Numerical Modeling of The Dysplastic Vessel Heating in PWS by Yellow 578 nm Copper Vapor Laser Radiation for Different Skin Phototypes.

Introduction: Many clinical studies and protocols have been written about laser treatment for fair skin phototypes. However, for dark-skinned phototypes, information is limited, and the risk of burns is higher, especially if the same settings are recommended for fair skin. Competitive epidermal melanin absorption decreases the light energy reaching dysplastic vessels in a port-wine stain (PWS), preventing the vessel from achieving the temperature of the desired clinical result. Therefore, the choice of safe laser settings for different skin phototypes can be realized using numerical modeling of PWS vessel heating. This study aimed to demonstrate the algorithm for choosing both effective and safe photodestruction of dilated dermal vessels in PWS with the copper vapor laser (CVL) at 578 nm for different skin phototypes. Methods: We used the multilayered skin model with different melanin content for detecting the safe laser parameters for PWS treatment. The calculation of the selective heating of the vascular component with CVL radiation at yellow 578-nm wavelengths for different skin phototypes was performed via Matlab mathematical programming system and its application Femlab for solving partial differential equations using the Finite element method. Results: We determined the location, depth, and size of blood vessels that could be selectively heated to coagulation temperature for different skin prototypes. CVL fluence values need to be reduced almost two times for skin phototype IV than for skin phototype II to provide safe CVL treatment. The maximum depth of the location of the vessels, which can be selectively heated to coagulation temperature, also decreased for dark skin phototypes. Histological and histochemical findings validated the results of our calculations. Conclusion: To our knowledge, the use of numerical simulation to optimize has not yet been considered. According to our calculations, CVL could selectively heat the dilated vessel, which occurred in purple and proliferative-type PWS for dark skin at the reduced fluence range and depth.

Treatment of Congenital Melanocytic Nevi With a Dual-Wavelengths Copper Vapor Laser: A Case Series.

Introduction: Congenital melanocytic nevus (CMN) is a severe challenge for dermatology. This pigmented skin lesion is undesirable for patients because of its localization in open areas of the body. Various visible and near-infrared laser systems and intense pulsed light (IPL) sources have been applied for CMN treatment. However, post-traumatic hyperpigmentation, structural changes, atrophy, and scarring due to non-specific thermal damage have been observed. Many patients have shown recurrence after treatment. Therefore, it highlights the need for testing new laser modalities for the management of CMN. Methods: Two adult II Fitzpatrick phototype patients (a 55-year-old male and a 30-year-old female) with middle-sized facial CMN (on the forehead and lower eyelid) are presented. All patients were treated with dual-wavelength copper vapor laser (CVL) radiation at 511 nm and 578 nm wavelengths with a power ratio of 3:2. The average power was 0.7-0.85 W with an exposure time of 0.3 seconds. The spot size amounted to 1 mm. Results: Both patients showed complete resolution of CMN after CVL treatments. CMN became crusted within a few days after the laser treatment and peeled off within seven days. No recurrences were observed during the follow-up period up to 24 months. Conclusion: The middle-sized CMN can be successfully treated with dual-wavelength CVL radiation.

Treatment of Basal Cell Cancer With a Pulsed Copper Vapor Laser: A Case Series.

Introduction: Basal cell carcinoma (BCC) is the most prevalent form of non-melanoma skin cancer commonly arising in elderly patients. Currently, many laser systems are applied for the treatment of BCC. However, up to the present, there have been several reports concerning ocular side effects due to the laser procedure in the borders of the periorbital area. This determines the feasibility of testing new laser surgical modes for the management of periorbital BCC. This stuay aimed to estimate both the efficacy, the early post-radiated side effects and long-term outcomes of the CVL treatment of periorbital BCC. Patients and Methods: Two men and 6 women aged 50 to 77 years were diagnosed with periorbital BCC according to the data of both the clinical evaluation and histological examination of the tissue samples taken from the involved area. Six months after the laser treatment, the histological examination of skin samples from the borderline of the irradiated area was made again. All patients were followed for 24 months after the laser treatment of BCC. The laser treatment was administered during one session of copper vapor laser (CVL) (Yakhroma-Med model). The treatment included CVL radiation with a wavelength of 511 nm and 578 nm, in the ratio of 3:2. The power level was set up to 3 W, and the exposure time was equal from 200 to 600 ms. The pulse duration accounted for 15 ns. The diameter of the light spot on the skin surface amounted to 1 mm. Results: Dual-wavelengths CVL treatment of periorbital BCC provided a complete elimination of malignant cells and dysplastic vessels during one procedure. The duration of skin healing amounted to 2-4 weeks. There were neither ocular injuries or pronounced skin side effects nor relapses within 24 months after the laser procedure. Conclusion: CVL treatment of periorbital BCC provides relevant cosmetic results without ocular injuries and relapses.

Rhinophyma Treatment by Copper Vapor Laser With the Computerized Scanner.

Introduction: Rhinophyma is recognized as a common and severe skin disease manifested as progressive thickening of the nasal skin due to hypertrophy of the soft tissue. The most severe complication of rhinophyma is telangiectasis. So far the pathogenetic approach for the treatment of rhinophyma should be based on the removal of the dysplastic vessels to provide the appropriate revascularization of the involved skin area. Case Report: This study presented the experience of the treatment of rhinophyma with the copper vapor laser (CVL) designed with the computerized scanner device. A 52-year-old elderly Caucasian male patient with typical clinical signs of rhinophyma was successfully managed during three sessions of CVL treatment. CVL emits light with a wavelength of 578 nm, exposure time of 0.2 seconds. The settings used for the CVL in scanner mode were set at 1.2 W. The scanner device has a hexagonal frame with a maximum width of 12 mm with the distance of 1 mm between centers of laser spots. The CVL treatment resulted in a restoration of the natural appearance of the nose without side effect during 18 months after treatment. Conclusion: The described clinical case demonstrates excellent results of the management of rhinophyma by means of the scanned CVL. CVL treatment was associated with the removal both of dysplastic superficial skin vessels, the solution of the inflammation, decline of the sebum production and the disappearance of the nasal hypertrophy.