Chromoendoscopy with indigo carmine dye added to acetic acid in the diagnosis of gastric neoplasia: a prospective comparative study

BackgroundConventional endoscopy and chromoendoscopy with indigo carmine dye are usually performed for recognizing adequate tumor-negative lateral margins for successful endoscopic resection of gastric neoplasia. However, chromoendoscopy with indigo carmine dye added to acetic acid has not been used for this purpose.ObjectiveOur purpose was to compare the diagnostic performance of chromoendoscopy with indigo carmine dye added to acetic acid with that of conventional endoscopy and chromoendoscopy with indigo carmine dye or acetic acid alone.DesignProspective study.SettingSocial Insurance Funabashi Central Hospital.PatientsForty-seven consecutive patients (53 lesions) with early gastric cancer and gastric adenomas who underwent endoscopic submucosal dissection (ESD) from April 2006 to July 2007 were studied.InterventionsAll the lesions were examined by the endoscopic modalities before ESD, and the resected specimens were analyzed histopathologically.Main Outcome MeasurementsTwo endoscopists independently evaluated the diagnostic performance of each image in terms of recognition of tumor borders with reference to macroscopic and histopathologic findings of resected specimens. We also conducted a substudy to assess interobserver variability.ResultsThere was good interobserver agreement between the 2 endoscopists in this study (κ index = 0.764). The diagnostic performance of chromoendoscopy with indigo carmine dye added to acetic acid was significantly greater than that of any of the other modalities (vs each: P < .005).ConclusionsThe diagnostic performance of chromoendoscopy with indigo carmine dye added to acetic acid was better compared with conventional endoscopy and chromoendoscopy by using only indigo carmine dye or acetic acid. The applicability of this method for gastric neoplasia merits further investigation.