Lidocaine-induced potentiation of thermal damage in skin and carcinoma cells.

OBJECTIVE: Lidocaine acts as a local anesthetic by blocking transmembrane sodium channel permeability, but also induces the synthesis of heat shock proteins and sensitizes cells to hyperthermia. A previous study reported two cases of deep focal skin ulceration at points corresponding to depot local lidocaine injection sites after treatment with non-ablative fractional resurfacing and it was hypothesized that lidocaine had focally sensitized keratinocytes to the thermal damage of laser treatment. The objective of this study was to investigate whether lidocaine potentiates hyperthermia damage to both normal and cancerous skin cells using an in vitro model. METHODS: Normal skin cell lines (fibroblasts, keratinocytes), skin cancer cell lines (melanoma, basal cell carcinoma), and a mucosal cancer cell line (cervical carcinoma) were exposed to various concentrations of lidocaine (0-0.3%) with or without hyperthermia (37°C, 42°C). RESULTS: Compared to normal skin cells, we demonstrate that cancer cell lines show significantly increased cell toxicity when a moderate temperature (42°C) and low lidocaine concentrations (0.1-0.2%) are combined. The toxicity directly correlates with a higher percentage of cells in S-phase (28-57%) in the cancer cell lines compared to normal skin cell lines (13-19%; R-square 0.6752). CONCLUSION: These results suggest that lidocaine potentiates thermal sensitivity of cell cycle active skin cells. The direct correlation between cell toxicity and S-phase cells could be harnessed to selectively treat skin and mucosal cancer cells while sparing the surrounding normal tissue. Additional research pre-clinically and clinically using several different heat sources (e.g., lasers, ultrasound, etc.) and lidocaine concentrations is needed to confirm and optimize these results. Lidocaine-enhanced hyperthermia may provide a non-invasive, alterative treatment option for highly proliferating, superficial skin, and mucosal lesions such as cancer or warts. Lasers Surg. Med. 51:88-94, 2019. © 2018 Wiley Periodicals, Inc.

Immediate skin responses to laser and light treatments: Warning endpoints: How to avoid side effects.

Lasers are versatile, commonly used treatment tools in dermatology. While it is tempting to follow manufacturer's guidelines or other "recipes" for laser treatment, this approach alone can be a recipe for disaster. Specific and immediate skin responses or endpoints exist and are clinically useful because they correlate with underlying mechanisms that are either desirable (ie, therapeutic), undesirable (ie, warning signs of injury or side effects), or incidental. The observation of clinical endpoints is a safe and reliable guide for appropriate treatment. This article presents the warning endpoints during specific dermatologic laser treatments, and the accompanying article presents the therapeutic endpoints, their underlying mechanisms, and the utility of these endpoints.

Immediate skin responses to laser and light treatments: Therapeutic endpoints: How to obtain efficacy.

Clinical endpoints are immediate or early tissue reactions that occur during laser treatment. They can guide the laser surgeon in delivering safe and effective laser treatment. Some endpoints act as warning signs of injury to the skin; others can indicate a therapeutic response. The first article in this series reviewed undesirable and warning endpoints, and this article focuses on desirable and therapeutic endpoints and their underlying mechanisms in laser surgery. We will also review treatments without clinical endpoints.

FDA MAUDE data on complications with lasers, light sources, and energy-based devices.

BACKGROUND AND OBJECTIVE: It is essential for physicians to be fully informed regarding adverse events and malfunctions associated with medical devices that occur in routine practice. There is limited information on this important issue in the medical literature, and it is mostly based on initial studies and case reports. More advanced knowledge regarding device adverse events is necessary to guide physicians towards providing safe treatments. The FDA requires that manufacturers and device users submit medical device reports (MDRs) for suspected injuries from device use or malfunction. The database of MDRs, entitled Manufacturer and User Facility Device Experience (MAUDE) enables the FDA to monitor device performance and identify potential safety issues. STUDY DESIGN/MATERIALS AND METHODS: We employed the following search strategy to identify reported adverse events. We searched the MAUDE electronic database on the FDA website in December 2013: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfmaude/search.cfm We collected all reported cases between 1991 and December 2013. The search terms utilized included a comprehensive list of device manufacturers, specific product names, and the wavelengths/technology of the devices used in the field of dermatology. RESULTS: Our search yielded 1257 MDRs. Forty-five MDRs were excluded due to insufficient data. The data is broken down into the adverse events observed, such as, but not limited to: blistering, burns, scarring, dyschromia, fat loss, and nerve palsy. The MDRs describe the adverse event and attempt to determine if it was related to device malfunction versus operator error. Radiofrequency devices, diode lasers, and intense pulsed light devices were the most commonly reported devices related to injuries. CONCLUSION: 1257 MDRs, from a myriad of devices used in dermatology, have been reported to the FDA as of December 2013. Despite the underreporting of adverse events, the MAUDE database is an untapped resource of post-market surveillance of medical devices. The database can offer additional information, which combined with the initial device studies and published case reports from our colleagues, will help raise awareness and improve patient safety.

Increased risk of litigation associated with laser surgery by nonphysician operators.

IMPORTANCE: Controversy exists regarding the role of nonphysicians performing laser surgery and the increased risk of injury associated with this practice. OBJECTIVE: To identify the incidence of medical professional liability claims stemming from cutaneous laser surgery performed by nonphysician operators (NPOs). DESIGN, SETTING, AND PARTICIPANTS: Search of an online national database of public legal documents involving laser surgery by NPOs. EXPOSURE: Laser surgery by nonphysicians. MAIN OUTCOMES AND MEASURES: Frequency and nature of cases, including year of litigation, certification of provider and operator, type of procedure performed, clinical setting of injury, and cause of legal action. RESULTS: From January 1999, to December 2012, we identified 175 cases related to injury secondary to cutaneous laser surgery. Of these, 75 (42.9%) were cases involving an NPO. From 2008 to 2011, the percentage of cases with NPOs increased from 36.3% to 77.8%. Laser hair removal was the most commonly performed procedure. Despite the fact that approximately only one-third of laser hair removal procedures are performed by NPOs, 75.5% of hair removal lawsuits from 2004 to 2012 were performed by NPOs. From 2008 to 2012, this number increased to 85.7%. Most cases (64.0%) by NPOs were performed outside of a traditional medical setting. CONCLUSIONS AND RELEVANCE: Claims related to cutaneous laser surgery by NPOs, particularly outside of a traditional medical setting, are increasing. Physicians and other laser operators should be aware of their state laws, especially in regard to physician supervision of NPOs.

Body contouring: the skinny on noninvasive fat removal.

Historically, the approach to body contouring has largely involved invasive procedures, such as liposuction. Recently, several new devices for noninvasive fat removal have received clearance by the Food and Drug Administration for the treatment of focal adiposity. Modalities are aimed primarily at targeting the physical properties of fat that differentiate it from the overlying epidermis and dermis, thus selectively resulting in removal. This review will focus on 3 novel approaches to noninvasive selective destruction of fat.

An assessment of traditional and novel therapies for cellulite.

There are numerous treatments for cellulite including topical, surgical, laser and other therapies. Many of these treatments are expensive. Part of the difficulty in treating cellulite arises from our incomplete understanding of this phenomenon. As noted previously in this journal, there is no consensus as to the etiology of cellulite. This article will focus on both traditional and novel treatments for cellulite and assess their efficacy based on the scientific literature.

Cellulite: Is there a role for injectables?

BACKGROUND: Cellulite describes the cutaneous dimpling of the thighs, buttocks, and hips that is seen predominately in women. Current evidence suggests that structural differences in fat architecture between the sexes account for its appearance. Mesotherapy, a method of delivering medication locally with the use of numerous cutaneous injections, has recently become a popular method to purportedly treat the condition. METHODS: An overview of cellulite and adipocyte physiology, with a literature review and appraisal of compounds commonly used in mesotherapy. RESULTS: Experimental studies using individual mesotherapy ingredients for other conditions suggest a number of mechanisms, including lipolysis, disrupting connective tissue and augmenting circulation, which may theoretically improve cellulite. Peer-reviewed studies have not evaluated whether these effects translate clinically. CONCLUSIONS: Until further studies are performed, patients considering mesotherapy for cellulite must be aware that the substances currently being injected to treat this cosmetically disturbing, but medically benign, condition have not been thoroughly evaluated for safety or efficacy.