Comparative Study of the Effectiveness of Pulsed and Continuous 450 nm Laser Radiation on Tissue for Layered Removal of Pigmented Nevi

Benign pigmented skin lesions, including congenital giant pigmented nevi (CGPN), are pathological formations located in various skin layers and consisting of melanocyte clusters. CGPN represent a serious psychological and medical problem associated with extensive unaesthetic changes in the patient’s skin appearance. These lesions are currently treated by various methods, including laser radiation. However, such methods often render ineffective and lead to unsatisfactory clinical and aesthetic results, with the incidence of complications in the form of scarring and recurrence sometimes reaching 41%. Therefore, the problem of effective and appropriate treatment of this pathology is relevant, deserving further research. In this work, we conduct an experimental biomedical study into the effect of blue laser radiation with a wavelength (λ) of 450 nm on the tissues of laboratory animals in order to determine its prospects in the treatment of pigmented nevi, including CGPN. Blue laser radiation (λ — 450 nm) was generated by an Lasermed 10-03 device (Russian Engineering Club, LLC, Tula, Russia). An experimental biomedical in vitro research was performed on chilled samples of the liver and muscles of mini-pigs and in vivo on the pigmented skin of live laboratory rats. The dynamics of the regenerative wound process in the exposure areas was studied at different periods, i.e., immediately after exposure and following up to 90 days. A morphometric assessment of the exposure areas was carried out in terms of penetration depth and coagulation changes. The results obtained allowed determination of optimal parameters of 450 nm blue laser radiation for a precision removal of various pigmented skin formations. Laser radiation with a wavelength of 450 nm is a promising treatment approach for pigmented skin lesions, including CGPN.

1. Vulf K. Dermatologiya po Tomasu Fitspatriku (atlas-spravochnik) [Dermatology by Thomas Fitzpatrick (atlas-handbook)]. Second edition. Moscow: Praktika Publ., 2007:1248. (in Russian)].

2. Gorbatova N.E., Zolotov S.A., Simanovsky Ya.O., Nikiforov S.M., Golubev S.V., Alimpiyev S.S., Geynits A.V., Eliseenko V.I., Stankova N.V. Eksperimental'naya sravnitel'naya otsenka effektivnosti rezhimov ablyatsii razlichnoy dlitel'nosti impul'sami CO2 lazerov na kozhnykh pokrovakh mini-sviney dlya tseley lazernoy dermabrazii [Experimental assessment of efficiency of modes of an ablyation impulses of CO2 of lasers of various duration of integuments of mini-pigs for a laser dermabraziya]. Biomeditsina [Journal Biomed]. 2013;4:90–106. (In Russian)].

3. Doronin V.A. Dermabraziya CO2-lazerom epidermal'no-dermal'nykh defektov, a takzhe uvyadayushchey kozhi v ambulatornykh usloviyakh: dis. … kand. med. nauk [CO2 laser dermabrasion of epidermal-dermal defects and aging skin in an outpatient setting: Cand. Sci. (Med.) Thesis]. Moscow, 2004:92. (In Russian)].

4. Doroshenko M.B., Utyashev I.A., Demidov L.V., Aliev M.D. Klinicheskie i biologicheskie osobennosti gigantskikh vrozhdennykh nevusov u detey [Clinical and biological features of giant congenital nevi in children]. Pediatriya. Zhurnal im. G.N. Speranskogo [Pediatrics. Journal named after G.N. Speransky]. 2016;95(4):50–56. (In Russian)].

5. Kapanadze G.D., Ashuev Zh.A. Svetlogorskaya populyatsiya mini sviney [Svetlogorsk population of mini pigs]. Biomeditsina [Journal Biomed]. 2007;6:71–81. (In Russian)].

6. Kapustina O.G. Diagnostika i optimizatsiya lecheniya novoobrazovaniy kozhi v ambulatornoy praktike dermatologa: dis. … kand. med. nauk [Diagnostics and optimization of treatment of skin neoplasms in outpatient practice of a dermatologist: Cand. Sci. (Med.) Thesis]. Moscow, 2009:177. (In Russian)].

7. Skomarovskiy V.S., Dorofeeva T.G. Tekhnologii na osnove svetovykh, radiochastotnykh i plazmennykh vozdeystviy v esteticheskoy meditsine [Technologies based on light, radio frequency and plasma effects in aesthetic medicine]. Almanac of Clinical Medicine. 2008;17(2):184–185. (In Russian)].

8. Tskhovrebova L.E. Vrozhdennye gigantskie pigment-nye nevusy u detey: klinika, diagnostika, lechenie [Congenital giant pigmented nevi in children: Clinical features, diagnostics, treatment]. Detskaya khirurgiya [Journal of Pediatric Surgery]. 2014;18(1):38–41. (In Russian)].

9. Chervonnaya L.V. Pigmentnye novoobrazovaniya kozhi [Pigmented skin neoplasms]. Moscow: GEOTARMedia Publ.; 2016:224. (In Russian)].

10. Arya S., Manali J., Motilal B., Rajendra P.T. Giant congenital melanocytic nevus with limb hypoplasia and lipomatosis: A rare association. Pigmentary Disorders. 2016;3(2):238. DOI: 10.4172/2376-0427.1000238

11. Ersen B., Selçuk A., Ayse S., Mehmet C.Ş., Ismail A., Orhan T., Furkan K., Suleyman C. Clinical and histopathological analysis of 790 naevi excised from 509 patients due to cosmetic reasons. Eur. J. Plast. Surg. 2014;38:133–138. DOI: 10.1007/s00238-014-1041-6

12. Hong K.T., Jung M.L., Sang E.L. A treatment of medium-to-giant congenital melanocytic nevi with combined Er:YAG laser and long-pulsed alexandrite laser. Med. Laser. 2017;6(2):77–85. DOI: 10.25289/ML.2017.6.2.77

13. Krengel S., Scope A., Dusza S.W., Vonthein R., Marghoob A.A. New recommendations for the categorization of cutaneous features of congenital melanocytic nevi. J. Am. Acad. Dermatol. 2013;68(3):441–451. DOI: 10.1016/j.jaad.2012.05.043

14. McCalmont T.H., Emanuel B., Fung M., Ruben B.S. Perineuriomatous melanocytic nevi. J. Cutan. Pathol. 2011;38(12):940–942. DOI: 10.1111/j.1600-0560.2011.01820_2.x

15. Nguyen D., Pang J.-Y., Madill C., Novakovic D. Effects of 445-nm laser on vessels of chick chorioallantoic membrane with implications to microlaryngeal laser surgery. The Laryngoscope. 2021;131(6):E1950– E1956. DOI: 10.1002/lary.29354

16. Roh M.R., Eliades P., Gupta S., Tsao H. Genetics of melanocytic nevi. Pigment Cell Melanoma Res. 2015;28(6):661–672. DOI: 10.1111/pcmr.12412

17. Roy K., Hayzen B.A., Page R.N., Googe P.B., Zeagler D., Mihm M.C. Jr. Recurrent nevus phenomenon: A clinicopathologic study of 357 cases and histologic comparison with melanoma with regression. Mod Pathol. 2009;22(5):611–617. DOI: 10.1038/modpathol.2009.22

18. Schaffer J.V. Pigmented lesions in children: when to worry. Curr. Opin. Pediatr. 2007;19(4):430–440. DOI: 10.1097/MOP.0b013e32825b0788

19. Sommer L.L., Barcia S.M., Clarke L.E., Helm K.F. Persistent melanocytic nevi: A review and analysis of 205 cases. J. Cutan. Pathol. 2011;38(6):503–507. DOI: 10.1111/j.1600-0560.2011.01692.x