A clinical and histological comparison of flashscanning versus pulsed technology in carbon dioxide laser facial skin resurfacing

Carbon Dioxide Laser Rejuvenation of the Facial Skin

This article reviews the evaluation and techniques for facial skin rejuvenation using the fractionated carbon dioxide laser. It includes a detailed overview of laser skin rejuvenation and discusses the potential complications associated with this procedure. A review of clinical outcomes in the literature is also included.

The Role of Elastic Fibers in Scar Formation and Treatment

BACKGROUND

Laser therapy is a continuously evolving treatment option for scars, and the underlying therapeutic mechanisms continue to be elucidated.

OBJECTIVE

To comprehensively review the literature to summarize the role of elastin in the formation scars, as well as treatment via therapeutic lasers.

METHODS

Review of the PubMED/MEDLINE database for available studies pertaining to the role of elastic fibers in scar formation and after laser-based therapy.

RESULTS

The loss and disorganization of elastic fiber components plays a role in the development of atrophic, hypertrophic, and keloid scars. While the majority of histologic studies focus on the underlying changes in collagen, neoelastogenesis and reorganization of elastic fibers have also been demonstrated in studies using ablative, nonablative, and fractional laser devices for the treatment of scars.

CONCLUSION

Production of novel elastin and normalization of elastic fiber organization occur after a variety of resurfacing procedures to treat scarring. As the treatment modalities to manage scars continue to evolve, further characterization of the role of elastin in the skin and in scar formation is merited.

Lasers and ancillary treatments for scar management: personal experience over two decades and contextual review of the literature. Part I: Burn scars

The formation of a wide range of excessive scars following various skin injuries is a natural consequence of healing. Scars resulting from surgery or trauma affect approximately 100 million people per annum in the developed world and can have profound physical, aesthetic, psychological and social consequences. Thus, scar treatment is a priority for the plastic surgeon. We aim to explore new approaches to the management of such scarring. The senior authors current use of laser technology, chemotherapeutic agents, pharmacotherapy and cryosurgery will be reviewed. This is placed in the context of the current literature and evidence base and is illustrated with case studies, starting with burns scars in part I, and focusing on keloid and hypertrophic scars in part II, acne scars in part III and finally pigmented scars in part IV. In Part I we focus on burns scar treatment with fractional ablative 10,600 nm wavelength carbon dioxide (CO2) laser therapy.

Lasers and optical technologies in facial plastic surgery

Lasers and optical technologies play a significant role in aesthetic and reconstructive surgery. The unique ability of optical technologies to target specific structures and layers in tissues to effect chemical, mechanical, or thermal changes makes them a powerful tool in cutaneous rejuvenation, hair removal, fat removal, and treatment of vascular lesions such as port-wine stains, among many other procedures. With the development of adjunct techniques such as epidermal cooling, lasers and optical technologies have become more versatile and safe. The constant improvement of existing applications and the emergence of novel applications such as photodynamic therapy, nanoparticles, spectroscopy, and noninvasive imaging continue to revolutionize aesthetic medicine by offering a minimally invasive alternative to traditional surgery. In the future, therapies will be based on individualized, maximum, safe radiant exposure to deliver optimal dosimetry. Lasers and optical technologies are headed toward safer, easier, more quantifiable, and more individualized therapy.

In vivo effect of carbon dioxide laser-skin resurfacing and mechanical abrasion on the skin's microbial flora in an animal model

BACKGROUND

Although beam-scanning carbon dioxide (CO2) lasers have provided a highly efficient tool for esthetic skin rejuvenation there has been no comprehensive animal studies looking into microbial skin changes following CO2 laser skin resurfacing.

OBJECTIVE

To evaluate the in vivo effects of CO2 laser skin resurfacing in an experimental rat model in comparison with mechanical abrasion on the skin microbial flora.

METHODS

Four separate cutaneous sections of the right dorsal surface of 10 Wistar rats were treated with a CO2 laser, operating at 18 W and delivering a radiant energy of 5.76 J/cm2, while mechanical abrasions of the skin were created on four sections of the left dorsal surface using a scalpel. Samples for culture and biopsies were obtained from the skin surfaces of the rats on day 1 of application of the CO2 laser or mechanical abrasion, as well as 10, 30, and 90 days after the procedure. The presence of four microorganisms (staphylococci, streptococci, diphtheroids, and yeasts) was evaluated as a microbe index for the skin flora, and colony counts were obtained using standard microbiological methods.

RESULTS

Skin biopsy specimens, following CO2 laser treatment, initially showed epidermal and papillary dermal necrosis and later a re-epithelization of the epidermis as well as the generation of new collagen on the upper papillary dermis. The reduction in microbial counts on day 1 of the CO2 laser-inflicted wound was statistically significant for staphylococci and diphtheroids compared with the baseline counts (p=.004 and p<.001, respectively), and for staphylococci, diphtheroids, and yeasts compared with the scalpel-inflicted wound on the same day (p=0.029, p<.001, and p=.030, respectively).

CONCLUSIONS

Skin resurfacing using CO2 lasers considerably reduces microbial counts of most microorganisms in comparison with either normal skin flora or a scalpel-inflicted wound. This might contribute to the positive clinical outcome of laser skin resurfacing.

Nonablative Laser Surgery for Pigmented Skin

BACKGROUND

Nonablative laser surgery has been proven to improve early photodamaged skin and acne scars. These techniques include treatments with lasers, light sources, and/or radiofrequency devices.

OBJECTIVES

To review the history of nonablative technology and its applicability to darker skin types and to provide an objective look at the various published studies documenting the efficacy of nonablative technology.

CONCLUSION

Nonablative laser surgery can improve skin quality and acne scars in all skin types. Complications are rare but can occur. Future studies are required to compare the efficacy of the various nonablative technologies.

Estudo das alterações relacionadas com a idade na pele humana, utilizando métodos de histo-morfometria e autofluorescência

FUNDAMENTOS: O processo de envelhecimento tecidual é evidente nas modificações visíveis na pele, resultando em importantes implicações psicológicas para o indivíduo e crescente interesse científico. OBJETIVOS: O presente trabalho objetivou analisar as alterações da pele normal com o envelhecimento mediante estratégias de histomorfometria e autofluorescência. MÉTODOS: Foram coletadas amostras de pele do abdômen de 18 cadáveres, incluindo cinco indivíduos jovens (menos de 20 anos), sete indivíduos com idade intermediária (20-60 anos) e seis indivíduos idosos (mais de 60 anos). Foram feitos cortes histológicos em parafina seguidos de coloração pela Hematoxilina-Eosina (H&E) e pelo tricrômio de Van Gieson-elastina. Avaliaram-se a espessura da epiderme e derme, e a superfície de contato epidermo-dérmica. Investigaram-se ainda as modificações qualitativas do aparelho colágeno-elástico, considerando sua disposição espacial na derme. Espécimes corados em H&E também foram utilizados para autofluorescência. RESULTADOS: A espessura da epiderme e derme do grupo idoso foi significativamente diminuída (p<0,05) em relação aos demais grupos. Os grupos idoso e intermediário exibiram acentuada redução na superfície de contato epiderme-derme (p<0,05). Detectaram-se a perda da distribuição em rede das fibras elásticas com sua progressiva fragmentação, alterações da compactação do colágeno e espessamento da membrana basal com o envelhecimento. CONCLUSÃO: O envelhecimento leva à redução da espessura da derme e epiderme, bem como ao aplanamento da junção dermo-epidérmica. As mudanças da pele ao longo da vida nem sempre seguem um perfil linear, mostrando drásticas alterações nas últimas décadas de vida. O método de autofluorescência mostrou-se um instrumento valioso no estudo da complexa relação espacial das fibras elásticas e colágenas.

Histological comparison of postoperative wound care regimens for laser resurfacing in a porcine model

BACKGROUND

The use of short-pulsed CO2 lasers for skin resurfacing is routinely performed, but few studies have examined postsurgical care.

OBJECTIVE

To determine which postoperative treatments are most beneficial in promoting optimal healing after laser resurfacing.

METHODS

Four pigs received laser resurfacing. The laser sites were randomly left untreated or treated with petroleum-based ointment or dressed with 1 of the following occlusive dressings: hydrocolloid, hydrogel or foam. Biopsies were taken from each treatment group on Days 2, 3, 4, 5, 8, 12, and 19. All samples were stained with hematoxylin and eosin. Each histological slide was evaluated by a blinded investigator.

RESULTS

Differences were observed between treatment groups in the amount of cellular infiltrate, presence of necrotic tissue, progression of the epidermal sheet, maturation of the epidermis, presence of rete ridges, and appearance of new collagen.

CONCLUSION

Postoperative treatments after laser resurfacing vary in their ability to influence the quality of healing.

The origin and role of erythema after carbon dioxide laser resurfacing. A clinical and histological study

BACKGROUND

Transient erythema, which can last up to 3 months after carbon dioxide (CO2) laser skin resurfacing, is a usual side effect with pulsed or rapidly scanned CO2 lasers.

OBJECTIVE

We evaluated the cause of erythema in the clinical setting and by histology in order to determine if and how we may decrease it, or even eliminate it.

METHODS

Ten patients who underwent resurfacing were recruited to this study. Skin punch biopsies were taken at 0, 7, 21, and 90 days and analyzed by light microscopy.

RESULTS

Erythema was noticed from about day 8, when the crusting on the skin surface was exfoliated. It reached its maximum intensity after 14 days, and had disappeared by 60-90 days. Histology showed an early inflammatory response, with an immature neopithelium, and rich vascularization. The normal epidermis had returned by 90 days, and during this period there was reduced optical scattering and absorption in melanin.

CONCLUSION

Although the erythema is an unwanted side effect in the patient's eyes, it is to be expected and thus represents the effects of a combination of epidermal immaturity, reduced melanin absorption of light, reduced dermal optical scattering, and increased blood flow secondary to the surgically induced inflammatory response.