Small-Dose India Ink Tattooing for Preoperative Localization of Colorectal Tumor

Introduction: India ink tattooing is widely used for tumor localization; however, the tattooing procedure is not yet standardized. This study aims to evaluate the efficacy of small-dose tattooing with sterile India ink using a saline test-injection method. Patients and Methods: Between April 2009 and August 2009, 20 patients underwent colonoscopic tattooing with prepackaged sterile India ink before resection of colorectal tumor. We injected 0.5 cc of India ink at three circumferential sites at the distal tumor using a saline test-injection method. Observation and leakage of India ink were evaluated during laparoscopic surgery, and the diameter of tattooing in the specimen was assessed. Results: Tattoos were observed intraoperatively in 18 patients (90%). In 2 patients, tattoos were not observed on the serosal surface but were detected on the mucosal surface. Localized leakage of ink was identified during surgery in 1 patient (5%), without fever or abdominal pain. Mean tattoo diameter was 2.1 cm on the serosal surface and 2.0 cm on the mucosal surface. Conclusions: Small-dose tattooing with sterile India ink using a saline test-injection method is effective for tumor localization.