Liver transplantation is the gold-standard treatment for irreversible liver failure. Biliary complications, particularly anastomotic choledocho-choledochal strictures, remain frequent and have a significant impact on patient survival. Endoscopie treatment with multiple plastic stents (MPS) is effective but is limiting due to the need for repeated procedures. Fully covered self-expandable metal stents (FCSEMS), especially transpapillary ones, reduce the number of procedures but have limitations, notably the risks of migration and post-ERCP pancreatitis. A new type of stent, the intraductal self-expandable metal stent (IDSEMS), has been designed to improve both safety and efficacy. The aim of this study was to directly compare transpapillary and intraductal covered metal stents in the management of post-liver transplantation anastomotic biliary strictures.

We performed a retrospective bicentric study in two university hospitals between 2010 and 2024, including liver transplant recipients with anastomotic strictures treated with either a transpapillary or an intraductal covered metal stent. Th eprimary endpoint was overal stricture resolution. Secondary outcomes included one-year success rate, recurrence, number of procedures needed, length of hospital stay and adverse events. Statical analysis was based on comparative tests and Kaplan-Meir curves, with a significance threshold set a p < 0.05.

A total of 61 patients were included, 30 treated with FCSEMS and 31 with IDSEMS. The overal stricture resolution rate was achieved in 76.6% of FCSEMS cases versus 89.7% of IDSEMS cases, with no significant difference (p = 0.299). For secondary outcomes, one-year success was 86.2% with IDSEMS vs 70.0% with FCSEMS (p = 0.209). Calibration duration was similar (median 232.5 days for IDSEMS vs 203.0 days for FCSEMS, p = 0.992), as were the number of procedures (2 for IDSEMS vs 3 for FCSEMS, p = 0.817) and hospital stay (11 vs 12 days, p = 0567). Reccurence occurred less frequently and later with IDSEMS (19.2% with a median delay of 301 days vs 27.3% and 164 days with FCSEMS), though without reaching statistical signifiance. Overall complication rates were comparable, however IDSEMS were associated with significantly fewer migrations (6.5% vs 26.7%, p = 0.041) and post-ERCP pancreatitis (6.5% vs 33.3%, p = 011).

This is the first retrospective study comparing the two models of covered metal stents. Both demonstrated similar efficacy in treating post-transplant anastomotic biliary strictures. However, IDSEMS showed a clear favorable trend in overall resolution and recurrence rates. They also appeared better tolerated, with fewer migrations and episodes of pancreatitis, representing a promising alternative. Prospective, randomized, multicenter studies are warranted to confirm these findings.