Laser welding of urinary tissues, ex vivo, using a tunable Thulium fiber laser

Anthony K. Ngo, Utkarsh Sharma, Jin U. Kang, Nathaniel M. Fried

Research output: Chapter in Book/Report/Conference proceedingConference contribution

14 Scopus citations


Recent advances in Thulium fiber laser technology have resulted in the availability of a compact, inexpensive, tunable, mid-infrared laser for potential use in laser surgery. The objective of this study was to tune the Thulium fiber laser wavelength and corresponding optical penetration depth to match the tissue thickness, and thus produce full-thickness, watertight tissue closure during microsurgical laser welding of urinary tissues. 1-cm-length incisions were made, ex vivo, in porcine ureters. Thulium fiber laser radiation with a wavelength of 1873 nm, power of 550-650 mW, and 750-μm-diameter spot was delivered to the tissue in continuous-wave mode through a 600-μm silica optical fiber. The fiber was scanned over the weld site once at a rate of 0.1 mm/s using a motion controller and linear stage controlled by a PC. Optical coherence tomography, histology, flow rates, and temperature measurements were used to optimize and evaluate laser welding success. Histologic analysis demonstrated full-thickness welding of the ureteral wall. Weld success rates ranged from 67% (8/12) at an incident laser power of 550 mW to 91% (10/11) at 650 mW. Peak flow rates greater than 200 ml/min were measured, however, mean flow rates were only about 50 ml/min. Average tissue temperatures increased with incident laser power from 59-89°C. The tunable Thulium fiber laser may be useful for surgical applications requiring variable control of thermal coagulation depth, such as microsurgical laser tissue welding.

Original languageEnglish (US)
Title of host publicationProgress in Biomedical Optics and Imaging - Proceedings of SPIE
StatePublished - 2006
EventPhotonic Therapeutics and Diagnostics II - San Jose, CA, United States
Duration: Jan 21 2006Jan 24 2006


OtherPhotonic Therapeutics and Diagnostics II
Country/TerritoryUnited States
CitySan Jose, CA


  • Closure
  • Coagulation
  • Fiber laser
  • Thulium
  • Tunable
  • Ureter
  • Welding

ASJC Scopus subject areas

  • Engineering(all)


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