Sterile carbon particle suspension vs India ink for endoscopic tattooing of colonic lesions: a randomized controlled trial

Background: Different markers have been used preoperatively to mark colonic lesions, especially India ink. In recent years, another kind of marker has been developed: sterile carbon particle suspension (SCPS). No comparison between these two markers has yet been made. The aim of the present study was to compare the pyrogenic, inflammatory and intraperitoneal effect of these two markers. Methods: From September 2015 to December 2018, adult patients who were candidates for elective laparoscopic colon resection were randomized to the SCPS or conventional India ink injection group using computer-based randomization. The primary endpoint of the study was the presence of intraoperative adhesions related to the endoscopic tattoo. Secondary endpoints were differences in white blood cell, C-reactive protein, and fibrinogen levels as well as, abdominal pain and body temperature at baseline (before endoscopic tattooing) and 6 and 24 h after colonoscopy. Finally, the visibility of the tattoo during the minimally invasive intervention was assessed. Results: Ninety-four patients were included in the study, 47 for each arm. There were 45/94 females (47.9%) and 49/94 males (52.1%), with a median age of 67.85 ± 9.22 years. No differences were found between groups in WBC, fibrinogen levels, body temperature or VAS scores, but we documented significantly higher CRP values at 6 and 24 h after endoscopic tattooing with India ink injection. There were significantly fewer adhesions in the SCPS Endoscopic Marker group. All the endoscopic tattoos were clearly visible. Conclusions: SCPS is an effective method for tattooing colonic lesions and has a better safety profile than traditional India ink in terms of post-procedure inflammatory response and intraoperative bowel adhesions. Clinical trial registration: clinicaltrials.gov (ID: NCT03637933).