title: Optimal dye concentration and irradiance for laser-assisted vascular anastomosis.
abstract: OBJECTIVE
  This investigation was done in order to find optimal indocyanine green (ICG) concentration and energy irradiance in laser vascular welding.
  
  
  BACKGROUND
  Many studies have shown that laser tissue welding with albumin solder/ICG may be an effective technique in surgical reconstruction. However, there are few reports regarding optimal laser settings and concentrations of ICG within the albumin solder in laser-assisted vascular anastomosis.
  
  
  METHODS
  Porcine carotid artery strips (n = 120) were welded in end-to-end by diode laser with 50% albumin solder of 0.01, 0.1, and 1.0 mM ICG at irradiance of 27.7, 56.7, and 76.9 W/cm(2), respectively. Temperature was measured by inserting thermocouples outside and inside the vessel. Tensile strength and histology were studied.
  
  
  RESULTS
  Temperature and strength of the anastomosis significantly decreased (all p < 0.05) with increasing ICG concentration at 56.7 W/cm(2). Histological study showed minimal thermal injury limited to adventitia and no appreciable difference between all groups.
  
  
  CONCLUSIONS
  ICG concentration within solder is the most important factor affecting both vascular temperature and tensile strength. The optimal balance between strength and minimal thermal injury may be achieved primarily at 56.7 W/cm(2) and 0.01 mM ICG.
authors.affiliation: Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, Oregon, USA. zhen.ren@providence.org
authors.forename: Zhen
authors.initials: Z
authors.lastname: Ren
authors.forename: Hua
authors.initials: H
authors.lastname: Xie
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Lagerquist
authors.forename: Allen
authors.initials: A
authors.lastname: Burke
authors.forename: Scott
authors.initials: S
authors.lastname: Prahl
authors.forename: Kenton W
authors.initials: KW
authors.lastname: Gregory
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Furnary
mesh_terms: D000714:Anastomosis, Surgical / Q000379:methods; D000818:Animals; D002339:Carotid Arteries / Q000601:surgery*; D004396:Coloring Agents / Q000032:analysis*; D006801:Humans; D066298:In Vitro Techniques; D007208:Indocyanine Green / Q000032:analysis*; D053685:Laser Therapy / Q000379:methods*; D011829:Radiation Dosage; D012709:Serum Albumin / Q000737:chemistry*; D013552:Swine; D013696:Temperature; D013718:Tensile Strength; D014656:Vascular Surgical Procedures / Q000379:methods*
chemical_list: D004396:Coloring Agents; D012709:Serum Albumin; D007208:Indocyanine Green