EFFECTS OF HIGH-ENERGY SHOCK-WAVE EXPOSURE ON RENAL-FUNCTION DURING EXTRACORPOREAL SHOCK-WAVE LITHOTRIPSY FOR KIDNEY-STONES

In order to study the effects of high energy shock wave exposure on the kidney in extracorporeal shock wave lithotripsy (ESWL) using Dornier HM3, renal hemodynamics and renal function before and after ESWL were analyzed by 99mTc-DTPA renoscintigraphy. Various urinary enzyme activities (LDH, GOT, GPT, NAG, gamma-GTP) and low molecular protein concentrations (alpha-1-microglobulin, beta-2-microglobulin) before and after ESWL were also compared. In the early phase of the renoscintigram obtained in the 1st min after injection of 99mTc-DTPA, the time required to reach maximum radioactivity was significantly prolonged after ESWL in both the affected and contralateral kidney. This indicated that renal blood flow decreased in both the affected and contralateral kidney immediately after ESWL. An analysis of the 30-min renoscintigram showed that urinary clearance was delayed in the affected kidney in spite of no overt obstruction due to stone fragments. As for urinary enzyme activities and low molecular protein concentrations, they were standardized by urinary creatinine concentration measured at the same time. Urinary LDH, GOT, GPT and NAG activities remarkably increased on the day of ESWL followed by a decrease close to pretreatment levels on the 4th day, though these levels were still significantly higher than pretreatment levels. Urinary gamma-GPT activity was significantly higher than the pretreatment level only on the day of ESWL. Urinary alpha-1-microglobulin and beta-2-microglobulin concentrations significantly increased on the day of ESWL and were still high on the 4th day. These results suggested that renal tissue may be damaged by ESWL using the high energy shock wave lithotriptor though temporarily, and that the impairment in proximal renal tubular function may continue over a comparatively long period of time.