The Energy Concept in Lithotripsy

The choice of lithotripters by clinicians have tended to be based on features other than the type of shock wave generator. These features included the type and configuration of imaging systems (ultrasound or fluoroscopy), table design (movable v fixed units including use for endoscopy), and purchase and operating costs. Total energy measurements have not been available to clinicians, and so they instead focussed on comparing the number of shock wave pulses. Acoustic output measurements have been performed on the shock heads of the Siemens Lithostar and Lithostar Plus in Bristol. The pulse intensity integral and energy per shock were calculated and compared for both systems. The emergence of the "lithotripter energy" concept could be a valuable yardstick to compare different lithotripters. When efficacy for lithotripters is to be assessed, total energy per session rather than total number of shocks should be compared.