Barry E. DiBernardo

Evaluation of tissue thermal effects from 1064/1320-nm laser-assisted lipolysis and its clinical implications.

Abstract Liposuction is a standard for removing fat. Recently developed, laser lipolysis can be used to simultaneously remove unwanted fat and tighten skin. Laser lipolysis is accomplished with single or multiple sequential wavelengths. Development of an optimal method requires detailed understanding of tissue heating for the wavelengths employed. This study systematically evaluates tissue heating for superficial and deep laser lipolysis using three approaches, and correlates temperature rise with histology changes, defining appropriate system parameters. Two individuals scheduled for abdominoplasty had laser testing on healthy abdominal skin scheduled for excision. Each treatment was applied to 3×3 cm squares with various laser parameters. Treatment was conducted in the fatty layer for lipolysis and subdermally for skin tightening. Individual squares were treated with SmartLipo (Cynosure, Inc. Westford, MA, USA) using 1064 nm, 1320 nm, or MultiPlex (1064 nm/1320 nm) with laser doses of 8.3 to 333 J/cm2. Exposures were applied at 3–5 mm or ∼20 mm depth below the skin surface. Skin temperatures at the surface and at depths of 5 mm to 37 mm were recorded immediately post-treatment for each exposure. Treated tissue was excised and evaluated for thermal injury using H&E and transmission polarization microscopy. Histology was correlated to tissue temperature to determine appropriate treatment limits. Superficial treatment with surface temperatures exceeding 47°C (50°C and 55°C at 5 mm depth) typically caused epidermal and dermal injury, with blistering above 58°C. Below this threshold, focal collagen change and dermal inflammatory response were found in many samples without epidermal injury. These acute thermal effects may link to skin tightening during the healing process. Deep treatments, at up to 133 J/cm2, exhibited minimal temperature rise and induced thermal effects in vessels and ligaments. Higher laser doses were associated with a significant temperature increase. In conclusion, superficial subdermal heating (within approximately 5 mm of the surface) during laser lipolysis should limit skin surface temperature to 42°C. The laser dose per surface temperature rise in treatments are 4.5 J/cm2/°C for 1320 nm, 6 J/cm2/°C for MultiPlex and 7.5 J/cm2/°C for 1064 nm. Clinical studies should be performed to validate these results.

Randomized, Blinded Split Abdomen Study Evaluating Skin Shrinkage and Skin Tightening in Laser-Assisted Liposuction Versus Liposuction Control

BACKGROUND Laser-assisted liposuction has shown great potential in facilitating fat removal, improving patient recovery time, and decreasing postoperative side effects. Clinical experience has indicated superior skin tightening after laser-assisted liposuction than with liposuction alone. OBJECTIVES The aim of the present study was to obtain quantitative, objective data for comparing tissue shrinkage and skin tightening achieved by laser-assisted liposuction versus liposuction alone. METHODS Ten female subjects from the authors private practice with unwanted abdominal adiposity and mild to moderate skin laxity were enrolled. On the abdominal skin of each patient, the corners of four rectangular regions (approximately 5 × 5 cm each) were tattooed with India ink and randomly assigned to treatment with laser-assisted liposuction (Smartly MPX laser, Cynosure, Inc., Westford, Massachusetts) or with liposuction alone. The laser system permits individual as well as sequential emission of 1064-nm and 1320-nm wavelengths. Skin shrinkage was quantified by calculating the changes in surface area of the regions. Skin tightening was quantified by changes in the skin stiffness index measured in the treated regions. RESULTS One month and three months after treatment, the mean skin shrinkage ratios were significantly higher on the laser-treated side than on the suction side. One month after treatment with or without laser, the mean skin stiffness and skin tightening showed no statistically significant difference from baseline. Three months after treatment, the mean skin stiffness and skin tightening were significantly higher on the laser-treated side. CONCLUSIONS Laser-assisted liposuction has a statistically significant effect on skin shrinkage and tightening of the skin in the abdominal area when compared to liposuction alone.

Evaluation of Skin Tightening After Laser-Assisted Liposuction

BACKGROUND Lasers have been used to enhance the emulsification of fat and coagulation of small blood vessels in conjunction with lipoaspiration. Although seen anecdotally, documented skin tightening has not been established. OBJECTIVE The authors sought to establish a model and a quantifiable method for documenting changes in skin tightening and skin shrinkage after laser lypolysis. METHODS Five female patients with focal abdominal adiposity were treated in a prospective evaluation with a sequentially firing 1064-/1320-nm laser. Skin shrinkage was measured from four quadrants of tattoo skin markings and evaluated using a three-dimensional camera. Skin tightening was measured with a skin elasticity device. Measurements were taken at baseline and at one and three months postoperatively. RESULTS At three months postoperatively, the average skin tightening index (elasticity) increase indicating skin elasticity improvement was 26%; the average reduction in area or skin shrinkage was 17%. Both the skin tightening index and skin shrinkage at three months postoperatively (P < .01) were higher than baseline. CONCLUSIONS Our findings represent the first documentation of quantifiable evidence of positive skin changes resulting from the addition of laser treatment to liposuction.

Laser hair removal: where are we now?

The hair removal market is evolving rapidly. The goal has always been long-term epilation. Success is dependent on understanding hair biology and physiology and on knowledge of laser physics, skin optics, and tissue preservation with respect to these emerging laser technologies. These topics will be reviewed, as will specific categories of laser systems in the hair removal arena and the clinical aspects of laser hair removal today.

Treatment of Cellulite Using a 1440-nm Pulsed Laser With One-Year Follow-Up

BACKGROUND Cellulite is characterized by a thickened hypodermal fat layer, along with hypodermal fat lobules that extend upward into the dermis, expanding and stretching the fibrous septae that separate the fat lobules. Eventually, the septae sclerose, contract, and harden, holding the skin at an inflexible length while the surrounding tissue continues to expand. OBJECTIVES The author evaluates the efficacy, safety, and duration of clinical benefit associated with a pulsed laser that delivers 1440-nm energy to the dermal-hypodermal interface for the treatment of cellulite. The changes in the dermal structure that affect the appearance of cellulite are also examined. METHODS Ten healthy women with cellulite on their thighs enrolled in a prospective Institutional Review Board-approved study conducted in the authors private plastic surgery clinic. Patients received a single treatment with a 1440-nm pulsed laser. Energy was delivered to the subdermal tissue through a fiber that was designed for side firing and enclosed in a cannula. Treatment addressed the thickened hypodermal fat layer, hypodermal fat lobules that extended upward into the dermis, and fibrous septae by thermal subcision. RESULTS The mean age of the patients was 47 years ± 5.4 years. Mean skin thickness (as shown by ultrasound) and skin elasticity were shown by objective measurements to increase significantly at one, three, six, and 12 months. Subjective physician and subject evaluations indicated improvement, high subject satisfaction, and minimal adverse effects. CONCLUSIONS In this study, a single treatment with the 1440-nm pulsed laser improved the appearance of cellulite, an improvement that persisted through at least one year of follow-up with minimal adverse effects.

Body ContouringPreliminary ReportEvaluation of Skin Tightening After Laser-Assisted Liposuction

BACKGROUND Lasers have been used to enhance the emulsification of fat and coagulation of small blood vessels in conjunction with lipoaspiration. Although seen anecdotally, documented skin tightening has not been established. OBJECTIVE The authors sought to establish a model and a quantifiable method for documenting changes in skin tightening and skin shrinkage after laser lypolysis. METHODS Five female patients with focal abdominal adiposity were treated in a prospective evaluation with a sequentially firing 1064-/1320-nm laser. Skin shrinkage was measured from four quadrants of tattoo skin markings and evaluated using a three-dimensional camera. Skin tightening was measured with a skin elasticity device. Measurements were taken at baseline and at one and three months postoperatively. RESULTS At three months postoperatively, the average skin tightening index (elasticity) increase indicating skin elasticity improvement was 26%; the average reduction in area or skin shrinkage was 17%. Both the skin tightening index and skin shrinkage at three months postoperatively (P < .01) were higher than baseline. CONCLUSIONS Our findings represent the first documentation of quantifiable evidence of positive skin changes resulting from the addition of laser treatment to liposuction.

Assessment of biomechanical skin properties: is cellulitic skin different?

BACKGROUND An objective in vivo measurement of viscoelastic skin properties is difficult. Consequently, the clinicians ability to evaluate the effectiveness of therapies that may affect skin pliability and skin surface characteristics is limited. OBJECTIVE The purpose of this study was to evaluate the usefulness of the Biomechanical Tissue Characterization BTC-2000 System for objective, noninvasive assessment of viscoelastic skin properties, specifically by testing the hypothesis that cellulite-affected skin may have different biomechanical characteristics than skin without a cellulitic appearance. METHODS A prospective study comparing 2 closely matched, nonrandomized groups of 15 women with and without cellulite in cellulite-prone areas was conducted. Biomechanical parameters including skin laxity, elastic and viscoelastic deformation, stiffness, energy absorption depicting overall tissue compliance, and elasticity were measured in an area prone to cellulite (the lateral thigh) and one not prone to cellulite (the posterior shoulder). RESULTS The degree of the elastic deformation on the maximum pressure, stiffness, and elasticity was similar for all areas in both groups (P > .05). Comparisons of individual parameters showed decreased elastic deformity and laxity of skin among individuals with no cellulite in the cellulite-prone area (P < .05), whereas there was no significant difference between the groups in the cellulite-nonprone area (P > .05). In addition, in volunteers with cellulite, lateral thigh and posterior shoulder skin was remarkably softer, as reflected by energy absorption, than in those without cellulite (P < .05). CONCLUSIONS An assessment of volunteers with and without cellulite in cellulite-prone and non-prone areas demonstrated that BMT-2000 technology allows noninvasive, reproducible measurements of selected biomechanical skin properties. Such measurements will be useful in assessing changes in skin laxity and elasticity in aesthetic surgical and nonsurgical treatments, and in evaluating skin, skin care programs, and cosmeceutical agents. (Aesthetic Surg J 2002;22:260-266.).

A Multicenter Study for a Single, Three-Step Laser Treatment for Cellulite Using a 1440-nm Nd:YAG Laser, a Novel Side-Firing Fiber, and a Temperature-Sensing Cannula

BACKGROUND Historically, treatments for cellulite have not been able to address all of its physiological components and require multiple sessions. OBJECTIVE The authors evaluate the safety and efficacy of a single, subdermal procedure to treat the underlying structure of cellulite. METHODS Fifty-seven patients underwent a 3-step cellulite treatment with a 1440-nm Nd:YAG laser with a side-firing fiber and temperature-sensing cannula. Efficacy was measured by the ability of blinded evaluators to distinguish baseline photos from those taken at 3 and 6 months posttreatment, as well as their rating of the results on a 5-point, 2-category ordinal photonumeric scale when comparing baseline photos to those taken at 2, 3, and 6 months posttreatment. Patient and physician satisfaction was assessed based on completion of a satisfaction survey at 2, 3, and 6 months posttreatment. Adverse events (AE) were recorded throughout the study. RESULTS At 6 months posttreatment, blinded evaluators rated at least a 1-point improvement in the appearance of cellulite in 96% of treated sites. Blinded evaluators were also able to correctly identify baseline versus posttreatment photos in 95% of cases. At least 90% of patients and physicians reported satisfaction with the results of treatment throughout 6 months. AE were mild in intensity and transient to treatment. CONCLUSIONS A single, 3-step, minimally invasive laser treatment using a 1440-nm Nd:YAG laser, side-firing fiber, and temperature-sensing cannula to treat the underlying structure of cellulite proved to be safe and maintained effectiveness at least 6 months posttreatment. LEVEL OF EVIDENCE 2.

A Multicenter Study for Cellulite Treatment Using a 1440-nm Nd:YAG Wavelength Laser with Side-Firing Fiber

BACKGROUND Treatment of cellulite using a 1440-nm YAG wavelength laser with side-firing fiber has proven safe and effective, lasting at least 6 months. OBJECTIVES The authors evaluate the safety and efficacy of a single, subdermal procedure to treat the underlying structure of cellulite for at least 1 year. METHODS Fifty-seven patients underwent a 3-step cellulite treatment with a 1440-nm Nd:YAG laser with a side-firing fiber and temperature-sensing cannula. Efficacy was measured by the blinded evaluators to distinguish baseline photos from those taken at 12 months posttreatment, with results on a 5-point, 2-category ordinal photonumeric scale when comparing baseline photos to 12 months posttreatment. Subject and physician satisfaction was assessed based on completion of a satisfaction survey. Adverse events (AE) were recorded throughout the study. Twelve month data were analyzed and compared to 6 month data. RESULTS Evaluators chose baseline photographs 97% on average from 6 (-1, +2) months and 91% from the 12 (-3, +2) months posttreatment photographs. At 6 (-1, +2) months, the average improvement score was 1.7 for dimples and 1.1 for contour irregularities. At 12 (-3, +2) months, the average improvement score was 1.4 for dimples and 1.0 for contour irregularities. The average satisfaction score for the physician was 5.6 and the patient was 5.3 on a 6-point scale. CONCLUSIONS A single, 3-step, minimally invasive laser treatment using a 1440-nm Nd:YAG laser, side-firing fiber, and temperature-sensing cannula to treat the underlying structure of cellulite proved to be safe and maintained effectiveness at least 1 year post treatment. LEVEL OF EVIDENCE 2: Therapeutic.

Intense Pulsed Light Therapy for Skin Rejuvenation.

Intense pulsed light (IPL), also known as pulsed light and broad band light, is a nonlaser light source used to treat a variety of vascular and pigmented lesions, photo damage, active acne, and unwanted hair. Current IPL systems are much improved from older-generation devices with better calibration, integrated cooling, and improved tuning. These devices are extremely popular because of their versatility and are often the first devices recommended and purchased in many offices.