Prognosis:
- Type II achalasia (best response to treatment)
- Younger age at treatment
- Shorter symptom duration before treatment
- Non-dilated oesophagus (<6 cm)
Poor Prognosis:
- Type III achalasia (worst treatment response)
- End-stage megaoesophagus (sigmoid oesophagus)
- Elderly patients with comorbidities
- Failed prior interventions (revision surgery less effective)
Key Guidelines
- ACG Clinical Guideline: Diagnosis and Management of Achalasia (2020) — Recommends high-resolution manometry for diagnosis; POEM or Heller's myotomy for definitive treatment; graded pneumatic dilation as alternative. American College of Gastroenterology
- ESGE/UEG Guideline on Motility Disorders (2020) — Endorses POEM as effective alternative to Heller's for Type I/II; recommends surveillance for oesophageal cancer. European Society of Gastrointestinal Endoscopy
Landmark Trials
POEM vs Laparoscopic Heller Myotomy RCT (Werner et al., 2019) — First major RCT comparing POEM to laparoscopic Heller's myotomy.
- 221 patients randomised
- Key finding: POEM non-inferior to Heller's at 2 years (83% vs 82% treatment success); POEM had higher GORD rates (57% vs 20%)
- Clinical Impact: Established POEM as a valid first-line option; highlighted need for PPI post-POEM
European Achalasia Trial (Boeckxstaens et al., 2011) — RCT comparing pneumatic dilation to laparoscopic Heller's myotomy.
- 201 patients randomised
- Key finding: Similar efficacy at 2 and 5 years (PD: 86%, Heller's: 90%)
- Clinical Impact: Validated pneumatic dilation as reasonable first-line, especially where surgical expertise is limited
Evidence Strength
| Intervention | Level | Key Evidence |
|---|---|---|
| POEM for Type I/II achalasia | 1b | Werner et al. RCT 2019; NEJM |
| Laparoscopic Heller's myotomy + fundoplication | 1a | Multiple RCTs; Cochrane review |
| Pneumatic dilation | 1b | European Achalasia Trial 2011 |
| Botulinum toxin injection | 1b | Multiple RCTs; short-term benefit only |
| Pharmacotherapy (CCB, nitrates) | 2b | Limited efficacy; poor long-term data |
What is Achalasia?
Achalasia is a swallowing disorder caused by damage to the nerves in your food pipe (oesophagus). Normally, when you swallow, a valve at the bottom of the food pipe relaxes to let food into the stomach. In achalasia, this valve doesn't relax properly, and the muscles in the food pipe don't work together to push food down. Think of it like a door that won't open — food gets stuck and builds up.
Why does it matter?
If left untreated, achalasia can cause:
- Difficulty eating: Food gets stuck, causing discomfort and weight loss
- Food coming back up: Especially at night, which can cause choking or lung infections
- Stretched food pipe: Over years, the food pipe can become very wide and floppy
- Slightly higher risk of food pipe cancer: Regular check-ups may be recommended
How is it treated?
- Keyhole surgery (Heller's myotomy): A small operation to cut the tight valve muscle, usually with a procedure to prevent acid reflux. Very effective long-term.
- POEM (camera treatment): A newer technique done through a camera swallowed into the food pipe, cutting the muscle from the inside. No scars, quick recovery.
- Balloon stretching: A balloon is inflated to stretch the valve. May need to be repeated.
- Botox injection: A temporary treatment where Botox is injected to relax the valve. Effects wear off after months.
What to expect
- Treatment is usually very effective (more than 90% of people have significant improvement)
- You may need to take acid-reducing tablets after treatment
- Some people may need follow-up treatments if symptoms return
- Recovery from keyhole surgery or POEM is usually 1-2 weeks
When to seek help
- Urgent: Choking episodes, breathing difficulties, severe chest pain, high fever (may indicate food pipe perforation or lung infection)
- Soon: Worsening difficulty swallowing, significant weight loss, food getting stuck more often
Primary Guidelines
- Vaezi MF, et al. ACG Clinical Guideline: Diagnosis and Management of Achalasia. Am J Gastroenterol. 2020;115(9):1393-1411. PMID: 32773454
- Kahrilas PJ, et al. Chicago Classification v4.0. Neurogastroenterology & Motility. 2021;33(1):e14058. PMID: 33373111
Key Trials
- Werner YB, et al. Endoscopic or Surgical Myotomy in Patients with Idiopathic Achalasia. N Engl J Med. 2019;381(23):2219-2229. PMID: 31800987
- Boeckxstaens GE, et al. Pneumatic Dilation versus Laparoscopic Heller's Myotomy for Idiopathic Achalasia. N Engl J Med. 2011;364(19):1807-1816. PMID: 21561346
Further Resources
- UpToDate: Achalasia Overview
- Radiopaedia: Achalasia Imaging
- BSG Guidelines: British Society of Gastroenterology
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists. This content does not constitute medical advice for individual patients.