Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2020 May 22;15(5):e0233135.
doi: 10.1371/journal.pone.0233135. eCollection 2020.

How to reduce 'double-firing'-induced scope damage by investigating the relationship between laser fiber core degradation and fiber jacket burn?

Seung Hoon Ryang  1 , Tam Hoai Ly  1   2 , Hyun Sik Yoon  1 , Dae Hyoung Park  1 , Sung Yong Cho  1
Affiliations

How to reduce 'double-firing'-induced scope damage by investigating the relationship between laser fiber core degradation and fiber jacket burn?

Seung Hoon Ryang et al. PLoS One. .

Abstract

Purpose: 'Double-firing effect' in which laser firing occurs in the fiber tip and its proximal part is caused by different breakdown rates between fiber jackets and cores. This study investigated a new safe distance concept to prevent scope damage by analyzing the breakdown of the laser fiber jacket and cores.

Methods: Laser fibers were fixed in a benchtop simulation model. The fiber tip was in contact with uniform phantom stones and submerged in saline. Four different energy settings (1.0 or 2.0J x 10Hz or 30Hz) and two different fiber sizes (200 μm and 365 μm) were tested. After three minutes of use at each energy setting, the length of fiber shortening and jacket burn were measured. The fibers were stripped to measure the length of core degradation.

Results: Mean degradation lengths were 4.2 to 7.8 mm. There was no statistical difference in the mean lengths of fiber core degradation and jacket burn. However, core degradation was longer than the jacket burn in half of the samples. The mean difference in lengths between core degradation and jacket burn was 0.49 ± 0.90 mm. Lengths of core degradation and the jacket burn were longer at the setting of high-power energy and 200 μm fiber - 2J with 30 Hz.

Conclusion: To reduce 'double-firing'-induced damage, the authors recommend that laser fiber should be cut 1.0 mm longer than visible jacket burn at high-power settings after 3-min continuous fragmentation. After cutting the fiber, the laser should be checked whether 'double-firing' is no more seen.

PubMed Disclaimer

Conflict of interest statement

No authors have competing interests.

Figures

Fig 1
Fig 1. Double firing effect.
The laser is firing at both the tip and proximal parts of the fiber.
Fig 2
Fig 2
(A) Diagram of experimental benchtop setup. (B) Actual experiment scene. Artificial stones with properties similar to calcium oxalate monohydrate are placed in clear plastic tubing. (Circle) Laser fiber is hand-held and the tip of fiber is nearly contact to artificial stones. To measure the shortened length, the laser fiber is marked every 3cm with a white marker. (Arrow).
Fig 3
Fig 3. Measurement of burnt length of jacket fiber.
Fig 4
Fig 4. Fiber was stripped to measure the length of fiber core degradation.
See this image and copyright information in PMC

References

    1. Sooriakumaran P, Kaba R, Andrews HO, Buchholz NP (2005) Evaluation of the mechanisms of damage to flexible ureteroscopes and suggestions for ureteroscope preservation. Asian J Androl 7: 433–438. 10.1111/j.1745-7262.2005.00077.x - DOI - PubMed
    1. Landman J, Lee DI, Lee C, Monga M (2003) Evaluation of overall costs of currently available small flexible ureteroscopes. Urology 62: 218–222. 10.1016/s0090-4295(03)00376-5 - DOI - PubMed
    1. Cecchetti W, Zattoni F, Nigro F, Tasca A (2004) Plasma bubble formation induced by holmium laser: an in vitro study. Urology 63: 586–590. 10.1016/j.urology.2003.09.010 - DOI - PubMed
    1. Mues AC, Teichman JM, Knudsen BE (2009) Quantification of Holmium:Yttrium Aluminum Garnet Optical Tip Degradation. J Endourol 23: 1425–1428. 10.1089/end.2009.0384 - DOI - PubMed
    1. Talso M, Emiliani E, Haddad M, Berthe L, Baghdadi M, Montanari E, et al. (2016) Laser Fiber and Flexible Ureterorenoscopy: The Safety Distance Concept. J Endourol 30: 1269–1274. 10.1089/end.2016.0209 - DOI - PubMed

Publication types

LinkOut - more resources