Division of Gastroenterology In the United States, chromoendoscopy with targeted biopsies remains the preferred method for dysplasia surveillance and is performed primarily in tertiary academic centers by trained endoscopists for high-risk patients with IBD, including long-term IBD and prior history of severe colitis requiring escalation therapy, dysplasia, or primary sclerosing cholangitis.15,16,33 However, random biopsies plus targeted biopsies remain an alternative when chromoendoscopy is not available or optimal (eg, poor bowel preparation, presence of pseudopolyps, active inflammation). 46. 2010;8(4):364-370. Ulcerative colitis practice guidelines in adults: American College of Gastroenterology, Practice Parameters Committee. Missed adenomas during colonoscopic surveillance in individuals with Lynch syndrome (hereditary nonpolyposis colorectal cancer). However, the adenoma detection rate was nearly doubled compared to well-documented historical controls, suggesting a benefit primarily from HD colonoscopy.64 Results of another prospective, randomized, back-to-back trial comparing NBI to conventional colonoscopy for adenoma detection found that the miss rate for polyps and adenomas is lower with HD-NBI than with conventional colonoscopy.108, A Cochrane meta-analysis compared polyp detection using NBI with SD- and HD-WLE either together or separately.109 Study results demonstrated no statistically significant difference between white-light imaging (SD or HD) and NBI in the detection of patients with colorectal polyps. Soetikno R, Subramanian V, Kaltenbach T, et al. 87. 40. Am J Gastroenterol. However, indigo carmine is very cheap, safe, easily obtained and produces a range of stunning colours. 12. They suggest the reaction proceeds as follows: under alkaline conditions, the glucose is ionised and tautomerises to the straight chain aldehyde and then to the key intermediate, an enediolate anion. Presumably these hydrogen bonds also weaken the N–H bond when compared to that in indole, which explains the lower pKa (12.2 vs 16.2) that facilitates the first colour change in the experiment. However, between approximately 15 and 45 minutes after making up the solution, the colour change will be much faster. Virtual Chromoendoscopy Virtual chromoendoscopy has been shown to be able to accurately distinguish neoplastic lesions from nonneoplastic lesions. Picco MF, Pasha S, Leighton JA, et al. 2010;72(1):136-142. 19. Rex DK, Kahi C, O’Brien M, et al. 60. Dysplastic lesions can be challenging to detect due to their subtle, flat nature; their location among inflammatory pseudopolyps; and scarring as a result of postinflammatory mucosal changes.22-26. Scand J Gastroenterol. Gastrointest Endosc. By Declan Fleming2014-05-06T00:00:00+01:00, Using indigo carmine to produce a range of stunning colours. Endosc Int Open. 104. Am J Gastroenterol. 2009;7(3):288-295. 50. If the solution appears more yellow than green at this stage, add a few more crystals of dye until the colour is convincingly green. Am J Gastroenterol. White-light or narrow-band imaging colonoscopy in surveillance of ulcerative colitis: a prospective multicenter study. Am J Gastroenterol. 2004;53(3):376-380. Dr Buchner has no relevant conflicts of interest to disclose. Replace the stopper or lid and wait. A full visualization occurs approximately 1 minute following the application of methylene blue. 31. Tung SY, Wu CS, Su MY. 32. Hurlstone DP, Karajeh M, Cross SS, et al. Narrow-band imaging as an alternative to chromoendoscopy for the detection of dysplasia in long-standing inflammatory bowel disease: a prospective, randomized, crossover study. Kamiński MF, Hassan C, Bisschops R, et al. The role of high-magnification-chromoscopic colonoscopy in hereditary nonpolyposis colorectal cancer screening: a prospective “back-to-back” endoscopic study. A study by Repici and colleagues83 assessed the accuracy and reliability of histologic prediction of polyps smaller than 1 cm by applying the NICE Classification to the FICE system. 2013;62(12):1704-1713. Wear eye protection. Marion JF, Waye JD, Israel Y, et al; Chromoendoscopy Study Group at Mount Sinai School of Medicine. Indigo carmine itself acts as both a pH and redox indicator. Gastroenterology. The American Society for Gastrointestinal Endoscopy PIVI (Preservation and Incorporation of Valuable Endoscopic Innovations) on real-time endoscopic assessment of the histology of diminutive colorectal polyps. Subramanian V, Mannath J, Hawkey CJ, Ragunath K. High definition colonoscopy vs. standard video endoscopy for the detection of colonic polyps: a meta-analysis. 2008;57(1):65-70. Presumably these hydrogen bonds also weaken the N–H bond when compared to that in indole, which explains the lower pKa (12.2 vs 16.2) that facilitates the first colour change in the experiment. These findings were supported by subsequent trials that confirmed that panchromoendoscopy increased the diagnostic yield of intraepithelial neoplasia when compared with conventional SD colonoscopy and biopsy techniques by a range of 3- to 4.5-fold.15,16,29,30 Currently, chromoendoscopy with targeted biopsies is the surveillance method recommended by the European Society of Gastrointestinal Endoscopy (ESGE) and the British Society of Gastroenterology (BSG).31,32 In the United States, chromoendoscopy with HD colonoscopy in patients with long-term IBD has been the suggested method of surveillance introduced by the recent SCENIC (Surveillance for Colorectal Endoscopic Neo-plasia Detection and Management in Inflammatory Bowel Disease Patients: International Consensus -Recom-mendations) international consensus statement and endorsed by the American Society for Gastrointestinal Endoscopy (ASGE) and the American Gastroenterological Association (AGA).15,16,33 Chromoendoscopy with HD colonoscopy has been primarily utilized in tertiary referral centers, although efforts for its broader implementation have been undertaken.12 Previous guidelines published by the American College of Gastroenterology (ACG) and the AGA recommend varied approaches for dysplasia surveillance in patients with IBD.34,35 AGA guidelines recommend that chromoendoscopy be used only by experienced physicians.34 With the use of enhanced endoscopic techniques, targeted biopsies of suspicious lesions may be performed as an alternative to random biopsies.34 By contrast, the guidelines provided by the ACG do not recommend routine use of chromoendoscopy-enhanced surveillance colonoscopy in low-risk patients.35. 59. 2005;3(9):897-902. Repici A, Ciscato C, Correale L, et al. Endoscopy. East JE, Saunders BP. 2006;4(3):349-354. A flask containing a colourless liquid (consisting of an alkaline solution of glucose and methylene blue) is shaken. Am J Gastroenterol. N Engl J Med. The dye solution flows through the fallopian tubes into the abdominal cavity and becomes visible on laparoscopy. The Role of Chromoendoscopy in Polyp Characterization and Histology Prediction, Chromoendoscopy appears to be a promising technique for the characterization and real-time prediction of lesion histology, known as a virtual or optical biopsy, and its use in discriminating neoplastic from nonneoplastic polyps has been studied extensively.46 As specified in guidelines from the ASGE, a polyp can be left in situ instead of being sent to pathology to be characterized, resected, and discarded if the technology has high accuracy and a high NPV (>90%).47 Thus, chromoendoscopy has been evaluated as a potential tool in a characterize-resect-and-discard approach, in which the histologic diagnosis is based solely on the endoscopic image with photographic confirmation. Methylene blue versus indigo carmine. The blue colour gradually becomes a beautiful purple colour, then red, orange and finally yellow. However, given the poor results for improved adenoma detection using NBI and FICE and the low level of adenoma detection in the control arm of the i-scan study (13%), additional studies are needed to determine whether i-scan improves adenoma detection and to evaluate the final application (including efficacy and cost-effectiveness) of FICE, NBI, and i-scan in routine endoscopy practice. 2008;40(10):818-822. 2011;74(3):603-609. 2002;55(6):687-694. Effect of screening colonoscopy on colorectal cancer incidence and mortality. Dig Endosc. Gut. 2015;81(3):489-501.e26. Total colonic dye-spray increases the detection of diminutive adenomas during routine colonoscopy: a randomized controlled trial. The effect of significant adsorption parameters, viz. 2010;105(6):1301-1307. Chromoendoscopy in inflammatory bowel disease. 112. Does chromoendoscopy with structure enhancement improve the colonoscopic adenoma detection rate? 2006;101(2):343-350. Gastroenterology. session so others can sign in. Kahi CJ, Anderson JC, Waxman I, et al. Gastroenterology. European guidelines, including the BSG and the ESGE, recommend chromoendoscopy with targeted biopsies as the procedure of choice. Shergill AK, Lightdale JR, Bruining DH, et al; American Society for Gastrointestinal Endoscopy Standards of Practice Committee. Expert Rev Gastroenterol Hepatol. Efficacy of computed virtual chromoendoscopy on colorectal cancer screening: a prospective, randomized, back-to-back trial of Fuji intelligent color enhancement versus conventional colonoscopy to compare adenoma miss rates.