Brian Zelickson1’2 and Susan Walgrave2
1Associate Professor of Dermatology, University of Minnesota, Minneapolis, MN, USA
2Zel Skin and Laser Specialists, Edina, MN, USA
10.6 Introduction 256
10.7 Fractional Photothermolysis Defined 256
10.8 Fractional Treatment Parameters to Consider 257
10.9 Biological Effects of Fractional Photothermolysis 258
10.10 Therapeutic Uses and Clinical Efficacy 261
10.10.1 Photodamage 261
10.10.2 Scarring 262
10.10.3 Melasma 262
10.10.4 Other Therapeutic Uses 263
10.11 Pretreatment Considerations 263
10.12 Posttreatment Considerations 264
10.13 Devices Currently Available 264
10.14 Treatment Complications and Management 264
10.15 Conclusions 268
Gurpreet S. Ahluwalia (ed.), Cosmetic Applications of Laser and Light-Based Systems, 255-270,
© 2009 William Andrew Inc.
Over the past hundred years, the US population has more than tripled, owing to the increased life expectancy (average 77 years) and declining mortality rate. Specifically, the population of those aged 65 and older is expected to increase rapidly starting in 2011, as the first of the baby boom generation reach this age [1]. With the majority of the population being female and living longer, the demand for cosmetic procedures is growing tremendously.
Skin rejuvenation is a term used to define a procedure that can reduce the signs of aging and photodamage. Traditionally, ablative lasers, such as the carbon dioxide (CO2 ) and erbium:yttrium-aluminum-garnet (Er:YAG), have been the most successful lasers for resurfacing the skin by improving texture, wrinkles, and pigmentation. These devices accomplish this by ablating the epidermis, and potentially the upper portions of the dermis, inducing a controlled wound and a subsequent healing response [2]. This improvement, however, is associated with prolonged downtime, including erythema, which can last from weeks to months, and carries with it significant risk of complications, including infection, pigmentary changes, and scarring.
Nonablative devices have since been developed to minimize the risk of side effects by sparing the epidermis while targeting structures within the dermis. Although patients typically experience minimal recovery time, the overall textural improvement has been mild and unpredictable, despite histological evidence of collagen remodeling [3-6].
To overcome the shortcomings of both the procedures, fractional photothermolysis was developed in an attempt to achieve a greater efficacy than nonablative procedures, without the downtime and side effects associated with ablative resurfacing. The concept of fractional photothermolysis was first developed in 2001 by Dr R. Rox Anderson of Massachusetts General Hospital. In 2003, Huzaira et al. [7,8] tested this theory with a 1500 nm laser to assess whether the thermal effects could be spatially confined within human tissues. Indeed, the laser created multiple foci of thermal injury that were approximately 50 to 150 pm in diameter and 0 to 550 pm in depth, while sparing surrounding tissues. After further studies by Manstein et al. [9], Reliant Technologies Inc. introduced this technology with the Fraxel® SR 750 laser system in 2004, which led the way for a new era of resurfacing devices.