Comparative study of the effects of argon and neodymium YAG laser beams on the normal fundic wall in the beagle dog.

A study was performed to compare the lesions induced by argon and neodymium YAG laser beams in the normal fundic wall of the same beagle dogs and to follow their healing over a 21-day period. The total energy per application was 21 joules for the argon laser and 53 joules for the neodymium YAG laser. Both laser beams were emitted from the same distance, directed at right angles to the tissue surface, and with the same flow rate of coaxial gas. Thirty-nine shots were performed with each type of laser. Differences between the two lasers were observed in the appearance of the impacts, the volume of tissue affected, and the rate of healing, but all the lesions healed without any perforation. The differences observed were probably due to differences between the two lasers in the radial distribution of luminous energy and its absorption and transformation within the tissue into heat. It was concluded, however, that under the experimental conditions chosen, both kinds of laser could be used to penetrate the mucosal and submucosal tissue without risk of damage either to the longitudinal or to the serosal layers of the fundic wall.