title: Preoperative endoscopic ultrasonography-guided tattooing of the pancreas with a minuscule amount of marking solution using a newly designed injector.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Gastroenterology, Sendai Kosei Hospital, Sendai, Japan. okuzonotoru@gmail.com.
authors.forename: Toru
authors.initials: T
authors.lastname: Okuzono
authors.affiliation: Department of Gastroenterology, Sendai City Center, Sendai, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Kanno
authors.affiliation: Department of Gastroenterology, Sendai Kosei Hospital, Sendai, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Nakahori
authors.affiliation: Department of Gastroenterology, Sendai Kosei Hospital, Sendai, Japan.
authors.forename: Hayato
authors.initials: H
authors.lastname: Aoki
authors.affiliation: Department of Gastroenterology, Sendai Kosei Hospital, Sendai, Japan.
authors.forename: Shun
authors.initials: S
authors.lastname: Sato
authors.affiliation: Department of Gastroenterology, Sendai Kosei Hospital, Sendai, Japan.
authors.forename: Tomoki
authors.initials: T
authors.lastname: Matsuda
authors.affiliation: Department of Gastroenterology, Sendai Kosei Hospital, Sendai, Japan.
authors.forename: Akimichi
authors.initials: A
authors.lastname: Chonan
mesh_terms: D019160:Endosonography; D005260:Female; D006801:Humans; D007267:Injections; D008297:Male; D008875:Middle Aged; D009339:Needles; D010179:Pancreas / Q000601:surgery; D013653:Tattooing
keywords: EUS-FNT; EUS-tattooing; a minuscule amount of marking solution; neuroendocrine tumor of the pancreas