High Resolution Magnification Endoscopy with Narrow Band Imaging in Patients with Barrett's Esophagus

Abstract

Background: Chromoscopy either as a vital or contrast stain has been shown to be useful to detect specialized intestinal metaplasia (SIM) and dysplasia in Barrett's esophagus (BE). Narrow Band Imaging (NBI) is a novel imaging technique that uses optical filters to enhance the mucosal contrast, revealing the superficial structural and microvascular patterns. The aim of our study was to study the utility of high resolution magnification endoscopy (HRME) with NBI in patients with BE. Methods: Consecutive patients with known BE undergoing surveillance endoscopy were enrolled in the study. Conventional white light endoscopy was followed by HRME with NBI using a high resolution magnification endoscope (Olympus GIF-Q240Z, 115×) and an NBI light source. Structural and microvascular patterns within the Barrett's segment were identified and biopsies taken that were read by pathologists blinded to NBI findings. Results: Thirty patients with BE were evaluated (mean age 63 yrs, 24 males). Mean length of Barrett's segment was 3.6 cm (range 1-10 cm). With NBI, striking contrast was observed between squamous and columnar mucosa. Three distinct mucosal pit patterns (tubular/villous/linear, circular, distorted) and two microvascular patterns (regular lace-like network, and irregular-dilated-tortuous) were seen. A total of 183 biopsies were taken. The yield of SIM on targeted biopsies according to the pit patterns was as follows: tubular/linear/villous structural pattern with regular microvessels 83/87 (95.4%), circular 0/9 (0%), and regular microvascular pattern (RMVP) with no structural pattern 52/53 (98.1%). Sensitivity, specificity, and positive predictive values of the combination of tubular/villous/linear pattern with regular microvessels and/or RMVP with no structural pattern for detecting SIM were 100%, 69%, and 97.5%, respectively. The sensitivity and specificity of the above patterns in patients with long segment BE and short segment BE were 100%, 75%, and 100%, 67% respectively. High grade dysplasia (HGD) was diagnosed in 5 cases. Sensitivity, specificity, and positive predictive values of the irregular microvascular pattern for the detection of HGD were 100%. In all cases with HGD we could visualise a demarcation line between the neoplastic and non-neoplastic tissue. Conclusion: Using HRME with NBI we described the non-dysplastic and dysplastic features in BE. It provides detailed images of capillaries and mucosal pit patterns without the need for chromoscopy. Further studies are required to prove the efficacy of this technique in routine clinical practice for BE surveillance.