EUS-guided submucosal implantation of a radiopaque marker: a simple and effective procedure to facilitate subsequent surgical and radiation therapy.
BACKGROUND
Endosonography (EUS) is widely used for locoregional staging of malignant GI tumors. Delineation of a tumor's margins with a long-lasting fluoroscopically visible material will facilitate subsequent surgical and radiation therapy.


OBJECTIVE
To assess the feasibility of EUS-guided submucosal implantation of a radiopaque marker in a porcine model.


METHODS
Survival experiments on four 50-kg pigs.


METHODS
A linear array echoendoscope was introduced into the esophagus and advanced to the stomach. With a 19-gauge FNA needle, a submucosal bleb was created by injecting 3 mL of normal saline solution into the gastric and esophageal wall followed by injection of 1 mL of tantalum suspension under fluoroscopic observation. Fluoroscopy was repeated after 1, 2, and 4 weeks followed by euthanasia and necropsy.


METHODS
Long-term depositions of the marker in the injection sites.


RESULTS
Submucosal injections of tantalum were easily performed through the 19-gauge FNA needle, resulting in good fluoroscopic opacification of injected material. Follow-up fluoroscopy in 1, 2, and 4 weeks demonstrated stable deposition of the tantalum at the sites of injection. There were no complications during and after the tantalum implantation. Histologic examination of the injection sites demonstrated submucosal tantalum depositions without signs of infection, inflammation, tissue damage, or necrosis.


CONCLUSIONS
Animal experiments with 4 weeks' follow-up.


CONCLUSIONS
EUS-guided implantation of tantalum as a radiopaque marker into the submucosal layer of the GI tract in a porcine model is technically feasible and safe. Long-lasting fluoroscopically visible tantalum markings could facilitate subsequent surgical and radiation therapy.
Department of Medicine, Division of Gastroenterology, Johns Hopkins University, Baltimore, Maryland 21205, USA.
Priscilla
P
Magno
Samuel A
SA
Giday
Kathleen L
KL
Gabrielson
Eun Ji
EJ
Shin
John O
JO
Clarke
Chung-Wang
CW
Ko
Jonathan M
JM
Buscaglia
Sanjay B
SB
Jagannath
Marcia I
MI
Canto
Sergey V
SV
Kantsevoy
D000818:Animals; D019160:Endosonography / Q000379:methods*; D004947:Esophagus / Q000000981:diagnostic imaging; D005240:Feasibility Studies; D005471:Fluoroscopy; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis / Q000628:therapy; D023421:Models, Animal; D011868:Radioisotopes / Q000494:pharmacology*; D018714:Radiotherapy, Adjuvant; D012680:Sensitivity and Specificity; D013194:Staining and Labeling / Q000379:methods*; D013270:Stomach / Q000000981:diagnostic imaging; D013514:Surgical Procedures, Operative / Q000379:methods; D034421:Sus scrofa; D013635:Tantalum / Q000494:pharmacology*; D018084:Ultrasonography, Interventional
D011868:Radioisotopes; D013635:Tantalum