[Functional changes in the biliary system following extrahepatic biliary obstruction].

Abstract

To assess the potential structural changes of the biliary tree and liver in patients with extrahepatic biliary obstruction, the resected specimens of 20 patients operated for benign biliary stricture were evaluated by means of immunocytochemical and histological methods. Furthermore, liver biopsies were taken for the same purposes. The results showed that in the dilated segment of the hepatic duct proximal to the stricture, innervation was greatly reduced or completely absent with associated advanced morphological and histological changes and high intrabiliary pressure levels. Similar findings were observed in the liver biopsies, too. These biopsies showed advanced morphological and histological changes associated with reduced innervation. By contrast, the nondilated segment of the hepatic duct, distal to the obstruction, showed normal innervation, normal morphology and histology and normal levels of intrabiliary pressure. The present study provides evidence that in cases of extrahepatic biliary obstruction, there are advanced pathological changes in the biliary tree associated with innervation impairment. These structural changes are associated with functional changes in both the liver and the biliary tree. Such functional changes represent a threat to the patient, particularly if major surgery is required. Increased biliary pressure appears to be a major cause of the development of these changes. Biliary drainage, either surgical or endoscopic, is indicated as the only alternative to reduce intrabiliary pressure and to contribute to a reversal of these structural and functional changes.