Feasibility of a Fully Covered Self-Expandable Metal Stent with a Central Waist and a Long Removal String for Management of Malignant Distal Biliary Obstruction: A Multicenter Prospective Pilot Study.

Background/

Objectives

A fully covered self-expandable metal stent (FCSEMS) with a central waist and long retrieval string has recently been introduced for benign biliary strictures; however, its role in malignant biliary obstruction (MBO) remains unclear. This prospective, multicenter study evaluated the feasibility of palliation for unresectable distal MBO.

Methods

Between April 2022 and March 2023, patients with extrahepatic MBO were enrolled across six tertiary referral centers. The FCSEMS was a silicone-covered, cross-wired nitinol stent with an anti-migration central waist 2 mm narrower than both ends, three radiopaque markers, and a 10 cm retrieval string. Stent-related outcomes and adverse events were analyzed.

Results

Both technical and clinical success rates were 100% (46/46). The median stent patency and survival times were 251 and 360 days, respectively. Stent dysfunction occurred in 18 patients (39.1%), including 10 with migration and 8 with occlusion. Stent migration was observed exclusively in the transpapillary stenting group and showed no significant association with stricture length, stent-bending angle, or the ratio of stent lengths above and below the maximal bending point. All the occluded stents were successfully removed. Early non-recurrent biliary obstruction (RBO) adverse events occurred in five patients (three with pancreatitis, one with bleeding, one with cholecystitis), whereas late non-RBO events were reported in three patients (two with cholecystitis, one with cholangitis).

Conclusions

An FCSEMS with a central waist and retrieval string is feasible for the palliation of unresectable distal MBO. Optimization of the mechanical properties is warranted to minimize migration.