Histologic comparison of microscopic treatment zones induced by fractional lasers and radiofrequency

Introduction : Fractional photothermolysis induces microscopic, localized thermal injury in the skin surrounded by undam- aged viable tissue in order to promote wound healing. Objective : This study evaluated acute histologic changes following each single pass of various fractional lasers and radiofrequency (RF). Methods : Three male domestic swine were used. We used fractional Erbium:glass (Er:glass), Erbium:yttrium-aluminum-garnet (Er:YAG), CO 2 lasers, and fractional ablative microplasma RF. We analyzed features and average values of the diameter, depth, and vertical sectional areas treated with each kind of laser and RF. Results : The microscopic treatment zone (MTZ) of fractional Er:glass resulted in separation of dermoepidermal junction with no ablative zone. Fractional Er:YAG provided the most superfi cial and broad MTZ with little thermal collateral damage. Fractional CO 2 resulted in a narrow and deep " cone " -like MTZ. Fractional RF resulted in a superfi cial and broad " crater " -like MTZ. Conclusions : This study provides the fi rst comparison of MTZs induced by various fractional lasers and RF. These data provide basic information on proper laser and RF options. We think that these fi ndings could be a good reference for information about fractional laser-assisted drug delivery.