WHEN AND HOW TO USE ENDOSCOPIC TATTOOING IN THE COLON: AN INTERNATIONAL DELPHI AGREEMENT.

ABSTRACT Background There is a lack of clinical studies to establish indications and methodology for tattooing, therefore technique and practice of tattooing is very variable. We aimed to establish a consensus on indications and appropriate techniques for colonic tattoo through a modified Delphi Process. Methods The baseline questionnaire was classified into 3 areas: where tattooing should not be used (1 domain, 6 questions), where tattooing should be used (4 domains, 20 questions) and how to perform tattooing (1 domain 20 questions). A total of 29 experts participated in the 3 rounds of the Delphi process. Results A total of 15 statements were approved. The statements that achieved the highest agreement were: Tattooing should always be used after endoscopic resection of a lesion with suspicion of submucosal invasion. (Agreement score 4.59; degree of consensus 97%). For a colorectal lesion that is left in situ but considered suitable for endoscopic resection, tattooing may be used if the lesion is considered difficult to detect at a subsequent endoscopy. (Agreement score 4.62; degree of consensus 100%). A tattoo should never be injected directly into or underneath a lesion that might be endoscopically removed at a later point in time. (Agreement score 4.79; degree of consensus 97%). Details of the tattoo injection should be clearly stated in the endoscopy report. (Agreement score 4.76; degree of consensus 100%) Conclusion This expert consensus has developed different statements about where tattooing should not be used, when it should be used and how that should be done.