The Technique of Gastrointestinal Laser Endoscopy

Application of the laser to the problem of gastrointestinal bleeding was first conceived by three separate groups: (1) the University of Washington group with Drs. Silverstein and Rubin; (2) Dr. Peter Kiefhaber at the University of Munich in Germany; and (3) our group in Los Angeles, California. The first successful application of endoscopic argon laser photocoagulation for bleeding in humans was accomplished by our group in 1974. Subsequently, in 1975, Dr. Peter Friihmorgen et al. in Erlangen, Germany, reported endoscopic coagulation by the argon laser. In 1975, Dr. Peter Kiefhaber first began using the neodymium-YAG laser, and most groups have since followed his lead. The argon laser was first adopted because it was easily focused with the current fiber-optic technology. In addition, the blue-green light of the argon laser is maximally absorbed in things that are colored red, leading to the assumption that since bleeding vessels produce red blood this would be an ideal hemostatic laser, selectively depositing energy in the blood. However, the argon laser’s lack of penetration without overlying-tissue vaporization minimizes its ability to stop massive hemorrhages from large-bore vessels such as esophageal varices or large arteries in the gastric and duodenal mucosa. The neodymium-YAG laser, which has greater penetrating power giving uniform heating and coagulation of deep large-diameter vessels, enables the therapeutic endoscopist to control esophageal varices and other massively bleeding vessels.