HEAT ABLATION OF THE NORMAL GALLBLADDER IN PIGS

PURPOSE: The,safety and efficacy of ablating gallbladder mucosa was in vestigated with a percutaneously placed heater catheter in animal stud y. MATERIALS AND METHODS: The study was performed in three stages with 39 pigs. In stage 1 (15 heat-treated animals, one control), the confi guration of the heater catheter was progressively improve and the temp erature settings for stage 2 were defined. In stage 2 (11 heat-treated animals, four controls), the predetermined settings we used with mech anical mixing and cystic duct ligation to test for safety and efficacy . In stage 3 (eight animals), prior heat ablation of the cystic duct w as added to reduce epithelial regeneration. RESULTS: Gallbladder ablat ion was achieved at temperatures below 60-degrees-C. Mechanical mixing of the intraluminal contents was essential for even heat distribution for ablation and to reduce the incidence of adjacent organ damage. Th ermal injury to adjacent organs occurred when gallbladder ablation tem perature exceeded 54-degrees-C and serosal temperatures of adjacent or gans exceeded 43-degrees-C. Thermal ablation at 54-degrees-C for 35 mi nutes was completely successful in 25%, partially successful in 50%, a nd failed in 25% of animals. Cystic duct ablation improved overall res ults and appears vital in removing duct epithelium as a source for reg eneration of the mucosal lining. CONCLUSION: Defunctionalization of th e retained gallbladder is potentially achievable with use of thermal t echniques, but the thermal range between complete gallbladder ablation and adjacent organ injury is narrow.