High incident fluence and long pulse laser irradiation in conjunction with cryogen spray cooling: an ex-vivo study

We have investigated the utilization of high incident fluence, long pulse laser irradiation in conjunction with cryogen spray cooling (CSC) on ex-vivo human skin. Abdominal skin samples of different types (Fitzpatrick type I-VI) were obtained from patients undergoing the trans-rectus myocutaneous flap procedures. Each skin type was irradiated with a Candela Vbeam/spl trade/ laser (wavelength /spl lambda/=595 nm) at incident dosages of D/sub /spl theta//=6, 10, 15, 20 J/cm/sup 2/, pulse durations of /spl tau//sub laser/=1.5, 10, 40 ms, without and with CSC. Preliminary results indicate that lightly pigmented skins can sustain higher incident fluence levels than those currently used in therapeutic settings. While the incident dosage of the laser pulse remains the same, longer pulse duration can decrease the degree of epidermal thermal injury.