Improvement of endoscopic laser therapy in gastrointestinal ulcer bleeding by tissue infiltration basic experiments on the dog stomach<em> in vivo.</em>

The therapeutic effect of Nd-YAG laser coagulation in arterial ulcer bleeding seems to be improved by local epinephrine infiltration. The purpose of this animal study was to evaluate the safety of this new therapeutic modality. The effect of Nd-YAG laser on normal and on infiltrated gastric mucosa was compared in acute and chronic experiments on 14 beagle dogs. On exposed normal gastric wall, perforation time and power output were inversely correlated. The required energies are nearly constant at different power levels. After infiltration of sodium chloride as well as of epinephrine into the mucosa, however, perforation time increased four- to live-fold. Volumes of mucosa defects and of the coagulation zones were also lower after pretreatment by infiltration. The results encourage further clinical use of this new therapeutic approach