Effect of extracorporeal shockwave lithotripsy on plasma and urine endothelin concentrations

Since the first reports of extracorporeal shockwave lithotripsy (SWL), there have been increasing numbers of articles in the literature documenting renal blood flow impairment and blood pressure elevation as complications. However, little is known about the pathophysiology and prevention of these complications. In this prospective study, the influence of high-energy shockwaves on plasma and urine endothelin concentrations was investigated in 20 patients with renal stones. The patients were randomly assigned to receive a calcium channel blocker, 10 mg of nitrendipine (Bypress; Bayer) (N = 10) 2 hours before SWL or no medication (control group; N = 10). Blood samples were taken just before and 1 minute after application of 3000 shocks. Urine samples were collected by ureteral catheters. The plasma endothelin-1 concentrations were significantly elevated after SWL in the control group (P = 0.003). On the other hand, nitrendipine significantly reduced plasma endothelin concentrations after SWL (P = 0.003). No significant change was observed in urine samples and blood pressure measurements. These results suggest that endothelin release after SWL may be a cause for lithotripsy-induced hemodynamic changes. Medical prevention with calcium channel blockers warrants further investigation.