Numerical Modeling and Clinical Evaluation of Pulsed Dye Laser and Copper Vapor Laser in Skin Vascular Lesions Treatment

Laser-Induced Blood Coagulation for Surgical Application: A Scoping Review

There is a lack of evidence-based reviews on the effects of laser irradiation on blood coagulation in the literature, despite a large number of clinical trials. We therefore evaluated the available evidence on laser irradiation parameters used in coagulation of blood to optimize physical parameters. We performed a literature search for recent scientific studies indexed between 2017 and 2023 using the databases of PubMed and ScienceDirect. Articles were selected based on defined inclusion and exclusion criteria, and 78 publications in total were eventually included in this scoping review. The following were found to produce significant benefits in blood coagulation for surgical application: (1) dentistry and oral surgeries: 980 nm, 27 s, 2 W, 1502.7 W/cm2, 26.5 J, 622 J/cm2, 400 μm; (2) urogenital disorders: 532 nm, 4 s, 40 W, 10600 W/cm2, 1.3 J, 424 J/cm2, 600 μm; (3) ophthalmic disorders: 810 nm, 1 s, 1 W, 3540 W/cm2, 0.75 J, 1326 J/cm2, 100 μm; (4) embryological surgeries: 1064 nm, 10 s, 25 W, 35400 W/cm2, 262.5 J, 371000 J/cm2, 332.5 μm; (5) dermatological disorders: 1064 nm, 20 W, 2440 W/cm2, 0.1 J, 24 J/cm2, 670 μm; (6) gastrointestinal disorders: 532 nm, 3 s, 20 W, 1051 W/cm2, 120 J, 26500 J/cm2, 760 μm; (7) neurological surgeries: 2.5 s, 1.5 W, 1035 W/cm2, 2 J, 1584 J/cm2, 385 μm; (8) pulmonary disorders: 1320 nm, 5s, 35 W, 12450 W/cm2, 250 J, 65000 J/cm2, 700 μm (9) cardiovascular disorders: 1064 nm, 16.5 s, 5 W, 1980.5 W/cm2, 900 J, 760 J/cm2, 400 μm. In conclusion, our scoping review identifies that combining data from all clinically heterogeneous studies suggests that laser irradiation reflects an effective method for inducing blood coagulation in several medical fields.

Treatments of palpebral congenital melanocytic nevus: a systematic review

PURPOSE

Palpebral congenital melanocytic nevi (PCMN) is a rare congenital skin lesion affecting the eyelids that can lead to cosmetic and psychological concerns and potential health risks such as malignancy. Several authors have analyzed therapeutical strategies to treat PCMN. However, there was no consensus in the literature. This systematic review aimed to evaluate the effectiveness, safety, and success of treatments of PCMN.

METHODS

We conducted a systematic review following PRISMA guidelines from October 2022 to April 2023. We included all types of study designs that described or compared PCMN treatments and interventions, as well as histology, recurrence, adverse events, patient satisfaction, and malignant transformation. The search strategy was based on specific search words through the following databases: PubMed, Embase, Latin American and Caribbean Health Sciences Literature (Lilacs), Web of Science, and Scopus. Ongoing studies and gray literature studies were included.

RESULTS

We analyzed 25 case reports with 148 participants. The effectiveness, success, and satisfaction with various treatments for PCMN depend on the specific treatment method and the individual patient's case.

CONCLUSIONS

Most of the studies showed that surgical procedures (exeresis) are able to treat PCMN in the eyelid. The variability in outcomes emphasizes the importance of further research to better understand the most effective and safe approaches for treating congenital melanocytic nevi.

Successful Treatment of Sebaceous Nevus With Copper Vapor Laser

Introduction: Sebaceous nevus (SN) is a benign skin hamartoma with a potent transformation in benign or malignant tumors in adolescents or adults. Due to the most common location in the esthetic zone, an SN makes patients seek a dermatologist for cosmetic concerns on the face or neck. The surgical excision of a large-sized SN in the esthetic zone may require reconstruction with a skin flap and be associated with recurrences and scar formation. Case Report: We describe the successful treatment of the large-sized neck SN with copper vapor laser (CVL) for the first time. A left-sided neck SN (linear size of 27 mm) in the 24-year-old Caucasian female completely resolved after eight CVL sessions. The settings were as follows: average power accounted for 0.8-1.0 W, with a ratio at green (511 nm) and yellow (578 nm) wavelengths of 3:2. The pulse duration was set as 20 nanoseconds, the repetition rate 16.6 kHz, the exposure time 200 ms, light spot diameter of 1 mm. The CVL treatment resulted in the complete disappearance of the SN without remote side effects such as hyperpigmentation, scarring or recurrences 24 months after the treatment. The patient was satisfied with the excellent cosmetic results. Conclusion: The CVL treatment of the SN provides the most relevant result due to the complete elimination of SN cells and the remodeling of the vascular bed supplying the involved areas.

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.

The Successful Treatment of Eyelid Intradermal Melanocytic Nevi (Nevus of Miescher)With the Dual-Wavelengths Copper Vapor Laser

Introduction: Surgical methods for removing eyelid nevus are associated with a risk of developing such side effects as scarring or loss of eyelashes. Although current laser modalities have shown promising results, eyelid laser surgery may cause skin discoloration and noticeable scarring. This study aims at evaluating the efficacy and safety of the dual-wavelengths copper vapor laser (CVL) treatment of eyelid intradermal nevus of Miescher (NM). Patients and Methods: We present three adult female patients with eyelid intradermal nevus treated with CVL. CVL settings were as follows: the average power of 0.6-0.8 W, under a power ratio of 3:2 at wavelengths of 511 nm and 578 nm, exposure time of 0.3 seconds, the light spot diameter of 1 mm. Results: The dual-wavelength CVL treatment of medium- and large-sized NM provides the complete removal of eyelid dome-like NM after one and two sessions with a month interval correspondingly. The duration of skin healing accounted for two weeks. Conclusion: The complete removal of eyelid NM lesions without side effects demonstrates the safety and efficacy of dual-wavelengths CVL in treating such skin lesions. This laser treatment mode of benign skin neoplasms seems promising for dermatologists and cosmetologists' clinical practice.

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 palpebral melanocytic nevi with a dual-wavelengths copper vapor laser

Acquired melanocytic nevi in aesthetically significant areas, especially palpebral nevi (PN), are becoming a frequent reason for patients to seek dermatologists. Surgical methods for removal of PN are reported to be associated with the risk of such side effects as scars and loss of eyelashes. Aim of the study. To evaluate the efficacy of the removal of PN on the eyelid area with dual-wavelength radiation of a copper vapor laser (CVL). Patients and methods. Laser removal of medium and large-sized PN (up to 10 mm) was performed in three fair-skin female patients. The procedures were carried out at an average CVL radiation power of 0.60.8 W, at a 3:2 ratio of radiation powers at wavelengths of 511 nm and 578 nm, exposure duration 0.3 s, light spot diameter 1 mm. The treatment was carried out during one session. Results. Removal of PN with dual-wavelength CVL radiation allowed achieving a significant lightening and reduction of the involved area, without scars. The skin healing after the procedure lasted 2 weeks. Conclusion. The high efficacy of the PN removing in the eyelid area using the dual-wavelength CVL radiation allows the introduction of this approach into dermatologists and cosmetologists clinical practice.

Treatment of palpebral melanocytic nevi with a dual-wavelengths copper vapor laser

Acquired melanocytic nevi in aesthetically significant areas, especially palpebral nevi (PN), are becoming a frequent reason for patients to seek dermatologists. Surgical methods for removal of PN are reported to be associated with the risk of such side effects as scars and loss of eyelashes. Aim of the study. To evaluate the efficacy of the removal of PN on the eyelid area with dual-wavelength radiation of a copper vapor laser (CVL). Patients and methods. Laser removal of medium and large-sized PN (up to 10 mm) was performed in three fair-skin female patients. The procedures were carried out at an average CVL radiation power of 0.60.8 W, at a 3:2 ratio of radiation powers at wavelengths of 511 nm and 578 nm, exposure duration 0.3 s, light spot diameter 1 mm. The treatment was carried out during one session. Results. Removal of PN with dual-wavelength CVL radiation allowed achieving a significant lightening and reduction of the involved area, without scars. The skin healing after the procedure lasted 2 weeks. Conclusion. The high efficacy of the PN removing in the eyelid area using the dual-wavelength CVL radiation allows the introduction of this approach into dermatologists and cosmetologists clinical practice.

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.