EFFECTS OF BILIARY ENDOPROSTHESES ON THE EXTRAHEPATIC BILE-DUCTS IN RELATION TO SUBSEQUENT OPERATION OF THE BILIARY-TRACT

Despite the widespread use of transpapillary biliary endoprostheses, l ittle is known about their effect on the extrahepatic bile ducts. In a n experimental study in dogs, we induced inflammatory changes in the b ile ducts by stent insertion and studied the reversibility of these ch anges after stent removal. In addition, the consequences of a period o f preoperative stenting for subsequent operation of the biliary tract and the eventual detrimental effects of stenting on the histologic fac tors of the liver were studied. Twenty-six mongrel dogs were randomly divided into four groups: group 1, stenting during four weeks; group 2 , after four weeks stenting, construction of a hepaticojejunostomy; gr oup 3, four days of common bile duct (CBD) Ligation, four weeks stenti ng and hepaticojejunostomy, and group 4, four days of CBD ligation and hepaticojejunostomy. Ah dogs were sacrificed two months after the las t procedure. Hepatic biopsies were obtained during each procedure and bile duct biopsies during hepaticojejunostomy and upon sacrifice. Four weeks of stenting of a normal or obstructed CBD resulted in fibrosed bile ducts, showing severe chronic inflammation with papillary hyperpl asia of the epithelium. Ah bile cultures grew fecal bacteria. Two mont hs after stent removal, inflammation was still present, albeit less se vere. Stenting and subsequent surgical treatment resulted in a higher incidence of postoperative complications (54 percent) compared with th e control group (14 percent), although this did not reach statistical significance. Hepatic histologic factors were not markedly changed aft er transpapillary endoprosthesis placement, but after hepaticojejunost omy cholangiolitis was observed. Whenever transpapillary biliary endop rostheses are used, the local effects on the extrahepatic bile ducts a nd the subsequent bacterial contamination of the bile should be consid ered.