FAILURE OF PIEZOELECTRIC LITHOTRIPSY OF A GALLSTONE IMPACTED IN THE GALLBLADDER NECK

Failure of extracorporeal shockwave lithotripsy is most frequently rel ated to total stone mass, the size of individual stones, or unrecogniz ed stone calcification which interferes with the dissolution effects o f orally administered bile salts. We report a case of piezoelectric ex tracorporeal shockwave lithotripsy failure in a young woman with a 2-c m stone impacted in the neck of the gallbladder. Despite adequate posi tioning of the shockwave focal point on two separate occasions, no fra gmentation was achieved. The stone was subsequently retrieved after th e woman underwent laparoscopic cholecystectomy. When treated ex vivo, the stone rapidly fragmented. We hypothesize that the impacted stone, lacking a uniform liquid interface, failed to fragment because of the inability of cavitational forces to achieve a surface effect.