Alavi Tamaddoni H, Roberts WW, Duryea AP, Cain CA, Hall TL.
J Endourol. 2016 Dec;30(12):1321-1325. FREE ARTICLE
Abstract
Cavitation plays a significant role in the efficacy of stone comminution during shockwave lithotripsy (SWL). Although cavitation on the surface of urinary stones helps to improve fragmentation, cavitation bubbles along the propagation path may shield or block subsequent shockwaves (SWs) and potentially induce collateral tissue damage. Previous in vitro work has shown that applying low-amplitude acoustic waves after each SW can force bubbles to consolidate and enhance SWL efficacy. In this study, the feasibility of applying acoustic bubble coalescence (ABC) in vivo was tested. Model stones were percutaneously implanted and treated with 2500 lithotripsy SWs at 120 SW/minute with or without ABC. Comparing the results of stone comminution, a significant improvement was observed in the stone fragmentation process when ABC was used. Without ABC, only 25% of the mass of the stone was fragmented to particles <2 mm in size. With ABC, 75% of the mass was fragmented to particles <2 mm in size. These results suggest that ABC can reduce the shielding effect of residual bubble nuclei, resulting in a more efficient SWL treatment.
Comment Peter Alken
It is always nice to see that ESWL, the least invasive technique of stone removal still offers not only room for improvement but for substantial, qualitative changes. The original paper and the previous publication of the authors (Duryea AP, Roberts WW, Cain CA, Tamaddoni HA, Hall TL. Acoustic bubble removal to enhance SWL efficacy at high shock rate: An in vitro study. J Endourol 2014;28:90–95) is a must-read for all who are interested in more than just positioning the next patient on a “third generation” lithotripter.