Endoscopic tattooing to mark distal margin for low anterior rectal and select sigmoid resections

Obtaining a reliable distal margin during anterior colorectal resection can be difficult. In this study, endoscopic transmural tattoos were placed to mark the distal transection point in patients with distal colorectal neoplasms who undergo bowel resection. In the operating room, before surgery, sigmoidoscopy is performed with a 2-channel scope using CO₂ insufflation. Through channel 1, a biopsy forceps, marked 5 cm from its end, is inserted to the tumor's distal edge; in channel 2, a sclerotherapy catheter is placed. The scope is then withdrawn and forceps inserted at the same rate until the mark is seen, next, via the needle catheter, 4 tattoos are placed at that level circumferentially. After rectal mobilization, visible external tattoos guide stapler placement. If no tattoo is seen, sigmoidoscopy is done and the tattoos used to guide stapler placement. In all 27 patients, the tattoos guided stapler placement; tattoos were seen via the abdomen in 26 and the stapler placed as per tattoos in 25. In 2 patients, repeat endoscopy was done and tattoos used to guide or confirm stapler placement. The margin was ≤1 cm from target in 74% while in 22% the margin was 2 to 3.5 cm off target (mean deviation from target margin = 0.33 cm). In conclusion, this method facilitates stapler placement and provides more reliable margins.