MP20-16 INTERIM RESULTS OF A RANDOMIZED TRIAL COMPARING NARROW VERSUS WIDE FOCAL ZONES FOR SHOCK WAVE LITHOTRIPSY OF RENAL CALCULI

Abstract

You have accessJournal of UrologyStone Disease: Basic Research I1 Apr 2014MP20-16 INTERIM RESULTS OF A RANDOMIZED TRIAL COMPARING NARROW VERSUS WIDE FOCAL ZONES FOR SHOCK WAVE LITHOTRIPSY OF RENAL CALCULI R. J. D'.A. Honey, Tarek Alzahrani, Daniela Ghiculete, and Kenneth T. Pace R. J. D'.A. HoneyR. J. D'.A. Honey More articles by this author , Tarek AlzahraniTarek Alzahrani More articles by this author , Daniela GhiculeteDaniela Ghiculete More articles by this author , and Kenneth T. PaceKenneth T. Pace More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2014.02.738AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The Modulith SLK-F2 electromagnatic lithotripter (Storz Medical) is the first lithotripter on the market with a unique design that allows for a dual focus system with the option of either a narrow (6x28 mm) or wide (9x50 mm) focal zone. Ex vivo data shows that disintegration capacity and renal vascular injury are independent of the focal diameter of the SW generator at the same peak pressure and disintegration power. The objective of this study is to compare the single-treatment success rates of narrow and wide focal zones for the shock wave lithotripsy (SWL) of renal stones. METHODS 118 patients with a previously untreated radio-opaque solitary stone located within the renal collecting system, measuring 5 to 15 mm in greatest diameter, were randomized to receive narrow or wide focus lithotripsy. Patients were followed with KUB x-rays and renal ultrasound at 2 and 12 weeks post lithotripsy to assess stone free status. Urinary markers indicating the degree of renal cellular damage (microalbumin and Beta-2 macroglobulin) were measured pre- and post-SWL, 24 hours post-SWL and 7 days post-treatment. Primary outcome was single-treatment success rate, defined as stone-free or adequate fragmentation (sand and asymptomatic fragments <=4mm) at 3 months post-treatment. RESULTS 61 (51.7%) patients were randomized to narrow focus lithotripsy versus 57 (48.3%) patients wide focus. The groups were similar in baseline characteristics including (age, gender, BMI, stone size and density and skin to stone distance). The overall success rates were not significantly different at 2 weeks post treatment (Narrow: 72.1% vs Wide: 61.4%; P = 0.216) nor at 3 months (Narrow: 68.3% vs Wide: 58.9%; P = 0.292). The overall complication rates was also comparable in the two groups (Narrow: 24.6% vs Wide: 17.5%; P = 0.349) including similar rates of perinephric hematoma (Narrow: 3.3% vs Wide: 3.5%; P = 0.945). The microalbumin-to-creatinine ratio was significantly different between the two groups (p=0.019), but that difference was gone within 24 hours after the treatment. CONCLUSIONS Interim results indicated that single-treatment success rate and complications are comparable when using the narrow or wide focus of the Modulith SLX-F2. There was a difference in renal injury as measured bymicroalbumin to creatinine ratio (with lower values in the narrow focal zone group), but these differences disappeared within 24h of treatment. We are continuing to recruit patients to a pre-planned sample size of 300. © 2014FiguresReferencesRelatedDetails Volume 191Issue 4SApril 2014Page: e202 Advertisement Copyright & Permissions© 2014MetricsAuthor Information R. J. D'.A. Honey More articles by this author Tarek Alzahrani More articles by this author Daniela Ghiculete More articles by this author Kenneth T. Pace More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...