Microlesion healing dynamics in in vivo porcine skin after treatment with 1064 nm picosecond‐domain Nd:YAG laser

The fractionated picosecond laser produces microscopic lesions in the epidermis and dermis due to laser-induced optical breakdown (LIOB). There have been multiple histological reports, but the present literature lacks detailed in vivo studies after treatment with high-power laser systems. Our study aimed to characterize the healing patterns of microlesions induced with 150 ps duration 1064 nm MLA-type picosecond laser. The induced picosecond laser-tissue reactions with pulse energy of 50-250 mJ and different treatment modes were observed in in vivo porcine skin model over 10 days after the laser procedure. A macroscopic evaluation was combined with microscopic histological analysis to observe the healing dynamics of laser-induced microlesions. Superficial, intraepidermal cavitation bubbles were induced using microbeam fluence of 4-20 J/cm2 . Skin irritation scores positively correlated with pulse energy and dose. Our findings demonstrate that dose and pulse energy had a direct impact on epidermal thickness and lesions healing dynamics.