A Prospective Randomized Study Comparing the Effect of Different Kidney Protection Treatment Protocols on Acute Renal Injury After Extracorporeal Shockwave Lithotripsy.

OBJECTIVES: To perform a prospective study to evaluate the renal protective effects of ramping protocol and pause protocol for extracorporeal shockwave lithotripsy (SWL) in human subjects.

PATIENTS AND METHODS: Three hundred twenty patients with solitary renal stone <15 mm were randomized to receive one of four protocols: (1) 80% power from beginning until the end of treatment; (2) the first 100 shockwaves (SWs) at 40% power, and then 80% power until the end of treatment; (3) the first 100 shocks at 40% power, followed by a 3-minute pause, and then further SWs at 80% power until the end of treatment; and (4) the first 100 shocks at 80% power, followed by a 3-minute pause, and then further SWs at 80% power until the end of treatment. The primary endpoint was the incidence of renal hematoma assessed by imaging on day 2. Spot urine samples were also collected before and after treatment for acute renal injury marker measurement.

RESULTS: The baseline information and treatment parameters of the four groups were comparable. The overall incidence of hematoma formation was 7.69% (24 patients). The number of patients developing hematoma in the four groups was 8 (10.26%), 7 (8.97%), 6 (7.59%), and 3 (3.90%), respectively, and the incidence of hematoma among the four groups was not significantly different. Only patient's body mass index and mean blood pressure during treatment were predictors for hematoma formation. There was also no significant difference in changes in the levels of all markers and complication and hospitalization rates between the four groups.

CONCLUSION: Comprehensive assessment of clinical parameters, imaging results, and urinary markers showed no obvious improvement in post-SWL renal insult by either protocol.