Continuous cooling system in conjunction with laser surgery for ear reshaping.

When the cartilage on the prominent ears is reshaped, the arising stress returns the tissue to its initial configuration. Laser irradiation of areas of maximal stress leads to stress relaxation and results in a stable configuration. Sixty auricles were harvested from 30 New Zealand white rabbits and cut into a rectangle measuring 50 mm by 25 mm with an average thickness of approximately 1.3 mm. Bilateral skin was included for ex vivo studies. Continuous cryogen spray cooling (CSC) with laser energy was delivered to the exposed cartilage for reshaping. In clinical applications, from January 2006 to December 2016, a total of 50 patients with 100 bat ears who underwent CO2 laser reshaping (otoplasty) were assessed. A continuous cooling system (4 °C) in conjunction with a CO2 laser was applied to make a retroauricular-approached incision and reshape the ear cartilage. The well cartilage bending correlated with the different parameters demonstrated in the continuous CSC protected group. All 100 (100%) of the subjects experienced early complications (≤ 1 month) related to laser exposure with swelling, while 5 (5%) experienced ecchymosis, 2 (2%) minimal hematoma, 2 (2%) scarring, 1 (1%) minor infection, 1 (1%) under correction, 1 (1%) overcorrection, and 1 (1%) relapse. These problems were corrected and/or had resolved after 3 months. All patients achieved good to excellent results in our final outcome assessment (> 6 months). Laser reshaping has a potential use in certain surgical procedures involving the cartilage. The appropriate conditions for laser ear reshaping clearly depend on the laser wavelength used, energy controlling, and tissue optical properties.

Real-time photothermal imaging and response in pulsed dye laser treatment for port wine stain patients.

BACKGROUND: This study was performed to assess the photothermal response of highly focused laser energy using infrared thermal imaging instrument to detect and assess the actual temperature distribution during flash lamp pumped pulsed dye laser (FLPPDL) treatment for port wine stain (PWS) patients and avoiding its complications. METHODS: A retrospective review of 40 patients with PWS birthmark treated with FLPPDL (l = 585 nm, tp = 1500 ms, 7 mm spot) was conducted over a 2-year period. Subjects' ages ranged between 28 and 46 years (mean 29 years); there were 24 females and 16 males. Twenty patients received non-cooling laser treatment (NC-LT) using light dosages of 5-12 J/cm 2 . Another 20 patients received cryogen spray cooling laser treatment (CSC-LT) using light dosages of 5-12 J/cm 2 . A real-time infrared thermal imaging and the thermal wave equation were used for assessment. The results of temperature distributions related to the energy change were analyzed. RESULTS: Proper temperature measurement using infrared thermal imaging instrument and thermal wave equation in non-cooled PWS patients showed that the energy density of pulsed dye laser (PDL) higher than 7 J/cm 2 can reach >44°C and result in burn injury. However, when energy densities beyond 10 J/cm 2 were administered, along with using CSC, thermal damage was could still be minimized without the risk of damage to the treated area. CONCLUSION: Using infrared thermal imaging instrument and thermal wave equation, we can predict the skin temperature distribution in FLPPDL for PWS patients during the treatment. In conjunction with CSC, the complications can be minimized.