Diagnosis and treatment of Barrett's oesophagus. A general survey.

Barrett's oesophagus is an acquired condition with columnar metaplasia of the distal oesophagus. This condition represents the most serious consequence of chronic gastro-oesophageal reflux as it is associated with an increased incidence of oesophageal adenocarcinoma. Since the exact pathophysiology is not known, prevention is not possible. The diagnosis of Barrett's oesophagus requires the presence of intestinal metaplasia in at least one biopsy specimen from the lower oesophagus. Barrett's oesophagus is considered a premalignant condition and some cases progress from dysplasia to invasive adenocarcinoma. Medical or surgical antireflux treatment controls symptoms and oesophagitis, but Barrett's oesophagus remains. Patients are usually followed up by endoscopy for detection of dysplasia or early cancer. Several reports in the literature have assessed the effects of H2-blocker and proton pump inhibitors treatment on Barrett's epithelium, but none has clearly documented a significant and consistent regression of the metaplastic epithelium. Even with high doses of proton pump inhibitors given for a prolonged period of time, it does not appear that a significant regression of Barrett's epithelium can be achieved. Various studies have assessed the effects of antireflux surgery on the regression of columnar epithelium and dysplasia and its potential protective effect on the subsequent development of carcinoma. Overall, it appears from these reports that antireflux surgery, despite adequate symptomatic results, does not significantly and consistently lead to a reduction in length or disappearance of the Barrett's mucosa, and does not prevent the development of dysplasia and its progression to carcinoma. Recently, numerous reports have documented the regression of Barrett's mucosa by using various experimental techniques: these thermal therapies focus on the removal of the columnar epithelium with restoration of the squamous epithelium. Technological advances including laser and especially photodynamic therapy have allowed for endoscopic mucosal ablation. Long-term results are more encouraging when this mucosal ablation is associated with antireflux medical or surgical therapy. Currently, none of these approaches can obviate the need for continued endoscopic surveillance; however the photodynamic therapy seems to be a promising alternative in the future.