Effect of Shock Wave Lithotripsy on Renal Hemodynamics

Extracorporeal shock wave lithotripsy (SWL) can injure tissue and decrease blood flow in the SWL‐treated kidney, both tissue and functional effects being largely localized to the region targeted with shock waves (SWs). A novel method of limiting SWL‐induced tissue injury is to employ the “protection” protocol, where the kidney is pretreated with low‐energy SWs prior to the application of a standard clinical dose of high‐energy SWs. Resistive index measurements of renal vascular resistance/impedance to blood flow during SWL treatment protocols revealed that a standard clinical dose of high‐energy SWs did not alter RI during SW application. However, there was an interaction between low‐ and high‐energy SWL treatment phases of the “protection” protocol such that an increase in RI (vasoconstriction) was observed during the later half of SW application, a time when tissue damage is occurring during the standard high‐energy SWL protocol. We suggest that renal vasoconstriction may be responsible for reducing the degree of tissue damage that normally results from a standard clinical dose of high‐energy SWs.