The joining of tissue by the application of heat through the use of hot-loop forceps was first described in the 1960s. In 1964, a neodymium laser was used to join small blood vessels — the first reported use of a laser for thermal welding of tissue. Since then, numerous experimental studies have been conducted using a variety of lasers for welding of soft tissues including blood vessels, the genitourinary tract, the gastrointestinal tract, liver, spleen, nerves, dura mater, skin, sclera, trachea, and cartilage. As we enter the 21st century, laser tissue welding has reached the threshold at which it is moving from the laboratory bench to clinical application, making this an exciting time for all involved. This chapter reviews the principles, theory, and application of laser tissue welding. An insight is also provided into several important developments that have been made involving the use of light-activated surgical adhesives to
assist in the welding procedure, infrared (IR) temperature feedback control of the laser device, and computer modeling of the welding process. In addition, this chapter provides a comprehensive review of current and future clinical applications of laser tissue welding including developments in the fields of endoscopic and laparoscopic surgeries.