Outcome of both-bare type nitinol metal stents in distal biliary malignant obstruction: A post-market clinical follow-up study

BACKGROUND Neoplastic stenosis of the distal biliary (DBS) tract is not rare and the most common treatment is an endoscopic stent placement. Partially covered self-expandable metal stents (PC-SEMS) have been recently introduced and preliminary data are controversial in terms of lower stent ingrowth compared to uncovered self-expandable metal stents (SEMS) at expense of higher risk of migration. AIM To confirm the safety and/or clinical performance of partially covered nitinol metal stents (Niti-S- Taewoong Medical Co. Ltd., Korea) in DBS management. METHODS This is a post-market clinical follow-up study which analyzed all consecutive patients from March 2021 to April 2022 who underwent PC-SEMSs [Niti-S Biliary Covered stent (Both Bare Type) - Taewoong Medical Co. Ltd., Korea] placement for drainage of malignant DBS. The follow-up time was 6 mo. The safety of the device was evaluated by occurrence of procedure-related and stent-related adverse events. RESULTS Thirty patients (21 males, median age 75 years) were enrolled: at the time of the procedure 24 patients had pancreatic cancer, 67% of patients had, at the time of the procedure, an advanced inoperable disease. Technical success rate was achieved in 96.7% of patients, while clinical success after 3-6 wk was achieved in 95% of patients and all surviving patients achieved normal bilirubin levels within 10 wk from the procedure. One patient had a mild procedure-related adverse event, and one experienced a moderate stent-related adverse event. Stent occlusion rate was 6.6%: 2 patients had recurrent biliary obstruction endoscopically treated, while stent migration was never recorded. CONCLUSION This PMCF study demonstrates that Niti-S SEMS (Both Bare Type – Taewoong) provides adequate palliation, no migration and fair duration of patency comparable with the best results in reported series of SEMS placement for DBS treatment.