Comparison of Fixed and Ramping Voltage Extracorporeal Shockwave Lithotripsy with Acute Kidney Injury Biomarkers: Prospective Randomized Clinical Study

Abstract

Objective: To compare extracorporeal shock wave lithotripsy (ESWL) induced renal injury in patients undergoing different ESWL treatment protocols by measuring urinary tissue metalloproteinase-2 inhibitor (TIMP-2) and insulin-like growth factor binding protein 7 (IGFBP7) excretion. Materials and Methods: This prospective, randomized study was conducted between April 2016 and June 2016 in group 1 patients undergoing fixed voltage ESWL and group 2 patients undergoing ramping voltage ESWL. Urinary TIMP-2 and IGFBP7 levels were analyzed before ESWL and 2 hours after ESWL, and urinary beta-2-microglobulin (β2-MG) and albumin were analyzed before ESWL and 1 week after ESWL to assess renal injury. The primary outcome was to compare the effect of ESWL on early renal injury with biochemical markers in the different treatment protocols, and the secondary outcome was to compare the two treatment protocols in terms of stone free rate and complications. Results: There was no statistically significant difference between groups in terms of demographic and stone characteristics. There were statistically significant differences in serum creatinine and e-GFR at baseline and one week after treatment (p<0.05). There was no significant change in serum urea, urinary β2-MG and albumin levels before and after ESWL. There was a statistically significant increase in urinary TIMP-2, IGFBP7 and TIMP-2 x IGFBP7/1000 levels in both groups compared to baseline (p<0.05). There was no statistically significant difference in the rates of stone free and complications between the groups (p>0.05). Conclusion:In this prospective randomized study, we observed a significant increase in TIMP-2, IGFBP7 and combination levels after ESWL treatment in both groups, suggesting that these two biomarkers could be used to identify acute kidney injury due to ESWL. However, the comprehensive evaluation of clinical parameters and urinary markers did not differ in the rates of renal injury, success, and complications after ESWL in both protocols.