CONTROLLED TEMPERATURE TISSUE FUSION - ARGON-LASER WELDING OF CANINE INTESTINE IN-VITRO

Background and Objective: Thermal denaturation of proteins is recogniz ed as a rate process governed by the local temperature-time response a nd is believed to be the principal mechanism for photothermal tissue w elding. Since rate processes are exponential with temperature, feedbac k control of tissue surface temperature is hypothesized to create a qu asi-constant rate of denaturation that will enhance the tissue welding process. Study Design, Materials and Methods: Controlled temperature tissue welding of severed edges of fresh canine jejunum was performed in vitro by remote sensing of tissue surface temperature with an infra red sensor. A hardware controlled temperature feedback system opened a nd closed a shutter located in the beam path of an argon ion laser to provide constant temperature welding. Results: Strong tissue fusion wa s not possible at or below a surface temperature of 70 degrees C, but was accomplished at 80 degrees, 90 degrees, 95 degrees, and 100 degree s C. Fusion was achieved with thermal coagulation of the collagenous s ubmucosa and mucosal tissues. The bursting strength of welds created a t 90 degrees C and 95 degrees C were significantly stronger than those performed at 80 degrees C. Conclusion: Laser-assisted intestinal anas tomoses created in vitro are optimally strong at 90-95 degrees C feedb ack control temperatures. (C) 1996 Wiley-Liss, Inc.