Exploring the limits of treatment used to invoke protection from extracorporeal shock wave lithotripsy induced injury

Previous studies with our juvenile pig model have shown that a clinical dose of 2000 shock waves (SWs) (Dornier HM-3, 24 kV, 120 SWs/min) produces a lesion ~3–5% of the functional renal volume (FRV) of the SW-treated kidney. This injury was significantly reduced (to ~0.4% FRV) when a priming dose of 500 low-energy SWs immediately preceded this clinical dose, but not when using a priming dose of 100 SWs [BJU Int. 110, E1041 (2012)]. The present study examined whether using only 300 priming dose SWs would initiate protection against injury. METHODS: Juvenile pigs were treated with 300 SW’s (12 kV) delivered to a lower pole calyx using a HM-3 lithotripter. After a pause of 10 s, 2000 SWs (24 kV) were delivered to that same kidney. The kidneys were then perfusion-fixed and processed to quantitate the size of the parenchymal lesion. RESULTS: Pigs (n = 9) treated using a protocol with 300 low-energy priming dose SWs had a lesion measuring 0.84±0.43% FRV (mean ± SE). This lesion was smaller than that seen with a clinical dose of 2000 SWs at 24 kV. CONCLUSIONS: A treatment protocol including 300 low-energy priming dose SWs can provide protection from injury during shock wave lithotripsy. [Research supported by NIH grant P01 DK43881.]