Current Status of Biliary Metal Stents

Abstract

Many advances have been achieved in biliary stenting over the past 30 years. Endoscopic stent placement has become the primary management therapy to relieve obstruction in patients with benign or malignant biliary tract diseases. Compared with plastic stents, a self-expandable metallic stent (SEMS) has been used for management in patients with malignant strictures because of a larger lumen and longer stent patency. Recently, SEMS has been used for various benign biliary strictures and leaks. In this article, we briefly review the characteristics of SEMS as well as complications of stent placement. We review the current guidelines for managing malignant and benign biliary obstructions. Recent developments in biliary stenting are also discussed.

ACR Appropriateness Criteria® Radiologic Management of Biliary Obstruction

“…Important causes of distal malignant biliary obstruction include pancreatic cancer, distal cholangiocarcinoma, ampullary cancer, and, less commonly, gallbladder cancer and metastasis [90]. Methods for palliative biliary drainage include surgical drainage, percutaneous transhepatic drainage, and endoscopic transpapillary drainage.…”

“…They have little risk of migration and have reported successful deployment rates of 85.2% to 100% [89]. However, patency rates beyond 3 months are poor, requiring maintenance exchanges to ensure continued adequate ductal drainage [89,90]. The use of plastic stents may be preferable in cases of obstructive lesions that may respond to chemotherapy or radiotherapy (eg, lymphoma) or in patients whose histological diagnosis has yet to be made.…”

“…With regards to selection of a covered or uncovered self-expanding metallic stent, there are several considerations. The main mechanism of occlusion for metallic stents is tumor ingrowth between the stent interstices, or tumor overgrowth, which results in the blockage of either the proximal or distal end of the stent [90]. Covered metallic stents were introduced in hopes of prolonging patency.…”

“…Additionally, while uncovered metallic stents cannot be removed once deployed, covered metallic stents have the advantage of being removable. Studies comparing the patency of a covered versus an uncovered metallic stent have demonstrated mixed results [90,98,99]. Krokidis et al [98] compared the clinical effectiveness of covered stents with uncovered stents for palliation of malignant jaundice in setting of pancreatic head cancer.…”

Locoregional therapies in cholangiocarcinoma

“…In patients with a life expectancy of more than 4 months, SEMS are superior to plastic stents [13]. Two recent SRMAs comparing SEMS and plastic stents (11 retrospective and prospective studies, n = 947 and 20 RCTs, n = 1713, respectively) found SEMS to be associated with longer stent patency, lower re-intervention rates and lower rates of cholangitis [14,15].…”