Achalasia: A review of clinical diagnosis, epidemiology, treatment and outcomes

Abstract

Achalasia is a neurodegenerative motility disorder of the oesophagus resulting in deranged oesophageal peristalsis and loss of lower oesophageal sphincter function. Historically, annual achalasia incidence rates were believed to be low, approximately 0.5-1.2 per 100000. More recent reports suggest that annual incidence rates have risen to 1.6 per 100000 in some populations. The aetiology of achalasia is still unclear but is likely to be multi-factorial. Suggested causes include environmental or viral exposures resulting in inflammation of the oesophageal myenteric plexus, which elicits an autoimmune response. Risk of achalasia may be elevated in a sub-group of genetically susceptible people. Improvement in the diagnosis of achalasia, through the introduction of high resolution manometry with pressure topography plotting, has resulted in the development of a novel classification system for achalasia. This classification system can evaluate patient prognosis and predict responsiveness to treatment. There is currently much debate over whether pneumatic dilatation is a superior method compared to the Heller’s myotomy procedure in the treatment of achalasia. A recent comparative study found equal efficacy, suggesting that patient preference and local expertise should guide the choice. Although achalasia is a relatively rare condition, it carries a risk of complications, including aspiration pneumonia and oesophageal cancer. The risk of both squamous cell carcinoma and adenocarcinoma of the oesophagus is believed to be significantly increased in patients with achalasia, however the absolute excess risk is small. Therefore, it is currently unknown whether a surveillance programme in achalasia patients would be effective or cost-effective.

Keywords: Epidemiology; Achalasia; Incidence; Treatment; Oesophageal cancer risk

Core tip: Achalasia remains a disease of unknown aetiology. Multicentre studies could help elucidate the cause, especially as it presents with a similar phenotype to Chagas disease which is much better understood. Improved understanding of aetiology could guide novel treatments. Current treat choice in fit patients lies between pneumatic dilatation and laparoscopic Heller’s myotomy. Botulinum toxin is appropriate and effective for those unfit for other intervention. Novel treatments such as metal stents and natural orifice surgery are being trialled.