Abstract
BackgroundSelf-expandable metal stents (SEMSs) are widely used for malignant biliary obstructions. Nitinol-covered SEMSs have been developed to improve stent patency. Currently, SEMSs may be uncovered, partially covered, or fully covered; however, there is no consensus on the best stent type for the management of malignant distal biliary obstruction (MDBO).MethodsPatients with unresectable MDBO receiving SEMS (Wallflex™) were retrospectively analyzed. Time to recurrent biliary obstruction (TRBO) and survival time were compared among the three types of SEMSs. Univariate and multivariate analyses were performed to identify risk factors for stent dysfunction.ResultsIn total, 101 patients received SEMSs for unresectable MDBO (44 uncovered, 28 partially covered, and 29 fully covered SEMSs). Median survival time was 200, 168, and 276 days in the uncovered, partially covered, and fully covered SEMSs groups, respectively. There were no differences in survival among the three groups. Median TRBO was 199, 444, and 194 days in the uncovered, partially covered, and fully covered SEMSs groups, respectively. Partially covered SEMSs had longer TRBO than uncovered (p = 0.013) and fully covered (p = 0.010) SEMSs. Tumor ingrowth occurred only with uncovered SEMSs and stent migration occurred only with fully covered SEMSs. Multivariate analyses confirmed that partially covered SEMSs have lower risk of dysfunction.ConclusionsPartially covered SEMSs with a proximal uncovered flared end have longer patency than uncovered and fully covered SEMSs by preventing tumor ingrowth and stent migration.
Highlights
Self-expandable metal stents (SEMSs) are widely used for malignant biliary obstructions
SEMSs expand to a larger diameter than plastic stents after placement, and many studies have demonstrated the superiority of stent patency in SEMSs compared with plastic stents [2,3,4,5,6,7]
SEMSs were more prone to occlusion than plastic stents, mainly by tumor ingrowth through the mesh
Summary
Self-expandable metal stents (SEMSs) are widely used for malignant biliary obstructions. Patients with cancer of the pancreatic head or bile duct are often diagnosed with advanced disease, which is usually unresectable These patients require adequate palliative treatment for malignant biliary obstructions. SEMSs were more prone to occlusion than plastic stents, mainly by tumor ingrowth through the mesh To overcome this issue, covered SEMSs, in which the stent mesh was Yokota et al BMC Gastroenterology (2017) 17:105 covered by a thin membrane, were developed in the 1990s. Several randomized studies have compared the patency of covered SEMSs with that of uncovered SEMSs [8,9,10,11,12,13,14,15,16] Some of these studies demonstrated the superiority of covered SEMSs to uncovered SEMSs, whereas others did not. Two meta-analyses of these studies and retrospective cohort studies have different conclusions [17,18,19,20,21,22,23]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
