BACKGROUND:?Excessive hepatocyte apoptosis and bile lakes in severe obstructive jaundice might impair liver functions. Although decompression of the bile duct has been reported to improve liver functions in animal studies, the mechanism of obstruction differs from that in humans. This study aimed to determine the profiles of hepatocyte apoptosis and bile lakes following bile duct decompression in patients with severe obstructive jaundice in the clinical setting. METHODS:?We conducted a "before and after study" on severe obstructive jaundice patients as a model of inhibition of the excessive process by bile duct decompression. Specimens of liver biopsies were taken before and after decompression of the bile duct and then stained by terminal deoxynucleotide transferase-mediated dUTP nick end-labeling (TUNEL) to identify hepatocyte apoptosis and by hematoxilin-eosin (HE) to identify bile lakes. All measurements were independently done by 2 observers. RESULTS:?Twenty-one severe obstructive jaundice patients were included. In all patients, excessive hepatocyte apoptosis and bile lakes were apparent. After decompression, the hepatocyte apoptosis index decreased from 53.1 (SD 105) to 11.7 (SD 13.6) (P