Laser safety: the need for protocols.

Lasers are being used in ever-expanding roles in dermatology. As our understanding of laser energy grew, the need for safety guidelines became apparent. The US Food and Drug Administration (FDA) published the first safety guidelines in 1984, which are updated on a regular basis. However, these are just guidelines, and their implementation is voluntary by the laser practitioner. In this article, we discuss the 4 regulatory entities for laser safety in the United States, laser principles in general, ocular hazards, laser-generated airborne contaminants (LGACs), fires, and unintended laser beam injuries. We also review the use of checklists in reducing adverse outcomes and the need for safety protocols for laser practitioners. We provide a modifiable checklist, which pertains specifically to lasers and can be customized to meet the needs of the individual laser practitioner.

Technological Advances in Surgical Equipment in Exotic Pet Medicine.

Surgery can be challenging in exotic pets owing to their small size and blood volume, and their increased anesthetic risk compared with small animals. Various devices are available to facilitate suturing, cutting, and hemostasis in the human and veterinary fields. These surgical equipment improve the simplicity, rapidity, and effectiveness of surgery. Vessel-sealing devices, radiosurgery, lasers, and ultrasound devices are commonly used because of their ease of use and increase in surgical efficiency. Other surgical devices are available (eg, stapling devices) but are not discussed in this article.

Impacto do tratamento com laser fracionado de CO2 em cicatrizes hipertróficas e queloides: uma revisão sistemática / Impact of fractional CO2 laser treatment on hypertrophic scars and keloids: a systematic review

Introdução: Cicatrizes hipertróficas e queloides causam dano estético e funcional e são de difícil tratamento. O objetivo desta revisão foi identificar estudos prospectivos do tratamento com o laser fracionado de CO2, mostrando as alterações clínicas e histológicas e a metodologia utilizada para a avaliação das cicatrizes antes e após intervenção. Métodos: Foi realizada uma revisão eletrônica (LILACS, Medline e SciELO) de estudos publicados entre janeiro de 2004 e dezembro de 2017, com os termos "keloid/queloide", "hypertrophic scar/cicatriz hipertrófica" e "laser CO2", de acordo com o PRISMA Statement, sendo selecionados os estudos que comparassem as cicatrizes antes e depois de tratamento isolado com laser fracionado de CO2. Os dados foram analisados por dois revisores independentes. Resultados: Foram analisados 102 artigos, sendo que 7 cumpriam os critérios estabelecidos. Destes, os 7 analisaram cicatrizes hipertróficas, 2 deles também analisaram queloides, e 3 estudaram alterações histológicas. Houve diferença estatística entre os escores clínicos medidos antes e após tratamento de cicatrizes hipertróficas na maioria dos estudos, com melhora nos sintomas, na flexibilidade e altura da cicatriz. Entre os 2 estudos que analisaram os queloides, 1 deles demonstrou diferença clínica após tratamento. Nas alterações histológicas, houve diferença na orientação e densidade das fibras de colágeno e na espessura da epiderme. Conclusão: O laser fracionado de CO2 deve ser considerado como opção promissora no tratamento de cicatrizes patológicas, visto que melhora os sinais e sintomas clínicos como cor, espessura e prurido.

Introduction: Hypertrophic scars and keloids cause aesthetic and functional damages, and are difficult to treat. This review aimed to identify prospective studies on fractional CO2 laser to present the clinical and histological changes and the methodology used for the evaluation of scars before and after intervention. Methods: We conducted an electronic review (LILACS, Medline, and SciELO) of studies published between January 2004 and December 2017, using the search terms "keloid/queloide," "hypertrophic scar/cicatriz hipertrófica," and "CO2 laser ," according to the PRISMA Statement. Studies that compared scars before and after isolated treatment with fractional CO2 laser were selected. Two independent reviewers analyzed the data. Results: One hundred two articles were analyzed, of which 7 met the inclusion criteria. Of the 7 articles, all analyzed hypertrophic scars, 2 analyzed keloids in addition to hypertrophic scars, and 3 analyzed histological changes. Most studies showed a statistically significant difference in clinical scores between before and after treatment of hypertrophic scars, with improvement in symptoms, flexibility, and scar height. Between the 2 studies that analyzed keloids, 1 reported a clinical difference after treatment. The histological changes showed significant differences in the orientation and density of the collagen fibers, and in the thickness of the epidermis. Conclusion: The use of fractional CO2 laser should be considered as a promising treatment option for pathological scars, as it improves clinical signs and symptoms such as color, thickness, and pruritus.

Electrode placement accuracy in robot-assisted epilepsy surgery: A comparison of different referencing techniques including frame-based CT versus facial laser scan based on CT or MRI.

BACKGROUND: Precise robotic or stereotactic implantation of stereoelectroencephalography (sEEG) electrodes relies on the exact referencing of the planning images in order to match the patient's anatomy to the stereotactic device or robot. We compared the accuracy of sEEG electrode implantation with stereotactic frame versus laser scanning of the face based on computed tomography (CT) or magnetic resonance imaging (MRI) datasets for referencing. METHODS: The accuracy was determined by calculating the Euclidian distance between the planned trajectory and the postoperative position of the sEEG electrode, defining the entry point error (EPE) and the target point error (TPE). The sEEG electrodes (n = 171) were implanted with the robotic surgery assistant (ROSA) in 19 patients. Preoperative trajectory planning was performed on three-dimensional (3D) MRI datasets. Referencing was accomplished either by performing (A) 1.25-mm slice CT with the patient's head fixed in a Leksell stereotactic frame (CT-frame, n = 49), fused with a 3D-T1-weighted, contrast enhanced- and T2-weighted 1.5 Tesla (T) MRI; (B) 1.25 mm CT (CT-laser, n = 60), fused with 3D-3.0-T MRI; (C) 3.0-T MRI T1-based laser scan (3.0-T MRI-laser, n = 56) or (D) in one single patient, because of a pacemaker, 3D-1.5-T MRI T1-based laser scan (1.5-T MRI-laser, n = 6). RESULTS: In (A) CT-frame referencing, the mean EPE amounted to 0.86 mm and the mean TPE amounted to 2.28 mm (n = 49). In (B) CT-laser referencing, the EPE amounted to 1.85 mm and the TPE to 2.41 mm (n = 60). In (C) 3.0-T MRI-laser referencing, the mean EPE amounted to 3.02 mm and the mean TPE to 3.51 mm (n = 56). In (D) 1.5-T MRI, surprisingly the mean EPE amounted only to 0.97 mm and the TPE to 1.71 mm (n = 6). In 3 cases using CT-laser and 1 case using 3.0 T MRI-laser for referencing, small asymptomatic intracerebral hemorrhages were detected. No further complications were observed. CONCLUSION: Robot-guided sEEG electrode implantation using CT-frame referencing and CT-laser-based referencing is most accurate and can serve for high precision placement of electrodes. In contrast, 3.0-T MRI-laser-based referencing is less accurate, but saves radiation. Most trajectories can be reached if alternative routes over less vascularized brain areas are used. This article is part of the Special Issue "Individualized Epilepsy Management: Medicines, Surgery and Beyond".

Guideline Implementation: Energy-Generating Devices, Part 2-Lasers.

Lasers have been used in the OR for many years and are essential tools in many different types of procedures. However, laser beams that come into contact with unintended targets directly or via reflection can cause injury to patients or personnel or pose other hazards, such as fires. The new AORN "Guideline for safe use of energy-generating devices" provides guidance on the use of all energy-generating devices in the OR. This article focuses on key points of the guideline that address the safe use of lasers. These include the components of the laser safety program, the responsibilities of the personnel in roles specific to use of a laser, laser safety measures, and documentation of laser use. Perioperative RNs should review the complete guideline for additional information and for guidance when writing and updating policies and procedures.

A new method and device of aligning patient setup lasers in radiation therapy.

The aim of this study is to develop a new method to align the patient setup lasers in a radiation therapy treatment room and examine its validity and efficiency. The new laser alignment method is realized by a device composed of both a metallic base plate and a few acrylic transparent plates. Except one, every plate has either a crosshair line (CHL) or a single vertical line that is used for alignment. Two holders for radiochromic film insertion are prepared in the device to find a radiation isocenter. The right laser positions can be found optically by matching the shadows of all the CHLs in the gantry head and the device. The reproducibility, accuracy, and efficiency of laser alignment and the dependency on the position error of the light source were evaluated by comparing the means and the standard deviations of the measured laser positions. After the optical alignment of the lasers, the radiation isocenter was found by the gantry and collimator star shots, and then the lasers were translated parallel to the isocenter. In the laser position reproducibility test, the mean and standard deviation on the wall of treatment room were 32.3 ± 0.93 mm for the new method whereas they were 33.4 ± 1.49 mm for the conventional method. The mean alignment accuracy was 1.4 mm for the new method, and 2.1 mm for the conventional method on the walls. In the test of the dependency on the light source position error, the mean laser position was shifted just by a similar amount of the shift of the light source in the new method, but it was greatly magnified in the conventional method. In this study, a new laser alignment method was devised and evaluated successfully. The new method provided more accurate, more reproducible, and faster alignment of the lasers than the conventional method.

[Carbonization in endovasal laser obliteration by radial light guide with wavelength of 1470 and 970 nm].

The authors assessed the effect of carbonization and its influence on the parameters of endovasal laser obliteration (EVLO) depending on wavelength of laser radiation (970 and 1470 nm) using a light guide with radial emission. They also analysed the value of drop of radiation power of the light guide after performing EVLO and visually assessed the degree of damage of the glass tip of the radial fibre by means of ultra-close-up photography. The study comprised a total of 20 patients with varicose disease. A total of ten procedures of EVLO were performed in two modes: mode one - W-laser 1470 nm, mode two - H-laser 970 nm, using fibre with radial emission, an automatic retractor of the light guide. It was determined that the median of power loss after EVLO with W-laser amounted to 0.6 W, and that for H-laser - 3.15 W (p=0.002). Ultra-close-up photography showed pronounced damage of the glass tip of the radial light guide while using H-laser and no damages while using the W-laser. It was proved that using laser radiation with wavelength of 970 nm using the light guide with radial emission leads to pronounced carbonization on the surface of the glass tip of the light guide, its damage, a decrease in radiation power and risk of mechanical destruction of the flask. Using the laser with wavelength of 1470 nm with the use of radial light guide did not result in the development of such negative effects, which increases the service life of laser fibre and makes it possible to use it for obliteration of several segments in one patient.

Safety of cornea and iris in ocular surgery with 355-nm lasers.

A recent study showed that 355-nm nanosecond lasers cut cornea with similar precision to infrared femtosecond lasers. However, use of ultraviolet wavelength requires precise assessment of ocular safety to determine the range of possible ophthalmic applications. In this study, the 355-nm nanosecond laser was evaluated for corneal and iris damage in rabbit, porcine, and human donor eyes as determined by minimum visible lesion (MVL) observation, live/dead staining of the endothelium, and apoptosis assay. Single-pulse damage to the iris was evaluated on porcine eyes using live/dead staining. In live rabbits, the cumulative median effective dose (ED50) for corneal damage was 231 J/cm2, as seen by lesion observation. Appearance of endothelial damage in live/dead staining or apoptosis occurred at higher radiant exposure of 287 J/cm2. On enucleated rabbit and porcine corneas, ED50 was 87 and 52 J/cm2, respectively, by MVL, and 241 and 160 J/cm2 for endothelial damage. In human eyes, ED50 for MVL was 110 J/cm2 and endothelial damage at 453 J/cm2. Single-pulse iris damage occurred at ED 50 of 208 mJ/cm2. These values determine the energy permitted for surgical patterns and can guide development of ophthalmic laser systems. Lower damage threshold in corneas of enucleated eyes versus live rabbits is noted for future safety evaluation.

Refining analgesia strategies using lasers.

Sound programs for the humane care and use of animals within research facilities incorporate experimental refinements such as multimodal approaches for pain management. These approaches can include non-traditional strategies along with more established ones. The use of lasers for pain relief is growing in popularity among companion animal veterinary practitioners and technologists. Therefore, its application in the research sector warrants closer consideration.

Guidelines of care for vascular lasers and intense pulse light sources from the European Society for Laser Dermatology.

AIM: Lasers and non-coherent intense pulse light sources (IPLS) are based on the principle of selective photothermolysis and can be used for the treatment of many vascular skin lesions. A variety of lasers has been developed for the treatment of congenital and acquired vascular lesions which incorporate these concepts into their design. Although laser and light sources are very popular due to their non-invasive nature, caution should be considered by practitioners and patients to avoid permanent side-effects. The aim of these guidelines is to give evidence-based recommendations for the use of lasers and IPLS in the treatment of vascular lesions. METHODS: These guidelines were produced by a Consensus Panel made up of experts in the field of vascular laser surgery under the auspices of the European Society of Laser Dermatology. Recommendations on the use of vascular lasers and IPLS were made based on the quality of evidence for efficacy, safety, tolerability, cosmetic outcome, patient satisfaction/preference and, where appropriate, on the experts' opinion. The recommendations of these guidelines are graded according to the American College of Chest Physicians Task Force recommendations on Grading Strength of Recommendations and Quality of Evidence in Clinical Guidelines. RESULTS: Lasers and IPLS are very useful and sometimes the only available method to treat various vascular lesions. It is of a paramount importance that the type of laser or IPLS and their specific parameters are adapted to the indication but also that the treating physician is familiar with the device to be used. The crucial issue in treating vascular lesions is to recognize the immediate end-point after laser treatment. This is the single most important factor to ensure both the efficacy of the treatment and avoidance of serious side-effects.

Remoção de tatuagem com laser Q-switched NdYAG em população brasileira / Tattoo removal with Q-switched Nd: YAG laser in a Brazilian population

INTRODUÇÃO: Na prática da remoção de tatuagem, já foram utilizadas a dermo a brasão e a cirurgia. Atualmente, se utiliza o laser. O objetivo deste trabalho foi avaliar a remoção de tatuagens utilizando-se o laser Q-switched NdYAG. MÉTODO: Estudo retrospectivo, com pacientes tratados com laser Q-switched NdYAG. Foram coletados dados a partir de prontuários e fotos dos pacientes, e de contato por telefone ou e-mail. A análise estatística foi feita através da análise de distribuição, regressão multivariada e regressão logística. RESULTADOS: Foram avaliados 304 pacientes com média de idade de 29,8 anos (±7,86), sendo que 297 (97,69%) foram classificados como brancos (fotótipos I, II e III); destes, 270 (88,81%) haviam feito tatuagens profissionais. A tatuagem mais antiga tinha 360 meses e a mais recente, um mês, obtendo-se uma média de 64,56 meses (± 63,54). O tamanho das tatuagens foi, em média, de 12,92 cm, sendo preta a cor predominante, estando presente em 291(86,51%) tatuagens. A média de sessões por paciente foi de 3,77 sessões (±2,99) e o intervalo entre estas foi de 49,23 dias. Com isso, foi observado, pelo terapeuta, que 52,96% das tatuagens foram parcialmente removidas; 21,38%, não removidas; 86,51%, cicatrização normal; 8,55%, cicatriz hipertrófica, e 3,29%, queloide. Dos 304 pacientes, 26,64% (81) relataram estar satisfeitos e 58,88% (179) relataram estar parcialmente satisfeitos com o resultado. A hipocromia esteve presente em 33,55% (102) dos indivíduos. CONCLUSÕES: O laser Q-switched NdYAG é um método seguro e eficaz, apresentando bom grau de satisfação e poucos efeitos indesejáveis na remoção de tatuagem.

INTRODUCTION: Both dermabrasion and surgery have been used in the practice of tattoo removal. Currently, laser is also being used. The aim of this study is to evaluate tattoo removal with Q-switched Nd:YAG laser. METHOD: This is a retrospective study on patients treated by using Q-switched Nd:YAG laser. The data were collected from medical records and patient photographs, and through phone or e-mail contact. Statistical tests were done through the analysis of distribution, multivariate regression, and logistic regression. RESULTS: A total of 304 patients with an average age of 29.8 years (±7.86 years) were assessed. Of the total, 297 (97.69%) were classified as white (phototypes I, II, and III), 270 (88.81%) of whom had professional tattoos done. The oldest tattoo was 360 months old and the most recent was 1 month old, with an average of 64.56 months (±63.54 months). The tattoo size was, on average, 12.92 cm, with black being the predominant color (i.e., present in 291 [86.51%] tattoos). The average number of sessions per patient was 3.77 (±2.99), and the interval between sessions was 49.23 days. The therapist observed that 52.96% of the tattoos were partially removed, 21.38% were not removed, 86.51% showed normal healing, 8.55% developed a hypertrophic scar, and 3.29% developed a keloid. Of the 304 patients, 81 (26.64%) reported being satisfied and 179 (58.88%) reported being partially satisfied with the outcome. Hypochromia was present in 102 (33.55%) patients. CONCLUSIONS: Q-switched Nd:YAG laser is a safe and effective method for tattoo removal that results in a good degree of patient satisfaction and few undesirable effects.

Variations in laser energy outputs over a series of simulated treatments.

BACKGROUND: Test patches are routinely employed to determine the likely efficacy and the risk of adverse effects from cutaneous laser treatments. However, the degree to which these represent a full treatment has not been investigated in detail. OBJECTIVES: This study aimed to determine the variability in pulse-to-pulse output energy from a representative selection of cutaneous laser systems in order to assess the value of laser test patches. METHODS: The output energies of each pulse from seven cutaneous laser systems were measured using a pyroelectric measurement head over a 2-h period, employing a regime of 10-min simulated treatments followed by a 5-min rest period (between patients). RESULTS: Each laser system appeared to demonstrate a different pattern of variation in output energy per pulse over the period measured. CONCLUSIONS: The output energies from a range of cutaneous laser systems have been shown to vary considerably between a representative test patch and a full treatment, and over the course of an entire simulated clinic list.

[Effects in eyes, caused by laser rays emitted by laser-beam projectors].

Health assessment of laser radiation emitted by laser-beam projectors used for laser shows in concert and theatrical events was carried out. The effects of various laser radiation wavelengths and regimes on functional state of eye retina were studied.

[The study of opportunity of aqueous humor filtration increase after nondestructive laser exposure of sclera in the site of pars plana projection (experimental study)].

Increase of scleral water permeability due to formation of porous structure after exposure of pulsed periodic radiation of erbium-glass optical fiber laser with wave length 1,56 pm was demonstrated in experimental study of cadaver human eyes in vitro and eyes of experimental animals (rabbits) in vivo. Simultaneous complex laser exposure of pars plana and ciliary processes results in summation of morphological changes that provide decrease of aqueous humor secretion, uveal drainage and extension of suprachoroid space. A base for new noninvasive technology of nondestructive laser exposure in glaucoma treatment is established.

[Role of optical properties of the venous wall for endovenous laser obliteration].

Presented herein are the results of studying the optical density of water, blood, and venous-wall tissue for various-wavelength laser radiation, with determining the peaks of absorption of radiation by the above-mentioned media. The absorption peaks in water and blood correspond to wavelengths of 1,450 and 1,935 nm, respectively. Peaks of absorption in the venous-wall tissue are within the intervals equaling 650-950 nm, 1,445-1,455 nm, and more than 1,900 nm. Also determined was the optical density of the veins for the most frequently used in clinical practice wavelengths, i. e. 1,030 and 1,470 nm, with the calculation of the portion of the absorbed energy depending on thickness of the layer of the absorbing substance. Based on the obtained findings, a conclusion was drawn on better utilization of the energy of one-and-a-half-micron range laser radiation and on its preferable use for endovenous laser obliteration (EVLO).

Laserlipólise com diodo 980 nm: experiência com 400 casos / Laser lipolysis with a 980-nm diode laser: experience with 400 cases

INTRODUÇÃO: A técnica de lipoaspiração recebeu várias contribuições desde sua primeira descrição, como modificações nas cânulas, variação na concentração da solução de infiltração e uso de aparelhos com tecnologias variadas. A utilização de aparelhos com tecnologia laser vem contribuir com o procedimento por meio da lipólise e com o estímulo de retração cutânea. Neste artigo é apresentada a experiência dos autores com a laserlipólise em 400 pacientes, no intervalo de 5 anos, sendo discutidos aspectos dos princípios da tecnologia e sua ação sobre os tecidos. MÉTODO: Estudo realizado entre julho de 2007 e julho de 2012, que incluiu 400 pacientes submetidos a procedimento de laserlipólise. Os procedimentos foram realizados seguindo protocolo original, com infiltração de soro gelado, passagem da cânula com fibra óptica para a condução da energia laser visando à laserlipólise, retração cutânea e, por último, lipoaspiração convencional. RESULTADOS: O período de internação variou de cirurgia em regime ambulatorial a pernoite. Cerca de 45% (180/400 pacientes) dos pacientes evoluíram com equimoses mínimas, com acometimento de 2% ou mais da superfície corporal comprometida. Os casos de hematoma, seroma e deiscência totalizaram 9% (36/400 pacientes). Em nenhum caso foi constatada queimadura por lesão térmica na pele. CONCLUSÕES: O procedimento de laserlipólise realizado com a técnica descrita demonstrou segurança e reprodutibilidade.

INTRODUCTION: Liposuction has undergone several improvements since its first description, including changes in the cannulas, variation in the concentration of the infiltrating solution, and the use of different devices and technologies. The use of laser technology devices for lipolysis and stimulation of skin retraction has contributed to the procedure. This article presents the authors' experience with laser lipolysis in 400 patients, within a 5-year period, and discusses the principles of the technology and its effect on tissues. METHODS: This is a study performed between July 2007 and July 2012 and included 400 patients who underwent laser lipolysis. All procedures were performed following the original protocol - infiltration of cold saline, passage of the cannula with an optic fiber for conducting the energy needed for laser lipolysis, skin retraction, and finally, conventional liposuction. RESULTS: Hospitalization type ranged from outpatient to overnight surgery. Approximately 45% (180 of 400) of patients had minimal bruising, with involvement of 2% or more of the affected body surface. Hematoma, seroma, and dehiscence occurred in a total of 9% (36 of 400) of patients. We did not find any case of thermal burn of the skin. CONCLUSIONS: Laser lipolysis performed according to the described technique was safe and reproducible.

[Comparative characteristics of laser-mediated and radiofrequency-powered thermal obliteration in varicose disease].

The article deals with a comparative analysis of the two most commonly used methods techniques of thermal ablation used for elimination of truncal varicosis in varicose disease, i. e., endovasal laser-mediated and radiofrequency-powered obliteration, underlining differences in the mechanisms of physical impact of the two competitive methods, clinical peculiarities of their application, as well as economic aspects of these interventions under the conditions of the present-day Russia.