Acoustic Enhancer Microbubble Cavitation: A Randomized Clinical Trial Evaluating the Safety and Efficacy of a Novel Treatment for Urolithiasis.

Abstract

PURPOSE The efficacy of ureteroscopy to treat urinary stones is often less than 60%. Acoustic Enhancer is an investigational device of microparticles with a tag designed with an affinity for calcium. We evaluated safety and efficacy of ureteroscopic laser lithotripsy with and without Acoustic Enhancer Microbubble Cavitation in a randomized clinical trial. MATERIALS AND METHODS Patients with urolithiasis were randomized to ureteroscopic laser lithotripsy with or without Acoustic Enhancer. The endpoints were the proportion of patients without residual fragments > 2mm on computed tomography 30 days post-procedure (fragment-free rate) and adverse events. RESULTS There were 103 and 93 patients in the investigational and control groups, respectively. There was no statistical superiority between the 2 groups. The fragment-free rate was 41.4% and 47% in the investigational and control groups, respectively (p=0.46). Residual fragment size was similar, 5.55mm versus 5.70mm for the investigational and control groups, respectively (p = 0.71). Among investigational patients treated with higher average powers > 12W, the fragment free rate was 51% compared to 32% (n=47) for the low-power group (p=0.06). Adverse events were noted in 35% and 46.2% of patients in the investigational and the control groups, respectively (p=0.11). The total number of adverse events was less for the investigational arm (p<0.001). CONCLUSIONS Although laser lithotripsy with microbubble cavitation did not increase efficacy, it was associated with significantly fewer adverse events. . Efficacy of microbubble cavitation may depend on laser power utilized. The low efficacy and high rates of adverse events with ureteroscopy highlights the need for novel management approaches for urinary stones.