In-Vivo Histological Analysis of a Fractional CO2 Laser System Intended for Treatment of Soft Tissue

BACKGROUND: Fractional ablative lasers have been shown to be safe and effective for improving wrinkles, scars, skin texture, and dyspigmentation. However, the exact effects of this technology in vivo on epidermal and dermal skin constituents have not been delineated. This study evaluated the in vivo histological effects over time of treatment with a fractional ablative CO2 system, using different treatment parameters.

Healthy adult volunteers were enrolled in this multicenter clinical study. Study participants, previously scheduled for abdominoplasty, received fractional CO2 laser treatment on the abdomen at a predetermined time prior to surgery. Biopsies were taken at baseline and after CO2 treatment. Morphological and morphometric analyses were performed in the ablated and coagulated tissue areas.

Nine healthy adult volunteers were treated. Histologic evaluation showed 800-900 micron diameter zones of ablation and coagulation confined to the upper most layer of the skin in the mode with the greatest fractional skin coverage using Light Mode 30 - 50% (spot diameter of 150 microns, 30-60 millijoules fluence), while ablation to levels of up to 900 microns in depth using the Deep Mode (spot diameter 150 microns, 50-80 millijoules). Healing times of treated tissue varied from 1-day post-treatment with the Light Mode, and up to 10 days post-treatment with the Deep Mode. No remnants of ablation or coagulation were seen after 30 days post CO2 treatment with either mode. There were no adverse events associated with treatments.

Treatment of the skin using the fractional CO2 device leads to skin resurfacing via ablation and coagulation of the treated area at a depth proportional to the delivered energy. The higher the energy used, the greater the degree of ablation and coagulation in tissue, which can lead to a greater tissue response in terms of fibroblast activity, collagen remodeling, and new collagen formation.

J Drugs Dermatol. 2017;16(11):1085-1090.