The Efficacy of Plastic Stent Anchoring to Reduce Migration of Metal Stent

The Efficacy of a Fully Covered Self-expandable Metal Stent Anchored by a Plastic Stent for Anti-migration in the Management of Malignant Biliary Strictures: a Prospective Randomized Controlled Study

The aim of this study is to demonstrate that the group with an additional plastic stent to anchor the fully covered self expandable metal stent (FCSEMS) in patients with malignant biliary stricture has less stent migration than the group with FCSEMS only. The primary outcome is stent migration for 6 months. The secondary outcomes are stent related adverse events, stent patency, and overall survival.

Endoscopic retrograde biliary drainage using a plastic stent for the treatment of malignant biliary stricture has advantages in that it is easy to perform and low cost, but it has a short period of patency. To overcome this drawback, self-expandable metal stents (SEMS) have been developed and are now widely used. But, over time, the SEMS also develop restenosis, due to tumor ingrowth and the tissue hyperplasia caused by the stimulation of the surrounding tissues by the metal thin wire. To overcome these disadvantages, a fully covered self-expandable metal stents (FCSEMS) covered with a polymer coating have been developed and used. However, the FCSEMS showed more stent migration than the uncovered SEMS, which was not superior to the uncovered SEMS in terms of loss of stent function. In order to overcome the limitations of the FCSEMS, small-scale studies have shown that stent migration can be reduced by anchoring the FCSEMS using a plastic stent. To date, there has been no randomized controlled study to determine whether the FCSEMS can be anchored with a plastic stent in patients with malignant biliary stricture to reduce the stent migration. Therefore, the purpose of this study is to evaluate the efficacy of plastic stent anchoring to reduce migration of FCSEMS.

Insert a fully covered self expandable metal stent (FCSEMS) for malignant biliary stricture and insert an additional plastic stent to anchor the metal stent. (Plastic stent anchoring)

Insert only a fully covered self expandable metal stent (FCSEMS) without a plastic stent for malignant biliary stricture.

Stent migration is classified as proximal or distal migration. Proximal stent migration is defined as any migration of the FCSEMS(Fully covered self expandable metal stent) into the bile duct, preventing its easy removal. Distal stent migration is defined in three ways. The first is when the stent is completely distally migrated without being lodged into the duodenum. The second is when the stent is lodged in the distal bile duct below the stricture. The third case is when the stent is migrated to the distal portion of the stricture and is lodged in the duodenum opposite the papilla

Inclusion Criteria: Malignant biliary stricture requiring biliary drainage through endoscopic procedure Exclusion Criteria: Previous history of metal stent placement for malignant biliary stricture Hilar cholangiocarcinoma Malignant biliary stricture of intrahepatic duct A recurrence after surgery due to malignant biliary stricture Life expectancy less than 3 months Pregnancy If endoscopy is not possible based on the judgement of the researcher

Paik WH, Woo SM, Chun JW, Song BJ, Lee WJ, Ahn DW, Lee YS, Choi YH, Ryu JK, Kim YT, Lee SH. Efficacy of an internal anchoring plastic stent to prevent migration of a fully covered metal stent in malignant distal biliary strictures: a randomized controlled study. Endoscopy. 2021 Jun;53(6):578-585. doi: 10.1055/a-1256-0571. Epub 2020 Oct 8.