LASER-TISSUE WELDING OF DURA-MATER AND PERIPHERAL-NERVES - A SCANNINGELECTRON-MICROSCOPY STUDY

Background and Objective: In order to elucidate the mechanism of tissu e welding, scanning electron microscopy (SEM) was used to investigate the ultrastructural changes on the surface of dura mater and periphera l nerves after CO2 laser welding. Study Design/Materials and Methods: The dura mater and the epineurium of the nerves was welded with a CO2 laser at 100 mW with pulses of 1.0 s (spot size 320 mu m), both with a nd without additional use of a protein solder (egg white). The specime ns were immediately examined using SEM. Results: The laser tissue bond ing mechanism is collagen-to-collagen attachment. After laser irradiat ion, the collagen fibrils are swollen, densely packed, and fused toget her. When a protein solder is used, the coagulated solder forms a soli d bridge between the tissue edges, which is melted on and between the collagen fibrils. Conclusion: Laser welds in dura mater and peripheral nerves are the result of collagen-to-collagen bending. In solder-assi sted laser welds, the tissue connection is made by an internal and an external matrix of coagulated solder. (C) 1996 Wiley-Liss, Inc.