posthepatisk

Posthepatisk (posthepatiskt) is a medical term used to describe the portion of the biliary system and related processes that occur after bile leaves the liver. In hepatology, it refers to obstructions or dysfunctions in the extrahepatic biliary tract, i.e., the bile ducts outside the liver parenchyma, such as the common hepatic duct, common bile duct, and related structures, including the pancreaticobiliary junction.

Anatomy and physiology: Bile is produced in the liver and drains through intrahepatic ducts to form the hepatic ducts, which unite to become the common hepatic duct and then the common bile duct. This pathway continues into the duodenum via the sphincter of Oddi. Conditions described as posthepatic involve obstruction or impairment distal to the liver, after bile has exited the liver tissue.

Clinical significance: Posthepatic obstruction prevents bile from reaching the intestine, leading to cholestasis and conjugated (direct) hyperbilirubinemia. Typical signs include jaundice, pale stools, dark urine, pruritus, and elevated alkaline phosphatase and GGT. Imaging and endoscopic procedures are used to identify the cause and guide treatment.

Common causes: Gallstone obstruction of the common bile duct, pancreatic head tumors, cholangiocarcinoma, biliary strictures, postoperative or traumatic injuries to the bile ducts, and certain inflammatory conditions.

Diagnosis and management: Diagnostic approaches include ultrasound, magnetic resonance cholangiopancreatography (MRCP), and endoscopic retrograde cholangiopancreatography (ERCP). Treatment targets the underlying cause and may involve stone extraction or stenting, sphincterotomy, or surgical reconstruction.

Distinction: Posthepatic disease is contrasted with prehepatic (before the liver, e.g., hemolysis) and hepatic (within the liver) disorders, which produce different patterns of bilirubin and liver enzyme changes.