Long-term risk of oesophagitis, Barrett's oesophagus and oesophageal cancer in achalasia patients.

Achalasia is a motility disorder of the oesophagus of unknown origin in which loss of relaxation of the lower oesophageal sphincter (LOS) and aperistalsis in the distal oesophagus leads to functional oesophageal obstruction. The treatment is symptomatic, aimed at lowering of the LOS pressure, and may be accompanied by various side effects, including gastro-oesophageal reflux, a risk factor for oesophagitis and its complications. Stasis and fermentation can also lead to inflammation of the oesophageal mucosa, giving rise to hyperplasia of the epithelium, multifocal dysplasia and in some patients eventually squamous cell carcinoma. Unfortunately, the sensitivity and specificity of endoscopical inspection to assess inflammation or dysplasia of the oesophageal lining is low, such that biopsy sampling is necessary for accurate assessment. Although it is generally accepted that achalasia is a pre-malignant disorder, the reported increased risk of patients with achalasia developing a squamous cell carcinoma varies from 0 to 140 times that of the normal population. In addition, achalasia may predispose to Barrett's metaplasia and oesophageal adenocarcinoma, which have been described in case reports after myotomy. Surveillance endoscopy with tissue sampling to detect pre-neoplastic lesions has been recommended, even though this can be very difficult due to mucosal adherence of food as well as hyperplastic changes of the mucosa. In the event of moderate to severe inflammation and/or persisting stasis of food despite adequate LOS pressure-lowering therapy, the surveillance interval should be shortened and performed after a 3-day liquid diet. The exact technique and time intervals still need to be established, however.