Laser-mediated fixation of collagen-based scaffolds to dermal wounds.
OBJECTIVE
Collagen scaffolds are popular for the reconstitution of dermal equivalents. Usually, these scaffolds are fixed with sutures or staples and in many cases these devices have to be removed in a second procedure. Laser-mediated tissue welding in a wet environment is a potential alternative for collagen scaffold fixation and may be advantageous to suture, staple, and tissue glue fixation.


METHODS
Welding was performed with a continuous-wave diode laser system emitting radiation at a wavelength of 968 nm. Tensile strength after fixation to porcine skin and laser parameters were determined in vitro. In vivo, 24 excisional deep partial thickness wounds were created on flanks of two Goettingen mini pigs and covered with collagen scaffolds. These were randomized and fixated with either (1) staples, (2) fibrin glue, or (3) laser-mediated welding. Tissue biopsies for histological analysis were periodically performed and analyzed for wound healing progression, epidermal thickness, and extracellular matrix formation.


RESULTS
Biomechanical stability after laser welding was time dependent. A dwell time of up to 10 seconds led to a strong bonding with a tensile strength of more than 30 g. In vivo, the wound healing process was macroscopically comparable in all groups and showed no significant differences. Microscopic analysis determined a more progressed and quicker wound closure in both the laser and staples group compared to the fibrin glue fixated scaffold. Laser-mediated fixation led to a significantly reduced epidermal thickness when compared with stapling or fibrin glue (P < 0.05).


CONCLUSIONS
Laser tissue welding is a feasible approach for temporary fixation of collagen scaffolds to the wound bed. It improves wound healing properties and may lead to faster wound healing and cosmetically better scarring. Laser tissue welding is thus a very interesting and promising alternative to currently established fixation methods in a single step, no touch procedure.
Steinstraesser
Lars
L
Department of Plastic Surgery, Burn Center, BG University Hospital Bergmannsheil, Ruhr University Bochum, 44789 Bochum, Germany. lars.steinstraesser@ruhr-uni-bochum.de
Wehner
Martin
M
Trust
Galina
G
Sorkin
Michael
M
Bao
Denxia
D
Hirsch
Tobias
T
Sudhoff
Holger
H
Daigeler
Adrien
A
Stricker
Ingo
I
Steinau
Hans-Ulrich
HU
Jacobsen
Frank
F
D000818:Animals; D003094:Collagen / Q000627:therapeutic use; D062109:Dermatologic Surgical Procedures; D004195:Disease Models, Animal; D005260:Female; D007150:Immunohistochemistry; D017075:Laser Coagulation / Q000379:methods*; D011336:Probability; D011897:Random Allocation; D018570:Risk Assessment; D012867:Skin / Q000293:injuries* / Q000469:parasitology; D013528:Surgical Staplers; D013552:Swine; D013556:Swine, Miniature; D013718:Tensile Strength; D014014:Tissue Adhesives / Q000627:therapeutic use; D014945:Wound Healing / Q000502:physiology*; D014947:Wounds and Injuries / Q000473:pathology / Q000601:surgery*
D014014:Tissue Adhesives; D003094:Collagen