#WCE2014 - Ball-tip holmium laser fiber: In vitro stone comminution and fiber tip degradation - Interview

TAIPEI, TAIWAN (UroToday.com) - Introduction and Objectives: Advancing a holmium laser fiber through a ureteroscope can damage the working channel. A ball-tip holmium laser fiber (TracTip - Boston Scientific) was designed to atraumatically pass through a deflected ureteroscope. We evaluated the stone comminution capabilities and tip degradation of this fiber.

wceMethods: A 200 micron ball-tip (BT) fiber and standard fiber (SF) (Flexiva - Boston Scientific) were compared by delivering 4 kJ of energy to a Begostone over a constant surface area controlled by a 3 dimensional positioning system. Laser settings were 0.2 J/50Hz, 0.6 J/6 Hz, 0.8 J/8Hz, and 1 J/10 Hz. Tip degradation was concurrently measured. Fiber-stone contact was adjusted every 1 kJ to account for any loss in length. ANOVA or Kruskal Wallace test was used for multiple groups, and post hoc tests with Bonferroni correction were then applied (t-test, Wilcoxon).

Results: Five virgin fibers were used to test each condition. Tip degradation trended with pulse energy for the SF but not the BT fiber. At 0.8 J/8 Hz and 1 J/10 Hz, SF degradation was greater than the BT fiber but the difference was not significant. Comminution was found to increase with pulse energy for both BT and SF fibers up to the 0.8 J/8 Hz setting (p < 0.003). No significant differences were found between BT and SF fibers at any energy setting.

Conclusions: The ball-tip fiber exhibits similar comminution efficiency to a standard fiber with minimal tip degradation at clinically relevant laser settings in our in vitro model. The new tip design may provide an advantage in reducing ureteroscope damage without loss of performance.

Source of Funding: Boston Scientific


View an interview with Adam Kaplan, one of the authors of this study.


Presented by Richard Shin,1 Jaclyn Lautz,2 Fernando Cabrera,1 Zachariah Goldsmith,1 Nicholas Kuntz,1 Ramy Youssef,1, 3 Adam Kaplan,1 Andreas Neisius,1, 4 Charles Scales,1, 5 Michael Ferrandino,1 Glenn Preminger,1 and Michael Lipkin1 at the 32nd World Congress of Endourology & SWL - September 3 - 7, 2014 - Taipei, Taiwan

1Division of Urologic Surgery, Duke University, USA
2Department of Mechanical Engineering and Materials Science, Duke University, USA
3Department of Urologic Surgery, University of California, Irvine, USA
4Department of Urology, University Medical Center Mainz, Germany
5Duke Clinical Research Institute, Duke University, USA