title: Nanoshell assisted laser soldering of vascular tissue.
abstract: OBJECTIVE
  Laser tissue soldering (LTS) is a promising technique for tissue fusion but is limited by the lack of reproducibility particularly when the amount of indocyanine green (ICG) applied as energy absorber cannot be controlled during the soldering procedure. Nanotechnology enables the control over the quantitative binding of the ICG. The aim of this study was to establish a highly reproducible and strong tissue fusion using ICG packed nanoshells. By including the chromophore in the soldering scaffold, dilution of the energy absorber during the soldering procedure is prevented. The feasibility of this novel nanoshell soldering technique was studied by assessing the local heating of the area and tensile strength of the resulting fused tissue.
  
  
  METHODS
  Nanoshells with a diameter of 250-270 nm were loaded with ICG and included in a porous polycaprolactone (PCL) scaffold doped with albumin solder. The nanoshell scaffold was used in a flexible, semi-dry formulation suitable for surgical use. Heat development, tensile strength as well as tissue damage were assessed.
  
  
  RESULTS
  Rabbit aortic arteries were successfully soldered using an ICG packed nanoshell scaffold. Tensile strengths of these nanoshell soldered anastomoses were found to be 734 ± 327 mN (median = 640 mN). Thermal damage was restricted to the adventitia at the irradiated area. In addition, absorber dilution was prevented during the soldering procedure resulting in significantly lower variance in maximum temperature (P = 0.03) compared to the classical liquid ICG soldering technique.
  
  
  CONCLUSIONS
  Using nanoshells, controlled amounts of chromophore could successfully be bound into the polymer scaffold. Diode laser soldering of vascular tissue using ICG-nanoshell scaffolds leads to strong and reproducible tissue fusion. With optimally chosen settings of irradiation time, nanoshells coating and scaffold properties, our improved LTS procedure demonstrates the potential for a clinically applicable anastomosis technique.
authors: Department of Neurosurgery, Inselspital Bern, University of Bern, Switzerland.
authors: Daniel S
authors: DS
authors: Schöni
authors: Serge
authors: S
authors: Bogni
authors: Amadé
authors: A
authors: Bregy
authors: Amina
authors: A
authors: Wirth
authors: Andreas
authors: A
authors: Raabe
authors: Istvan
authors: I
authors: Vajtai
authors: Uwe
authors: U
authors: Pieles
authors: Michael
authors: M
authors: Reinert
authors: Martin
authors: M
authors: Frenz
mesh_terms: D000714:Anastomosis, Surgical / Q000379:methods; D000818:Animals; D001011:Aorta / Q000601:surgery*; D005240:Feasibility Studies; D007208:Indocyanine Green; D053685:Laser Therapy / Q000379:methods; D054023:Lasers, Semiconductor / Q000627:therapeutic use*; D057145:Nanoshells / Q000737:chemistry; D011073:Polyamines; D011817:Rabbits; D015203:Reproducibility of Results; D012822:Silicon Dioxide; D013696:Temperature; D013718:Tensile Strength; D014014:Tissue Adhesives; D054457:Tissue Scaffolds / Q000737:chemistry; D058106:Wound Closure Techniques
chemical_list: D011073:Polyamines; D014014:Tissue Adhesives; C063994:polyallylamine; D012822:Silicon Dioxide; D007208:Indocyanine Green