Chromoendoscopy of gastric adenoma using an acetic acid indigocarmine mixture

AIM:To investigate the usefulness of chromoendoscopy,using an acetic acid indigocarmine mixture(AIM),for gastric adenoma diagnosed by forceps biopsy.METHODS:A total of 54 lesions in 45 patients diagnosed as gastric adenoma by forceps biopsy were prospectively enrolled in this study and treated by endoscopic submucosal dissection(ESD)between January 2011 and January 2012.AIM-chromoendoscopy(AIMCE)was performed followed by ESD.AIM solution was sprinkled and images were recorded every 30 s for 3min.Clinical characteristics such as tumor size(<2cm,≥2 cm),surface color in white light endoscopy(WLE)(whitish,normochromic or reddish),macroscopic appearance(flat or elevated,depressed),and reddish change in AIM-CE were selected as valuables.RESULTS:En bloc resection was achieved in all 54 cases,with curative resection of fifty two lesions(96.3%).Twenty three lesions(42.6%)were diagnosed as welldifferentiated adenocarcinoma and the remaining 31lesions(57.4%)were gastric adenoma.All adenocarcinoma lesions were well-differentiated tubular adenocarcinomas and were restricted within the mucosal layer.The sensitivity of reddish color change in AIM-CE is significantly higher than that in WLE(vs tumor size≥2 cm,P=0.016,vs normochromic or reddish surface color,P=0.046,vs depressed macroscopic type,P=0.0030).On the other hand,no significant differences were found in the specificity and accuracy.In univariate analysis,normochromic or reddish surface color in WLE(OR=3.7,95%CI:1.2-12,P=0.022)and reddish change in AIM-CE(OR=14,95%CI:3.8-70,P<0.001)were significantly related to diagnosis of early gastric cancer(EGC).In multivariate analysis,only reddish change in AIM-CE(OR=11,95%CI:2.3-66,P=0.0022)was a significant factor associated with diagnosis of EGC.CONCLUSION:AIM-CE may have potential for screening EGC in patients initially diagnosed as gastric adenoma by forceps biopsy.

Toward an easier indigocarmine chromoendoscopy

Indigocarmine chromoendoscopy has been proven to improve the detection of colonic lesions during screening colonoscopy, and is associated with increased adenoma detection rates. Furthermore, it is commonly used to help in the delineation and characterization of colorectal neoplasms. However, it usually requires the use of a spraying catheter that decreases the suction capacity of the endoscope, and is time- consuming. Herein, we report on the feasibility of indigo carmine chromoendoscopy during colonoscopy without using a spraying catheter, with the dye being administered through the air/water channel of the endoscope. Since the suction channel remains free, the air can be exsufflated and the staining then applies uniformly onto the colonic walls with the excess indigocarmine dye being immediately eliminated. In our experience with various types of colonoscopes and cap-assisted colonoscopy, this procedure makes indigocarmine chromoendoscopy much easier and quicker to perform, and might save the use of a spray catheter.