New antireflux plastic stent for patients with distal malignant biliary obstruction

Abstract

BACKGROUND Endoscopic biliary stenting is a well-established palliative treatment for patients with unresectable distal malignant biliary obstruction (MBO). However, the main problem with stent placement is the relatively short duration of stent patency. Although self-expanding metal stents (SEMSs) have a longer patency period than plastic stents (PSs), the higher costs limit the wide use of SEMSs. A PS with an antireflux valve is an attractive idea to prolong stent patency, but no ideal design for an antireflux PS (ARPS) has been proposed. We developed a new ARPS with a “duckbilled” valve attached to the duodenal end of the stent. AIM To compare the patency of ARPSs with that of traditional PSs (TPSs) in patients with unresectable distal MBO. METHODS We conducted a single-center, prospective, randomized, controlled, double-blind study. This study was conducted at the West China Hospital of Sichuan University. Consecutive patients with extrahepatic MBO were enrolled prospectively. Eligible patients were randomly assigned to receive either an ARPS or a TPS. Patients were followed by clinic visits or telephone interviews every 1-2 mo until stent exchange, death, or the final study follow-up in October 2018. The primary outcome was the duration of stent patency. Secondary outcomes included the rate of technical success, the rate of clinical success, adverse events, and patient survival. RESULTS Between February 2016 and December 2017, 38 patients were randomly assigned to two groups, with 19 patients in each group, to receive ARPSs or TPSs. Stent insertion was technically successful in all patients. There were no significant differences between the two groups in the rates of clinical success or the rates of early or late adverse events ( P = 0.660, 1.000, and 1.000, respectively). The median duration of stent patency in the ARPS group was 285 d [interquartile range (IQR), 170], which was significantly longer than that in the TPS group (median, 130 d; IQR, 90, P = 0.005). No significant difference in patient survival was noted between the two groups ( P = 0.900). CONCLUSION The new ARPS is safe and effective for the palliation of unresectable distal MBO, and has a significantly longer stent patency than a TPS.

Antireflux metal stent for biliary obstruction: Any benefits?

“…In a subsequent clinical RCT involving 60 patients with distal MBO, the antireflux plastic stent provided 1.5‐fold prolonged patency time compared to a conventional plastic biliary stent (median patency times, 145 days vs. 101 days, respectively) 43 . However, inconsistent results were reported by subsequent trials investigating the same stent or other types of antireflux plastic stents 44–46 …”

“…43 However, inconsistent results were reported by subsequent trials investigating the same stent or other types of antireflux plastic stents. [44][45][46] According to the increasing popularity of SEMSs in the setting of nonresectable distal MBO, researchers were motivated to develop ARMSs for this indication. While the designs of antireflux valves in prior studies were heterogeneous, 47 ARMSs have been generally associated with lower risks of stent occlusion and non-occlusion cholangitis compared to conventional SEMSs.…”

Innovation in Pancreatic Stents

“…Plastic stent obstruction might occur due to sludge reflux pancreatitis. Recently, a novel plastic stent to prevent duodenal juice reflux has been developed [9]. This stent has a 1.5-cm-long antireflux valve made of silicone rubber material attached to the duodenal site.…”

Design and Optimization of a New Anti-reflux Biliary Stent With Retractable Bionic Valve Based on Fluid-Structure Interaction Analysis

“…Efforts have been made towards the design of anti-reflux biliary stents for preventing duodenobiliary reflux after biliary stent implantation. Recently, some types of anti-reflux stents with different valves have been proposed, such as duckbilled ( Yuan et al, 2019 ), hemispheric ( Hu et al, 2011 ), funnel-shaped ( Morita et al, 2018 ), S-shaped ( Lee et al, 2013 ), nipple-shaped ( Hu et al, 2014 ), wine-glass-shaped ( Kim et al, 2013 ), and windsock-shaped valves ( Lee et al, 2016 ). It has been reported that implantation of anti-reflux biliary stents was safe and feasible, giving its higher technical success rate, longer stent patency, and no influence on the antegrade flow of bile ( Dua et al, 2007 ; Hu et al, 2011 ; Renno et al, 2019 ; Yuan et al, 2021 ).…”

“…The incidence of adverse events after anti-reflux biliary stent implantation may be as high as 20% ( Hamada et al, 2017 ). In addition, anti-reflux valves such as duckbilled ( Yuan et al, 2019 ), nipple-shaped ( Hu et al, 2014 ), and windsock-shaped valves ( Lee et al, 2016 ) do not significantly improve patient survival. Consequently, ideal anti-reflux biliary stents are still in the stage of design and research.…”