Neodynium YAG laser photocoagulation in experimental gastric lesions in pigs.

Gastric lesions produced in pigs were used as a model to assess the efficiency and safety of Neodynium YAG laser in photocoagulation of bleeding upper gastrointestinal lesions. Bleeding gastric lesions were induced in heparinized animals and photocoagulated by a series of pulses of varying duration. Depth of necrosis in the intact gastric wall was examined as a function of radiation density and exposure time. Histologic examination was performed 1 hour and 3,7 and 21 days after exposure. The results showed that tissue destruction was less with intermittent application of energy than with a continuous radiation. intermittent administration of energy of high density (82 watts) and a short exposure time (1 sec) resulted in efficient photocoagulation, with tissue destruction not deeper than halfway through the muscularis propria. No perforation was observed in these experiments.