WAYS TO PERFORM AN ENDOSCOPIC TATTOO. PROSPECTIVE AND RANDOMIZED STUDY IN PATIENTS WITH COLORECTAL NEOPLASM.

BACKGROUND AND STUDY AIMS Intraoperative identification of colonic lesions previously detected at colonoscopy may be difficult. Endoscopic tattooing facilitates this 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 Prospective and randomized study. All tattoo candidate patients prior to surgery were included and randomized into 4 groups (tattoo at 2 or 3 injection points and with a volume of 1 or 1.5 ml of labeling). Multiple variables were registered. RESULTS 195 patients were included in which endoscopic tattoo and subsequent surgical intervention was performed, with a mean age of 70.1 years, 67.2% being men. The laparoscopic approach was applied in 57.9% of cases. The intraoperative visibility of the endoscopic tattoo was 89.7%. 30% of rectal lesions were not visible. Excluding the rectum, the marking was visible intraoperatively in 92% of the 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%. No 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 2 injection points and 1 ml of marking volume for its simplicity, efficiency and safety.