Tattoo you?

Tattoos are all the rage. Once the exclusive territory of sailors, there are now nearly twenty television programs devoted to tattoos and it almost seems as if no self-respecting professional sportsman would be seen without one. The placement of tattoos endoscopically in the colon has been described for over 50 years. With the rise of laparoscopic resection for colorectal cancer, surgeons have increasingly recommended the preoperative placement of a tattoo to enable them to swiftly and accurately locate colorectal tumors and prevent the inadvertent resection of the wrong segment or inadequate resection margins. In a meta-analysis, tattoo placement lowered the risk of location errors from 16% to 10% [1].

“Before a decision can be taken to recommend not placing tattoos to mark polypectomy sites, it would be wise to perform additional research.”

Several gastroenterological societies have published guidelines on tattoo placement. European Society for Gastrointestinal Endoscopy (ESGE) guidelines recommend that lesions which may need to be located again during future endoscopic or surgical procedures should be tattooed during colonoscopy using highly purified carbon particles (Spot; GI Supply, Camp Hill, Pennsylvania, USA) [2]. Two or three separate injections should be performed into the submucosa ≥3 cm from the lesion on the anal side, with initial creation of a saline bleb to prevent inadvertent injection into the peritoneum.

While this is a good thing for lesions that proceed to surgical resection, little attention has been paid to the potential disadvantages of tattoo placement or its necessity in lesions that are suitable for endoscopic resection. With screening programs leading to a shift toward the detection of colorectal neoplasia at earlier stages, the relative proportions of lesions proceeding to surgery or endoscopic therapy have also changed, with a far larger proportion now treated exclusively endoscopically.

Tattoo placement is not usually necessary to help find lesions during subsequent endoscopic resections. Not only does it not help, it frequently complicates endoscopic resection when tattoo ink has spread under the polyp. The diffusion of tattoo ink is variable but can extend over several centimeters and leads to submucosal fibrosis, making the formation of the submucosal fluid cushion necessary for safe endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) impossible [3]. There have been reports of perforations at polypectomy as a result [4].

Nevertheless, large numbers of benign colorectal lesions are marked endoscopically with tattoos at the initial colonoscopy. This occurs for several reasons. First, despite improvements in training in optical diagnosis and increasing recognition of the limitations of endoscopic biopsies, many colonoscopists still rely on biopsies to differentiate between benign and malignant lesions. If all surgical referrals must be tattooed, relying on histopathology will mean that all large lesions will require tattooing. Second, as already mentioned, rigid quality indicators in endoscopy, where the disadvantages of tattoo placement are insufficiently recognized, push endoscopists toward placing tattoos [5]. Lastly, and most relevant here, tattoos are felt to be necessary to help detect the polypectomy scar at endoscopic surveillance to check for residual or recurrent polyp tissue in or around the scar.

In this edition of Endoscopy, Michael Bourke and his prolific research group from Westmead Hospital, Australia try to bring some evidence to the discussion regarding the necessity of tattoo placement to aid in the subsequent detection of the polypectomy site [6]. Their results showed that there was no difference in the detection rate of the polypectomy scar between lesions that were marked with a tattoo and the majority in which no tattoo was placed.

While this is welcome evidence, it should be noted that there are some limitations. In this series, whether to place a tattoo or not was left to the discretion of the endoscopist, raising the possibility that polyps in positions that would be difficult to relocate may have been more likely to receive a tattoo. Second, while polypectomy scars can be reliably found without a tattoo, perhaps it is quicker to find them if a tattoo has been placed. This could not be ascertained from their study. Third, the detection of the polypectomy scars described here was predominantly at the first post-polypectomy surveillance colonoscopy 6 months after polypectomy. While a smaller number of scars were also reliably detected after a year, it is conceivable that, without a tattoo, scars will become more difficult to detect over time.

Before a decision can be taken to recommend not placing tattoos to mark polypectomy sites, it would be wise to perform additional research into these issues. At the same time colonoscopists who choose not to place a tattoo should make sure that they document the polyp position as accurately as possible, based on reliable landmarks and the position of the patient required for optimal visualization, and preferably not only the, frequently unreliable, insertion distance of the colonoscope beyond the anus. Good photographic documentation of the polyp site and a photograph of the magnetic colonoscope imaging picture should also facilitate the subsequent detection of the polypectomy site.

Publication History

Received: 21 May 2021

Accepted: 31 May 2021

Article published online:
13 September 2021

• References

• 1 Acuna SA, Elmi M, Shah PS. et al. Preoperative localization of colorectal cancer: a systematic review and meta-analysis. Surg Endosc 2017; 31: 2366-2379 DOI: 10.1007/s00464-016-5236-8. (PMID: 27699516)
• 2 Ferlitsch M, Moss A, Hassan C. et al. Colorectal polypectomy and endoscopic mucosal resection (EMR): European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline. Endoscopy 2017; 49: 270-297 DOI: 10.1055/s-0043-102569. (PMID: 28212588)
• 3 Ono S, Fujishiro M, Goto O. et al. Endoscopic submucosal dissection for colonic laterally spreading tumors is difficult after target tattooing. Gastrointest Endosc 2009; 69: 763-766 DOI: 10.1016/j.gie.2008.08.024. (PMID: 19251026)
• 4 Moss A, Bourke MJ, Pathmanathan N. Safety of colonic tattoo with sterile carbon particle suspension: a proposed guideline with illustrative cases. Gastrointest Endosc 2011; 74: 214-218 DOI: 10.1016/j.gie.2011.01.056. (PMID: 21481865)
• 5 Bronzwaer MES, Depla A, van Lelyveld N. et al. Quality assurance of colonoscopy within the Dutch national colorectal cancer screening program. Gastrointest Endosc 2019; 89: 1-13 DOI: 10.1016/j.gie.2018.09.011. (PMID: 30240879)
• 6 Shahidi N, Gupta S, Whitfield A. et al. Simple optical evaluation criteria reliably identify the post-endoscopic mucosal resection scar for benign large non-pedunculated colorectal polyps without tattoo placement. Endoscopy 2021; DOI: 10.1055/a-1469-9917. (PMID: 33784758)