Extracorporeal Shockwave Lithotripsy Could Lead to a Prolonged Increase in the Renal Fibrotic Process of Up to 2 Years.

INTRODUCTION AND OBJECTIVE: This prospective study aimed to evaluate the effect of ramping and pause protocols on renal fibrosis, blood pressure control, and renal function in patients receiving extracorporeal shockwave lithotripsy (SWL). PATIENTS AND METHODS: This study prospectively recruited 320 patients with solitary radiopaque renal stones <15 mm in size. Patients were randomized to receive one of four shockwave protocols: (1) standard protocol (no ramping or pause); (2) ramping protocol alone; (3) ramping and pause protocols; or (4) pause protocol alone. Spot urine samples were collected before and for 2 years after treatment to monitor the levels of the renal fibrosis marker procollagen III aminoterminal propeptide (PIIINP) by blinded research staffs. Blood pressure and serum creatinine levels were also monitored during follow-up. RESULTS: The four groups had comparable baseline data and treatment parameters. Significant increases (p < 0.05) in the urinary PIIINP levels from 6 weeks until 18 months after SWL were observed among all patients and in individual groups. PIIINP levels peaked at 1 year after SWL and gradually decreased to the baseline at 2 years. At the 2-year follow-up point, the overall serum creatinine levels remained significantly elevated (76.21-80.01 µmol/L, p < 0.001). Twenty (9.95%) patients developed new-onset hypertension and another 43 (36.4%) experienced worsening blood pressure control. However, no differences were observed among the four treatment groups. CONCLUSIONS: SWL led to significant increases in renal fibrosis marker levels for up to 18 months after treatment. However, no differences in changes in renal fibrosis marker and serum creatinine levels and worsening of blood pressure control were observed with respect to the use of either ramping or pause treatment protocols.

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.

The effect of renal cortical thickness on the treatment outcomes of kidney stones treated with shockwave lithotripsy.

PURPOSE: Because the shock wave passes through various body tissues before reaching the stone, stone composition may affect the treatment efficacy of shock wave lithotripsy (SWL). We investigated the effect of various tissue components along the shock wave path on the success of SWL. MATERIALS AND METHODS: From October 2008 to August 2010, a total of 206 patients with kidney stones sized 5 to 20 mm were prospectively recruited for a study of the factors that affect the outcome of treatment with a Sonolith Vision lithotripter. Successful SWL was defined as either stone-free status or residual fragments <4 mm at 12 weeks. Logistic regression analysis was performed to assess the factors that predicted treatment outcomes. Potential predictors included the patient's age, shock wave delivery rate, stone volume (SV), mean stone density (MSD), skin-to-stone distance (SSD), and the mean thickness of the three main components along the shock wave path: renal cortical thickness (KT), muscle thickness (MT), and soft-tissue thickness (ST). RESULTS: The mean age of the patients was 53.8 years (range, 25-82 years). The overall treatment success rate after one session of SWL was 43.2%. The mean KT, MT, and ST were 26.9, 16.6, and 40.8 mm, respectively. The logistic regression results showed that a slower shock wave delivery rate, smaller SV, a lower MSD, and a thicker KT were found to be significant predictors for successful SWL. SSD, MT, and ST were not predictors of successful treatment. CONCLUSIONS: Among the main tissue components along the shock wave path, a thicker KT was a favorable factor for successful SWL after adjustment for SV, MSD, and the shock wave delivery rate.