Most Common Site of Biliary Stones
The gallbladder is the most common site of biliary stones, with approximately 80-90% of all biliary stones forming there. 1, 2 Secondary stones that migrate from the gallbladder into the common bile duct (CBD) account for 10-20% of patients with symptomatic gallstones. 1, 3, 4
Primary Stone Location
- Gallbladder stones (cholelithiasis) represent the vast majority of biliary stones, affecting approximately 15-20% of the general population in Western countries. 5, 6
- Most gallstones remain in the gallbladder throughout their existence, with only 10-20% eventually migrating into the bile ducts. 1, 7, 8
Secondary Stone Locations
When stones do migrate from the gallbladder, they follow a predictable pattern:
Common Bile Duct (CBD)
- Secondary CBD stones (those originating in the gallbladder) are found in 10-20% of patients with symptomatic gallstones. 1, 3, 2
- These stones migrate through the cystic duct into the extrahepatic bile duct system. 4, 7
- In European populations, most CBD stones are secondary rather than primary (formed de novo in the duct). 1, 4
Less Common Sites
- Primary bile duct stones that form de novo within the intrahepatic or extrahepatic ducts are more common in East Asian populations but remain less frequent overall than gallbladder stones. 1, 7
- Intrahepatic stones are relatively rare in Western populations. 7
Clinical Implications
The predominance of gallbladder as the primary stone location has important management implications:
- When CBD stones are discovered, they typically represent secondary migration from the gallbladder rather than primary formation. 4, 2
- Cholecystectomy is recommended for patients with CBD stones and gallbladder stones to prevent recurrent stone migration. 1
- Even after successful endoscopic CBD stone extraction, patients with residual gallbladder stones have a 15-23.7% risk of recurrent CBD stones compared to only 5.9-11.3% in those with an empty gallbladder. 1
Important Caveat
When spilled gallstones occur during laparoscopic cholecystectomy, the most common sites for retained stones are the right subhepatic, perihepatic, retroperitoneal, right flank, and pelvic regions, which can lead to delayed complications including abscess formation (56.5% of cases). 1