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New Perspectives in Surgical Marking Since the Advent of Infrared Laser Angiography
摘要： This study investigates the utility of common surgical dyes under direct visualization and infrared laser angiography. Pigments affecting light within the visual (λ = 400–700 nm) and infrared (λ = 700–1000 nm) spectra were placed on subjects spanning the Fitzpatrick scale. Photometric properties of these pigments were assessed under direct visualization and infrared laser angiography. Among patients of various Fitzpatrick classifications, black ink pigment and pigment within the violet spectrum (λ = 380–450 nm) were most distinguishable under direct visualization. Colored inks, gentian violet and methylene blue dyes, were not visualized under infrared laser angiography. Black permanent ink appeared under both direct visualization and infrared laser angiography. Indocyanine green suspended in ethyl alcohol and applied to skin as a marking pen appeared clear under direct visualization and was detectable under infrared laser angiography. Black permanent marking ink allows visualization of surgical markings under infrared laser angiography, whereas gentian violet and methylene blue did not interfere with infrared visualization. Indocyanine green suspended in ethyl alcohol is a contemporary marking pen that may be used to outline anatomical surface landmarks under infrared laser angiography.
关键词： dye,methylene blue,skin marking,surgical marking,infrared laser angiography,marking pen,indocyanine green,gentian violet,surgical planning,ink
更新于2025-09-12 10:27:22
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Skin and subcutaneous fat morphology alterations under the LED or laser treatment in rats in vivo
摘要： The main objective of this work is to quantify the dynamic/photothermal treatment by using visible LED and NIR laser irradiation through the skin of subcutaneous fat in vivo followed up by tissue sampling and histology. The optical method may provide reduction of regional or site-specific accumulations of abdominal or subcutaneous adipose tissue precisely and least-invasively by inducing cell apoptosis and controlled necrosis of fat tissue. As photo-dynamic/photothermal adipose tissue sensitizers Brilliant Green (BG) or Indocyanine Green (ICG) dyes were injected subcutaneously in rats. The CW LED device (625 nm) or CW diode laser (808 nm) were used as light sources, respectively. Biopsies of skin together with subcutaneous tissues were taken for histology. The combined action BG-staining and LED-irradiation (BG + LED) or ICG-staining and NIR-laser irradiation (ICG + NIR) causes pronounced signs of damage of adipose tissue characterized by a strong stretching, thinning, folding and undulating of cell membranes and appearance of necrotic areas. As a posttreatment after 14 days only connective tissue was observed at the site of necrotic areas. The data obtained are important for safe light treatment of site-specific fat accumulations, including cellulite. This work provides a basis for the development of fat lipolysis technologies and to move them to clinical applications.
关键词： visible light,laser,optical microscopy,fat morphology,skin,subcutaneous adipose tissue,photodynamic and photothermal treatment,LED,Brilliant Green,NIR,Indocyanine Green (ICG)
更新于2025-09-11 14:15:04
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Safety of light emitting diode‐red light on human skin: two randomized controlled trials
摘要： Background: Therapeutic applications of light emitting diode-red light (LED-RL) are expanding, yet data on its clinical effects are lacking. Objectives: To evaluate the safety of high fluence LED-RL (≥160 J/cm2). Methods: In two phase I, single-blind, dose escalation, randomized controlled trials, healthy subjects received LED-RL or mock irradiation to the forearm thrice weekly for three weeks at fluences of 160 to 640 J/cm2 for all skin types (STARS 1, n=60) and at 480 to 640 J/cm2 for non-Hispanic Caucasians (STARS 2, n=55). The primary outcome was the incidence of adverse events (AEs). The maximum tolerated dose was the highest fluence that did not elicit predefined AEs. Results: Dose-limiting AEs, including blistering and prolonged erythema, occurred at 480 J/cm2 in STARS 1 (n=1) and 640 J/cm2 in STARS 2 (n=2). AEs of transient erythema and hyperpigmentation were mild. No serious AEs occurred. Conclusions: LED-RL is safe up to 320 J/cm2 for skin of color and 480 J/cm2 for non-Hispanic Caucasian individuals. LED-RL may exert differential cutaneous effects depending on race and ethnicity, with darker skin being more photosensitive. These findings may guide future studies to evaluate the efficacy of LED-RL for the treatment of various diseases. Trial Registration: ClinicalTrials.gov, NCT02630303 and NCT03433222
关键词： Randomized Controlled Trial,Skin Pigmentation,Phototherapy,Low-Level Light Therapy
更新于2025-09-11 14:15:04
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Transformation of the dermal collagen framework under laser heating
摘要： The aim of this study was to compare between the changes undergone by the framework when dermal collagen heated by IR laser radiation and by traditional means and to reveal the specific features of the dermal matrix modification under moderate IR laser irradiation. Rabbit skin specimens were heated to 50°C, 55°C, 60°C and 65°C in a calorimeter furnace and with a 1.68-μm fiber Raman laser. The proportion of the degraded collagen macromolecules was determined by differential scanning calorimetry. Changes in the architectonics of the collagen framework were revealed by using standard, phase-contrast, polarization optical and scanning electron microscopy techniques. The collagen denaturation and dermal matrix amorphization temperature in the case of laser heating proved to be lower by 10°C than that for heating in the calorimeter furnace. The IR laser treatment of the skin was found to cause a specific low-temperature (45°C-50°C) transformation of its collagen framework, with some collagen macromolecules remaining intact. The transformation reduces to the splitting of collagen bundles and distortion of the course of collagen fibers. The denaturation of collagen macromolecules in the case of traditional heating takes its course in a threshold manner, so that their pre-denaturation morphological changes are insignificant.
关键词： calorimetry,collagen transformation,skin,laser heating
更新于2025-09-11 14:15:04
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Topical Nanofat Biocrème Improves Aesthetic Outcomes of Nonablative Fractionated Laser Treatment: A Preliminary Report
摘要： Background: Improvements in skin erythema and elasticity have been seen with topical application of platelet-rich plasma after fractional laser treatment. Nanofat, when injected in small needles into the dermis has shown improvements in tissue thickness, discoloration and wrinkle depth. Objective: To evaluate improvements in skin following a nonablative fractional laser (FXD) treatment combined with the application of a novel topical nanofat biocrème, called neo-U. Methods: Fifty patients were treated with a nonablative FXD followed by application of a topical nanofat biocrème. Harvested fat was processed into nanofat, which was compounded with a transdermal liposomal delivery vector to produce a topical biocrème. In two patients, post-auricular skin punch biopsies were performed pre/post-treatment and examined for histological changes. Photos of a historical group treated with only the FXD laser were compared to photos of the patients treated with topical nanofat biocrème and a FXD laser. Results: Findings from postauricular skin biopsies show the skin exposed to FXD with nanofat biocrème had more elastin fibers and a slight increase in the thickness of the epidermis. Patients having FXD plus nanofat biocrème had a statistically significant improvement in the degree of wrinkles, nasolabial fold depth and texture compared to historical controls. Conclusions: Transdermal delivery of nanofat topical biocrème applied after fractional laser treatment can serve as a delivery system to improve fine lines, depth of nasolabial folds and overall texture of the tissue to a greater degree than laser resurfacing alone.
关键词： fractional laser,nanofat,transdermal delivery,skin rejuvenation,biocrème
更新于2025-09-11 14:15:04
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Comparison of laser speckle contrast imaging and laser-Doppler fluxmetry in boys and men
摘要： Objective We compare microvascular reactivity assessed by laser-Doppler fluxmetry (LDF) and laser speckle contrast imaging (LSCI) of boys and men during rest, post-occlusive reactive hyperaemia (PORH), and cycling exercise. Methods 19 boys (9±1 y) and 18 men (22±2 y) participated. LDF and LSCI measures were taken of the forearm during rest, PORH, and exercise. Results For all 3 assessments, the LSCI presented with higher flux values than the LDF for both boys and men (p<0.001). Bland-Altman analyses indicated that there was a positive linear bias between LSCI and LDF measurements in both boys and men. Regression analyses showed that the responses for the two methods were variable, depending on the particular assessment. For instance, at rest in boys there was no relationship between LDF and LSCI (r2=0.002), whilst in men there was a strong relationship (r2=0.86). Conclusions LSCI presented with higher values than LDF during rest, PORH, and exercise; the disparity between the two measures was larger as blood flow increased. The assessments were generally consistent, both methods appear to provide usable data for the assessment of microvascular reactivity in both boys and men. There are biases to each method and the data are not interchangeable between LDF and LSCI.
关键词： reactive hyperaemia,exercise,local control,Skin blood flow,paediatric
更新于2025-09-11 14:15:04
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Preclinical vascular alterations in obese adolescents detected by Laser-Doppler Flowmetry technique
摘要： Background and aims: Childhood obesity promotes adverse changes in cardiovascular structure and function. This study evaluated whether alterations in skin microcirculation were already present in obese adolescents in a pre-clinical phase of cardiovascular disease. Methods and results: After an overnight fasting 22 obese adolescents and 24 normal-weight controls of similar age and gender distribution underwent clinical and blood examination and assessment of microvascular function by using two non-invasive techniques such as Peripheral Artery Tonometry (PAT) and Laser-Doppler Flowmetry (LDF). As compared to normal weight subjects, obese children had higher blood pressure, were significantly more hyper-insulinemic and insulin resistant, showing significantly higher plasma total cholesterol, LDL cholesterol, triglycerides and alanine aminotransferase (ALT). LDF showed lower pre- and post-occlusion forearm skin perfusion (perfusion units/second (PU/sec); median [IQR]) in obese than in normal weight subjects (pre-occlusion: 1633.8 [1023.5] vs. 2281.1 [1344.2]; p Z 0.015. Post-occlusion: 4811.3 [4068.9] vs. 7072.8 [7298.8]; p Z 0.021), while PAT revealed similar values of reactive hyperemia index (RHI). In entire population, fat mass % (FM%) was an independent determinant of both pre-and post-occlusion skin perfusion. Finally, being obese was associated with a higher risk to have a reduction of both pre- and post-occlusion skin perfusion (OR Z 5,82 and 9,27, respectively). Conclusion: LDF showed very early, pre-clinical, vascular involvement in obese adolescents, characterized by impaired skin microcirculation, possibly reflecting a more diffuse microvascular dysfunction to other body tissues. Whether changing life style and improving weight may reverse such pre-clinical alterations remains to be established.
关键词： Microcirculation,Obesity,Skin,Peripheral artery tonometry,Laser-Doppler flowmetry
更新于2025-09-11 14:15:04
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Lasers for Reduction of Unwanted Hair in Skin of Color: A Systematic Review and Meta‐analysis
摘要： Light-based therapies are one of the most effective and widely used strategies for removal of undesired hair, with a broadly favorable safety profile. However, subjects with pigmented skin are found to be more prone to laser-related adverse events. While prolonged pulse-width and longer treatment duration were proposed to minimize adverse events, the optimal treatment option among available phototherapy modalities—long-pulsed (Nd: YAG), pulsed diode, and alexandrite lasers as well as intense pulsed light (IPL)—remains unclear, particularly for skin of color. To determine superiority in terms of effectiveness and tolerability, we conducted a systematic review of literature on different types of in-office laser and IPL for hair removal in subjects with Fitzpatrick skin types III-VI. The meta-analysis was performed using Review Manager (RevMan) version 5.3 and included 12 eligible comparative trials (9 randomized controlled trials and 3 quasi-randomized). In terms of hair count reduction, pooled effect estimates for long-pulsed ND:YAG laser (OR 0.26, 95% CI [0.1, 0.78]) and diode laser (SMD -0.11, 95% CI [-0.62, 0.39) were not statistically significant from those of IPL; in contrast, alexandrite laser was found to be superior to IPL in reducing hair count (SMD -1.7, 95% CI [-2.6, -0.78]. In terms of adverse events, the pooled effect estimates favoured long‐pulsed Nd: YAG laser to IPL with respect to post-inflammatory hyperpigmentation (OR 0.26, 95% CI [0.1, 0.78]). However, both pulsed diode and alexandrite lasers exhibited a comparable safety profile to IPL, despite higher pain scores with lasers. In conclusion, this systematic review suggests that treatment outcomes for different in-office laser devices and IPL in subjects with skin type III-VI are broadly similar; nevertheless, we observed a trend toward greater hair reduction following laser therapy compared to IPL.
关键词： Hair removal,Dark skin,Intense pulsed light,Laser
更新于2025-09-11 14:15:04
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Quantitative and qualitative evaluation of recovery process of a 1064?nm laser on laser-induced skin injury: <i>in vivo</i> experimental research
摘要： Laser biological effects are a hot topic in laser medicine. In this study, to explore the quantitative biological effect of laser-induced wound healing and to provide guidance for expanding the clinical application of laser therapy, the injury effects and repair characteristics of skin tissue are studied through infrared laser irradiation of the skin of miniature pigs. Live pig skin was irradiated at multiple spots one time by using a grid-array method with a 1064 nm laser at different power outputs. The skin injury reaction was observed immediately after laser irradiation from low to high doses. The incidence of skin injury was calculated quantitatively. The healing and pathological changes after laser-induced skin injury were observed dynamically within 6 h and for 28 d after laser irradiation. With the increase of irradiation dose, laser-induced skin injuries ranging from mild to severe appeared in turn. The damage threshold of laser irradiation ED50 is 47.4 J cm?2 with the laser; from 3 d to 28 d after irradiation, the pathological results showed that wound healing tended to be different in all groups, but this trend weakened with the increase in laser irradiation intensity. With the increased irradiation dose, skin injury appears as different types of injury plaques, ranging from mild to severe. Skin injury is worsened and the tissue repair trend is weakened with the increase in laser irradiation dose, producing a good dose-effect and time-effect relationship.
关键词： laser-induced skin wound,infrared (IR) laser,wound healing,in vivo laser experiment
更新于2025-09-11 14:15:04
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Reflections on the Er:YAG Laser Used in “Nonthermal Mode” to Rejuvenate Skin
摘要： CO2 and Er:YAG lasers are both actively used for laser skin rejuvenation, both ablative and microablative. Despite seeming similarities in efficiency of their radiation’s absorption by soft tissues, these lasers may have completely different effects on skin: tissue vaporization with CO2 laser radiation always assumes existence of areas with irreversible thermal effects such as coagulation, dehydration, carbonization, and vaporization. If Er:YAG and vaporization is used for the same purpose, same thermal damage areas may be obtained but smaller in size. However, in case of sufficiently high energy density and short duration of pulses, an ablation mode may be implemented, in the case in which areas of irreversible thermal changes are contained within vaporization zone. Thus, underlying layers of irradiated tissue are not thermally damaged.
关键词： ablation mode,cavitation,Er:YAG laser,microablation,CO2 laser,skin rejuvenation,thermal damage
更新于2025-09-11 14:15:04