A Study on the Renal Damage after Repeated Extracorporeal Shock Wave Lithotripsy (ESWL) in Patients with Renal Stone

Chung, Byung Soo; Kim, Hayoung

Abstract

Extracorporeal shock wave lithotripsy (ESWL) is chosen as a primary treatment modality due its non-invasiveness and high effectiveness. But renal damage is reported in 65-85% of patients with renal stone after ESWL. It is Know that the renal collecting tubular enzyme, N-acety1-glucosaminidase (NAG), is increased in urine and 3-4 weeks are needed to be normal in most patients in case of damage by ESWL. Nevertheless, ESWL is performed repeatedly with 1 or 2 weeks interval and moreover daily without checking the renal damage in most ESWL centers. So, this study is performed to know how severely the renal damage is caused by ESWL and to know the safe interval of ESWL in patients with renal stones. We measured the urinary NAG/Creatinine ratio to check the renal damage in 9 patients with renal stone after repeated ESWL (19kV, 2000-3000 shock wave/session) using Lithostar Ultra manufactured by Siemens. The results are as follows; 1. In 3 patients who received ESWL once a day for 2 days repeatedly, one patient had normal urinary NAG/Creatinine ratio, one patient had rapidly increased urinary NAG/Creatinine ratio immediately and the ratio decreased from two weeks later and it needed 4 weeks to be normal. The other one patient had rapidly increased urinary NAG/Creatinine ratio immediately and the ratio was normal 1 week later. 2. All 6 patients who received ESWL with one or two weeks interval had normal urinary NAG/ Creatinine ratio. In conclusion, it is thought that repeated ESWL by Lithostar Ultra (Siemens) with more than 1 week interval is safe. In case of repeated ESWL more than 3 times with one day interval, it is needed to confirm the normal urinary NAG/Creatinine ratio before procedure.