Ho: YAG laser has tissue cutting capability through silica glass fiber, so that it may become to be useful laser in gastroenterological therapy. We experimentally studied ablation characteristics of Ho: YAG laser. We used extracted fresh porcine gastric wall as a sample. Ho: YAG laser was deliverd by 400um i. d. silica glass fiber. The irradiation were performed by the contact method with 200 to 500J/cm2in fluences. One or two shots of Ho: YAG could ablation whole mucosal layer. At 200J/cm2 in fluence, the ablation hole was limited at mucosal muscular layer because of strong tensile strength of this layer. In case of 500J/cm2 the ablation hole was easily penetrated throug proper muscle layer.In some case of 500J/cm2 in fluence, a dissection on the submucosal layer was seen due to generation of the ablation bubble in front of the fiber tip. Ho: YAG laser ablation might be available not only for ablation/coagulation, but also atripping of submucosal using laser induced disection.
