Cavitation microjets as a contributory mechanism for renal calculi disintegration in ESWL.

The rarefaction shock wave produced by an extracorporeal shockwave lithotripter can result in liquid failure at numerous discrete sites near the second focus. When the liquid fails, vapor-filled cavities can grow to relatively large sizes and subsequently collapse with enormous violence. This phenomenon, called acoustic cavitation, has been shown to cause severe erosion in materials exposed to cavitation fields. It is proposed in this paper that ESWL devices generate acoustic cavitation in vivo and that the high speed liquid microjets produced during cavitation bubble collapse play an important role in renal calculi disintegration.