[Indigo carmine contrast staining in combination with high resolution electronic endoscopy].

INTRODUCTION Chromoendoscopy is an old endoscopic technique which has a renascence in the era of high resolution electronic endoscopy. Indigo carmine, this deep blue stain is not absorbed by gastrointestinal epithelium. It pools in crevices and valleys and highlights small lesions and defines irregularities in mucosal architecture. METHOD The indigo carmine dye contrast method was introduced in author's endoscopic laboratory in 1994 and high resolution (400 k.pixels) endoscopy in 1997. 0.1-0.5% indigo carmine solution was administered to the gastric, duodenal or colonic mucosa through the biopsy channel of the endoscope. The author found the dye method gave dramatic accentuation of abnormalities of mucosal architecture (i.e. small irregularities, ulcer scars, extent of small tumours, polyps) and was suitable to evaluate villous atrophy in the duodenum. RESULTS Using indigo carmine and high resolution electronic endoscopy it was possible to diagnose 3 times more gastric adenomas than was in the past. In the colon it was studied the surface appearance of colonic crypts and was able to discriminate between hyperplastic polyps which had a tipical "pit" pattern ("dots") and adenomatous polyps, which had a "groove" or "sulci" pattern. After histological examination the diagnostic accuracy was proved 59/64 in adenomatous and 18/23 in hyperplastic polyps. CONCLUSION One should improve minute endoscopical observation and it is believed the administration of indigo carmine dye and high resolution endoscopy are suitable method for that.