1. Covered versus uncovered self-expandable nitinol stents in the palliative treatment of malignant distal biliary obstruction: results from a randomized, multicenter study Gastrointest Endosc 2010;72(5):915-23. Eric Kullman, MD, PhD, Farshad Frozanpor, MD, Claes Söderlund, MD, PhD, Stefan Linder, MD, PhD, Per Sandström, MD, PhD, Anna Lindhoff-Larsson, RN, PhD, Bo Ohlin, MD, PhD, Rebecka Zacharias, MD, Carl-Eric Leijonmarck, MD, PhD, Kalev Teder, MD, Anders Ringman, MD, Gunnar Persson, MD, PhD, Mehmet Gözen, MD, Olle Eriksson, PhD R1 이민혜

2. Background Obstructive jaundice caused by a malignant bile duct obstruction ▫ Advanced stage of the disease ▫ Unfit for surgical resection for other medical reasons Endoscopic stent placement has played a pivotal role in the palliative management Self-expandable metal stents(SEMSs) are now used instead of traditional plastic stents

3. Background 13% to 44% reintervention rate attributed to stent failure with SEMSs ▫ Epithelial Hyperplasia ▫ Tumor ingrowth and overgrowth ▫ Dislocation ▫ Debris formation ▫ Clot accumulation

4. Objectives of this trials ▫ In the palliative treatment of patients with a distal malignant bile duct obstruction To compare differences between cSEMSs and uSEMSs  Stent patency  Patient survival time  Complication rates, including the incidence of cholecystitis, pancreatitis, and stent migration Background

5. Patients and methods Multicenter, randomized, controlled trial conducted between January 2006 and October 2008 Involving 10 Swedish hospitals serving a total catchment area of approximately 2.8 million inhabitants A total of 400 patients with unresectable distal malignant biliary obstruction

6. Interventions ▫ ERCP with insertion of covered or uncovered metal stent ▫ Biliary sphincterotomy was performed routinely in all patients Follow-up ▫ Conducted monthly for symptoms indicating stent obstruction for 12months Patients and methods

7. Results

8. Table 1. Eligibility and exclusion criteria

9. Figure 1. CONSORT flowchart illustrating the progress of patients throughout the randomized controlled trial

10. Table 2. Patient characteristics at inclusion

11. Figure 2. Kaplan-Meier graph showing patient survival time (intent-to-treat analysis). Figure 3. Kaplan-Meier graph showing stent patency time (intent-to-treat analysis).

12. Table 3. Mortality without stent failure and observed stent failures during follow-up

13. TABLE 4. Etiology and measures taken in patients with observed stent failures

14. Table 5. Complications

15. Table 6. Previous studies comparing covered and uncovered metal stents in malignant distal biliary obstruction

16. Conclusions No significant differences between covered and uncovered nitinol metal stents in the palliative treatment of malignant distal biliary obstruction ▫ Stent patency time ▫ Patient survival time ▫ Complication rates Covered stents migrated significantly more often compared with uncovered stents Tumor ingrowth was more frequent in uncovered stents