title: Temperature-controlled two-wavelength laser soldering of tissues.
abstract: OBJECTIVE
  Laser tissue soldering is a method for bonding of incisions in tissues. A biological solder is spread over the cut, laser radiation heats the solder and the underlying cut edges and the incision is bonded. This method offers many advantages over conventional techniques (e.g., sutures). Past researches have shown that laser soldering, using a single laser, does not provide sufficient strength for bonding of cuts in thick (>1 mm) tissues. This study introduces a novel method for laser soldering of thick tissues, under temperature control, using two lasers, emitting two different wavelengths.
  
  
  METHODS
  An experimental system was built, using two lasers: (i) a CO(2) laser, whose radiation heated the upper surface of the tissue and (ii) a GaAs laser that heated an albumin layer under the tissue. An infrared fiber-optic radiometer monitored the temperature of the tissue. All three devices were connected to a computer that controlled the process. A computer simulation was written to optimize the system parameters. The system was tested on tissue phantoms, to validate the simulation and ensure that both the upper and lower sides of the cut were heated, and that the temperature could be controlled on both sides. The system was then used ex vivo to bond longitudinal cuts of lengths ∼12 mm in the esophagi of large farm pigs.
  
  
  RESULTS
  The theoretical simulations showed a good stabilization of the temperatures at the upper and lower tissue surfaces at the target values. Experiments on tissue phantom showed a good agreement with these simulations. Incisions in esophagi, removed from large farm pigs, were then successfully bonded. The mean burst pressure was ∼3.6 m of water.
  
  
  CONCLUSIONS
  This study demonstrated the capability of soldering cuts in thick tissues, paving the way for new types of surgical applications.
authors: Raymond and Beverly Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel Aviv University, Israel. gabayila@post.tau.ac.il
authors: Ilan
authors: I
authors: Gabay
authors: Avraham
authors: A
authors: Abergel
authors: Tamar
authors: T
authors: Vasilyev
authors: Yaron
authors: Y
authors: Rabi
authors: Dan M
authors: DM
authors: Fliss
authors: Abraham
authors: A
authors: Katzir
mesh_terms: D000818:Animals; D006358:Hot Temperature; D053685:Laser Therapy / Q000379:methods*; D013536:Suture Techniques; D013552:Swine