1 June 1990 Alternative infrared lasers for endoscopic surgery
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There are substantial technical problems attendant to the removal of sessile polyps from the lumen of thin walled gastrointestinal organs such as the colon. A laser system which is capable of precise and circumscribed mucosal tissue vaporization would be useful for this task. Because of technical shortcomings of existing medical laser systems, we investigated the possibilities of mid-infrared lasers which could take advantage of large water absorption peaks in the 2 micron region to produce precise vaporization while retaining fiberoptic transmissibility. In addition to a high absorption wavelength, pulsed energy delivery contributes to precise vaporizing capabilities. The laser system that best fits our criteria is the 2.15 micron thulium-holmium- chromium:YAG which produces 200 microsecond pulses of energies up to 1 joule at firing rates up to 6 Hz. The laser output is transmitted efficiently via low hydroxyl quartz fibers. Ablative efficiency, defined here as the slope of the vaporization depth versus energy, reveals that the THC:YAG produces approximately 3 times greater depth of vaporization per joule than the cw Nd:YAG. On average, the Nd:YAG produced 1.5 times the amount of thermal damage as the THC:YAG for a given depth of vaporization. The THC:YAG laser should have an important clinical role since its use could reduce the risk of perforation in endoscopic laser procedures such as the removal of sessile polyps.
© (1990) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Lawrence S. Bass, Lawrence S. Bass, David E. Font, David E. Font, Mehmet Cengiz Oz, Mehmet Cengiz Oz, Stephen L. Trokel, Stephen L. Trokel, Michael R. Treat, Michael R. Treat, } "Alternative infrared lasers for endoscopic surgery", Proc. SPIE 1200, Laser Surgery: Advanced Characterization, Therapeutics, and Systems II, (1 June 1990); doi: 10.1117/12.17500; https://doi.org/10.1117/12.17500

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