Skin tissue welding with near infrared lasers: investigation of the optimal parameters

Abstract

Laser tissue welding/soldering is an alternative to conventional closure techniques in surgery. In the present study, the closure capability and the contribution to recovery period of laser welding techniques were investigated through comparative experiments. E ects of three near infrared (NIR) wavelengths, 809 nm diode laser, 980 nm diode laser and 1070 nm ytterbium ber laser, were compared not only among themselves but also with classical manual suturing for skin closure competency. Lasers with di erent NIR wavelengths were delivered to skin incisions via optical bers and laser power was adjusted according to predosimetry studies. In dosimetry experiments all the three NIR lasers were tested for their e cacy in welding; besides, 809 nm diode laser was also tested for its e cacy in laser soldering. E ects of 980 nm laser welding at same energy but di erent irradiation levels were also compared. Throughout this period, healing was inspected at particular days (1, 4, 7, 14, 21) by histological and mechanical methods. Skin samples were stained with Hematoxylin and Eosin (H&E) in order to assess gross pathological changes along epidermis and dermis created either by photothermal laser tissue interactions or suturing and suture material itself. These changes were quanti ed as closure index (CI), thermally altered area (TAA), granulation area (GA) and epidermal thickness (ET) by using di erent microscopy techniques such as bright eld, polarized light and phase contrast. The laser welding techniques were found reliable in terms of immediate and mechanically strong closure compared to suturing.|Keywords: Skin welding/soldering, 809 nm diode laser, 980 nm diode laser, 1070-nm YFL, ICG, Tensile test, H&E staining, Closure index.