Multiple fractional erbium: yttrium-aluminum-garnet laser sessions for upper facial rejuvenation: clinical and histological implications and expectations.

Background: Fractional photothermolysis is a modern resurfacing technique, in which microscopic zones of thermal injury are created, stimulating turnover of both epidermis and dermis. Fractional laser rejuvenation has been developed to overcome the drawbacks of traditional ablative laser.

Objectives: To objectively evaluate the effectiveness of multiple sessions of fractional Er:YAG laser rejuvenation for aging upper face clinically, histologically and immunohistochemically.

Patients/methods: Ten volunteers asking for facial rejuvenation were subjected to multiple sessions (3-5) of fractional Er:YAG laser. Clinical evaluation with both histopathological and immunohistochemical assessment for skin biopsies was carried out before, after 1 month and 6 months of laser resurfacing. Histometry for epidermal thickness and quantitative assessment for neocollagen formation, collagen I, III, and VII, elastin and tropoelastin were carried out for all skin biopsies.

Results: Comparing before, after 1 month and 6 months of fractional Er:YAG laser resurfacing resulted in improved clinical appearance with increased epidermal thickness (P < 0.001). Dermal collagen showed increased neocollagen formation (P = 0.006), with increased concentration of collagen types I (P < 0.001), III (P < 0.001), and VII (P = 0.001). Dermal elastic tissue studies revealed decreased elastin, while tropoelastin concentration increased after laser resurfacing (P < 0.001). An increase in collagen (I and III) and tropoelastin level and decreased elastin content was encountered with increasing the number of sessions, yet it was not significant.

Conclusions: Multiple sessions are effective in rejuvenation of the aging face with high safety, short downtime, and no adverse effects. They stimulated formation of new collagen (type I, III, and VII) up to 6 months after treatment with better improvement in skin texture and fine wrinkles. The variable number of fractional Er:YAG laser sessions (3-5) showed no significant difference as regards efficacy.