Comparison of white-light endoscopy, optical-enhanced and acetic-acid magnifying endoscopy for detecting gastric intestinal metaplasia: A randomized trial

Abstract

Background: Gastric intestinal metaplasia (GIM) is a precancerous lesion of the stomach, which severely affects human life and health. Currently, a variety of endoscopic techniques are used to screen/evaluate GIM. Traditional white-light endoscopy (WLE) and acetic-acid chromoendoscopy combined with magnifying endoscopy (ME-AAC) are the interventions of choice due to their diagnostic efficacy for GIM. Optical-enhanced magnifying endoscopy (ME-OE) is a new virtual chromoendoscopy technique to identify GIM, which combines bandwidth-limited light and image enhancement processing technology to enhance the detection of mucosal and vascular details. We hypothesized that ME-OE is superior to WLE and ME-AAC in the evaluation of GIM.

Aim: To directly compare the diagnostic value of WLE, ME-AAC, and ME-OE for detection of GIM.

Methods: A total of 156 patients were subjected to consecutive upper gastrointestinal endoscopy examinations using WLE, ME-AAC, and ME-OE. Histopathological findings were utilized as the reference standard. Accuracy, sensitivity, specificity, and positive and negative predictive values of the three endoscopy methods in the diagnosis of GIM were evaluated. Moreover, the time to diagnosis with ME-AAC and ME-OE was analyzed. Two experts and two non-experts evaluated the GIM images diagnosed using ME-OE, and diagnostic accuracy and intra- and inter-observer agreement were analyzed.

Results: GIM was detected in 68 of 156 patients (43.6%). The accuracy of ME-OE was highest (91.7%), followed by ME-AAC (86.5%), while that of WLE (51.9%) was lowest. Per-site analysis showed that the overall diagnostic accuracy of ME-OE was higher than that of ME-AAC (P = 0.011) and WLE (P < 0.001). The average diagnosis time was lower in ME-OE than in ME-AAC (64 ± 7 s vs 151 ± 30 s, P < 0.001). Finally, the inter-observer agreement was strong for both experts (k = 0.862) and non-experts (k = 0.800). The internal consistency was strong for experts (k = 0.713, k = 0.724) and moderate for non-experts (k = 0.667, k = 0.598).

Conclusion: For endoscopists, especially experienced endoscopists, ME-OE is an efficient, convenient, and time-saving endoscopic technique that should be used for the diagnosis of GIM.

Keywords: Acetic-acid; Gastric intestinal metaplasia; Magnifying endoscopy; Optical-enhanced.

Figure 1

Endoscopic images in the magnifying mode. A and B: In the optical-enhanced endoscopy Mode 1 and magnifying endoscopy image, light blue crest appears as blue-white lines visible on the epithelial surface; C and D: After spraying acetic acid, villous or cerebral gyrus-like structure, partial pits missing, and irregular arrangement are usually shown in magnifying mode.

Figure 2

Flow chart of the examinations: 180 patients enrolled, 156 patients eligible for white-light endoscopy (24 patients excluded: 4 with gastrointestinal hemorrhage, 5 with gastrectomy, 14 with coagulopathy, and one patient with advanced gastric cancer). WLE: White-light endoscopy; ME-AAC: Acetic-acid chromoendoscopy combined with magnifying endoscopy.

Figure 3

Appearance of gastric intestinal metaplasia under three different endoscopic methods. A and D: Lesions as ash-colored nodular changes (white-light endoscopy); B and E: Bluish-whitish lesion area (optical-enhanced endoscopy, Mode 1); C and F: The clearer, whitish patches observed after spraying with acetic acid (acetic-acid chromoendoscopy).

Figure 4

The time required for optical-enhanced magnifying endoscopy and acetic-acid chromoendoscopy combined with magnifying endoscopy to diagnose gastric intestinal metaplasia. Fold change was calculated by dividing the time required for optical-enhanced magnifying endoscopy by the time required for acetic-acid chromoendoscopy combined with magnifying endoscopy. ME-OE: Optical-enhanced magnifying endoscopy; ME-AAC: Acetic-acid chromoendoscopy combined with magnifying endoscopy.