Applied Physics Laboratory, Center for Industrial and Medical Ultrasound, University of Washington, Seattle, Washington, USA.
Department of Urology, University of Washington School of Medicine, Seattle, Washington, USA.
J Endourol. 2020 Nov;34(11):1167-1173. doi: 10.1089/end.2019.0873. Epub 2020 Mar 20.
Our goals were to validate stone comminution with an investigational burst wave lithotripsy (BWL) system in patient-relevant conditions and to evaluate the use of ultrasonic propulsion to move a stone or fragments to aid in observing the treatment endpoint. The Propulse-1 system, used in clinical trials of ultrasonic propulsion and upgraded for BWL trials, was used to fragment 46 human stones (5-7 mm) in either a 15-mm or 4-mm diameter calix phantom in water at either 50% or 75% dissolved oxygen level. Stones were paired by size and composition, and exposed to 20-cycle, 390-kHz bursts at 6-MPa peak negative pressure (PNP) and 13-Hz pulse repetition frequency (PRF) or 7-MPa PNP and 6.5-Hz PRF. Stones were exposed in 5-minute increments and sieved, with fragments >2 mm weighed and returned for additional treatment. Effectiveness for pairs of conditions was compared statistically within a framework of survival data analysis for interval censored data. Three reviewers blinded to the experimental conditions scored ultrasound imaging videos for degree of fragmentation based on stone response to ultrasonic propulsion. Overall, 89% (41/46) and 70% (32/46) of human stones were fully comminuted within 30 and 10 minutes, respectively. Fragments remained after 30 minutes in 4% (1/28) of calcium oxalate monohydrate stones and 40% (4/10) of brushite stones. There were no statistically significant differences in comminution time between the two output settings ( = 0.44), the two dissolved oxygen levels ( = 0.65), or the two calyx diameters ( = 0.58). Inter-rater correlation on endpoint detection was substantial (Fleiss' kappa = 0.638, < 0.0001), with individual reviewer sensitivities of 95%, 86%, and 100%. Eighty-nine percent of human stones were comminuted with a clinical BWL system within 30 minutes under conditions intended to reflect conditions . The results demonstrate the advantage of using ultrasonic propulsion to disperse fragments when making a visual determination of breakage endpoint from the real-time ultrasound image.
我们的目标是在与患者相关的条件下验证研究中的冲击波碎石（BWL）系统的碎石效果，并评估使用超声推进将结石或碎片移动以辅助观察治疗终点的效果。在临床试验中使用的 Propulse-1 系统用于超声推进，并针对 BWL 试验进行了升级，用于在水（溶解氧水平分别为 50%和 75%）中的 15 毫米或 4 毫米直径 calix 模型中破碎 46 个人工结石（5-7mm）。根据大小和成分将结石配对，并以 6MPa 峰负压（PNP）和 13Hz 脉冲重复频率（PRF）或 7MPa PNP 和 6.5Hz PRF 施加 20 个循环、390kHz 的冲击波。以 5 分钟的增量进行曝光，并进行筛分，将 >2mm 的碎片称重并返回进行进一步治疗。在生存数据分析框架内对配对条件的有效性进行了统计学比较，用于区间 censored 数据。三位对实验条件不知情的评审员根据超声推进对结石的反应，对超声成像视频进行了基于破碎程度的盲法评分。总的来说，分别有 89%（41/46）和 70%（32/46）的人工结石在 30 分钟和 10 分钟内完全粉碎。在 4%（1/28）的一水合草酸钙结石和 40%（4/10）的 Brushite 结石中，30 分钟后仍有碎片残留。在两种输出设置（ = 0.44）、两种溶解氧水平（ = 0.65）或两种 calix 直径（ = 0.58）之间，碎石时间无统计学差异。终点检测的组内相关性很高（Fleiss' kappa = 0.638， < 0.0001），单个评审员的敏感性分别为 95%、86%和 100%。在旨在反映临床条件的条件下，用临床 BWL 系统在 30 分钟内粉碎了 89%的人结石。结果表明，在从实时超声图像确定破碎终点时，使用超声推进来分散碎片具有优势。
