Efficacy and safety of ultrasonic longitudinal-axis vibration for the reduction of ureteral access sheath insertion force: A randomized controlled trial in a porcine model

Kyo Chul Koo, Kwang Suk Lee, Gyu Rang Min, Hye Sun Lee, Beom Jin Lim, Ji Sup Kim, Dong Wook Kim, No Cheol Park

Research output: Contribution to journalArticle


Purpose: Excessive bulking force during ureteral access sheath (UAS) placement may induce injury. The sliding friction between surfaces can be reduced with the application of ultrasonic vibration. We investigated the efficacy and safety of an ultrasonic vibration transducing device for reducing the maximal ureteral access sheath insertion force (UASIF). Materials and Methods: A device was developed for transducing ultrasonic longitudinal-axis vibration onto the UAS at an adjustable amplitude and frequency while measuring the degree of UASIF. In the pilot study, six porcine models were used to investigate the optimal amplitude and frequency of vibration and to calculate sample size. Twelve porcine models were utilized in a randomized controlled trial. Resected ureters were pathologically evaluated for ureteral injury. Results: The transduction of ultrasonic vibration at an amplitude of 0.04 g and a frequency of 18,000 Hz resulted in a maximal UASIF reduction of 36.4% (interquartile range 32.7-43.1). Maximal UASIF tended to decrease with increasing vibration frequency. No significant differences in UASIF reductions were observed according to amplitude. In the randomized controlled trial, the maximal UASIF reduction was 37.0% (interquartile range 21.4-44.2). Grade II injury was pathologically diagnosed in 8.3% (1/12) of the ureters in both groups. Conclusions: The transduction of ultrasonic longitudinal-axis vibration onto the UAS reduces maximal UASIF and does not harm the ureter. Reducing the velocity of sheath insertion may further reduce maximal UASIF.

Original languageEnglish
Pages (from-to)140-145
Number of pages6
JournalJournal of Endourology
Issue number2
Publication statusPublished - 2019 Feb


All Science Journal Classification (ASJC) codes

  • Urology

Cite this