Feasibility of the placement of a novel 6-mm diameter threaded fully covered self-expandable metal stent for malignant hilar biliary obstructions (with videos)

Abstract

Uncovered self-expandable metal stents (USEMSs) are used to treat unresectable malignant hilar biliary obstructions (MHBOs). However, ingrowth is not prevented, and reintervention is often troublesome. A novel 6-mm threaded fully covered self-expandable metal stent (T-FCSEMS) is available that may mitigate these issues. We aimed to clarify the safety and efficacy of T-FCSEMS placement for MHBO. Thirty patients underwent T-FCSEMS placements for MHBOs between 2014 and 2015. T-FCSEMSs were used for initial stenting in 17 patients (initial group) and for reinterventions for USEMS occlusions caused by ingrowth in 13 patients (reintervention group). The technical success rates, times to recurrent biliary obstruction, and the reintervention success rates were evaluated. The technical success rates were 94% (16/17) and 92% (12/13) in the initial group and reintervention group, respectively. Intrahepatic bile duct occlusions caused liver abscesses 8 days and 22 days after T-FCSEMS placements in 2 cases (7%) in the initial group, in which T-FCSEMSs were placed across the intrahepatic bile duct bifurcation. The median times to recurrent biliary obstruction were 210 days in the initial group after bilateral placement and 112 days and 152 days in the reintervention group after bilateral and unilateral placements, respectively. During reintervention, T-FCSEMS removal was successful in all patients in whom it was attempted, and the success rate of endoscopic reintervention was 100% in both groups. T-FCSEMS placement is a promising option for both initial stenting and reintervention for MHBO. However, we should consider the possibility of intrahepatic bile duct occlusion.