Introduction Ectopic gastric mucosa in the cervical oesophagus (inlet patch) is easily missed on endoscopic examination because of its localization, usually just below the upper oesophageal sphincter. In some individuals, an inlet patch might cause symptoms such as dysphagia, globus sensation, odynophagia or coughing.

We prospectively investigated whether narrow band imaging (NBI) during endoscopic inspection of the cervical oesophagus improves the visualisation of heterotopic gastric mucosa and increases the detection rate of inlet patches.

Methods Subsequent upper gastrointestinal endoscopies were performed by three experienced endoscopists using videoendoscopes with NBI option (Olympus Lucera Spectrum system). Between 01/02/2010 and 01/12/2011, patients with various indications for upper gastrointestinal endoscopy were consecutively assigned to the lists of three specialists in endoscopy. One endoscopist routinely applied NBI during extubation of the endoscope (NBI) in addition to standard white light endoscopy, the second was aware of the study, but did not routinely use NBI, the third was unaware of the study and did not use NBI. The presence of an inlet patch was documented by photo imaging.

Results 1407 upper endoscopies were performed. When NBI was used during extubation of the oesophagus, inlet patches were detected in 17 out of 510 endoscopies. The detection rate of inlet patches using NBI (3.3%) was significantly higher than in conventional white light endoscopy only (10/897; 1.1%; p = 0.007 ), whether the endoscopist was aware (4/382; 1.1%; p = 0.026) or unaware of the study (6/515; 1.2%; p = 0.02. ). Using NBI, the relative chance to detect an inlet patch increases about threefold (odds ratio 3.05, 95% CI 1.39–6.71).

Conclusion Withdrawal of the endoscope from the cervical oesophagus using narrow band imaging increased the detection rate of inlet patches about threefold compared to standard white light endoscopy. NBI may assist in the accurate assessment of patients presenting with globus sensation, dysphagia or chronic cough, to identify rare causes such as an inlet patch that may be amenable to therapy.

Disclosure of Interest None Declared.