Initially, the endoscopist should aim to coagulate the tumor thoroughly rather than destroy it by vaporization. Charring of tissues, especially at the beginning of the procedure, should be avoided. The tumor blanches first and then shrinks as treatment progresses. This tissue effect is characteristic of the YAG or YAP lasers. The goal is to diminish blood flow to the tumor using moderate power settings.

We fire the YAG laser choosing approximately 30 watts of power during 0.7 to 1 second intervals. The optimal distance from the fiber to the target should be sought in order to obtain ideal results based on the effect of the first few impacts. This is perhaps more important than choosing a given power setting, as the energy delivered to the tissues can be modified significantly by altering this distance. We generally keep the tip of the fiber 4 or 5 mm away from the target.