Ex vivo histological characterization of a novel ablative fractional resurfacing device

BACKGROUND AND OBJECTIVES: We introduce a novel CO(2) laser device that utilizes ablative fractional resurfacing for deep dermal tissue removal and characterize the resultant thermal effects in skin. STUDY DESIGN/MATERIALS AND METHODS: A prototype 30 W, 10.6 microm CO(2) laser was focused to a 1/e(2) spot size of 120 microm and pulse duration up to 0.7 milliseconds to achieve a microarray pattern in ex vivo human skin. Lesion depth and width were assessed histologically using either hematoxylin & eosin (H&E) or lactate dehydrogenase (LDH) stain. Pulse energies were varied to determine their effect on lesion dimensions. RESULTS: Microarrays of ablative and thermal injury were created in fresh ex vivo human skin irradiated with the prototype CO(2) laser device. Zones of tissue ablation were surrounded by areas of tissue coagulation spanning the epidermis and part of the dermis. A thin condensed lining on the interior wall of the lesion cavity was observed consistent with eschar formation. At 23.3 mJ, the lesion width was approximately 350 microm and depth 1 mm. In this configuration, the cavities were spaced approximately 500 microm apart and interlesional epidermis and dermis demonstrated viable tissue by LDH staining. CONCLUSION: A novel prototype ablative CO(2) laser device operating in a fractional mode was developed and its resultant thermal effects in human abdominal tissue were characterized. We discovered that controlled microarray patterns could be deposited in skin with variable depths of dermal tissue ablation depending on the treatment pulse energy. This is the first report to characterize the successful use of ablative fractional resurfacing as a potential approach to dermatological treatment.     

Correlation of histological findings of single session Er:YAG skin fractional resurfacing with various passes and energies and the possible clinical implications

BACKGROUND AND OBJECTIVES: Ablative fractional resurfacing shows promise for skin resurfacing and tightening and also to improve treatment of epidermal and dermal pigmentary disorders. This study aimed at determining any correlation between epidermal ablation and effects on the dermis when using an Er:YAG laser in ablative fractional resurfacing mode. MATERIALS AND METHODS: Ten female subjects participated in the study, mean age 52 years, Skin phototypes: 1 Fitzpatrick type II; 8 type III and 1 type IV. The degree of wrinkles (Glogau scale II or III) was similar in all cases. The laser used was the Pixel Er:YAG system (Alma Lasertrade mark, Israel) which delivers the laser beam via a hand-piece equipped with a beam splitter to divide the 2,940 nm beam into various microbeams of 850 microm in diameter in an 11 mmx11 mm treatment area. Using a constant energy of 1,400 mJ/cm(2), on a test area of 4 cmx2 cm. Two, 4, 6, and 8 passes on the preauricular area of the face were evaluated immediately after treatment. In all cases, the handpiece was kept in the same position, and rotated slightly around its perpendicular axis between passes, then moved on to the next spot. Biopsies were performed and tissue samples were routinely processed and stained with hematoxylin and eosin (H&E). RESULTS: No patient reported any noticeable discomfort, even at 8 passes. The histological findings revealed that, independent of the degree of the wrinkles, more laser passes produced more ablative removal of the epidermis. Residual thermal damage (RTD) with 2 laser passes was not observed but with 4 and 6 passes increased thermal effects and vacuole formation in the epidermal cells were noticed. With 8 laser passes, total epidermal removal was seen together with frank RTD-related changes in the upper part of the papillary dermis. CONCLUSION: In this study, we have demonstrated that high density fractional Er:YAG laser energy in a single session with multiple passes targeted not only the skin surface with elimination of the epidermis, but could also achieve heat deposition in the upper dermis. When performing ablative fractional resurfacing with an Er:YAG laser, treatment of varying degrees of damage could be achieved by varying the number of passes.     

The prevalence and risk factors of post-inflammatory hyperpigmentation after fractional resurfacing in Asians

BACKGROUND: Ablative laser resurfacing is considered to be the main therapeutic option for the treatment of wrinkles and acne scarring. However, in Asians, post-inflammatory hyperpigmentation (PIH) is a common adverse effect of laser resurfacing. Fractional resurfacing is a new concept of skin rejuvenation whereby zones of micro thermal injury are generated in the skin with the use of a 1,540-nm laser. The risk and prevalence of hyperpigmentation in dark-skinned patients using this approach have not been studied. OBJECTIVE: To assess the prevalence and risk factors of PIH that is associated with the use of fractional resurfacing in Asians. METHOD: A retrospective study of 37 Chinese patients who were treated with fractional resurfacing for acne scarring, skin rejuvenation, and pigmentation was carried out. In all of the cases, pre- and post-treatment clinical photographs (from standardized and cross-polarized views) were taken using the Canfield CR system. Two independent observers assessed the photographs. A prospective study of treatments of nine different density and energy levels that were applied to the forearms of 18 volunteers was also performed. Clinical photographs were assessed pre- and post-treatment for evidence of PIH. RESULT: In the retrospective study, 119 treatment sessions were performed. Sixty-eight treatment sessions were high energy, low density; 51 sessions were low energy, high density. Patients who underwent a high energy but low-density treatment (range of energy 7-20 mJ; average energy 16.3 mJ, 1,000 MTZ) were associated with a lower prevalence of generalized PIH (7.1% vs. 12.4%) than those who underwent a low energy but high-density (range of energy 6-12 mJ; average energy 8.2 mJ, 2,000 MTZ) treatment. However, the difference was not statistically significant. Localized PIH occurred in the peri-oral area among patients who did not receive air cooling as an adjunctive therapy. CONCLUSION: Both the density and energy of the treatment determines the risk of PIH in dark-skinned patients. Density may be of more important but further studies are necessary to determine this. Cooling to prevent bulk tissue heating is also important, especially in small anatomical areas. By using adequate parameters, the risk of PIH in dark-skinned patients can be significantly reduced.     

Variable pulse erbium:YAG laser skin resurfacing of perioral rhytides and side-by-side comparison with carbon dioxide laser

BACKGROUND AND OBJECTIVE: Laser resurfacing of facial rhytides has become a popular treatment option for many patients with wrinkles, photoaging, and acne scarring. Laser wavelength/pulse duration options and new techniques continue to shorten the healing phase associated with laser skin resurfacing while maintaining clinical efficacy. Variable pulse erbium:YAG (Er:YAG) laser systems are now available that offer the surgeon the ability to vary the Er:YAG pulse duration from a pulse that is primarily ablative to one that is more thermal. The objective of this study was to evaluate the histologic effects created with a variable pulse Er:YAG laser. To study prospectively the clinical effects on upper lip rhytides with a variable pulse Er:YAG laser when compared side by side with pulsed carbon dioxide (CO(2)) laser resurfacing. STUDY DESIGN/MATERIALS AND METHODS: Forty-two treatment sites on 21 patients were randomized and evaluated after treatment of the upper lip region with CO(2) laser resurfacing on one side and a variable pulse Er:YAG laser on the other. Patient diaries were maintained to assess erythema, crusting, pain, and pigmentary changes. Blinded objective grading of improvement was performed. Chromometer measurements were obtained to analyze erythema. RESULTS: The variable pulse Er:YAG laser treatment reduced the duration of crusting on average from 7.7 days with CO(2) to 3.4 days. Chromometer measurements noted decreased postoperative erythema. Grading by physicians in a blinded manner showed 63% improvement for the CO(2) treatment site and 48% improvement in the variable pulse Er:YAG site. No cases of permanent hyperpigmentation, hypopigmentation, or scarring occurred. CONCLUSION: The variable pulse Er:YAG laser resurfacing is a safe and effective resurfacing tool, which combines ablative and thermal modalities. The protocol used in this study approaches but does not equal the results we have traditionally seen with CO(2) laser resurfacing.     

超脉冲CO_2激光治疗眼睑缘痣细胞痣的疗效观察

目的：探讨超脉冲CO2激光治疗眼睑缘痣细胞痣的疗效与安全性。方法：使用超脉冲CO2激光治疗仪在眼罩保护,局部注射麻醉下,采用能量18～35mJ/cm2,频率20～30Hz治疗眼睑缘痣细胞痣42例。结果：随访3个月后其中39例皮损完全消退,无复发,3例皮损明显缩小,残留芝麻大小黑点,再次治疗后皮损消失。总有效率100%,患者满意,无不良反应及副作用。结论：采用超脉冲CO2激光治疗眼睑缘痣细胞痣操作简单、安全,效果显著,无副作用。     

Safe and Effective One-Session Fractional Skin Resurfacing Using a Carbon Dioxide Laser Device in Super-Pulse Mode: A Clinical and Histologic Study

Carbon dioxide (CO₂) laser ablative fractional resurfacing produces skin damage, with removal of the epidermis and variable portions of the dermis as well as associated residual heating, resulting in new collagen formation and skin tightening. The nonresurfaced epidermis helps tissue to heal rapidly, with short-term postoperative erythema. The results for 40 patients (8 men and 32 women) after a single session of a fractional CO₂ resurfacing mode were studied. The treatments included resurfacing of the full face, periocular upper lip, and residual acne scars. The patients had skin prototypes 2 to 4 and wrinkle degrees 1 to 3. The histologic effects, efficacy, and treatment safety in various clinical conditions and for different phototypes are discussed. The CO₂ laser for fractional treatment is used in super-pulse mode. The beam is split by a lens into several microbeams, and super-pulse repetition is limited by the pulse width. The laser needs a power adaptation to meet the set fluence per microbeam. Laser pulsing can operate repeatedly on the same spot or be moved randomly over the skin, using several passes to achieve a desired residual thermal effect. Low, medium, and high settings are preprogrammed in the device, and they indicate the strength of resurfacing. A single treatment was given with the patient under topical anesthesia. However, the anesthesia was injected on areas of scar tissue. Medium settings (2 Hz, 30 W, 60 mJ) were used, and two passes were made for dark skins and degree 1 wrinkles. High settings (2 Hz, 60 W, 120 mJ) were used, and three passes were made for degree 3 wrinkles and scar tissue. Postoperatively, resurfaced areas were treated with an ointment of gentamycin, Retinol Palmitate, and DL-methionine (Novartis; Farmaceutics, S.A., Barcelona, Spain). Once epithelialization was achieved, antipigment and sun protection agents were recommended. Evaluations were performed 15 days and 2 months after treatment by both patients and clinicians. Treatment improved wrinkle aspect and scar condition, and no patient reported adverse effects or complications, irrespective of skin type, except for plaques of erythema in areas that received extra laser passes, which were not seen at the 2-month assessment. The results evaluated by clinicians were very much in correlation with those of patients. Immediately after treatment, vaporization was produced by stacked pulses, with clear ablation and collateral heat coagulation. An increased number of random pulses removed more epidermis, and with denser pulses per area, a thermal deposit was noted histologically. At 2 months, a thicker, multicelluar epidermis and an evident increase in collagen were observed. Fractional CO₂ laser permits a variety of resurfacing settings that obtain safe, effective skin rejuvenation and correct scar tissue in a single treatment.     

The effects of pulse energy variations on the dimensions of microscopic thermal treatment zones in nonablative fractional resurfacing

BACKGROUND AND OBJECTIVES: We examined the effects of pulse energy variations on the dimensions of microscopic thermal injury zones (MTZs) created on human skin ex vivo and in vivo using nonablative fractional resurfacing. MATERIALS AND METHODS: A Fraxel SR laser system emitting at 1,550 nm provided an array of microscopic spots at variable densities. Pulse energies ranging from 4.5 to 40 mJ were tested on human abdominal skin ex vivo and in vivo. Tissue sections were stained with hematoxylin and eosin (H&E) or nitro blue tetrazolium chloride (NBTC) and MTZ dimensions were determined. Ex vivo and in vivo results were compared. Dosimetry analyses were made for the surface treatment coverage calculation as a function of pulse energy and collagen coagulation based on H&E stain or cell necrotic zone based on NBTC stain. RESULTS: Each MTZ was identified by histological detection of a distinct region of loss of tissue birefringence and hyalinization, representing collagen denaturation and cell necrosis within the irradiated field immediately, 1, 3, and 7 days after treatment. At high pulse energies, the MTZ depth could exceed 1 mm and width approached 200 microm as assessed by H&E. NBTC staining revealed viable interlesional tissue. In general, no statistically significant difference was found between in vivo and ex vivo depth and width measurements. CONCLUSIONS: The Fraxel SR laser system delivers pulses across a wide range of density and energy levels. We determined that increases in pulse energy led to increases in MTZ depth and width without compromising the structure or viability of interlesional tissue.     

Risk assessment of excess drug and sunscreen absorption via skin with ablative fractional laser resurfacing

The ablative fractional laser is a new modality used for surgical resurfacing. It is expected that laser treatment can generally deliver drugs into and across the skin, which is toxicologically relevant. The aim of this study was to establish skin absorption characteristics of antibiotics, sunscreens, and macromolecules via laser-treated skin and during postoperative periods. Nude mice were employed as the animal model. The skin received a single irradiation of a fractional CO₂ laser, using fluences of 4–10 mJ with spot densities of 100–400 spots/cm². In vitro skin permeation using Franz cells was performed. Levels of skin water loss and erythema were evaluated, and histological examinations with staining by hematoxylin and eosin, cyclooxygenase-2, and claudin-1 were carried out. Significant signs of erythema, edema, and scaling of the skin treated with the fractional laser were evident. Inflammatory infiltration and a reduction in tight junctions were also observed. Laser treatment at 6 mJ increased tetracycline and tretinoin fluxes by 70- and 9-fold, respectively. A higher fluence resulted in a greater tetracycline flux, but lower skin deposition. On the other hand, tretinoin skin deposition increased following an increase in the laser fluence. The fractional laser exhibited a negligible effect on modulating oxybenzone absorption. Dextrans with molecular weights of 4 and 10 kDa showed increased fluxes from 0.05 to 11.05 and 38.54 μg/cm²/h, respectively. The optimized drug dose for skin treated with the fractional laser was 1/70–1/60 of the regular dose. The skin histology and drug absorption had recovered to a normal status within 2–3 days. Our findings provide the first report on risk assessment of excessive skin absorption after fractional laser resurfacing.     

Fractional Photothermolysis for Photoaging of Hands

BACKGROUND Laser treatment for photoaging of the hands should ideally address pigmentary alteration as well as associated skin roughness and wrinkling. Fractional resurfacing has been previously shown to effectively treat facial rhytids and dyschromia.
OBJECTIVE We examined the effect of fractional resurfacing for photoaging of the hands.
METHODS AND MATERIALS Ten patients (skin phototypes II to IV) with hand photodamage were randomized to receive five treatments with a 1,550-nm diode-pumped erbium fiber laser (Fraxel SR, Reliant Technologies) laser on either the right or left hand. Treatments were performed at settings of 8 to 9 mJ/microscopic treatment zone and density of 2,500 microscopic treatment zones/cm². Subjective assessments by the patients and investigator were performed for skin roughness, wrinkling, and pigmentation using a 5-point scale. Skin biopsies were taken at baseline and at 1 and 3 months.
RESULTS Patient subjective assessment and physician clinical assessment at 1 and 3 months revealed a mean 51% to 75% improvement in skin pigmentation and 25% to 50% improvement in skin roughness and wrinkling. Biopsies of the skin showed increased density of dermal collagen. Patients experienced transient erythema and edema and none had scarring or other adverse effects.
LIMITATIONS This was a small study.
CONCLUSION Fractional resurfacing appears to be an effective and safe treatment modality for correcting both the pigmentary and the textural aspects of photoaging of the hand.     

Laser skin resurfacing using a frequency doubled Nd:YAG laser after topical application of an exogenous chromophore.

BACKGROUND AND OBJECTIVES: Although laser skin resurfacing performed with CO(2) or Er:YAG lasers is efficient, side effects such as prolonged postoperative erythema, delayed healing, scarring, and pigmentation, have been reported. These side effects are due to skin characteristics but also to variations of the thermal effects associated with laser skin resurfacing. The study aimed to evaluate a new laser resurfacing method based on a previous topical application of an exogenous chromophore in order to have reproducible thermal effects. MATERIALS AND METHODS: Exogenous chromophore consisted in carbon dispersed and mixed with film-forming polymers and water. The resultant solution was applied to the skin surface using an airbrush. Experimental evaluation was performed in vivo on hairless rat skin using the following parameters (532 nm, 2.7 W, 1 mm, 50-200 ms, 17.2-68.8 J/cm(2), single pass). Skin biopsies were taken to evaluate histological changes and to quantify epidermis ablation and dermal coagulation depth. Wound healing was followed up during 10 days. RESULTS: Total epidermis ablation was achieved with all pulse durations used. Dermal coagulation depth increased as a function of exposure time. Scar formation was correlated with dermal coagulation depth. CONCLUSION: The concept of applying a carbon-based solution onto skin in order to obtain laser light conversion into heat followed by heat transfer to the tissue is valid for laser skin resurfacing. By selecting exposure time, the thermal effects are predictable and dermal coagulation depth can be either that observed with a Er:YAG laser or that obtained with a CO(2) laser. Moreover, frequency doubled Nd:YAG laser, already used in dermatology for angiodysplasias treatment, could be easily used for resurfacing of periorbital or perioral zones.     

Application of reflectance confocal microscopy to evaluate skin damage after irradiation with an yttrium-scandium-gallium-garnet (YSGG) laser

The objective of this study was to observe the characteristics of the skin after irradiation with a 2790-nm yttrium-scandium-gallium-garnet (YSGG) laser using reflectance confocal microscopy (RCM). A 2790-nm YSGG laser was used to irradiate fresh foreskin (four doses, at spot density 3) in vitro. The characteristics of microscopic ablative columns (MAC), thermal coagulation zone (TCZ), and microscopic treatment zones (MTZ) were observed immediately after irradiation using digital microscope and RCM. The characteristics of MAC, TCZ, and MTZ with variations in pulse energy were comparatively analyzed. After irradiation, MAC, TCZ, and MTZ characteristics and undamaged skin between MTZs can be observed by RCM. The depth and width of MTZ obviously increased with the increase in pulse energy. At 80, 120, and 160 mJ/microbeam (MB), the MTZ actual area and proportion were about two times that of the theoretical value and three times at 200 mJ/MB. With increases in depth, the single MAC gradually decreased in a fingertip-shaped model, with TCZ slowly increasing, and MTZ slightly decreasing in a columnar shape. RCM was able to determine the characteristics of thermal injury on the skin after the 2790-nm YSGG laser irradiation with different pulse energies. Pulse energy higher than 200 mJ/MB may have much larger thermal injury and side effect. RCM could be used in the clinic in future.     

Use of a novel erbium laser in a Yucatan minipig: a study of residual thermal damage, ablation, and wound healing as a function of pulse duration

BACKGROUND AND OBJECTIVE: Theoretical models show that varying pulse duration influences residual thermal damage in erbium YAG skin resurfacing. Accordingly, our objective was to compare residual thermal damage, ablation, tissue shrinkage, and wound healing between a variable pulsewidth erbium YAG laser and a popular CO2 resurfacing laser. STUDY DESIGN/MATERIALS AND METHODS: The erbium laser delivered a typical ablative pulse (250 microseconds), followed by a heating pulse of variable duration. Pulse durations for specific coagulation depths were selected based on existing heat transfer models. The bilateral flanks of one Yucatan pig were irradiated. Eight sites were treated per group. Biopsies were performed just after treatment and 1, 3, 7, 21, and 60 days postoperatively. RESULTS: Just after irradiation, gross examination of "cold" (without a coagulation pulse) erbium sites showed a reddish papillary dermis consistent with conventional erbium laser ablation. Two and three pass CO2 sites showed uniform surface yellowing. The longer pulsewidth ("hot") erbium groups showed only slight surface yellowing. Biopsies showed immediate thermal damage that increased with erbium pulse duration; however, actual residual thermal damage (RTD) was sometimes less than that predicted by the laser control panel. All wounds healed uneventfully by 14 days. CONCLUSIONS: An erbium laser with a variable macropulse pulsewidth was capable of achieving RTD of up to 80 mum. Even greater RTD depths may be obtainable with future manipulations of fluence and pulse duration.     

Results of fractional ablative facial skin resurfacing with the erbium:yttrium-aluminium-garnet laser 1 week and 2 months after one single treatment in 30 patients

The erbium:yttrium-aluminium-garnet (Er:YAG) laser has recently been used in the fractional resurfacing of photo-aged skin. Our study evaluated the results after one single session of fractional resurfacing with Er:YAG. Thirty women participated in the study, with an average age of 46 years, skin types from II to IV, and wrinkle grades I to III. The 2,940 nm Er:YAG system used (Pixel, Alma Laser, Israel) had variable pulse durations (1 ms to 2 ms) and energy densities (800 mJ/cm(2) to 1,400 mJ/cm(2)) which, together with the number of passes (four to eight), were selected as a function of wrinkle severity. All patients received only one treatment. Postoperative side effects were evaluated. The number of wrinkles was documented with clinical photography and was scored. Histological assessment was carried out on two patients before and 2 months after treatment. All patients completed the study. Of the patients, 93% reported good or very good improvement of the degree of their wrinkles, with a satisfaction index of 83%. Pain was not a problem during treatment, and there were no side effects except for in one phototype IV patient, who had hyperpigmentation. Histology 2 months after the single treatment demonstrated younger morphology of both the epidermis and dermis, with improvement of the pretreatment typical elastotic appearance. At the parameters used in our study, only one treatment session of Er:YAG laser could achieve effective skin rejuvenation, with effects recognized in both the dermis and, more importantly, the epidermis. This regimen offers an interesting alternative to the conventional approach of multi-session fractional resurfacing.     

点阵模式激光在瘢痕治疗中的临床应用

目的 评价两种剥脱性点阵模式激光治疗浅表瘢痕的安全性及有效性.方法 共88例患者,其中痤疮瘢痕66例,烧伤瘢痕12例,其他瘢痕10例.所有患者均经以下任何一种治疗:像柬激光≥3次;或点阵激光≥2次;或像束激光+点阵激光综合治疗≥3次.治疗过程中视病情需要配合应用脉冲染料激光抑制瘢痕增生,减轻红斑.结果 本组共88例,瘢痕改善程度评价标准:改善程度>25%视为有效,>50%视为显效,本组患者显效率50%(44/88),有效治疗达80%(70/88).像束激光治疗共244人次,点阵激光治疗共86人次,色素沉着共7例,均在半年内消退,无其他严重并发症.结论 点阵模式的激光治疗创伤小,风险低,是治疗浅表瘢痕,尤其是痤疮瘢痕的有效手段,其作用的机制包括组织气化、磨削作用及热损伤带来的促进组织修复的强大动力.     

Application of reflectance confocal microscopy to investigate the non-ablative,micro-ablative,and ablative effects of CO2 fractional laser irradiation on skin

Lasers in Medical Science - CO2 fractional laser, as an ablative fractional laser, is commonly used in cosmetic treatment. We applied CO2 fractional laser irradiation to skin in vitro and used...     

Laser skin rejuvenation: epidermal changes and collagen remodeling evaluated by in vivo confocal microscopy

Fractionated carbon dioxide (CO₂) laser resurfacing is an effective treatment of skin aging. Several studies investigated the morphologic changes due to this laser treatment by using skin biopsies or animal model. Recently, reflectance confocal microscopy (RCM) has emerged as a new tool that can “optically” scan the skin in vivo with a nearly histologic resolution and in a totally noninvasive modality. Our study aims to analyze the skin changes following the ablative fractional CO₂ laser sessions by using RCM. Ten patients were subjected to ablative fractional CO₂ laser sessions for skin aging. Confocal microscopic images were acquired at baseline (w0), 3 weeks (w3), 6 weeks (w6), and 12 weeks (w12) after laser session. Previously identified confocal parameters were used to assess the skin aging at baseline and after treatment. At w3, the epidermis showed a complete disappearance of the mottled pigmentation upon RCM along with the presence of few Langherans’ cells. The collagen type as seen upon RCM observed at baseline was replaced by a newly formed collagen type of long, bright and straight fibers (collagen remodeling). These fibers were parallel arranged and observed throughout the entire RCM mosaic. At w6 and w12 the confocal aspects of the skin was unchanged compared to w3. RCM confirmed the presence of an intense collagen remodeling following laser resurfacing. In line with previous studies, this collagen showed a peculiar arrangement and distribution. The collagen remodeling was still present after 3 months and confirms the long-term effect of the treatment. This is the first time that the skin can be analyzed in vivo at patient’s bedside. In the near future, RCM can be an essential adjunct for Clinicians to measure the effects of laser treatment and possibly to gain new insights into the development of side effects.     

Novel Use of Erbium:YAG (2,940-nm) Laser for Fractional Ablative Photothermolysis in the Treatment of Photodamaged Facial Skin: A Pilot Study

BACKGROUND The use of CO₂ or conventional erbium laser ablation or more recent nonablative laser photothermolysis for skin rejuvenation is associated with significant disadvantages.
OBJECTIVE The objective was to assess the efficacy of the erbium:YAG laser (2,940 nm) using the "ablative" fractional resurfacing mode to improve photodamaged skin.
METHODS A total of 28 patients, 27 women and 1 man, aged 28 to 72 years (mean age, 54.2 years), with Fitzpatrick Skin Types II to IV, were treated for mild to moderate actinic damage using fractional erbium:YAG laser (2,940 nm) combined with Pixel technology. Sessions were scheduled at 4-week intervals. Response to treatment was evaluated by two physicians on a five-tiered scale.
RESULTS Patients underwent one to four treatment sessions (mean, 3.2). The initial reaction consisted of erythema and minimal swelling. On clinical assessment 2 months after the final treatment, the results were rated excellent by 21 patients (75%) and good by 7 (25%). Nineteen of the 21 were also evaluated 6 to 9 months after final treatment without any significant change in the results.
CONCLUSIONS Fractional ablative photothermolysis using erbium:YAG laser (2,940 nm) is a promising option for skin resurfacing with reduced risk and downtime compared to existing laser methods.     

Micro-fractional ablative skin resurfacing with two novel erbium laser systems

BACKGROUND AND OBJECTIVES: Fractional ablation offers the potential benefits of full-surface ablative skin resurfacing while minimizing adverse effects. The purpose of this study was to evaluate the safety, damage profile, and efficacy of erbium fractional lasers. MATERIALS AND METHODS: Histology from animal and human skin as well as clinical evaluations were conducted with erbium YAG (2,940 nm) and erbium YSGG (2,790 nm) fractional lasers varying pulse width, microbeam (microb) energy, number of passes, and stacking of pulses. RESULTS: Single-pulse treatment parameters from 1 to 12 mJ per 50-70 microm diameter microbeam and 0.25-5 milliseconds pulse widths produced microcolumns of ablation with border coagulation of up to 100 microm width and 450 microm depth. Stacking of pulses generated deeper microcolumns. Clinical observations and in vivo histology demonstrate rapid re-epithelization and limited adverse side effects. Facial treatments were performed in the periorbital and perioral areas using 1-8 passes of single and stacked pulses. Treatments were well-tolerated and subjects could resume their normal routine in 4 days. A statistically significant reduction in wrinkle scores at 3 months was observed for both periorbital and perioral wrinkles using blinded grading. For periorbital treatments of four passes or more, over 90% had > or =1 score wrinkle reduction (0-9 scale) and 42% had > or =2. For perioral wrinkles, over 50% had substantial improvements (> or =2). CONCLUSION: The clinical observations and histology findings demonstrate that micro-fractional ablative treatment with 2,790 and 2,940 nm erbium lasers resulted in safe and effective wrinkle reduction with minimal patient downtime. The depth and width of the ablated microcolumns and varying extent of surrounding coagulation can be controlled and used to design new treatment procedures targeted for specific indications and areas such as moderate to severe rhytides and photodamaged skin.     

Fractional photothermolysis—an update

The novel concept of non-ablative fractional photothermolysis was introduced to the market in 2003 as an answer to the need for effective, yet low risk, resurfacing techniques. Unlike conventional ablative and non-ablative lasers, fractional ablative and non-ablative photothermolysis treats only a fraction of the skin, leaving up to a maximum of 95% of the skin uninvolved. The undamaged surrounding tissue allows for a reservoir of viable tissue, permitting rapid epidermal repair. Non-ablative fractional photothermolysis is currently approved by the US Food and Drug Administration (FDA) for the treatment of pigmented lesions, periorbital rhytides, skin resurfacing, melasma and soft tissue coagulation, acne and surgical scars, and actinic keratoses. However, its off-label use is clearly more extended. In 2007 the concept was further developed, and ablative fractional photothermolysis was introduced, using an erbium yttrium aluminium garnet (Er:YAG) or carbon dioxide laser. These devices are FDA cleared to treat wrinkles, rhytides, furrows, fine lines, textural irregularities, pigmented lesions and vascular dyschromia. In this review we discuss the two concepts, their technical details and clinical indications, and we describe the current literature available.     

Laser techniques associated with facial aesthetic and reparative surgery

Chronological aging is a natural biological event that is seen particularly in the face. Attempts to correct the results of this facial loss of structural form are sometimes successful. The skin itself is usually neglected, and surgery sometimes fails to achieve the goals expected by the patient. The surgical laser offers an extremely elegant and powerful solution to this problem to complement or enhance the results of selected surgical facial aesthetic procedures as follows: (1) ablative full-face CO2 laser resurfacing in combination with facelifting; (2) laser surgical technique for upper eyelid ptosis; (3) lower eyelid blepharoplasty with the aid of the CO2 laser; (4) full-face resurfacing following minilifting of the lower part of the face; (5) endoscopic eyebrow lifting combined with laser resurfacing; (6) perioral CO2 laser resurfacing in combination with facelifting; and (7) several miscellaneous procedures (e.g., treatment of upper and lower xanthelasma with laser upper blepharoplasty, laser resurfacing in combination with fillers, and laser resurfacing of periocular wrinkles after surgical blepharoplasty). In the hands of the authors, the combination of laser and standard surgical procedures presented herein has consistently produced good results and high patient satisfaction. The complication rate is low and the recovery rate is excellent. Laser treatment enhances the natural look obtained by conventional surgeries.