Thermal responses of ex vivo human skin during multiple cryogen spurts and 1,450 nm laser pulses. Academic Article uri icon


  • BACKGROUND AND OBJECTIVE: Although cryogen spray cooling (CSC) is used to minimize the risk of epidermal damage during laser dermatologic surgery, concern has been expressed that CSC may induce cryo-injury. The objective of this study is to measure temperature variations at the epidermal-dermal junction in ex vivo human skin during three clinically relevant multiple cryogen spurt-laser pulse sequences (MCS-LPS). STUDY DESIGN/MATERIALS AND METHODS: The epidermis of ex vivo human skin was separated from the dermis and a thin-foil thermocouple (13 microm thickness) was inserted between the two layers. Thermocouple depth and epidermal thickness were measured using optical coherence tomography (OCT). Skin specimens were preheated to 30 degrees C before the MCS-LPS were initiated. Three MCS-LPS patterns, with total cryogen spray times of 38, 30, and 25 milliseconds respectively, were applied to the specimens in combination with laser fluences of 10 and 14 J/cm(2), while the thermocouple recorded the temperature changes at the epidermal-dermal junction. RESULTS: The thermocouple effectively recorded fast temperature changes during three MCS-LPS patterns. The lowest temperatures measured corresponded to the sequences with longer pre-cooling cryogen spurts. No sub-zero temperatures were measured for any of the MCS-LPS patterns under study. CONCLUSIONS: The three clinically relevant MCS-LPS patterns evaluated in this study do not cause sub-zero temperatures in ex vivo human skin at the epidermal-dermal junction and, therefore, are unlikely to cause significant cryogen induced epidermal injury.

published proceedings

  • Lasers Surg Med

author list (cited authors)

  • Zhang, R., Ramirez-San-Juan, J. C., Choi, B., Jia, W., Aguilar, G., Kelly, K. M., & Nelson, J. S.

citation count

  • 6

complete list of authors

  • Zhang, Rong||Ramirez-San-Juan, Julio C||Choi, Bernard||Jia, Wangcun||Aguilar, Guillermo||Kelly, Kristen M||Nelson, J Stuart

publication date

  • January 2006