EAU 2018: A Prospective Randomized Study To Investigate The Effect Of Power Ramping On Treatment Outcome In Extracorporeal Shockwave Lithotripsy Of Renal Calculi

Copenhagen, Denmark (UroToday.com) Dr. Ng, a clinical urologist from The Chinese University of Hong Kong, SH Ho Urology Centre, Hong Kong, Hong Kong, presented on a randomized prospective study that assessed the effects of increasing voltage in shockwave lithotripsy (SWL). Shockwave lithotripsy is a common treatment for kidney stones, however there is limited knowledge on the potential damage a change in voltage could cause.

In this study, the success rate and degree of renal injury, specifically pertaining to post-SWL hematoma and change in acute renal injury markers in the urine were examined. The study included 208 patients, with renal stones, randomly stratified into two groups, of which one received power ramping shockwaves (Group 1) and another was given shockwaves at a constant voltage (Group 2). Difference between the two groups were noticed in successful rate, stone free rate, hematoma rate, and unplanned hospitalization rate. While group 2 showed a significantly higher successful rate, defined as stone free or stone fragment less than 4mm on computerized tomography (CT), no statistical significance was found between group 1 and 2 when considering stone free rate only. Furthermore, group 2 showed a higher rate of perinephric hematoma and unplanned hospital admissions. A rise in renal injury marker (N-acetyl-beta-D-glucosaminidase) was also observed, however this rise was only temporary and returned to normal levels six weeks after the procedure.

In conclusion, Dr. Ng reiterated that while power ramping SWL provided a similar stone free rate as constant voltage SWL, it had a significantly lower overall successful rate. However, it was also able to significantly decrease incidence of perinephric hematoma and unplanned hospital stay.

Speaker: Dr. Ng

Authors: Ng C.F., Teoh J.Y.C., Yee C.H., Chiu P., Li C., Leung S., Lau B., Wong K.T., Chu W.

Written by: Whitney Zhang, Department of Urology, University of California-Irvine, at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark