Investigating the efficacy of a fractionated 1927 nm laser for diffuse dyspigmentation and actinic changes.

OBJECTIVES: Facial actinic irregularities are frequent targets for noninvasive, energy-based treatment. These irregularities are multifactorial and driven by both intrinsic factors such as aging, genetics, and hormone exposure, and extrinsic factors, such as UV exposure. Clinically, this photodamage manifests as dyschromic skin disorders like melasma and actinic features such as solar lentigines. Fractionated 1927 nm (f1927 nm) nonablative lasers are suitable for targeting epidermal lesions and have been shown to be effective in resurfacing photoaged skin as well as addressing pigmented lesions without exacerbation. The purpose of this study was to quantify the magnitude and duration of actinic pigment and photodamage response in patients of Fitzpatrick Skin Phototypes (SPT) I-IV who underwent two treatments with a fractionated, nonablative 1927 nm thulium laser (MOXI™, Sciton). METHODS: The authors conducted an IRB-approved, single-center, prospective, nonrandomized study to evaluate the efficacy of f1927 nm nonablative lasers in the treatment of diffuse dyspigmentation and actinic irregularities. Patients underwent two treatments with f1927 nm nonablative laser at a 1-month interval. F1927 nm treatment and energy parameters included a pulse energy of 15 mJ, density of 15% with 15% coverage, and six total passes. The primary endpoint for this study was pigment response after treatment, measured using the VISIA Skin Imaging and Analysis System (Canfield Scientific). Pigmentary lesions measured and analyzed included spots, UV spots, and brown spots. The Physician's Global Assessment Scale was used by plastic surgeons to provide a subjective clinical assessment of melasma response. Nonparametric testing was used to assess and compare VISIA results across the study period as well as clinician evaluations. A p value ≤ 0.05 was considered statistically significant. RESULTS: Twenty-seven patients underwent two treatments with nonablative, f1927 nm laser in May and June 2022. Ninety-six percent of patients (n = 26) completed 1-month follow-up and 89% of patients (n = 24) completed 3-month follow-up. The study cohort was 100% female, with a mean ± SD age of 47.0 ± 11.5 (range: 29-74), and a mean Fitzpatrick SPT of 2.8 (range: I-IV). No serious adverse events were observed during study treatment or follow-up. Overall, analysis showed statistically significant improvements in dyspigmentation at 1 month and an increase in pigment toward baseline at 3 months. At 1 month, there was a statistically significant decrease in spots (p = 0.002), UV spots (p < 0.001), and brown spots (p < 0.001) compared to baseline. At 3 months, Brown spots remained significantly improved compared to baseline (p = 0.05). Analysis showed 9.9% improvement in pigment on the left (p < 0.0001) and 7.5% improvement in pigment on the right (p < 0.0001) face. Right dyspigmentation remained significantly improved at 3-month follow-up (p = 0.02). Subjectively, clinician evaluators' mean Physician's Global Assessment Scale score was 3.4 (p < 0.0001) at 1-month follow-up and 3.7 (p < 0.0001) at 3-month follow-up, which correspond to an approximately 50% improvement hyperpigmentation when at both time points. CONCLUSION: These results demonstrate that fractionated, nonablative 1927 nm laser treatment is an effective modality for improving clinical and subclinical photodamage. The magnitude and duration of pigment improvement are potentially influenced by the propensity for photodamage during the summer months, which may suggest the need for multiple f1927 nm treatments over time to maintain results.

A Correlation of the Glogau Scale With VISIA-CR Complexion Analysis Measurements in Assessing Facial Photoaging for Clinical Research.

BACKGROUND: Historically, standard evaluations for photoaging have involved subjective analysis; recently, however, investigators have turned to noninvasive systems for more objective evaluation of facial aging. OBJECTIVES: The aim of this study was to establish a clinical correlation between the Glogau Photoaging Scale and the VISIA-CR Complexion Analysis System (Canfield Imaging Systems, Fairfield, NJ), and thereby reduce intra- and interobserver variability when assessing photodamage. METHODS: In total, 117 subjects aged between 18 and 89 years were included. Two-dimensional facial photographs were analyzed by 3 independent reviewers and assigned Glogau scores. Images were also captured and analyzed with VISIA software. Data were grouped by median Glogau score and compared between groups. RESULTS: All groups were statistically different (P < 0.05) for Spots, Wrinkles, and Remasked Wrinkles, except for Glogau 1 and 2 for Spots and Remasked Wrinkles. Scores for Wrinkles were plotted against age, and an exponential regression model was noted to be a better fit (R2 = 0.5) than a linear model (R2 = 0.47). The same was true for Spots with an exponential model (R2 = 0.36) compared with a linear model (R2 = 0.33). Scores were also evaluated based on sun exposure history, but no significant differences were observed. CONCLUSIONS: The results illustrate that an imaging system can be used to reliably determine objective scores correlating to Glogau photoaging evaluations, and indicate that aging appears to be an exponential process. Collectively, these findings will assist future investigations of facial aging and the therapeutic options available for facial skin rejuvenation, and enable objective assessment of treatment outcomes.

A Randomized, Placebo-Controlled Trial Evaluating the Single and Combined Efficacy of Radiofrequency and Hybrid Fractional Laser for Nonsurgical Aesthetic Genital Procedures in Post-Menopausal Women.

BACKGROUND: The efficacy of interventions that provide long-term relief of genitourinary symptoms of menopause has not been determined. OBJECTIVES: The authors sought to evaluate radiofrequency and hybrid fractional laser (HFL) treatments for menopausal vulvovaginal symptoms. METHODS: Thirty-one postmenopausal women completed all treatments and at least 1 follow-up. Outcomes included the Vulvovaginal Symptom Questionnaire (VSQ), Vaginal Laxity Questionnaire (VLQ), Urogenital Distress Short Form, Incontinence Impact Questionnaire (IIQ), Female Sexual Function Index (FSFI), laxity measurements via a vaginal biometric analyzer probe, and gene expression studies. RESULTS: Mean VSQ score decreased 2.93 (P = 0.0162), 4.07 (P = 0.0035), and 4.78 (P = 0.0089) among placebo, dual, and HFL groups 3 months posttreatment and decreased to 3.3 (P = 0.0215) for dual patients at 6 months. FSFI scores increased in the desire domain for placebo and dual groups and in arousal, lubrication, orgasm, satisfaction, and pain domains for the HFL group 3 and 6 months posttreatment. An increase of 1.14 in VLQ score (P = 0.0294) was noted 3 months and 2.2 (P = 0.002) 6 months following dual treatment. There was also a mean decrease of 15.3 (P = 0.0069) in IIQ score for HFL patients at 3 months. Dual, HFL, and RF treatments resulted in statistically significant decreases in collagen I, elastin, and lysyl oxidase expression. CONCLUSIONS: Several self-reported improvements were noted, particularly among HFL, dual, and placebo groups 3 and 6 months posttreatment. Objective biopsy analysis illustrated decreased gene expression, suggesting that treatments did not stimulate new extracellular matrix production.

Safety Guidelines Concerning the Use of Protective Eyewear and Gauze During Laser Procedures.

The advancement of laser technology has seen its use gain popularity across a wide range of specialties to treat diseases, as well as address aesthetic concerns. In order to protect both the patient and the healthcare personnel providing treatment, instruction and knowledge of laser safety remain of utmost importance. In this paper, we discuss the classification of laser systems, review ocular injuries that may be caused by inappropriate laser exposure, and provide background on laser protective eyewear. In addition, we highlight the current recommendations for proper eyewear during laser use outlined in the American National Standards Institute standard Z136.3, Safe Use of Lasers in Health Care. Finally, although it is common in some healthcare facilities to place gauze under external eye shields or use gauze alone over eyes during laser procedures, this practice poses an extreme risk to both patients and healthcare personnel. Therefore, we discuss why the use of gauze under eyewear for any laser procedures is not recommended, and instead, offer suggestions to consider when acquiring safe and comfortable patient eyewear.

The Role of the Laser Safety Officer and Laser Safety Programs in Clinical Practice.

Recent advancements in laser technology have led to its expanded utilization in smaller clinical settings and medical spas, particularly for facial rejuvenation and the treatment of other aesthetic concerns. Despite the increasing popularity of this technology, discussion of laser safety programs has remained limited, mostly to operating rooms at larger clinical institutions. Although smaller facilities do not operate at the same capacity as a large hospital or medical center, the requirements for utilizing a laser are no less stringent. Employers must comply with local and federal regulations, the Occupational Safety and Health Administration (OSHA) General Duty Clause, American National Standards Institute (ANSI) standards, and professional recommended practices applicable to their business. Although the laser safety officer (LSO) is often a full-time position within larger facilities, smaller clinical settings and medical spas may be limited in staff number. It is important, therefore, that clinical practices establish laser policies and procedures with consideration of their individual needs and capabilities. In this paper, we will define a laser safety program, highlight basic requirements needed to establish this program, and outline the specific responsibilities of the LSO. To ensure that safe laser practices are being conducted at the healthcare facility, it is imperative that small business owners are aware of these regulations and standards in place for the operation of laser systems.

Laser and Light-Based Device Education in a Plastic Surgery Residency Program: A Continuing Medical Education Overview.

The increasing prevalence of laser use, particularly in plastic surgery, demands education of both practitioners and trainees to ensure efficacy and patient safety. The purpose of this continuing medical education module is to provide the learner with a detailed outline for laser training education for plastic surgery trainees. In this overview, a discussion of the characteristics of light, an introduction to fundamental laser principles, a comparison of lasers and pulsed light systems, and examples of several therapeutic applications for light-based devices in the clinical setting will be presented. Additionally, the 5 parameters necessary for operation of light-based devices, as well as the importance of laser safety education, will be reviewed. We hope this continuing medical education will provide both practicing plastic surgeons and trainees with the proper education on the lasers and pulsed light devices they will use in their clinical practices.

The Effects of Aesthetic Lasers on Three Study Materials Used for Ocular Protection.

BACKGROUND: It is dangerous, although not uncommon, in some clinical settings for laser operators to place gauze underneath external patient protective eyewear when performing laser procedures. OBJECTIVES: The purpose of this study was to evaluate 4 lasers, commonly used for aesthetic facial procedures, on 3 materials commonly found in the clinical setting. METHODS: We performed tests with 4 lasers: the 2940-nm erbium-doped yttrium aluminum garnet (Er:YAG) laser, the 532-nm potassium titanyl phosphate (KTP) laser, the 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, and a Lumenis UltraPulse 10,600-nm carbon dioxide (CO2) laser. Their effects were evaluated on dry gauze pads, wet gauze pads, and adhesive external eye shields. RESULTS: When exposed to the 2940-nm Er:YAG and 10,600-nm CO2 lasers, dry gauze smoked on the first pulse and ignited on the second pulse, whereas no damage occurred to the wet gauze or adhesive eye shields after 8 and 4 pulses, respectively. No damage to any material or the underlying surface was seen after 30 pulses of the 532-nm KTP laser. After 2 pulses of the 1064-nm Nd:YAG laser, the adhesive eye shields sparked; dry gauze smoked after 1 pulse, but no damage to the underlying surface occurred after 30 pulses. CONCLUSIONS: The results of our study highlight the inherent flammability of gauze when exposed to lasers commonly used to address aesthetic facial concerns. Although moistened gauze conveyed more protection than dry gauze, these results do not guarantee patient ocular safety. Therefore, we do not recommend the use of any gauze under protective eyewear.

Clinical Evaluation of the Safety and Efficacy of a 1060-nm Diode Laser for Non-Invasive Fat Reduction of the Abdomen.

BACKGROUND: Despite the proven efficacy of liposuction, there is a population of patients who prefer non-surgical alternatives. Laser hyperthermia-induced lipolysis has emerged as one non-invasive alternative to liposuction. OBJECTIVES: The authors sought to evaluate the safety and efficacy of a 1060-nm (±10 nm) diode laser for non-invasive fat reduction of the abdomen. METHODS: This single-arm, 2-center study enrolled 30 patients. Patients received a 25-minute 1060-nm diode laser treatment on their abdomen. Ultrasound adipose measurements, body weight, and circumference were taken at baseline and at 6- and 12-week follow-up visits. Blinded evaluators identified "before" and "after" photos of each patient. A patient satisfaction questionnaire was completed by each patient at study exit. RESULTS: A total 29 patients completed all treatment and follow-up visits. Ultrasound images showed an adipose reduction of 8.55% at 12 weeks post-treatment (P < 0.0001). Blinded evaluators correctly identified 67% of the pre- and post-treatment images at site 01 (Sacramento, CA) and 56% at site 02 (Dallas, TX). Satisfaction was high, with 72% of patients reporting being either "satisfied" or "very satisfied" with their results on a 5-point Likert scale. Pain was rated as mild by 62% of patients, moderate by 38%, and severe by none on the Wong-Baker Scale. CONCLUSIONS: These results indicate that a single treatment with a 1060-nm (±10 nm) diode laser, per the treatment protocol, is safe and effective in reducing unwanted fat in the abdomen as objectively measured employing ultrasound. The treatment was well-tolerated among all patients, with minimal discomfort reported and high patient satisfaction.

Clinical Translation of Scarless 0.33-mm Core Microbiopsy for Molecular Evaluation of Human Skin.

BACKGROUND: Skin scarring can occur after punch biopsies, prohibiting their routine utilization, especially in the central face. OBJECTIVES: This paper describes a scarless, 0.33-mm-diameter skin microbiopsy for molecular analysis of skin. METHODS: This is was single-center, randomized, prospective study with 15 patients receiving no biopsy or biopsy on the left or right nasolabial fold. Six blinded raters assessed participant photos at baseline, 1 month, and 3 months post biopsy to evaluate for a visualized scar. Patient and Observer Scar Assessment Scale was completed. Additionally, biopsies from various skin regions of body along with arm skin after treatment with a single Erbium-YAG laser were processed for molecular analysis. RESULTS: No patients exhibited scar formation based on evaluation of photographs and patient feedback. There was no mark at the biopsy site 7 days post-procedure. Optical coherence tomography showed a complete closing of the biopsy-punch wound 48 hours post-biopsy. One month post-biopsy, photography reviewers were unable to identify a scar, on average, 90% of the time at 3-month follow-up. Microbiopsies from various anatomical regions were successfully extracted for histology, electron microscopy, and gene expression analysis. Selected skin rejuvenation markers in the biopsies from Erbium-YAG-treated forearm skin resulted in significant gene upregulation in extracellular matrix molecules at 1 month posttreatment compared with untreated skin. CONCLUSIONS: A core microbiopsy of 0.33 mm can be extracted reproducibly for histological, ultrastructural, and gene expression analysis without scarring. This allows repeated sampling for assessment of skin treatments and diseases, including aesthetics and wound-healing progress.

Bipolar Fractional Radiofrequency Treatment of Suprapatellar Skin Assessment Using Noninvasive Devices and Microbiopsy.

BACKGROUND: Noninvasive treatments for skin tightening are gaining popularity. However, no studies have assessed bipolar fractional radiofrequency treatment on suprapatellar skin. OBJECTIVES: The purpose of this study was to evaluate the efficacy of bipolar fractional radiofrequency treatment on suprapatellar skin. METHODS: Twenty patients received 1 bilateral suprapatellar bipolar fractional radiofrequency treatment. They returned 7 days, 3 weeks, 3 months, and 6 months posttreatment. Noninvasive measurements were obtained at each visit, including high-resolution ultrasonography, optical coherence tomography, transepidermal water loss and skin elasticity. Microbiopsies were collected in the treatment area for histologic and gene expression analyses. Three clinicians completed photographic evaluations comparing texture and laxity at baseline vs 6 months posttreatment. RESULTS: Fifteen subjects completed all 6 visits. Both transepidermal water loss and dermal-epidermal junction roughness were increased at 3 weeks and 3 months posttreatment. Both attenuation coefficient and stiffness were increased significantly at 3 and 6 months posttreatment. Blood flow 0.5 mm below the surface and expression of epidermal hyaluronic acid and inflammatory genes IL-1b and IL-6 were significantly higher at 7 days posttreatment compared with pretreatment and 3 months posttreatment. There were no statistically significant changes in collagen- or elastin-related genes and proteins at 7 days or 3 months posttreatment. An improvement in texture and laxity was observed at 6 months posttreatment in 17.7% and 24.4% of photographs, respectively. CONCLUSIONS: Radiofrequency treatment by microneedling of suprapatellar skin shows limited effects in decreasing skin laxity and improving skin appearance. At a molecular level, the treatment resulted in lower elastin and hyaluronic acid levels and increased dermal-epidermal junction roughness based on histology and optical coherence tomography imaging.

Use of Optical Coherence Tomography (OCT) in Aesthetic Skin Assessment-A Short Review.

Assessments of non-surgical office-based aesthetic treatments' efficacy including lasers are mostly based on subjective evaluation of clinical photography. Accumulating evidence suggest that non-invasive skin imaging such as optical coherence tomography (OCT) can be effectively used to assess not only the skin surface but also the underlying epidermis and dermis, providing objective and clinically relevant data. In this review, we highlight the potential of OCT imaging for the aesthetic medicine field along with OCT measurement parameters and their clinical relevance to healthy and pathological skin conditions. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

Novel Use of Non-Invasive Devices and Microbiopsies to Assess Facial Skin Rejuvenation Following Laser Treatment.

BACKGROUND AND OBJECTIVE: Patient-reported outcomes and blinded observer rating scales are subjective and unreliable but are extensively utilized to evaluate cosmetic office-based treatments, including ablative lasers. This study aims to assess the practicality of using non-invasive and minimally invasive methods for objective skin assessment following a skin rejuvenation treatment. STUDY DESIGN/MATERIALS AND METHODS: Twelve patients received a single 1,470/2,940 nm laser treatment for facial rejuvenation. Assessments were performed before treatment, and 7 days, 3 weeks, and 3 months post-treatment. Images were taken with the VISIA Skin Analysis System to measure wrinkles, textures, pores, ultraviolet (UV) spots, brown spots, red areas, and porphyrins. Other non-invasive skin measurements-high-resolution ultrasonography, optical coherence tomography, transepidermal water loss and BTC 2000-were used to measure epidermal/dermal thickness, blood flow, surface roughness, wrinkle depth, attenuation coefficient, elasticity, laxity, and viscoelasticity. Microbiopsies (0.33 mm in diameter or the equivalent of a 23-gauge needle) were collected for histology and gene expression of tissue rejuvenation. RESULTS: Significant improvement in facial skin aesthetics after laser treatment was recorded in UV spots, brown spots and pores after 3 weeks and in UV spots and brown spots after 3 months. The dermal attenuation coefficient decreased significantly at 3 weeks, while blood flow 0.5 to 0.7 mm below the skin surface increased significantly between 5 days and 3 weeks following treatment. Epidermal hyaluronic acid expression assessed by immunostaining and expression of inflammatory genes were elevated at 7 days post-treatment compared with untreated or 3 months post-treatment. There were no statistically significant changes in collagen or elastin-related genes between groups at the studied parameters. CONCLUSION: Non-invasive devices can be effectively used to provide objective measurements of skin structure, pigmentation, blood flow, and elasticity to assess the efficacy of facial skin rejuvenation treatments. Furthermore, microbiopsies can objectively evaluate facial skin rejuvenation without scarring. Using non-invasive skin imaging, a single treatment with the 1,470/2,940 nm laser was observed to be effective in improving skin appearance after 3 months, namely in reducing UV spots and brown spots, without significant changes in the tissue at the molecular level, as assessed by microbiopsy. Lasers Surg. © 2020 Wiley Periodicals, Inc.

Carbon Dioxide Laser Resurfacing for Rhinophyma: A Case Report and Discussion of the Literature.

Rhinophyma, an unsightly and obstructive skin lesion of the nasal area, can be difficult to treat. Numerous modalities have been tried, including medical, excision, and ablation, with various tools and results. In the present report, we have demonstrated the use of the carbon dioxide (CO2) laser on the nose of a 56-year-old man, with excellent cosmetic results even at 59 months after treatment. Discussion of the disease entity and the advantages and disadvantages of the different treatment options are presented. Given the results shown in our patient, we believe that CO2 laser ablation should be a standard treatment of rhinophyma, given its practicality, predictability, and excellent outcomes.

Holmium:YAG laser bronchoscopy ablation of benign and malignant airway obstructions: an 8-year experience.

Patients suffering from severe tracheobronchial obstruction are vulnerable to dyspnea, respiratory failure, obstructive pneumonia, and death. Treatment with a holmium:YAG laser, an alternative to the neodymium:YAG laser, may provide symptomatic relief. This is the largest case series to date describing the application of the holmium:YAG laser via bronchoscopy for benign and malignant obstructive disease. The data were retrospectively collected from 99 patients, with either benign or malignant tracheobronchial obstruction, who underwent 261 interventional bronchoscopy procedures in the operating room with laser ablation between January 2004 and November 2011. Categorical variables were analyzed with the chi-square and Fisher's exact tests as appropriate in contingency tables, whereas Student's t-test was performed for comparison of continuous variables. Patient follow-up was concluded on September 15, 2013. The holmium:YAG laser was used in 261 procedures performed on 99 patients with either benign or malignant disease. Symptomatic improvement was demonstrated in 90 % of all benign etiology cases and 77 % of all malignant etiology cases. Within the benign and malignant subgroups, improvement was dependent on anatomical location rather than etiology of the lesion. Complications occurred in 2.3 % of the procedures, with mortality in less than 1 % of procedures. Results confirm the usefulness and safety of the holmium:YAG laser in the treatment of patients with severe benign and malignant obstructive tracheobronchial obstructions. The holmium:YAG laser is an appealing alternative to the neodymium:YAG laser.

Five parameters you must understand to master control of your laser/light-based devices.

In this article, the authors review basic fundamental principles of light characteristics and their interaction with the target tissue. It is imperative for the practitioner to understand these concepts to deliver appropriate, efficacious, and safe phototherapeutic treatment for their patients. Once a diagnosis is made and a laser is chosen as a treatment tool, a basic knowledge and understanding of the physics and properties of light/tissue interaction is essential to allow practitioners to provide their patients with optimal results.

Clinical evaluation of the safety and efficacy of a 1060 nm diode laser for non-invasive fat reduction of the flanks.

BACKGROUND: Laser hyperthermia-induced lipolysis is a non-invasive method of localized fat treatment. Non-invasive approaches could be an option for a growing number of patients who are risk-averse and are seeking out non-invasive alternatives to surgical procedures such as liposuction. This study evaluated the safety and efficacy of a 1060 nm diode laser for the non-invasive fat reduction of the flanks. METHODS: A total of 30 subjects were enrolled in this prospective, single center study. Subjects received one 25-min treatment with a 1060 nm diode laser to both flanks. Follow-up visits were conducted at 6 and 12 weeks after the last treatment. Ultrasound adipose thickness, body weight, and circumference measurements were taken at baseline and at the 6- and 12-week follow-up visits. Subject satisfaction was assessed using a self-assessment of fat reduction, pain, and tolerability scales, and a subject satisfaction questionnaire. Safety was assessed via the presence or absence of any adverse events. RESULTS: The average age of subjects was 47.3 years. A total of 27 subjects completed the treatment and returned for both follow-up visits. An adipose reduction of 7.57 ± 1.15% at 6 weeks post-treatment (p < 0.0001) was measured using ultrasound. High subject satisfaction was seen, with 74% of subjects reporting being either "satisfied" or "very satisfied" with their results on a 5-point Likert Scale. Eighty-two percent of subjects stated they would recommend the treatment to their friends. All subjects had either mild or moderate pain, with 52% of subjects rating their pain as "mild" (1-3), while 48% rated their pain as moderate (4-7) on the Wong-Baker Scale. CONCLUSIONS: A single treatment with a 1060 nm diode laser was both safe and effective in reducing unwanted fat in the flanks without any unanticipated adverse events. Subjects described their treatment pain as mild or moderate and were highly satisfied with their treatment outcomes.

Optimal power settings for Holmium:YAG lithotripsy.

PURPOSE: We determined the optimal Ho:YAG lithotripsy power settings to achieve maximal fragmentation, minimal fragment size and minimal retropulsion. MATERIALS AND METHODS: Stone phantoms were irradiated in water with a Ho:YAG laser using a 365 µm optical fiber. Six distinct power settings were tested, including 0.2 to 2.0 J and 10 to 40 Hz. For all cohorts 500 J total radiant energy were delivered. A seventh cohort (0.2 J 40 Hz) was tested post hoc to a total energy of 1,250 J. Two experimental conditions were tested, including with and without phantom stabilization. Total fragmentation, fragment size and retropulsion were characterized. In mechanism experiments using human calculi we measured crater volume by optical coherence tomography and pressure transients by needle hydrophone across similar power settings. RESULTS: Without stabilization increased pulse energy settings produced increased total fragmentation and increased retropulsion (each p <0.0001). Fragment size was smallest for the 0.2 J cohorts (p <0.02). With stabilization increased pulse energy settings produced increased total fragmentation and increased retropulsion but also increased fragment size (each p <0.0001). Craters remained symmetrical and volume increased as pulse energy increased. Pressure transients remained modest at less than 30 bars even at 2.0 J pulse energy. CONCLUSIONS: Holmium:YAG lithotripsy varies as pulse energy settings vary. At low pulse energy (0.2 J) less fragmentation and retropulsion occur and small fragments are produced. At high pulse energy (2.0 J) more fragmentation and retropulsion occur with larger fragments. Anti-retropulsion devices produce more efficient lithotripsy, particularly at high pulse energy. Optimal lithotripsy laser dosimetry depends on the desired outcome.

The use of non-invasive instruments in characterizing human facial and abdominal skin.

BACKGROUND AND OBJECTIVE: The skin is highly variable. This variation, although helpful for function, causes inconsistencies when assessed using subjective scales. The purpose of this study is to measure differences in skin on the face and abdomen using non-invasive, objective devices as a method to eliminate subjective error and help reduce intra- and inter-observer variability in clinical analysis. STUDY DESIGN/MATERIALS AND METHODS: Eighty-eight subjects between the ages of 18 and 61 were enrolled in this study. These subjects varied in age, ethnicity, and Fitzpatrick score. Facial analysis was performed by clinical evaluation and utilizing non-invasive objective devices which included the DermaScan C 20 MHz HFUS (Cyberderm, Broomall, PA), Tru Vu (Johnson and Johnson), BTC 2000 (SRLI Technologies, Nashville, TN), Derma Unit SSC3 (CK Electronic, Köln, Germany), and the Chromometer. RESULTS: Non-invasive devices were shown to be consistent and accurate through repeated measurement at each of the anatomical points with error rates of less than 5%. Chromometer measurements were able to categorize patients into Fitzpatrick level. DermaScan measurements demonstrated decreasing skin thicknesses associated with increasing age, smoking, and female gender. Derma Unit SSC 3 showed gender and sun exposure related differences in sebum concentration, pH, and moisture content. The Derma Unit SSC 3 sebum concentration also showed correlation with Tru Vu readings for clogged pores and bacterial activity. CONCLUSION: The skin assessment scales that are in use today are often prone to variability and inaccuracy due to their subjectivity. Use of the described objective non-invasive facial analysis method provides an accurate, objective analysis of human skin which can be used to measure changes pre- and post-operatively, or even screen patients prior to procedure to identify non-responders or those prone to adverse events. Utilization of these devices introduces a foundation on which a strong evidence-based approach to aesthetic medicine can be built.

An intra-individual quantitative assessment of acute laser injury patterns in facial versus abdominal skin.

INTRODUCTION: Clinical laser settings have traditionally been calibrated on abdominal skin to predict and anticipate patterns of injuries in facial skin. This experimental approach has limitations as facial skin and abdominal skin have differences that may influence the depth of laser injury. OBJECTIVE: The primary objective of this study is to analyze the acute pattern of laser injury in abdominal skin and facial skin samples from the same subject and detail the anatomical and biophysical properties that can influence the laser tissue interaction. The secondary objective is to develop a conversion factor that will allow the prediction laser column depths in facial skin based upon laser column depths in abdominal skin. METHODS: Fifteen healthy subjects were consented and screened. Two 2 mm spots on the face and abdomen were identified and measured and treated with a fractional CO(2) laser (Lumenis Ltd, Yokneum, Israel), with an energy setting of 15 mj, 300 Hz at a density of 10. Treatment areas were biopsied and analyzed histologically using hematoxylin and eosin and TUNEL staining. RESULTS: Facial skin and abdominal skin have several significant anatomical and biophysical differences (concentration of pilosebaceous units, sebum concentration, and moisture content). Facial tissue demonstrated divergence of laser energy around pilosebaceous units and lateral spread of laser energy along blood vessels. These differences cause attenuation (28%) of the laser energy and result in column depths that are significantly (P < 0.003) shorter in facial tissues (mean depth 415 µm) in comparison to abdominal tissues (mean depth 582 µm). CONCLUSION: The variations in anatomic, biophysical, and biomechanical properties in facial skin cause an attenuation of the laser column depths in facial skin when compared to abdominal skin. A correction factor of 28% is required to predict the depth of laser columns in facial skin based on laser column depths observed in abdominal skin.

In vivo histopathologic comparison of the acute injury following treatment with five fractional ablative laser devices.

BACKGROUND: Both erbium (Er:YAG) and carbon dioxide (CO(2)) devices are commonly-used, efficient laser systems for aggressive skin resurfacing procedures. The devices each have different adjustable parameters (density, spot size, number of pulses, pattern, etc) and utilize variable energy capabilities to tailor individual treatments depending on the skin pathology and goals of treatment. Overall, the consensus has been that multiple-pass erbium treatments needed for efficacious wrinkle reduction had similar downtime and comorbidity to the traditional CO(2) treatments. Unfortunately, there were limited data comparing the histological differences and changes throughout the wound-healing process over time between the two treatment methods. OBJECTIVES: The authors compare the difference in injury following treatment with five novel fractional ablative laser systems in vivo. Differences in damage pattern, treatment depth, and degree of surrounding cellular injury following treatment with each device at common clinical settings are evaluated in a side-by-side histopathologic comparison. METHODS: Prior to planned excisional surgery, the panni of 20 abdominoplasty patients were treated with five novel ablative fractional carbon dioxide or Er:YAG laser systems at various clinical parameters, in accordance with the manufacturers' treatment guidelines. After tissue removal two to four hours later, the skin was biopsied and processed for histopathologic evaluation. Specimens were stained with hematoxylin and eosin, along with a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) assay, to highlight the degree of irreversible cellular injury. RESULTS: The acute damage profile differed between the fractional Er:YAG and CO(2) devices with respect to depth of penetration and extension of coagulation surrounding the microcolumns. The damage pattern was dependent on the parameters set with each device (eg, fluence, pulses, density, pulse width). The TUNEL-stained sections demonstrated more collateral cellular injury surrounding the ablated columns with the CO(2) devices than with the Er:YAG systems. CONCLUSIONS: Following treatment with the fractional Er:YAG and CO(2) devices, deep tissue injury with various coagulative and ablative properties was observed, and it was confirmed that carbon dioxide and erbium devices result in different patterns of injury. As such, each may be better suited for different clinical situations. It is important for practitioners to understand the limitations of a specific device, as well as the tissue injury following a given treatment pattern or protocol, to appropriately tailor their treatment algorithm for a given patient. This extensive histopathologic evaluation of the acute characterization of injury across devices is helpful in clarifying the differences/similarities in laser-tissue interaction following treatment in an in vivo human model.