Antireflux Metal Stent as a First-Line Metal Stent for Distal Malignant Biliary Obstruction: A Pilot Study.
OBJECTIVE
In distal malignant biliary obstruction, an antireflux metal stent (ARMS) with a funnel-shaped valve is effective as a reintervention for metal stent occlusion caused by reflux. This study sought to evaluate the feasibility of this ARMS as a first-line metal stent.


METHODS
Patients with nonresectable distal malignant biliary obstruction were identified between April and December 2014 at three Japanese tertiary centers. We retrospectively evaluated recurrent biliary obstruction and adverse events after ARMS placement.


RESULTS
In total, 20 consecutive patients were included. The most common cause of biliary obstruction was pancreatic cancer (75%). Overall, recurrent biliary obstruction was observed in seven patients (35%), with a median time to recurrent biliary obstruction of 246 days (range, 11 to 246 days). Stent occlusion occurred in five patients (25%), the causes of which were sludge and food impaction in three and two patients, respectively. Stent migration occurred in two patients (10%). The rate of adverse events associated with ARMS was 25%: pancreatitis occurred in three patients, cholecystitis in one and liver abscess in one. No patients experienced nonocclusion cholangitis.


CONCLUSIONS
The ARMS as a first-line biliary drainage procedure was feasible. Because the ARMS did not fully prevent stent dysfunction due to reflux, further investigation is warranted.
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Tsuyoshi
T
Hamada
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.|Department of Gastroenterology, Tokyo Metropolitan Police Hospital, Tokyo, Japan.
Hiroyuki
H
Isayama
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Yousuke
Y
Nakai
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Osamu
O
Togawa
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Naminatsu
N
Takahara
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Rie
R
Uchino
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Suguru
S
Mizuno
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Dai
D
Mohri
Department of Gastroenterology, Tokyo Metropolitan Police Hospital, Tokyo, Japan.
Hiroshi
H
Yagioka
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Hirofumi
H
Kogure
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Saburo
S
Matsubara
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Natsuyo
N
Yamamoto
Department of Gastroenterology, Japanese Red Cross Medical Center, Tokyo, Japan.
Yukiko
Y
Ito
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Minoru
M
Tada
Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Kazuhiko
K
Koike
D000368:Aged; D000369:Aged, 80 and over; D002760:Cholangiopancreatography, Endoscopic Retrograde; D002779:Cholestasis / Q000209:etiology / Q000601:surgery*; D003138:Common Bile Duct Neoplasms / Q000150:complications / Q000601:surgery*; D005260:Female; D005706:Gallbladder Neoplasms / Q000150:complications / Q000601:surgery*; D006801:Humans; D007564:Japan; D008207:Lymphatic Metastasis; D008297:Male; D010190:Pancreatic Neoplasms / Q000150:complications / Q000601:surgery*; D010865:Pilot Projects; D011474:Prosthesis Design; D012189:Retrospective Studies; D000069322:Self Expandable Metallic Stents
Antireflux; Biliary obstruction; Cholangiopancreatography, endoscopic retrograde; Covered; Metal stent