title: Controlled temperature tissue fusion: argon laser welding of canine intestine in vitro.
abstract: OBJECTIVE
  Thermal denaturation of proteins is recognized as a rate process governed by the local temperature-time response and is believed to be the principal mechanism for photothermal tissue welding. Since rate processes are exponential with temperature, feedback control of tissue surface temperature is hypothesized to create a quasi-constant rate of denaturation that will enhance the tissue welding process.
  
  
  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 infrared sensor. A hardware controlled temperature feedback system opened and closed a shutter located in the beam path of an argon ion laser to provide constant temperature welding.
  
  
  RESULTS
  Strong tissue fusion was not possible at or below a surface temperature of 70 degrees C, but was accomplished at 80 degrees, 90 degrees, and 95 degrees, and 100 degrees C. Fusion was achieved with thermal coagulation of the collagenous submucosa and mucosal tissues. The bursting strength of welds created at 90 degrees C and 95 degrees C were significantly stronger than those performed at 80 degrees C.
  
  
  CONCLUSIONS
  Laser-assisted intestinal anastomoses created in vitro are optimally strong at 90-95 degrees C feedback control temperatures.
authors.affiliation: Biomedical Engineering Program, University of Texas, Austin 78712-1084, USA.
authors.forename: I
authors.initials: I
authors.lastname: Cilesiz
authors.forename: T
authors.initials: T
authors.lastname: Springer
authors.forename: S
authors.initials: S
authors.lastname: Thomsen
authors.forename: A J
authors.initials: AJ
authors.lastname: Welch
mesh_terms: D000818:Animals; D004285:Dogs; D006358:Hot Temperature; D007583:Jejunum / Q000601:surgery*; D017075:Laser Coagulation; D053685:Laser Therapy / Q000295:instrumentation / Q000379:methods*; D013718:Tensile Strength