The Optimal Metallic Stents for Malignant Distal Biliary Strictures: According to a Primary Disease and Axial Force

Abstract

AIM: Primary diseases for malignant distal biliary strictures vary, and many metallic biliary stent types are marketed. This study aimed to investigate factors, including axial force (AF), which affect patency periods of metallic biliary stents placed for malignant distal biliary strictures according to primary diseases. METHODS: This retrospective study involved 198 patients (114 with pancreatic head carcinoma, 53 with bile duct carcinoma, 24 with metastasis, and 7 with papillary carcinoma) who underwent metallic biliary stent placement for unresectable malignant distal biliary strictures at our department and 2 neighboring institutions between January 2001 and February 2011. RESULTS: Employing multivariate analysis, diseases and stent types were extracted as factors affecting stent patency periods. There were no significant differences among stent types in biliary strictures due to pancreatic head carcinoma and lymph node metastasis. For bile duct carcinoma, stent patency periods and AF correlated positively (correlation coefficient, 0.92). Stent non-occlusion periods associated with food impaction as a cause for occlusion showed a positive correlation with AF (correlation coefficient, 0.89). CONCLUSIONS: For unresectable distal bile duct carcinoma, metallic stents with high AF may prevent stent occlusion due to food impaction and prolong stent patency periods.