Abstract:

Coagulation or fulguration of lesions is a technique that has long been used in medicine. A variety of thermal devices are available for coagulation and tissue destruction. In flexible endoscopy, tissue coagulation is performed by introducing a supplementary instrument through the accessory channel, which is also used for suctioning debris and fluid from the hollow structure of the GI-tract. Most tissue coagulation is performed in a monopolar mode with a ball-electrode, electrically activated biopsy forceps (hot biopsy), or utilizing a wire snare during polypectomy. Bipolar electrodes, which do not require a patient return late, but pass the electrical current from closely spaced alternating positive and negative electrodes on the instrument tip, are useful for cautery of bleeding sites and superficial desiccation of tissues, and they are available for snare polypectomy devices. Another thermal device is the heater probe, which consists of a long plastic tube with a Teflon-coated metal tip, which, when activated, becomes as hot as 200°C. This, too, can be used for thermal application directly to tissues of the GI-tract but derives its coagulation power from heat generated in the metal tip. Laser energy produces heat by molecular excitation. Laser use in the GI-tract enjoyed great popularity a decade ago, but because of its cost, its lack of portability, the need to wear protective glasses, and the variable depth of penetration, this modality has decreased in popularity among gastroenterologists. With the exception of the laser, all of the heat-producing coagulation modalities required direct tissue contact for transfer of energy from the source to tissues.

Authors:

Jerome D. Waye, M.D. - Mount Sinai Medical Center, Lenox Hill Hospital, New York, N.Y.

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