Narrow band imaging for the detection of gastric intestinal metaplasia and dysplasia during surveillance endoscopy.

Background Surveillance of premalignant gastric lesions relies mainly on random biopsy sampling. Narrow band imaging (NBI) may enhance the accuracy of endoscopic surveillance of intestinal metaplasia (IM) and dysplasia.We aimed to compare the yield of NBI to white light endoscopy (WLE) in the surveillance of patients with (IMa)and dysplasia.Methods Patients with previously identified gastric IM or dysplasia underwent a surveillance endoscopy. Both WLE and NBI were performed in all patients during a single procedure. The sensitivity of WLE and NBI for the detection of premalignant lesions was calculated by correlating endoscopic findings to histological diagnosis.Results Forty-three patients (28 males and 15 females,mean age 59 years) were included. IM was diagnosed in 27 patients; 20 were detected by NBI and WLE, four solely by NBI and three by random biopsies only. Dysplasia was detected in seven patients by WLE and NBI and in two patients by random biopsies only. Sixty-eight endoscopically detected lesions contained IM: 47 were detected by WLE and NBI, 21 by NBI only. Nine endoscopically detected lesions demonstrated dysplasia: eight were detected by WLE and NBI, one was detected by NBI only.The sensitivity, specificity, positive and negative predictive values for detection of premalignant lesions were 71, 58,65 and 65% for NBI and 51, 67, 62 and 55% for WLE,respectively.Conclusions NBI increases the diagnostic yield for detection of advanced premalignant gastric lesions compared to routine WLE.