 Malignant bile duct obstruction is a common sequela of pancreatic cancers or distal bile duct cancers, and its development can hinder the use of chemotherapy, decrease patient quality of life, and decrease survival. To relieve obstructive jaundice as a result of the obstruction, endoscopic stent placement is usually required. The use self-expandable metal stents SEMSs have been shown to result in a longer patency times as compared with plastic stents. However, despite improvements in materials and stent design, stent obstruction still occurs in 13 to 44 of the patients. Tumor in-growth is the most common mechanism of stent obstruction. 