Biliary Sludge & Gallstones

Comments:
Biliary sludge is an important intermediate stage in the formation of both cholesterol and pigment gallstones. It is a dark greenish-black viscous gel containing mucin, precipitates of multilamellar vesicles of cholesterol and phospholipids, cholesterol monohydrate crystals, and/or calcium bilirubinate. It facilitates further rounds of deposition of cholesterol crystals as well as calcium bilirubinate precipitates and ultimately develops into macroscopic stones.

Biliary sludge can cause acute cholecystitis, cholangitis, and acute pancreatitis. It is found in many conditions that predispose to gallstone formation, including pregnancy, rapid weight loss, long-term TPN, spinal cord injury, and drugs such as octreotide. Biliary sludge is reversible in most cases. However, in about 15-20% of cases, it persists or disappears and reappears, eventually leading to stone formation. Biliary sludge can be detected on ultrasound.