Temperature Feedback and Collagen Cross-Linking in Argon Laser Vascular Welding

• DOI: 10.1007/s101030050061
• Publication Date: 2002-08-25T05:57:49Z
• Authors: W. Small IV; P.M. Celliers; G.E. Kopchok; K.M. Reiser; N.J. Heredia; D.J. Maitland; D.C. Eder; R.A. London; M. Heilbron; F. Hussain; R.A. White; L.B. Da Silva; D. Matthews
• Keywords: 0103 physical sciences; 01 natural sciences

A preliminary single-animal study of in vivo argon laser vascular welding was conducted using a canine model. The effects of temperature feedback control and saline drip cooling on patency and collagen cross-linking were investigated. The surface temperature at the centre of the laser spot was monitored using a two-colour infrared thermometer. The surface temperature was limited by either a saline drip or feedback control of the laser. Acute patency was evaluated and collagen cross-link assays were performed. Though both protocols yielded successful tissue fusion, welds maintained at a surface temperature of 50°C using feedback control had an elevated cross-link count compared to controls, whereas tissues irradiated without feedback control experienced a cross-link decrease. Simulations using the LATIS (LAser-TISsue) computer code suggest that drip-cooled procedures achieve significantly higher temperatures beneath the tissue surface than temperature feedback-controlled procedures. Differences between the volumetric heating associated with drip-cooled and feedback-controlled protocols may account for the different effects on collagen cross-links. Covalent mechanisms may play a role in argon laser vascular fusion.