Nonablative skin remodeling: Selective dermal heating with a mid-infrared laser and contact cooling combination

Background and Objective: Many of the microscopic changes associated with p hotodamage reside in the dermis. It follows that subsurface heating of the skin might allow for cosmetic enhancement without loss of the epidermis. Ac cordingly, we investigated the clinical and microscopic changes produced by a mid-infrared laser coupled with a contact cooling device. Study Design/Materials and Methods: Nine patients were treated with an erbi um glass laser and sapphire cooling handpiece in contact with the skin. Pos tauricular sites were irradiated with pulse energies varying from 400-1,200 mJ and numbers of pulses from 4 to 40. Outcome measures included pain, ede ma, and erythema at predetermined postoperative intervals. Biopsies were pe rformed just after treatment and 2 months postoperatively for selected puls e energy-pulse number combinations. Results: Erythema, edema, and pain increased with pulse energy and number o f pulses. Likewise, immediate epidermal necrosis and subsequent scarring we re observed for larger pulse energy-pulse number combinations. At sites wit h epidermal preservation, on biopsy, immediate dermal thermal damage was ob served in a band-like pattern. The deep boundaries of this band were depend ent on pulse energy and pulse number. After 8 weeks, biopsies showed dermal fibroplasia roughly correlating to the band of immediate dermal thermal da mage. Conclusion: Selective dermal heating can be achieved with a midinfrared las er coupled to a contact surface cooling device. In this study, the range of fibroplasia and lack of clinically substantial cosmetic enhancement sugges t that the dermal thermal damage achieved may be too deep and that the inju ry should be confined to more superficial levels to alter the most severely photodamaged dermis. Published 2000 Wiley-Liss, Inc.