Achalasia Cardia

Achalasia is a primary oesophageal motility disorder characterised by absent peristalsis in the oesophageal body and failure of the lower oesophageal sphincter (LES) to relax in response to swallowing. The underlying pathology is degeneration of inhibitory (nitric oxide and vasoactive intestinal peptide producing) neurons in the myenteric plexus, followed by loss of ganglion cells and chronic inflammation.

Incidence is about 1 to 2 per 100,000 per year, with a peak at 30 to 60 years. The cause of idiopathic achalasia is not established; proposed mechanisms include autoimmunity, viral triggers (herpes simplex, varicella zoster) and genetic susceptibility.

Secondary achalasia (pseudoachalasia) is caused by:

• Infiltration or compression at the gastro oesophageal junction by tumour (gastric cardia carcinoma, oesophageal carcinoma, lymphoma, metastases).
• Paraneoplastic neuropathy (anti-Hu antibodies, with small cell lung cancer).
• Anti-reflux surgery or gastric banding.
• Chagas disease (Trypanosoma cruzi destroying the myenteric plexus, endemic in South America).

Triple A syndrome (Allgrove: achalasia, alacrima, adrenal insufficiency) is a rare genetic form in children.

The Chicago classification (version 4.0) uses high resolution manometry to define three subtypes:

• Type I (classic): 100% failed peristalsis, minimal pressurisation
• Type II: panoesophageal pressurisation in at least 20% of swallows, the best treatment response
• Type III (spastic): premature (spastic) contractions in at least 20% of swallows, without peristalsis, the poorest response to dilation or myotomy of the standard length

The integrated relaxation pressure (IRP) is abnormal above 15 mmHg (cutoff depends on the manometry system). Oesophagogastric junction outflow obstruction (EGJOO) is a related entity with elevated IRP but preserved peristalsis.

Dysphagia to both solids and liquids is the cardinal symptom, present in more than 90%, usually developing gradually over months to years. Other features:

• Regurgitation of undigested food or saliva (60 to 90%), worse when lying down, with nocturnal aspiration, cough, and aspiration pneumonia
• Chest pain (up to 40 to 60%, especially type III), which may mimic angina
• Weight loss (average 10 to 15 kg), more marked in advanced disease
• Heartburn (30 to 50%), which is due to fermentation of stagnant food and lactic acid and does not respond to proton pump inhibitors, a classic diagnostic trap
• Hiccups, belching difficulty, and halitosis
• Respiratory complications: chronic cough, recurrent chest infections, bronchiectasis, lung abscess

Red flags suggesting pseudoachalasia: age above 60, short duration of symptoms (under 1 year), rapid weight loss (over 10 kg in 6 months), and difficulty passing an endoscope through the gastro oesophageal junction. Long standing achalasia has an increased risk of squamous cell carcinoma (about 0.15 to 0.5% per year; risk is 10 to 50 times that of the general population) and, after myotomy with reflux, adenocarcinoma.

The Eckardt score (0 to 12) combines dysphagia, regurgitation, chest pain and weight loss; each scored 0 to 3. A score of 3 or below after treatment indicates success.

1. Upper endoscopy first, to exclude mechanical obstruction and malignancy. Findings in achalasia: retained saliva, liquid and undigested food in a dilated oesophagus, a puckered LES, and a gastro oesophageal junction that opens with gentle pressure. A normal endoscopy does not exclude achalasia in early disease. Biopsy suspicious areas. Endoscopic ultrasound or CT is indicated when pseudoachalasia is suspected.
2. High resolution oesophageal manometry: the gold standard. Findings are impaired LES relaxation (IRP above 15 mmHg) and absent peristalsis, with subtype classification.
3. Timed barium oesophagram: shows a dilated oesophagus with an air fluid level, a "bird's beak" narrowing at the GEJ, and delayed emptying.
4. Barium column heights at 1 and 5 minutes (over 5 cm at 5 minutes is abnormal; above 5 cm column at 5 minutes post-treatment indicates poor emptying).
5. Stage by diameter: grade I under 4 cm, grade II 4 to 6 cm, grade III over 6 cm, grade IV a sigmoid oesophagus, which predicts poor outcome after dilation or myotomy.
6. Functional lumen imaging probe (EndoFLIP) assesses distensibility of the GEJ and is useful in equivocal cases.
7. Serology for Chagas disease in endemic populations (IgG ELISA with confirmatory test).
8. Chest CT if pseudoachalasia or aspiration complications are suspected.

• Treatment is palliative and aims to reduce the LES pressure and improve emptying. No treatment restores peristalsis. Choice depends on subtype, age, comorbidity and local expertise.

Pneumatic dilation.

• Endoscopic or fluoroscopic placement of a 30, 35 or 40 mm polyethylene balloon (Rigiflex) across the LES, inflated to 7 to 15 psi for 1 to 3 minutes. Start with the 30 mm balloon and progress at intervals of 2 to 4 weeks according to symptoms.
• Short term success about 70 to 90%; durable success about 50 to 60% at 5 years with repeated dilations.
• Perforation rate is about 1 to 3%, requiring immediate surgical or endoscopic repair, so a water soluble contrast study is done after dilation if there is pain.
• Reflux is uncommon. Best results in age over 40 and type II.

Laparoscopic Heller myotomy with partial fundoplication.

• A 6 cm myotomy on the oesophagus and 2 to 3 cm onto the gastric cardia, with a Dor (anterior 180 degree) or Toupet (posterior 270 degree) fundoplication to limit reflux.
• Success about 85 to 95% at 5 years. Best long term durability among standard options.
• Complications: mucosal perforation (about 5 to 10%, repaired intraoperatively), reflux (10 to 20% symptomatic).

Peroral endoscopic myotomy (POEM).

• Submucosal tunnel, endoscopic myotomy of circular muscle of about 6 to 8 cm of oesophagus and 2 to 3 cm of stomach, with clip closure of mucosal entry.
• Success is 90 to 95% at 1 to 2 years, equal to Heller; it allows a longer myotomy.
• It is the preferred treatment for type III achalasia (the myotomy can extend across the spastic segment) and for sigmoid oesophagus and prior failed treatment.
• Reflux after POEM is more common (30 to 50% on pH testing; reflux oesophagitis 20 to 40%), so patients need proton pump inhibitor therapy (for example omeprazole 20 to 40 mg daily) and surveillance endoscopy or pH testing.

Botulinum toxin injection.

• 100 units divided into 4 quadrants (25 units per quadrant, using 100 units in 4 mL saline) just above the squamocolumnar junction.
• Effective initially in 70 to 80% but relapse in over half by 6 to 12 months.
• Reserved for elderly or very frail patients who are unfit for other options, or as a bridge.
• Repeat injection becomes less effective, and causes fibrosis that makes later myotomy harder.

• Pharmacological therapy. Nifedipine 10 to 20 mg sublingually or orally 30 to 45 minutes before meals, isosorbide dinitrate 5 mg sublingually before meals, or sildenafil. Limited efficacy and side effects (headache, hypotension), used only for patients who refuse or cannot undergo other treatments.
• Oesophagectomy. For end stage disease: sigmoid oesophagus, persistent failed myotomy, or malignancy.
• Chagas disease achalasia. Same procedures, with cardiac and colonic evaluation; specific antiparasitic treatment has limited effect on established disease.
• Follow up. Symptom scores and timed barium oesophagram at 1 to 6 months; repeat as needed. Because of the risk of squamous carcinoma, some experts recommend endoscopic surveillance every 2 to 3 years beginning 10 to 15 years after diagnosis, though evidence is limited.
• Treat reflux after myotomy. Advise patients to eat slowly, chew thoroughly, elevate the head of the bed, and avoid late night meals.