Lasers in Surgery and Medicine 47:103–105 (2015)

Introduction Mathew Avram, MD, JD1 and Arisa Ortiz, MD2 Department of Dermatology, Massachusetts General Hospital, Wellman Center for Photomedicine, Harvard Medical School 2 Department of Dermatology, University of California, San Diego, California

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It is our distinct honor to serve as Guest Editors for this Special Issue in Dermatology and Plastic Surgery of Lasers in Surgery and Medicine. We have carefully chosen papers that highlight cutting-edge scientific advances in our field, shed light on innovative treatment modalities in energybased devices, and provide evidence-based support for safe and effective energy-based treatments. We are indebted to the clinicians and scientists who selected LSM to display their novel work. It is a testament to the leadership of Dr. Stuart Nelson that LSM continues to publish highimpact, high quality work with significant clinical and scientific implications. We would also like to acknowledge the tremendous efforts of Beth Mallen, whose tireless work was instrumental in the preparation of this special issue. BASIC SCIENCE SECTION The pathophysiology of cellulite remains a conundrum that has hampered efforts to produce truly effective treatment options. Gonz alez-Su arez et al. investigate the architecture of cellulite and its thermal and elastic response to radiofrequency (RF) in two different clinical grades of severity (cellulite grade 0 and 2.5). It is known that RF electric current preferentially circulates through fibrous septae in the subcutaneous tissue because fat is a poor electric conductor. Their results show that there is higher absorption in septae with vertical orientation compared with horizontal orientation. Further, highdensity morphology (i.e., increased number of fibrous septae) seen in lower grades of cellulite (grade 0) had a more uniform and larger cross-sectional area of thermal damage due in part to the larger number of septae available for preferential heating. This would suggest a more effective treatment in patients with less severe grades of cellulite, given the same treatment parameters. These results highlight the multidimensional, non-linear properties of subcutaneous tissue in response to RF electric current. The increased understanding of tissue interactions from heating via RF gained from this paper may provide insight into improving upon currently available RF treatments for cellulite. The severity of burn injuries can be clinically challenging to assess. This can lead to unnecessary surgery, or alternatively, delayed intervention. Laser Doppler Imaging (LDI) is a noninvasive scanner that examines the skin microcirculation to determine depth of burn injury via back-scatter. By assessing blood perfusion in burn wounds, Sˇtetinsk y et al. provide a strategic algorithm ß 2015 Wiley Periodicals, Inc.

using LDI to assess wound healing and the need for surgical intervention. Due to vascular compression artifact from local edema, the authors indicate that LDI is likely most accurate 2 days after burn injury when edema has subsided. Numerous clinical studies have shown improvement in keloids after treatment with the pulsed dye laser (PDL). Existing data indicate that keloid growth is regulated by various growth factors. Prior investigations into the mechanism of PDL on keloids have focused on evaluating its effects on the expression and proliferation of growth factors, such as transforming growth factor beta 1. In a preceding study, PDL was shown to down-regulate connective tissue growth factor (CTGF) expression of keloids. In this issue, Zhu et al. further investigate the effects of PDL on the proliferation and expression of CTGF in cultured keloid fibroblasts at varying pulse durations and fluences. CTGF mRNA expression was significantly down-regulated in a fluence-dependent manner when the pulse duration was held constant. However, when fluence was held constant, there was no significant difference in improvement between various pulse durations. The current paradigm for the treatment of keloids with the PDL is the use of a short pulse duration and low fluence. This study suggests, however, that higher fluences may be more effective in the treatment of keloids, while pulse duration may play less of a role. Light-emitting diodes (LEDs) create numerous biological effects, such as the inhibition of skin fibroblast proliferation, that are not well characterized. Current modalities for treatment of fibrotic skin diseases are suboptimal and alternative strategies are warranted. Mamalis et al. examine the potential for LED blue light (LED-BL) for the treatment of keloids and other fibrotic skin diseases via its effect on human skin fibroblast proliferation, viability, migration speed, and reactive oxygen species generation in vitro. The results were consistent with previous studies showing a dosedependent decrease in the proliferation of fibroblasts after LED-BL. A decrease in migration speed and increase in

 Correspondence to: Arisa Ortiz, MD, 8899 University Center Ln. #350, Department of Dermatology, University of California, San Diego, CA 92122. E-mail: [email protected] Accepted 13 December 2014 Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/lsm.22337

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reactive oxygen species was also observed suggesting a potential mechanism for the prevention and/or treatment of keloids with LED-BL photobiomodulation. CLINICAL SECTION Basal cell carcinoma (BCC) is the most common form of skin cancer in the United States. Traditional surgical and destructive treatments can result in poor cosmesis, prolonged healing time, and scarring. This has created interest in noninvasive treatment options. In this prospective, non-randomized, open-label, pilot study, Ortiz et al. investigate the clinical efficacy and safety of pulsed, highfluence 1,064 nm Nd:YAG laser treatment for BCC on the trunk and extremities. After one laser treatment, there was complete histologic clearance in 92% of tumors. At higher fluences, there was 100% histologic clearance without any adverse side effects. While this initial study is promising, further investigation with larger sample size is warranted to better assess the safety and efficacy of this treatment. Ablative fractional resurfacing is a popular treatment for wrinkle reduction, photodamage, and other cosmetic concerns. Despite the popularity of this procedure, there is little data investigating patient satisfaction. Kohl et al. investigated patient expectations prior to and patient satisfaction after completion of three fractional CO2 laser treatments. They also sought to correlate objective measurements of rhytid reduction with patient satisfaction after treatment. Their data show high patient satisfaction with ablative fractional resurfacing treatments even in the face of high pretreatment expectations. Interestingly, patient satisfaction was not correlated to objective data regarding wrinkle reduction achieved by the treatment. Cryolipolysis has been shown to selectively target adipose tissue in a safe and noninvasive manner. Traditional areas of treatment have included the abdomen and flanks. With time, there has been increasing interest in the application of cooling to other sites of the body. Zelickson et al. report on the efficacy of cryolipolysis for the treatment of inner thighs. Efficacy was measured by ultrasound, circumference measurements, and photography. At 16-week follow-up, baseline photography, ultrasound data, and circumference measurements all demonstrated fat layer reduction with no serious adverse side effects. This indication for cryolipolysis treatment has now received FDA clearance. Non-ablative fractional laser resurfacing has proven to be a very safe procedure for over a decade. Reported side effects tend to be mild and temporary in most cases. In this way, non-ablative fractional resurfacing has gained tremendous popularity, particularly in comparison to traditional ablative resurfacing. Xu et al. present a case series of non-ablative fractional resurfacing treatments complicated by rapidly progressive bacterial infections. These cases highlight the potential for both gram-positive and gram-negative bacterial infection following nonablative fractional resurfacing. Although rare, this potential complication merits close post-treatment surveillance,

appropriate workup, and timely intervention in order to prevent potentially serious sequelae. With the increasing popularity of laser and light source treatments, there remains a paucity of data regarding device safety. Clearly, laser and light source device operators need to be fully apprised of the adverse events that occur with the routine use of these devices in medical practice. Tremaine et al. examine the largest public resource documenting such complications, the FDA’s MAUDE database, in an effort to determine the incidence of such adverse events. While acknowledging the many limitations of such a review, the authors do present data regarding the reported complications of a myriad of laser and light source devices. In combination with initial device studies and published case reports, this review of the MAUDE database provides additional information for laser and light source operators that can help them provide safe and effective treatments. Ablative and non-ablative fractional resurfacing have revolutionized the treatment of burn scars. In an effort to quantify the degree of improvement, Taudorf et al. evaluated three monthly combined superficial and deep non-ablative fractional laser treatments with a clinical assessment scale and histologic outcome. Importantly, the scars were randomized into side-by-side treated and control areas. Patient follow-up was at 1, 3, and 6 months. Their data indicate both clinical and histologic improvement of mature burn scars 6 months post-treatment. This study adds to the growing literature confirming the efficacy of fractional resurfacing in the treatment of burn scars. Post-acne erythema is a common cosmetic complaint in acne patients. Panchaprateep et al. investigate the safety and efficacy of a low-fluence 585 nm Q-switched Nd:YAG laser for treatment of post-acne erythema in Asian patients as a treatment alternative to pulsed dye laser. Twenty-five patients with post-acne erythema underwent three treatment sessions at 2-week intervals. The authors report significant improvement in post-acne erythema and acne lesion count at 6 weeks after the last treatment session. Further investigation is needed to determine the mechanism of action and the potential clinical utility of this novel therapy for post-acne erythema. Endovenous thermal ablation is an effective treatment for venous insufficiency. Various laser and light sources can be utilized to thermally contract vein wall collagen. Weiss et al. conduct a 14-year retrospective review of three different thermal ablation sources for the treatment of great and small saphenous vein insufficiency. All systems, including the 1,320 nm Nd:YAG laser, 810 nm diode laser, and radiofrequency achieved a high success rate. Evaluation by Duplex ultrasound showed recanalization in 16.7% of cases reviewed. At 5-year follow-up, they report that the 1,320 nm laser, which targets water, had the highest rate of saphenous vein ablation. This retrospective study confirms prior data that endovenous thermal ablation remains the gold-standard for venous insufficiency due to its long-term effectiveness and low risk of complications. “Laser toning” is a technique that is gaining popularity in Asian countries for the treatment of dermatoheliosis and

INTRODUCTION

melasma. It is performed with a 1,064 nm Nd:YAG laser using a large spot size and low fluences. Hypopigmentation and depigmentation are complications seen with this technique. Sugawara et al. assess the relationship between leukoderma and the frequency of laser treatments versus the total number of laser treatments. They also investigate the effectiveness of ultraviolet (UV) imaging as a method for the early detection of leukoderma. The authors report that the frequency of the treatment sessions did not have a significant effect on the incidence of leukoderma. UV imaging was useful in the early detection of leukoderma resulting from the total number of treatments or cumulative laser energy, but not in leukoderma related to direct phototoxicity or destruction of melanocytes seen with higher laser fluences. The authors report that leukoderma resulting from direct phototoxicity is not evident on UV imaging prior to presenting clinically. Whether laser toning is a reasonable therapeutic option for the treatment of melasma requires further study. Moreover, further investigation is required to elucidate its mechanism of action and how leukoderma is produced as an adverse effect of this treatment. Conventional photodynamic therapy (PDT) has been performed with various laser and light sources for the safe and effective treatment of actinic keratoses and photodamage. In this case series, Lane et al. utilize ambient visible sunlight to investigate the efficacy of “daylight PDT” for the improvement of actinic keratoses and photodamage. After examining the experience of 80 patients, the authors found the treatments to be safe and well tolerated. While promising, these data require further investigation into the optimal dosimetry of sunlight necessary for effective PDT. It is important to note that this case series was limited to the treatment of actinic keratoses and photodamage. Other indications of PDT, such as the treatment of acne, were not included in this study.

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Axillary hyperhidrosis is a common dermatologic complaint with various treatment options such as antiperspirants, botulinum toxin injections, non-invasive microwave therapy and surgery. Leclere et al. evaluate the efficacy of the following: (1) a 975 nm diode laser treatment alone; (2) simultaneous 924 and 975 nm diode laser treatment; (3) curettage alone; and (4) combination 924 and 975 nm laser therapy followed by curettage. The group treated with the combination of 924 and 975 nm laser followed by curettage achieved the best results as assessed by the Hyperhidrosis Disease Severity Scale, starch iodine test, and Global Analogical Improvement Scale. The 975 nm diode laser as monotherapy produced burns in two patients that required one month to heal. Noting efficacy at 1-year follow-up, the authors conclude that combination 924 and 975 nm laser treatment with curettage represents an alternative treatment option for axillary hyperhidrosis. Despite the increasing popularity of tattoos, there is currently little regulation governing the content of tattoo inks. Among the side effects reported from tattoo inks is allergic reaction. Importantly, laser treatment may trigger an allergic response due to the sudden release of the ink particles into the lymphatics. Bernstein reports the first case of a widespread allergic reaction following Q-switched laser treatment of a black ink tattoo. This case report and review of the literature underscores the importance of tattoo ink safety and the need for its appropriate regulation. CONCLUSION The investigations reported by our contributing authors represent the most innovative scientific and clinical findings in our field. They are a great tribute not only to LSM but also to the diverse membership of clinicians and basic scientists within the American Society for Laser Medicine and Surgery. We hope you enjoy reading these contributions as much as we did.