Free-electron laser and heat-conducting templates: a study of reducing cutaneous lateral thermal damage

We developed novel heat-conducting templates, and tested whether they could effectively remove damaging heat from the tissue during laser ablation. The reduction of lateral thermal damage during cutaneous incisional laser procedures should decrease the time in wound healing. In addition, we selected various infrared wavelengths to determine whether the template effects would be influenced by the laser penetration depth and the particular chromophore absorbing the laser light.

This study utilized the Free-Electron Laser at wavelengths of 3.0, 5.5, 6.45, 7.5, and 7.7 microm to produce 1.0 cm incisions on in vitro lightly pigmented human skin. At each of these wavelengths, copper, aluminum, glass, and Plexiglas heat conducting templates were tested. At wavelength 5.5 microm, the study was duplicated using in vitro darkly pigmented skin. Histological samples were evaluated using computerized morphometric analysis.

The adjunct use of both the copper and aluminum templates provided a decrease in thermal damage at each wavelength. Using the copper template reduced lateral thermal damage an average of 67% with no apparent wavelength dependence. The aluminum template reduced thermal damage an average of 54% with no apparent wavelength dependence. The glass and Plexiglas templates did not reduce the lateral thermal damage. At 5.5 microm, no statistically significant difference in lateral thermal damage was observed between darkly and lightly pigmented tissues.

Heat-conducting templates are an effective new method to reduce lateral thermal damage from thermal laser incisions.