Endoscopic laser applications in the gastrointestinal tract.

The Nd:YAG and, to a lesser degree, the argon laser have become valuable tools for the surgical endoscopist. Over the last 10 years, the impetus for application of these expensive instruments has changed from what the laser can do to what the laser can do better than less expensive technology. Whereas a few controlled randomized studies suggest that the Nd:YAG laser is better than no therapy and equivalent to other heat-producing instruments for control of upper gastrointestinal bleeding, such studies do not exist for other laser applications. Despite the lack of such studies, we remain convinced that, where available, lasers are the instrument of choice for palliation of unresectable mucosal-based cancers, coagulation of arteriovenous malformations, and ablation of certain adenomatous polyps in selected patients. New techniques on the horizon include the use of endoscopic photo-dynamic therapy for treatment of gastrointestinal cancers and endoscopic laser fragmentation of large common bile duct stones. The potential role for a nonthermal "endoscopic scalpel" is questionable because most gastrointestinal tissues are well vascularized; however, a pulsed laser capable of cutting and coagulation, such as the holmium:YAG laser, may be of some value for incisional endoscopic procedures.