During percutaneous transhepatic cholangiography (PTC) or ERCP-guided biliary stenting, which type of stent is PREFERRED for malignant biliary obstruction to provide longer patency?
- A Plastic (polyethylene) stent of 7 Fr diameter
- B Self-expanding metal stent (SEMS) — uncovered or covered ✓
- C Percutaneous external drainage catheter alone
- D Biodegradable stent for temporary drainage
Correct answer: B. Self-expanding metal stent (SEMS) — uncovered or covered
Explanation
Self-expanding metal stents (SEMS) provide significantly longer patency (median 6–12 months) compared to plastic stents (median 3–4 months) for malignant biliary obstruction, due to their larger calibre (~10 mm expanded) and mesh structure. Covered SEMS prevent tumour in-growth but carry a risk of cystic duct/pancreatic duct orifice occlusion. Uncovered SEMS allow epithelial ingrowth but resist migration. Plastic stents are preferred for benign strictures and as temporary measures. External drainage alone is a bridge to definitive treatment.
Reference: Grainger & Allison's Diagnostic Radiology, 7th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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