title: Management of heat in laser tissue welding using NIR cover window material.
abstract: BACKGROUND
  Laser tissue welding (LTW) is a novel method of surgical wound closure by the use of laser radiation to induce fusion of the biological tissues. Molecular dynamics associated with LTW is a result of thermal and non-thermal mechanisms.
  
  
  OBJECTIVE
  This research focuses exclusively on better heat management to reduce thermal damage of tissues in LTW using a near infrared laser radiation.
  
  
  METHODS
  An infrared continuous-wave (CW) laser radiation at 1,450 nm wavelength corresponding to the absorption band from combination vibrational modes of water is used to weld together ex vivo porcine aorta.
  
  
  RESULTS
  In these studies we measured the optimal laser power and scan speed, for better tensile strength of the weld and lesser tissue dehydration. Significant amount of water loss from the welded tissue results in cellular death and tissue buckling. Various thermally conductive optical cover windows were used as heat sinks to reduce thermal effects during LTW for the dissipation of the heat. The optimal use of the method prevents tissue buckling and minimizes the water loss. Diamond, sapphire, BK7, fused silica, and IR quartz transparent optical cover windows were tested.
  
  
  CONCLUSIONS
  The data from this study suggests that IR-quartz as the material with optimal thermal conductivity is ideal for laser welding of the porcine aorta.
authors: Institute for Ultrafast Spectroscopy and Lasers, The City College of City University of New York, CUNY Graduate Center, New York, New York 10031, USA.
authors: Vidyasagar
authors: V
authors: Sriramoju
authors: Howard
authors: H
authors: Savage
authors: Alvin
authors: A
authors: Katz
authors: Ronex
authors: R
authors: Muthukattil
authors: Robert R
authors: RR
authors: Alfano
mesh_terms: D000537:Aluminum Oxide; D000818:Animals; D001011:Aorta / Q000473:pathology / Q000601:surgery*; D003681:Dehydration / Q000517:prevention & control; D018130:Diamond; D006358:Hot Temperature / Q000009:adverse effects; D066298:In Vitro Techniques; D053685:Laser Therapy / Q000295:instrumentation* / Q000379:methods; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D011791:Quartz; D012822:Silicon Dioxide; D013552:Swine; D013718:Tensile Strength; D013814:Thermal Conductivity; D058106:Wound Closure Techniques / Q000295:instrumentation*
chemical_list: D011791:Quartz; D012822:Silicon Dioxide; D018130:Diamond; D000537:Aluminum Oxide