Larger Stones Hike Re-treatment Risk After Shock Wave Lithotripsy

NEW ORLEANS—Patients with renal or ureteral stones larger than 20 mm are more likely to require re-treatment after shock wave lithotripsy (SWL) than those with smaller stones, data presented at the 2015 American Urological Association annual meeting suggest.

Jonathan Witten, MD, and colleagues at Oregon Health & Science University in Portland analyzed data from 2,855 patients who underwent SWL for upper tract stones from 2010–2014. Patients with a stone size larger than 20 mm were 85% and 72% more likely to require retreatment than those who had a stone size smaller than 10 mm and 10–20 mm, respectively.

Results also showed that patients with post-SWL computed tomography scans are as likely to be retreated as those with post-SWL ultrasound scans. Patients with post-SWL KUB x-rays were 65% less likely to be retreated compared with those who had post-SWL ultrasound scans, according to the investigators.