- Tattooing agent- commonly sterile carbon-based ink like SPOT)
- Distal to the tumour in 3 places
- Insert injection needle tangentially to mucosa and create a submucosal bleb with a small amount of saline.
- Once bleb is seen, inject 0.5–1.0 mL of tattoo ink into the submucosa.
- Avoid deep (transmural) injections — may cause peritonitis or ink spread.
- Withdraw the needle and repeat in three points
- Place tattoo distal
