Ways to perform an endoscopic tattoo. Prospective and randomized study in patients with colorectal neoplasm

Background and aims: intraoperative identification of colonic lesions previously detected via colonoscopy may be difficult. Endoscopic tattooing facilitates identification, but there is no evidence regarding which is the best tattoo technique. The goal of the study was to describe the efficacy and safety of endoscopic tattooing and to detect technical and clinical factors associated with its efficacy. Patients and methods: a prospective and randomized study was performed. All tattoo candidate patients were included prior to surgery and randomized into four groups; tattoo at two or three injection points and with a volume of 1 or 1.5 ml of labeling. Multiple variables were registered. Results: one hundred and ninety-five patients were included with an endoscopic tattoo and who subsequently underwent a surgical intervention, the mean age was 70.1 years and 67.2 % were male. The laparoscopic approach was applied in 57.9 % of cases. The intraoperative visibility of the endoscopic tattoo was 89.7 % and 30 % of rectal lesions were not visible. Excluding the rectum, the marking was visible intraoperatively in 92 % of patients, without significant differences according to the surgical approach, the type of marking or any of the variables collected. The tattoo was safe in 92.3 % of the cases. The adverse effect rate was 7.7 % and none of the complications were clinically significant. There were no significant differences between any variables collected in relation to adverse effects. Conclusions: endoscopic colon tattoo is safe and effective regardless of the technique used. We recommend the technique of two injection points and 1 ml of marking volume for its simplicity, efficiency and safety.