*3.3.7 Surgical usefulness of ICG as an alternative to India ink for endoscopic marking*

India ink has been largely used for preoperative colonic tattooing, but different complications have been reported. A study performed by Miyoshi et al. [37] looked at the surgical usefulness of ICG as an alternative to India ink for endoscopic marking and evaluated 40 patients between the time of ICG marking and the intervention, the median time period was 4 days (range, 1–73 days).

**Figure 13.** *A perineal wound with infection and inflammation after colorectal surgery.*

At the time of surgery, all 29 patients who were operated on within 8 days of tattooing stained positive in green with ICG dye.

Positive staining was clearly obviated in just two of the remaining 10 cases after 9 days or more.

The staining faded over time and finally vanished.

There was no mention of the dye's perioperative side effects.

The authors concluded that this study supports the use of ICG as a safe approach that may be consistently detected within 8 days of endoscopic injection (**Figure 14**).
