Biliary lithotripsy and what we learned from Carstensen

In the early 1990s, kidney-stone lithotripsy was a new burgeoning field and applications to gallstone destruction were being investigated. I came as the 1989-90 Hunt Fellow to work on the mechanisms of lithotripsy and related areas with Edwin Carstensen and his collaborators at the University of Rochester. The composition and liquid environment of gallstones is very different from that of kidney stones, however, and successful fragmentation of gallstones was rare. Comparing a Diasonics piezoelectric lithotripter and Dornier HM-3 lithotripter provided insights, as did studies of the mechanical and acoustical properties of gallstones. More generally, biliary lithotripsy led to fundamental studies of mechanisms of fragmentation and the interaction of acoustic shock waves outside and inside stones. While eventually the success of laproscopic surgery spelled the end of biliary lithotripsy as a competing technology, Ed Carstensen and his collaborators added knowledge that later paid dividends in related fields of biomedical acoustics, such as atherosclerotic plaque removal, sonothrombolysis, and cavitation-based imaging and therapy.