Types of Baskets Used in ERCP
Baskets used in ERCP procedures include standard Dormia baskets for stone extraction, mechanical lithotripsy baskets for crushing large stones, and choledochoscopic baskets for retrieval under direct vision.
Standard Stone Extraction Baskets
Dormia Baskets
- Dormia baskets are the primary tool for conventional stone extraction during ERCP after sphincterotomy 1
- These baskets are used for engaging and retrieving stones that are small enough to pass through the sphincterotomy 2, 3
- Standard Dormia baskets are effective for stones that can be directly extracted without fragmentation 4
- Basket impaction can occur when stones are too large or become entrapped, requiring alternative management strategies 5, 6
Mechanical Lithotripsy Baskets
BML System and Similar Devices
- Mechanical lithotripsy baskets are specifically designed to crush large common bile duct stones that cannot be extracted by standard Dormia baskets 2, 3
- The Olympus basket mechanical lithotriptor (BML-1Q) is one example that has demonstrated 81% success rates for crushing stones ranging from 1.0 to 4.9 cm in diameter 2
- These baskets work by entrapping the stone and then applying mechanical force through a metal sheath to fragment it 2, 3
- Mechanical lithotripsy is indicated when standard extraction techniques fail due to stone size 1
- Success rates of 80% have been reported, with most patients requiring only one session 3
Soehendra Lithotriptor
- The Soehendra lithotriptor represents an alternative mechanical lithotripsy basket system 2
- This device can be used when other mechanical lithotripsy systems fail to engage or crush stones 2
Choledochoscopic Baskets
Baskets for Direct Vision Retrieval
- Choledochoscopic baskets are used during cholangioscopy-guided procedures for stone removal under direct visualization 1
- These baskets are deployed through the working channel of a choledochoscope during laparoscopic bile duct exploration or peroral cholangioscopy 1, 5
- Direct vision allows for precise targeting and safer stone retrieval, particularly after lithotripsy fragmentation 1, 5
Balloon Catheters (Alternative to Baskets)
ERCP Stone Extraction Catheters
- While not technically baskets, balloon-tipped catheters serve as complementary extraction devices 1
- Fogarty balloon catheters can sweep stones into the duodenum or retrieve fragments after lithotripsy 1, 5
- Balloon catheters are particularly useful when basket engagement fails or for clearing multiple small fragments 3
Clinical Algorithm for Basket Selection
Initial Approach
- Begin with standard Dormia basket extraction after sphincterotomy for stones ≤5 mm 1
- If the stone can be engaged but not extracted due to size, proceed to mechanical lithotripsy basket 2, 3
When Standard Baskets Fail
- For stones that cannot be engaged in a Dormia basket, consider cholangioscopy-guided basket retrieval or alternative lithotripsy methods 1, 4
- Mechanical lithotripsy baskets achieve stone clearance in approximately 80-95% of difficult cases 2, 4
- If mechanical lithotripsy fails (typically due to inability to engage the stone in 20% of cases), electrohydraulic or laser lithotripsy under cholangioscopic guidance becomes necessary 1, 4
Important Caveats
Basket Impaction Risk
- Basket impaction with entrapped stones occurs rarely but requires immediate intervention, potentially including surgical removal 5, 6
- Mechanical failure of the basket handle or wire can necessitate laparoscopic or open surgical exploration 5, 6
- Six patients in one series required immediate open surgery for basket removal through choledochotomy 6