Use of a novel shorter minimum caliber needle for creating endoscopic tattoos for preoperative localization: a comparative ex vivo study

BACKGROUND AND STUDY AIMS  In colorectal cancer surgery, inadvertent deep injections during endoscopic tattooing can cause India ink leakage into the peritoneum, leading to complications or to poor visualization of the surgical plane. This ex vivo animal study compared the use of novel shorter, minimum caliber needles versus conventional injection needles for endoscopic tattooing. ANIMALS AND METHODS  Four endoscopists used the novel needles and conventional needles to make ten endoscopic tattoos (five tattoos/needle type/endoscopist) in harvested porcine rectum using a saline test-injection method. India ink leakage and the success of the tattoo (i. e. visible, < 40 mm, plus no India ink leakage) were compared. RESULTS India ink leakage was observed for 30 % (6/20) of the conventional needle tattoos but for none of the novel needle tattoos ( P  = 0.02). Tattoos created using the novel needles were more successful than those made with the conventional needles: 18/20 (90 %) vs. 11/20 (55 %); P  = 0.01. CONCLUSIONS The use of novel shorter minimum caliber needles may be safe and effective for endoscopic tattooing for preoperative localization prior to colorectal cancer surgery.