Objectives: Colonoscopy has an appreciable miss rate for adenomas and colorectal cancer. The goal of advanced endoscopic imaging is to improve lesion detection. Compared with standard definition, high-definition (HD) colonoscopes have the advantage of increased field of visualization and higher resolution; narrow band imaging (NBI) utilizes narrow band filters for enhanced visualization of surface architecture and capillary pattern. The objective of this study was to compare the yield and miss rates of HD-NBI and HD-WLE (white light endoscopy) for the detection of colon polyps using meta-analysis.
Methods: A recursive literature search of randomized controlled trials (RCTs) comparing the yield of HD-NBI and HD-WLE for detection of colon polyps in patients undergoing screening/surveillance colonoscopy. Authors were contacted for missing data. In RCT with tandem colonoscopy (RCT-t), findings from the first-pass examinations were used in the yield analysis and from the tandem pass for the miss rate analysis. Data on the yield of polyps were extracted, pooled, and analyzed using RevMan 4.2.9 software. Odds ratio (OR) and 95% confidence intervals (CIs) for the pooled data for the yield and miss rates of NBI and WLE were calculated. A fixed effect model (FEM) was used for analyses without, and a random effect model (REM) for analyses with heterogeneity.
Results: The yield analysis revealed no significant difference between HD-NBI and HD-WLE for the detection of adenomas (six studies; n=2,284; OR: 1.01; CI: 0.74-1.37; REM); patients with polyps (six studies; n=2,275; OR: 1.15; CI: 0.8-1.64; REM); patients with adenomas (four studies; n=2,177; OR: 1.0; CI: 0.83-1.20; FEM); detection of adenomas <10 mm (five studies; n=1,618; OR: 1.32; CI: 0.92-1.88; FEM); flat adenomas (five studies; n=1,675; OR: 1.26; CI: 0.62-2.57; REM); and flat adenomas per patient (five studies; n=2,200; OR: 1.63; CI: 0.71-3.74; REM). The miss rate analysis revealed no difference in polyp miss rate (three studies; n=524; OR: 1.17; CI: 0.8-1.71; FEM) or adenoma miss rate (three studies; n=524; OR: 0.65; CI: 0.4-1.06; FEM) between the two techniques.
Conclusions: Compared with HD-WLE, HD-NBI does not increase the yield of colon polyps, adenomas, or flat adenomas, nor does it decrease the miss rate of colon polyps or adenomas in patients undergoing screening/surveillance colonoscopy.