Related Experiment Video
Updated: Feb 15, 2026

Endoscopic Ultrasound-Guided Biliary Drainage: Endoscopic Ultrasound-Guided Hepaticogastrostomy in Malignant Biliary Obstruction
Published on: March 25, 2022
New 14-mm diameter Niti-S biliary uncovered metal stent for unresectable distal biliary malignant obstruction
Masataka Kikuyama1, Naofumi Shirane1, Shinya Kawaguchi1
1Department of Gastroenterology, Komagome Metropolitan Cancer and Infectious Diseases Center Komagome Hospital, Tokyo 113-8677, Japan.
Aim:
To investigate whether an uncovered self-expandable metal stent (UCSEMS) with a large diameter could prevent recurrent biliary obstruction (RBO).
Methods:
Thirty-eight patients with malignant biliary obstruction underwent treatment with an UCSEMS with a 14-mm diameter (Niti-S 14). Retrospectively, we evaluated technical and functional success rate, RBO rate, time to RBO, survival time, and adverse events in these patients.
Results:
Stent placement success and functional success were achieved in all patients. Two patients (5.3%) had RBO due to tumor ingrowth or overgrowth. The median time to RBO was 190 (range, 164-215) d. The median survival time was 120 (range, 18-502) d. The 6-mo non-RBO rate was 91%. Other adverse events other than RBO occurred as follows: Acute cholecystitis, post-ERCP pancreatitis, hemobilia, and fever without exacerbation of liver injury, and liver abscess in 4 (10.3%), 3 (7.9%), 2 (5.3%), 1 (2.6%), and 1 (2.6%), respectively. Migration of the stents was not observed.
Conclusion:
Niti-S 14 is considered to be a preferable metal stent because of a low rate of RBO with no migration.
Related Concept Videos
Properties of Transition Metals
Bonding in Metals
Metallic Solids
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
Alkali Metals
Table 1: Properties of the alkali metals
Metal-Ligand Bonds
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
Design Example: Calculating Safe Diameter for Wind-Exposed Disc

