Long-term soft-tissue effects of biliary extracorporeal shock waves: an animal study

Although delayed effects of renal extracorporeal shock-wave lithotripsy (ESWL) have been reported, the long-term soft-tissue effects after biliary ESWL have not been investigated. We report soft-tissue effects seen up to 1 year after biliary extracorporeal shock waves were administered to 18 Yucatan pigs. The gallbladder received 4000 electromagnetic shock waves from a Siemens Lithostar overhead module. Blood samples were drawn from each pig for hematologic, coagulation, and biochemical profiles immediately before and then at prescribed time intervals after administration of shock waves. Autopsy and histopathologic examination of the gallbladder and surrounding organs were performed. Kidneys and adrenal glands also were examined in five pigs followed up for 1 year. There were no gross or microscopic abnormalities in 11 animals, including all five animals in the 1-year group in which kidneys and adrenal glands also were normal. One animal (3-week group) had two 2-mm foci of parenchymal necrosis in the right lobe of the liver, probably related to ischemia after shock-wave therapy. Transient rise in liver and pancreatic enzyme levels was seen in most animals after administration of shock waves. The levels returned to normal within 2 months in all but one animal. We conclude that biliary ESWL with the Lithostar Plus does not produce long-term histologic evidence of organ damage in Yucatan pigs.