Skin closure with dye-enhanced laser welding and fibrinogen

The topical application of wavelength-specific dye and fibrinogen has been used to enhance laser closure of vascular anastomoses. We compared the closure of skin incisions by two different dye-enhanced, fibrinogen-based laser welding systems [argon laser (power density 4.78 W/cm²) with fluorescein isothiocyanate dye (n = 32) and diode laser (power density 9.55 W/cm²) with indo-cyanine green dye (n = 32)] with closure by interrupted 5-0 nylon suture (n = 64) and examined tensile strength, hydroxyproline production, histology, and cosmesis. Two 3-cm full-thickness incisions were made on the shaved backs of 64 rats. One incision was closed with suture, whereas the other, after treatment with the appropriate dye, was welded with either argon- or diode-lasered fibrinogen. At postoperative days 5, 10, 15, and 28, the closure sites were harvested and sectioned for analysis. Initially, wounds closed with argon-lasered fibrinogen showed less inflammatory response, greater collagen production (34.61 ± 0.74 mg/gm), and greater mean peak stress at rupture (64.85 lbs/in²) than those closed with suture (16.42 ± 3.20 mg/gm, 26.68 lbs/in²) (p < 0.05). By 15 days, both argon and diode laser closures are superior in strength and collagen production to suture closure (p < 0.05). At 28 days, diode laser closures (1315.60 lbs/in²) are stronger than suture closures (998.09 lbs/in²), whereas both are stronger than argon laser closures (813.16 lbs/in²) (p < 0.05). Cosmetically, argon-welded wounds consistently appeared finer and lacked cross-hatched suture scars. Variations in the total laser energy delivered and in the amount of energy absorbed by a particular dye may explain the different short- and long-term trends in healing and inflammation. Laser welding with dye-enhanced fibrinogen offers a promising alternative means of skin closure that fosters a natural healing base without greatly compromising wound strength.