Pathophysiologic effects of biliary shockwave lithotripsy in a canine model

At least 10 extracorporeal shockwave lithotripters are under investigation in the United States for treatment of biliary stone disease. Few reports, however, have documented the potential side effects of this new treatment method. In this study, we performed a series of acute and chronic studies in dogs exposed to varying numbers of shockwaves directed at the gallbladder wall via a transthoracic or transabdominal targeting approach. When shockwaves were directed transthoracically, pulmonary hemorrhagic contusions were found which were sometimes large in size. When a transabdominal approach was used, however, only focal areas of hemorrhage were found in the gallbladder wall and adjacent liver with no alterations in postlithotripsy pancreatic or liver enzymes, and normal cholecystokinin-octapeptide stimulated oral cholecystograms were obtained 6 days after treatment. Biliary shockwaves appear to cause few side effects under normal conditions but should be used with caution in patients with potential bleeding disorders. Until further studies are performed, lung tissue should be avoided in the shockwave beam path during treatment.