Passage of stone fragments after extracorporeal
shock wave
lithotripsy (ESWL) of
gallstones has resulted in biliary
colic, duct obstruction, and
pancreatitis in some patients. Rapid dissolution of these fragments with
methyl tert-butyl ether (
MTBE) may prevent such side effects and achieve complete clearance of
gallstones within hours rather than several months to a year or longer. This study examines the safety of same-day ESWL fragmentation and
MTBE dissolution of surgically implanted human
gallstones in 15 dogs. The animals were randomly assigned to one of four treatment groups to assess
MTBE absorption from the gallbladder and to observe hematology and chemistry profiles after 0, 400, and 1,200
shock waves from a lithotriptor followed by
MTBE dissolution
therapy. They were sacrificed either immediately
after treatment (12 dogs) or 2 weeks later (3 dogs). The results demonstrated that although ESWL causes moderate
trauma to the gallbladder, this did not result in increased
MTBE absorption or histologic evidence of mucosal disruption. Blood profiles demonstrated an increase in only the level of
aspartate aminotransferase. The three dogs that were sacrificed 2 weeks after the combined treatment had no residual evidence of gallbladder injury or remaining stone material. In all animals, severe injury occurred where
shock waves passed through lung or air-filled colon. This study suggests that same-day sequential fragmentation of
gallstones by ESWL followed by dissolution of stone fragments with use of
MTBE may be associated with only mild to moderate and reversible gallbladder
trauma and can rapidly achieve clearance of
gallstones.