The thermal properties and maximum temperatures attained during CO₂ (n=20) and Argon (n=20) laser welded repair of arteries were compared in a canine model. An AGA 782 digital thermographic system with spatial and thermal resolution of +0.2mm and +0.2°C was used to continually record and analyze the measurements. Longitudinal incisions of 1 cm length were made in each vessel with a 6-0 prolene stay suture at each apex and the midpoint, forming two 5mm segments. A Sharplan CO₂ laser was used at an energy fluence of 1500 J/cm², 150mw power, spot size of .00049 cm² and exposure of 5 seconds to induce fusion of each 0.5 cm of vessel wall. Argon fusion was accomplished with the HGM Argon laser using a 300 micron diameter fiber held 1 cm from the surface of the vessel, energy fluence of 570 J/cm², 500mw power, spot size of 0.066cm² and total exposure of 75 seconds per 0.5cm length. Continuous irrigation of room temperature saline at 1 drop/second (approx. 3m1/min) was used during argon welding. With CO2 laser welding temperature increased quickly to its maximum (MAX=84.0, MEAN=60.7+ 9.8°C) which was maintained as the laser energy moved slowly (0.1cm/sec) along the vessel edges. In contrast the argon laser welding temperatures rose to a maximum (MAX=48.8, MEAN=45.1+2.7°C) and returned to a baseline temperature with each drop of saline. The thermal difference with these two laser wavelengths may bring about different welding mechanisms and provide an explanation for the increased incidence of thrombus aneurysm formation that has been reported in CO₂ laser fusion.

Date Published: 15 June 1988
PDF: 4 pages
Proc. SPIE 0907, Laser Surgery: Characterization and Therapeutics, (15 June 1988); doi: 10.1117/12.945318

Published in SPIE Proceedings Vol. 0907:
Laser Surgery: Characterization and Therapeutics
Kazuhiko Atsumi M.D.; Stephen N. Joffe M.D., Editor(s)