An experimental study on effects of occlusion of the cystic duct in mice with or without emptying of the gallbladder.
To study consequences of cystic duct occlusion, 121 NMRI mice were operated: 40 had cystic duct ligature (L group), 41 had cystic duct ligature and evacuation of bile from the gallbladder (LE group), and 40 were sham-operated (S group). Ten mice from each group were sacrificed at 1 week, 1, 3 and 6 months, respectively. All but 2 mice showed signs of wellbeing during the observation time, and weight gain was the same in the three groups. Distended gallbladder occurred in 14 animals, 7 each in the L and the LE group, more frequent after 3 and 6 months. In the remainder mice the gallbladders were smaller than at the time of operation (p < 0.0001). Fibrosis and adhesions around the gallbladder were frequent in the L and the LE groups, and more pronounced in the latter (p = 0.0001). At microscopy there were signs of inflammation in the gallbladder wall in 16 cases in the L group, 28 in the LE group and 2 in the S group, and the degree of inflammation was more pronounced in the LE group than in the L group (p = 0.002). Eleven mice in the LE group had empyema, and slight intralumininal inflammation was more frequent in the LE group than in the L group (p < 0.0001). In conclusion, despite a high incidence of microscopic inflammation the study gave no indication that occlusion of the cystic duct did serious harm to the mice in this series.