Functional self-expandable metal stents in biliary obstruction

Abstract

Biliary stents are widely used not only for palliative treatment of malignant biliary obstruction but also for benign biliary diseases. Each plastic stent or self-expandable metal stent (SEMS) has its own advantages, and a proper stent should be selected carefully for individual condition. To compensate and overcome several drawbacks of SEMS, functional self-expandable metal stent (FSEMS) has been developed with much progress so far. This article looks into the outcomes and defects of each stent type for benign biliary stricture and describes newly introduced FSEMSs according to their functional categories.

Keywords: Bile ducts, extrahepatic; Biliary tract; Drug-eluting stents; Stents.

Fig. 1

Fully covered self-expandable metal stent attached with antimigratory anchoring fins (Viabil; Conmed).

Fig. 2

Fully covered self-expandable metal stent attached with anchoring fins (M.I.Tech). Permission for use granted by M.I.Tech.

Fig. 3

Antireflux fully covered self-expandable metal stent (FCSEMS; M.I.Tech). FCSEMS attached with antireflux valve at distal ends to enable biliary drainage while preventing reflux of contents. Permission for use granted by M.I.Tech.

Fig. 4

Fully covered self-expandable metal stent with ball-shaped distal ends (Bumpy stent; Taewoong Medical). Permission for use granted by Taewoong Medical and by courtesy of Prof. Jae Chul Hwang, Ajou University, Korea.

Fig. 5

A shape-modifying fully covered self-expandable metal stent (BONASTENT M-Intraductal; Standard Sci-Tech Inc.) and cases of stent insertion for benign biliary stricture. Lasso is placed in the duodenal lumen outside the duodenal ampulla for easier stent removal in the future. Permission for use granted by Standard Sci-Tech Inc. and courtesy of Prof. Jong Ho Moon, Soonchunhyang University, Korea.