Preoperative endoscopic ultrasonography-guided tattooing of the pancreas with a minuscule amount of marking solution using a newly designed injector.

Background And Aim: Recent studies have reported the usefulness of preoperative endoscopic ultrasonography-guided fiducial tattooing (EUS-tattooing) of the pancreas. However, problems of proper procedure, including markers and amounts, have not been resolved. The aim of the present study was to evaluate the feasibility of EUS-tattooing with a minuscule amount of marking solution using a new injector.

Methods: Six consecutive patients who underwent EUS-tattooing between June 2013 and April 2015 at our center were retrospectively analyzed (mean age, 60.7 years; males, 4). A 25-gauge needle was inserted into the surface of the pancreas near the tumor with EUS guidance. Then, 0.02 mL marking solution was injected three to five times (maximal total amount was defined as 0.1 mL). The marking solution used in this study was a compound of aqueous solution of sodium hyaluronate and India ink with proportions of 4 to 1. The newly developed injector for precise injection of minuscule amount of solution was used.

Results: All six patients were successfully injected with the intended amount of marking solution. The tattoo mark was easily detected during surgery and localized in a small area in five patients. In one patient, however, the tattoo mark was not detected during surgery. There were no adverse events, including bleeding, perforation, and acute pancreatitis, by EUS-tattooing.

Conclusions: EUS-tattooing with a minuscule amount of marking solution using the newly developed injector was feasible and seemed useful and relatively safe. Further studies are warranted to confirm the safety and efficacy of EUS-tattooing.