Closure of skin incisions by 980-nm diode laser welding

A 980-nm diode laser is proposed to be an alternative welding laser in dermatology due to its optimal penetration in tissue. An in vivo predosimetry study was done to estimate the optimal laser energy delivery conditions (6 W, 400 ms). Next, in vivo experiments were comparatively performed to examine healing of wounds closed either with suture or laser welding. One-centimeter-long, full-thickness incisions were done on the dorsal side of Wistar rats. Wounds were surgically removed at 1, 4, 7, 14, and 21 days postoperatively. Macroscopic examinations showed that welding had minimal scarring and a fine quality healing. According to histological (hematoxylin and eosin staining) results, change of epidermal thickness and granulation tissue formation through 21 days of healing period showed similarities in both methods. Epidermal thickness of welded wounds decreased from 62.46±6.87 μm (first day) to 36.49±0.92 μm (21st day) and that of sutured wounds decreased from 62.94±13.53 μm (first day) to 37.88±7.41 μm (21st day). At day 14, epidermal thickness of sutured wounds (61.20±6.60 μm) were higher than welded wounds (49.69±6.31 μm) (p<0.05). Besides, granulation values were greater for the sutured wounds but the difference was statistically significant (p<0.05) only for the seventh day (197,190.29±.89,554.96 μm² for sutured wounds, 138,433.1±51,077.17 μm² for welded wounds). Those differences indicate a faster recovery with laser welding. It is concluded that tissue welding with a 980-nm diode laser can be a good candidate for tissue welding applications with accelerated and improved healing, but further investigations are in progress for clinical use.