Histologic Effects of Fractional Lasers and Energy-Based Devices on Intradermally Injected Hyaluronic Acid Filler for Improving Skin Smoothness.

[BACKGROUND] Prior studies have shown that energy-based devices (EBDs) over pre-injected hyaluronic acid (HA) fillers do not significantly affect clinical outcomes. However, the impact of EBDs over newly FDA-approved HA filler for improving skin smoothness is still undetermined.

[OBJECTIVE] To evaluate the immediate histologic changes after various popular EBDs are performed over pre-injected, newly FDA-approved intradermal HA filler.

[MATERIALS AND METHODS] Abdominoplasty skin was injected with HA superficially. Zone 1 was used as untreated control, while the other zones treated with the 755-nm picosecond laser with diffractive lens array, 1064-nm picosecond and 1064-nm Q-switched lasers, radiofrequency with insulated microneedles, volumetric directional thermal impact ultrasound (VDTI), and thermomechanical fractional injury (TMFI) devices.

[RESULTS] Histology shows HA in the superficial to mid dermis. Treatment with fractional Q-switched and picosecond lasers showed expected laser-induced optical breakdown in the epidermis and dermis. RF microneedling, VDTI, and TMFI devices caused thermal damage of collagen bundles with dermal dehydration.

[CONCLUSION] No immediate morphological changes to HA were noted following device treatment. However, the effect of heat-generating devices on the molecular integrity of HA fillers, which are composed of HA and water, remains uncertain.