How to Become an 'Ink Master': Endoscopic Colonic Tattooing Tips

David A. Johnson, MD


March 12, 2021

This transcript has been edited for clarity.

Hello. I'm Dr David Johnson, professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia. Welcome back to GI Common Concerns.

Today I'd like to talk to you about endoscopic colonic tattooing.

This topic recently came up in a conversation I had with one of my younger partners. I was complimenting him on his endoscopic tattooing technique whereby he lifted up the mucosa and then carefully injected the needle to ensure proper distribution of the India ink.

To date, we've lacked expert guidelines or recommendations on the endoscopic tattooing technique. Thankfully, a recent publication resulting from a Delphi consensus conference remedies this. The conference included 29 experts from across the globe, representing views from Europe, the United States, and the Asian-Pacific region. Using successive rounds of a Delphi decision-making process, the group ultimately identified 15 recommendations they considered to be best practice.

Indications and Contraindications

They began by establishing two contraindications for endoscopic tattooing, the first of which being that an injection is not needed in the cecum. If you have the ileocecal valve and the appendiceal orifice well identified, then there is no reason to risk transmural injection with the India ink.

Second, they said that tattooing should generally not be performed in the rectum. This is due to the relative risk of mesorectal spilling of the tattooing, and inflammation, fibrosis, and infection. These factors may complicate a transanal or endoscopic resection. Also, it should already be very easy to identify location by documenting the distance from the anal verge, without the need for photo documentation.

From there, the guidance document moves on to address the indications for tattooing.

First, they recommend tattooing in the case of an endoscopic diagnosis of deep invasive cancer, such as a Kudo type V or an NBI International Colorectal Endoscopic (NICE) type 3 pattern. We're not going to attempt endoscopic resection in those cases. Instead, we need to document it so we can refer the patient to a surgeon. In this indication, it is also recommended to perform tattooing before the biopsy. The concern here is that by not doing so, you could cause inadvertent contamination of the needle with malignant cells via the biopsy channel of the scope and then subsequent cancer inoculation into another colonic site or into the abdominal cavity.

The second indication is after patients undergo an endoscopic resection with suspicion of submucosal invasion. In those cases, circumferential tattooing is recommended.

The third indication is in patients who have a lesion left in situ considered suitable for endoscopic resection after subsequent referral to another endoscopist. Although injection of the India ink compounds is generally safe and very sterile, rare complications can occur, particularly related to transmural injection, so unnecessary tattooing should be avoided. Instead, place a reasonable tattoo in one place, not circumferentially.

The fourth indication is for resected polyps that require further surveillance. A tattoo should be placed after endoscopic resection to identify where the scar is or where the monitoring should be focused. Again, the tattoo should be placed in that patient upon the completeness of the resection.

Proper Technique

When it comes to proper technique, the experts recommend placing a saline bleb prior to tattooing. For those not regularly doing endoscopic colonic tattooing, this is done via a tangential injection into the mucosa with saline. Then, once you have that little mucosal bleb, you inject it with the India ink. It's a very easy way to get in the submucosal layer before tattooing and has been associated with fewer errors in localization. For these reasons, it is strongly recommended by the expert panel, depending on your level of expertise.

The tattoo should never be injected directly into the lesion or adjacent to the lesion, because the dispersion of the India ink is hard to predict. Direct injection also represents a potential problem when considering future endoscopic treatments, as submucosal fibrosis could develop as a result.

The authors recommend that the maximum volume of each tattoo should not exceed 1 mL per injection site. There is no reason to have a large-volume injection at any one site given the risk for unwanted dispersion.

Regarding the localization of the lesion, the expert recommendation was to place the tattoo 3-5 cm distal to the anal side.

For the number of tattoos, they recommend placing two to three circumferentially when you're going to be referring patients for surgery. If it is just localization for an in-situ lesion or a post-endoscopic resection to monitor where they go, only one tattoo is generally needed. Again, the concept is really to minimize the tattoo, with the recognition that they're generally safe but not completely so.

The final recommendation related to documentation of the tattooing. In your endoscopy report, you want to clearly document where the tattoo is, including the distance away from the lesion. This should be done with photodocumentation, which should be a standardized technique in institutions.

This new guidance document really unifies the science around endoscopic tattooing, which is something we rely on quite a bit but can certainly do a better job at performing. I recommend you seek out this expert Delphi consensus paper for its recommendations so we all can learn how to best deliver this process.

I'm Dr David Johnson. Thanks for listening. I look forward to seeing you again soon.

David A. Johnson, MD, a regular contributor to Medscape, is professor of medicine and chief of gastroenterology at Eastern Virginia Medical School in Norfolk, Virginia, and a past president of the American College of Gastroenterology. His primary focus is the clinical practice of gastroenterology. He has published extensively in the internal medicine/gastroenterology literature, with principal research interests in esophageal and colon disease, and more recently in sleep and microbiome effects on gastrointestinal health and disease.

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