Low‐energy shock wave pretreatment results in greater vasoconstriction and less injury in the kidney compared to high‐energy shock wave lithotripsy treatment alone.

Pretreating the kidney with low‐energy shock waves (SWs) before administering a clinical dose of high‐energy SWs has been found to greatly decrease the hemorrhagic lesion that normally results from high‐energy shock wave lithotripsy (SWL) treatment alone. We tested the hypothesis that this novel pretreatment SWL protocol results in a greater and/or earlier renal vasoconstriction than clinical SWL alone, which could potentially explain the reduced bleeding in the kidney. Anesthetized pigs were treated with a clinical dose of SWs (2000 SWs, 24 kV, 120 SWs/min) or the pretreatment protocol (500 SWs, 12 kV, 120 SWs/min + 3‐min pause + 2000 SWs, 24 kV, 120 SWs/min) using the HM3 lithotripter. Sonography (color and pulsed ultrasound) was used to locate a resistance artery within the SW‐treated pole of the kidney and to take resistance index (RI) measurements from the blood vessel to estimate the resistance/impedance to blood flow. The results demonstrated that RI increased (renal vasoconstriction) earlier and greater during the pretreatment protocol compared to normal clinical SWL. Constricted blood vessels would likely be less prone to rupture by SWs and, if broken, would bleed less—resulting in a smaller hemorrhagic lesion.