Diagnostic Yield of Methylene Blue Chromoendoscopy (MB) and Conventional 4-Quadrant Random Biopsy (RB) for Detecting Specialized Intestinal Metaplasia (SIM) and Dysplasia in Barrett's Esophagus (BE): A Meta-Analysis

Abstract

The reported yield of MB targeted biopsy in detecting SIM and dysplasia in BE in controlled studies has been variable. Aim: To perform a metaanalysis of published studies for assessment of yield of MB compared to RB in detecting SIM and dysplasia in BE. Methods: Studies comparing the diagnostic yield of MB and RB were identified by recursive search of the MEDLINE, EMBASE and Cochrane Databases using predefined search criteria along with manual search of cross-references of eligible articles. Data on yield of both modalities were extracted, pooled, and analyzed controlling for variation in technique as well patterns of staining with MB and stratified by grades of dysplasia. Weighted Incremental yield (IY) (yield of MB - yield of RB) and 95% confidence intervals (95% CI) of MB over RB were calculated using a fixed effect model (FEM) for analyses without and a random effect model (REM) for analyses with heterogeneity. Results: Six studies compared the yield MB with RB for detection of high-grade dysplasia (HGD) and early adenocarcinoma (108 patients). The IY for MB with RB for detection of HGD and early adenocarcinoma was 20% with FEM (p = 0.0003, 95% CI = 9-31%) with a number needed to test (NNT) of 5 to yield one additional detection (Fig). Four studies (153 patients) compared yield of MB with RB for detection of SIM. The IY for MB with RB for detection of SIM was 1% with REM [p = 0.86, 95% CI = -14 to17%]. Seven trials compared yield of MB with RB for detection of dysplasia (352 patients). The IY for MB with RB for detection of dysplasia was 7% with REM [p = 0.16, 95%CI = -3 to18%]. Six studies compared yield MB with RB for detection of low grade dysplasia (LGD) (74 patients). The IY for MB with RB for detection of LGD was 13% with REM. [p = 0.37, 95% CI = -15 to 42%]. Conclusion: Technique of MB is superior to RB for detection of HGD and early adenocarcinoma in Barrett's esophagus.