Etiologies of Difficult Biliary Stone Extraction (Modified from Podboy et al.12)
| Stone characteristics | Papillary access issues | Bile duct characteristics | Stone location |
|---|---|---|---|
| Large stones >1.5 cm | Surgically altered anatomy | Sigmoid ductal shape | Intrahepatic stones |
| Numerous stones | Luminal narrowing (intrinsic or extrinsic) | Short ductal length | Cystic duct stones |
| Barrel-shaped stones | Duodenal/biliary diverticula | Hyper-acute biliary ductal angulation | Impacted ampullary stones |
| Stones with unusual hardness | Papillary stenosis | Downstream biliary stricture | Mirizzi syndrome |
| Redundant papillary tissue | Bile duct diverticulum | ||
| Recessed or obscured papilla |