Benign biliary strictures (BBS) are commonly managed by progressive calibration using plastic or metallic stents. While fully covered metallic stents (FC-SEMS) enable immediate calibration to a larger diameter compared to plastic stents, they remain prone to migration and their use is limited in intrahepatic and peri-hilar strictures. We report on using uncovered expandable bioresorbable stents in a series of selected BBS patients.

This retrospective bicentric case series included selected patients treated between 2023 and 2025 in two tertiary hospitals (Beaujon Hospital, Clichy, France and HEGP, Paris, France). All patients presented benign strictures not amenable to conventional stenting, due to inability to retrieve the stent because of altered anatomy or because of intrahepatic location (precluding FC-SEMS) with benign indication (precluding Uncovered SEMS).

The bioresorbable stents used (Unity-B™, Q3 Medical, Germany) are fastened onto a balloon and expanded to the desired diameter (up to 10 mm). Complete resorption occurs over 3 months. All patients were followed for several months after the procedure. Technical success, clinical success, and adverse events were recorded.

7 procedures were performed in 7 patients, with a total of 10 bioresorbable stents implanted.

• Four patients had altered anatomy with a stricture of a bilio-digestive anastomosis. All initially underwent external drainage with placement of an internal–external drain. Deployment of a Unity-B™ stent percutaneously enabled removal of the drain and internalization of biliary drainage while maintaining dilation of the anastomosis for an additional 3 months. Three of these patients received two Unity-B™ stents: two because of a right–left liver disconnection requiring a dual-access approach, and one because of a long stricture.
• Two patients were treated with extra-anatomical endoscopic drainage (one choledochojejunostomy and one hepaticogastrostomy) for an anastomotic bilio-digestive stricture after pancreaticoduodenectomy, associated with lithiasis. Placement of a bioresorbable stent allowed replacement of the lumen-apposing metal stent used to create the neo-anastomosis in one case and completed an anterograde lithotripsy in the second case. Both ensured calibration of the tract, and facilitated removal of the upstream bile duct stone. 
• One patient was treated for dilation of an intrahepatic stricture following radiofrequency ablation, achieving a larger calibration than would have been possible with a plastic stent and while FC-SEMS of Uncovered SEMS were precluded. A follow-up ERCP showed no residual stricture and no remaining stent debris.

Technical success was achieved in all cases (100%). 86% had clinical success with one patient experiencing recurrence due to tumoral relapse. No per-procedural or long-term adverse events were reported.

The use of bioresorbable UNITY-B stents appears feasible, efficient and safe for selected benign biliary strictures, including intrahepatic locations. Its use allowed calibration of strictures that would have been inaccessible with standard stents. Further studies are needed to confirm these preliminary findings