Achalasia Type 1

Achalasia type I (classic achalasia) is the manometric subtype with impaired lower oesophageal sphincter relaxation and complete absence of oesophageal peristalsis, without pressurisation.

Chicago classification: elevated integrated relaxation pressure (over 15 mmHg), 100% failed peristalsis, no panoesophageal pressurisation (under 20% of swallows with pressurisation).

Pathophysiology: degeneration of inhibitory myenteric neurons (nitric oxide and vasoactive intestinal peptide) of the distal oesophagus, likely immune mediated; associated with Chagas disease in endemic areas.

Dilated oesophagus with stasis is common, often a sigmoid shaped dilated oesophagus in late disease.

Response to therapy is intermediate between type II (best) and type III (worst), with the dilated, atonic oesophagus carrying risk of persistent symptoms.

Progressive dysphagia for solids and liquids, regurgitation of undigested food, nocturnal aspiration, chest pain (less than type III), weight loss, heartburn like symptoms from fermentation.

Complications: aspiration pneumonia, oesophagitis, squamous cell carcinoma (risk 1 in 300 patient years, 10 fold), megaoesophagus.

Distinguish from pseudoachalasia (malignancy at the gastro oesophageal junction, Chagas disease, amyloidosis).

• High resolution manometry confirms the subtype.
• Barium oesophagram: dilated oesophagus, bird beak narrowing at the gastro oesophageal junction, retained barium column at 1, 2, and 5 minutes.
• Upper endoscopy: retained food, dilated oesophagus, resistance at the lower oesophageal sphincter; biopsies to exclude eosinophilic oesophagitis and tumour; endoscopic ultrasound or CT for suspected pseudoachalasia (age over 60, weight loss under 6 months).
• Functional lumen imaging probe measures distensibility.
• Chagas serology in endemic exposure.

• Definitive treatments are procedures that disrupt the lower oesophageal sphincter; medical therapy is a bridge.
• Peroral endoscopic myotomy (POEM): preferred in many centres, success 85 to 95% at 2 years; high rate of post procedure reflux (30 to 50%), so PPI long term (omeprazole 20 mg daily).
• Laparoscopic Heller myotomy with partial fundoplication (Dor or Toupet): success 85 to 90%, lower reflux; suitable for fit patients.
• Pneumatic dilation (30, 35, 40 mm graded balloons): success 70 to 80% initially, retreatment needed in 25 to 35% over 5 years; perforation risk 1 to 2%.
• Botulinum toxin injection 100 units for patients unfit for definitive therapy (benefit 6 to 12 months).
• Medical therapy: nifedipine 10 to 20 mg or isosorbide dinitrate 5 mg sublingually before meals, sildenafil.
• Oesophagectomy for end stage (sigmoid) megaoesophagus failing other treatment.
• Follow up with timed barium oesophagram and Eckardt score; surveillance endoscopy every 3 years from 10 to 15 years after diagnosis is considered.
• Treat aspiration, nutrition.