The temperature for fusing blood vessels using a copper vapour laser.
Specimens of canine femoral or carotid artery were preserved at the temperature of liquid nitrogen and restored to room temperature before use. Fusing experiments were performed by repeatedly scanning along cuts of 1.0 cm long using a copper vapour laser at a power level of 500 mW. The laser was delivered via a 0.2 mm diameter optical fibre, 10 cm from the specimen, providing a beam spot area of 0.125 mm2 (a power density of 400 W cm-2). Drops of saline solution were applied to the irradiated areas for cooling at a rate of one drop every five seconds. At a scanning rate of 1 cm s-1, about 300 s were taken to successfully fuse a cut of 1 cm long with minimum tissue damage. Direct measurement of tissue temperatures whilst the beam was applied was not possible because of the interference of the laser, therefore the fusing temperature was estimated by the method of extrapolation. Time dependence of the surface temperature at the centre of the target area immediately after exposure and the spatial distribution of the surface temperature around the target area during exposures were measured using a thermocouple thermometer. The fusing temperature was estimated to be 62 degrees C by extrapolation of the time dependence and spatial distributions.
Wong
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Centre for Medical and Health Physics, School of Physics, Queensland University of Technology, Brisbane.
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D000714:Anastomosis, Surgical; D000818:Animals; D001011:Aorta / Q000601:surgery; D001158:Arteries / Q000601:surgery*; D002339:Carotid Arteries / Q000601:surgery; D004285:Dogs; D005263:Femoral Artery / Q000601:surgery; D006358:Hot Temperature; D066298:In Vitro Techniques; D053685:Laser Therapy; D051381:Rats; D013552:Swine; D013696:Temperature