In vivo histological evaluation of a novel ablative fractional resurfacing device

Treatment of split-thickness skin graft-related forearm scar contractures with a carbon dioxide laser protocol: 3 case reports

Split-thickness skin grafts in the forearm can lead to motion restriction and disability through the dense scarring of the skin and formation of graft-tendon adhesions. Three patients were referred for laser treatment of motion-limiting scar-associated split-thickness skin grafts to the forearm. All patients had reached a plateau in range of motion despite aggressive hand therapy and underwent serial laser scar treatments at 6- to 8-week intervals. Treatments were performed in a clinic setting and were initiated 2 to 5 months after reconstructive surgery. Rapid subjective functional and objective improvements in range of motion were noted after laser therapy. Results were cumulative and durable at final follow-up ranging from 10 to 15 months after the initial treatment. No complications were noted. Fractionated carbon dioxide laser therapy is a promising adjunct to hand therapy when the main restraint to motion is superficial skin scarring and skin-tendon adhesions.

Fractionated ablative carbon dioxide laser for the treatment of rhinophyma

BACKGROUND

Rhinophyma is a progressive and disfiguring proliferative disorder of the nose, which is related to chronic rosacea. Many different treatment modalities have been utilized both alone and in combination including: loop cautery, CO2 laser, argon laser, dermabrasion, cryotherapy, radiotherapy, full-thickness excision, skin graft, flap reconstruction, and cold scalpel. CO2 resurfacing has been considered first line therapy but is often associated with a shiny, scarred appearance, with patulous pores, and with loss of pigmentation. We report a technique using aggressive parameters with the fractionated ablative CO2 laser, resulting in improvement of appearance with very few complications.

MATERIALS AND METHODS

Five patients who presented with rhinophyma of varying degrees were treated with a series of fractional ablative CO2 laser treatments (Fraxel re:Pair, Solta Medical, Hayward, CA). These patients were treated with settings of up to 70 mJ, 70% density and 16-18 passes. All patients received HSV prophylaxis using either acyclovir 400 mg TID or valacyclovir 500 mg BID. Patients were rendered anesthetic by 1% lidocaine and epinephrine regional perinasal nerve block.

RESULTS

All of the patients tolerated the procedure well with reepithelialization at days 4-7 and self-limited edema and erythema. Patients with relatively early to moderate signs of rhinophyma proved optimal candidates for this treatment. There were no adverse events. Patients and physicians noted significant improvement and reduction in the rhinophyma without the typical scarring noted with most other treatments.

CONCLUSION

Rhinophyma treated with fractionated ablative CO2 laser using relatively aggressive parameters achieved good cosmetic outcomes in this group of early to moderate cases of rhinophyma, while still retaining the benefits of a fractionated treatment such as faster healing times and fewer adverse events.

Current status of surgery in dermatology

An article titled "Current issues in dermatologic office-based surgery" was published in the JAAD in October 1999 (volume 41, issue 4, pp. 624-634). The article was developed by the Joint American Academy of Dermatology/American Society for Dermatologic Surgery Liaison Committee. A number of subjects were addressed in the article including surgical training program requirements for dermatology residents and selected advances in dermatologic surgery that had been pioneered by dermatologists. The article concluded with sections on credentialing, privileging, and accreditation of office-based surgical facilities. Much has changed since 1999, including more stringent requirements for surgical training during dermatology residency, and the establishment of 57 accredited Procedural Dermatology Fellowship Training Programs. All of these changes have been overseen and approved by the Residency Review Committee for Dermatology and the Accreditation Committee for Graduate Medical Education. The fertile academic environment of academic training programs with interaction between established dermatologic surgeons and fellows, as well as the inquisitive nature of many of our colleagues, has led to the numerous major advances in dermatologic surgery, which are described herein.

Characterization of microthermal zones induced by fractional radiofrequency using reflectance confocal microscopy: a preliminary study

BACKGROUND

The microthermal zone (MTZ) produced by fractional device have been mostly evaluated through histopathologic analysis. Study of ablative type MTZ created by fractional device and skin thermal interaction using in vivo reflectance confocal microscopy (RCM) has been rarely reported.

OBJECTIVES

We evaluated the in vivo human RCM skin images of ablated fractional radiofrequency (RF) treatment to demonstrate the thermal interaction between RF and skin tissue.

SUBJECTS AND METHOD

Three healthy male subjects underwent a single irradiation of fractional RF on the upper back area. The diameter, area, and depth of the MTZ was measured using RCM. Three female domestic swine were used for comparative histopathological study.

RESULTS

After RF treatment, crusted holes surrounding pale edematous rings were visible in RCM images. The empty spaces correlated to the location of ablative channels, and the presence of thermal modification zones corresponded to areas with a whitish ring showing high reflectance. Ablation depth increased in proportion to the energy of fractional RF. However, the diameter of the thermal modified zone was relatively constant regardless of RF energy.

CONCLUSIONS

RCM successfully identified in vivo acute thermal changes after fractional RF. The results obtained in this study provide a clearer picture of tissue-thermal interactions in the skin.

Treatment of lymphangioma circumscriptum using fractional carbon dioxide laser ablation

Lymphangioma circumscriptum remains a challenging entity to treat given anatomic considerations and a significant tendency for recurrence regardless of the modality selected. Surgical excision offers the greatest potential for definitive management but is often beset by procedural morbidity and suboptimal cosmetic outcomes. A range of palliative options have been reported for the treatment of lymphangioma circumscriptum, with varying degrees of associated efficacy and morbidity. This report describes the novel use of fractional carbon dioxide laser ablation for the treatment of lymphangioma circumscriptum, with promising cosmetic results and durable symptomatic relief.

Fractional CO2 resurfacing: has it replaced ablative resurfacing techniques?

The author uses the pulsed ablative CO2 laser regularly for skin rejuvenation. This decision is based on the gold standard status of the CO2 modality and an innovative aftercare treatment shown in the author's practice to greatly reduce the complications of ablative pulsed CO2 laser treatment. Depending on the patient and the severity of the skin condition, the author customizes each treatment, which may also include fractional CO2 lasers, fat grafting, facelifting, or any combination of these techniques. This article presents a detailed description of the evolution of skin rejuvenation with lasers and the current role of lasers as an adjunct to face and necklift surgery.

A new multi-modal fractional ablative CO2 laser for wrinkle reduction and skin resurfacing

BACKGROUND

The concept of fractional delivery modality of the energy with both ablative and non-ablative devices is now well known and accepted as an effective method to attain significant aesthetic improvements on facial aging skin. A new, multi-modal, fractional, ablative CO2 laser that can create, using same scanner/handpiece, deep columns in addition to superficial ablation has been recently proposed and therefore investigated.

METHOD

Twenty-four patients were enrolled in this evaluation. Each of them received one multi-modal, fractional ablative treatment. Patients were clinically and photographically evaluated at baseline and 6 months after the procedure. The degree of photoaging and the efficacy of treatment were evaluated using a VAS five-point scale of some skin features. A 3D images comparison was furthermore performed to objectify the improvements.

RESULTS

For all of the analysed skin features of photodamage a significant, statistical improvement was obtained. The data collected with the 3D system demonstrated an average improvement of 42% of the wrinkles and an average improvement of the melanin variation of 40.1%.

CONCLUSIONS

The multi-modal approach with a single handpiece allows obtaining good outcomes with a very low incidence of adverse effects and a short downtime.

Ablative fractional resurfacing for the treatment of traumatic scars and contractures

After a decade of military conflict, thousands of wounded warriors have suffered debilitating and cosmetically disfiguring scars and scar contractures. Clearly, there is a need for effective scar treatment regimens to assist in the functional and cosmetic rehabilitation of these patients. Traditional treatments, including aggressive physical and occupational therapy and dedicated wound care, are essential. Adjunctive treatments with established laser technologies, such as vascular lasers and full-field ablative lasers, have had a somewhat limited role in scar contractures due to modest efficacy and/or an unacceptable side effect profile in compromised skin. Refractory scar contractures often require surgical revision, which can be effective, but is associated with additional surgical morbidity and a significant risk of recurrence. Furthermore, current scar treatment paradigms often dictate scar maturation for approximately a year to allow for spontaneous improvement before surgical intervention. Since 2009, the Dermatology Clinic at the Naval Medical Center San Diego has been treating scars and scar contractures in wounded warriors and others using ablative fractionated laser technology. Although traditionally associated with the rejuvenation of aged and photo-damaged skin, our clinical experience and a handful of early reports indicate that laser ablative fractional resurfacing demonstrates promising efficacy and an excellent side effect profile when applied to the functional and cosmetic enhancement of traumatic scars and contractures. This article discusses our clinical experience with ablative fractional resurfacing and its potential prominent role in rehabilitation from traumatic injuries, including a possible shift in scar treatment paradigms toward earlier procedural intervention. Potential benefits include the optimization of scar trajectory and higher levels of full or adapted function in a more favorable time course.

Fractionation: past, present, future

The development of fractional photothermolysis is a milestone in the history of laser technology and cutaneous resurfacing. Based on the concept that skin is treated in a fractional manner, where narrow cylinders of tissue are thermally heated and normal adjacent skin is left unaffected, the fractional devices have shown effectiveness in treating a variety of conditions. Since its development, we are becoming more adept at using optimal parameters to induce near carbon dioxide laser benefits with a much more comfortable postoperative period and fewer complications. The future remains bright for fractionated laser devices and with new devices and wavelengths, the applications of this technology continue to grow.

Treatment of hypertrophic scars using laser and laser assisted corticosteroid delivery

BACKGROUND AND OBJECTIVES

Hypertrophic scars and contractures are common following various types of trauma and procedures despite skilled surgical and wound care. Following ample time for healing and scar maturation, many millions of patients are burdened with persistent symptoms and functional impairments. Cutaneous scars can be complex and thus the approach to therapy is often multimodal. Intralesional corticosteroids have long been a staple in the treatment of hypertrophic and restrictive scars. Recent advances in laser technology and applications now provide additional options for improvements in function, symptoms, and cosmesis. Fractional ablative lasers create zones of ablation at variable depths of the skin with the subsequent induction of a wound healing and collagen remodeling response. Recent reports suggest these ablative zones may also be used in the immediate post-operative period to enhance delivery of drugs and other substances. We present a case series evaluating the efficacy of a novel combination therapy that incorporates the use of an ablative fractional laser with topically applied triamcinolone acetonide suspension in the immediate post-operative period.

METHODS

This is a prospective case series including 15 consecutive subjects with hypertrophic scars resulting from burns, surgery or traumatic injuries. Subjects were treated according to typical institutional protocol with three to five treatment sessions at 2- to 3-month intervals consisting of fractional ablative laser treatment and immediate post-operative topical application of triamcinolone acetonide suspension at a concentration of 10 or 20 mg/ml. Three blinded observers evaluated photographs taken at baseline and six months after the final treatment session. Scores were assigned using a modified Manchester quartile score to evaluate enhancements in dyschromia, hypertrophy, texture, and overall improvement.

LIMITATIONS

Small sample size and lack of a control arm.

RESULTS

Combination same session laser therapy and immediate post-operative corticosteroid delivery resulted in average overall improvement of 2.73/3.0. Dyschromia showed the least amount of improvement while texture showed the most improvement.

CONCLUSION

Combination same-session therapy with ablative fractional laser-assisted delivery of triamcinolone acetonide potentially offers an efficient, safe and effective combination therapy for challenging hypertrophic and restrictive cutaneous scars.

Treatment of cosmetic tattoos using carbon dioxide ablative fractional resurfacing in an animal model: a novel method confirmed histopathologically

BACKGROUND

Treating cosmetic tattoos using quality-switched lasers is difficult.

OBJECTIVE

We used carbon dioxide ablative fractional resurfacing (CO2 AFR) to remove cosmetic tattoos and examined the pathophysiologic mechanisms involved in this technique in an animal model.

METHODS AND MATERIALS

Twelve rats were tattooed on their backs with white and flesh-colored pigments. Half of each tattoo was treated with CO2 AFR (5 sessions at 1-month intervals), and the other half was the untreated control. An independent observer reviewed photographic documentation of clinical response. Serial skin samples obtained at baseline and at various times after laser treatment were evaluated using histologic and immunohistochemical methods.

RESULTS

Four rats had excellent responses to laser treatment and eight had good responses. White and flesh-colored tattoos had similar clearance rates and tissue reactions. Histologic analysis showed immediate ablation of tattoo pigments in the microscopic ablation zones. Tattoo pigments in the microscopic coagulation zones migrated to the epidermis and became part of the microscopic exudative necrotic debris appearing on day 2 that was exfoliated after 5 days. Increased fibronectin expression around the microscopic treatment zones during the extrusion of tattoo pigments indicated that wound healing facilitates this action.

CONCLUSION

CO2 AFR successfully removes cosmetic tattoos.

Ablative fractional resurfacing in topical drug delivery: an update and outlook

BACKGROUND

The effective delivery of therapeutic molecules to varied targets in the skin and elsewhere has been an area of ongoing research and development.

OBJECTIVE

To review the structure of the skin with an emphasis on topical drug delivery and to present the rationale for the use of ablative and nonablative fractional resurfacing in assisted drug delivery.

METHODS AND MATERIALS

Review of the currently available scientific literature on laser-assisted drug delivery.

RESULTS

A number of strategies can be employed to enhance topical drug delivery. Ablative fractional resurfacing (AFR) has been demonstrated to be effective in enhancing drug delivery. Further studies are needed to assess the use of nonablative fractional resurfacing in assisted drug delivery.

CONCLUSION

AFR-assisted drug delivery is a promising tool for the future of dermatology. We expect to see a number of agents to be paired with AFR for enhanced drug delivery. Further investigation is necessary to evaluate appropriate drug specific channel density and depth parameters. Factors that must be considered include the physicochemical properties of the drug, the target tissue, skin wounding, and cost when evaluating the drugs and conditions that will most benefit from this promising new drug delivery system.

Efficacy and safety evaluation of an innovative CO2 laser/radiofrequency device in dermatology

BACKGROUND

CO2 laser has not only become the most widely used laser in dermatological surgical practice, but it has also proved to be highly effective in treating aesthetic imperfections.

OBJECTIVE

To examine the efficacy and safety of a novel fractional CO2 laser combined with a radiofrequency device in different dermatological, surgical and aesthetic fields.

METHODS

A total of 79 patients were treated in our Outpatient Service with a novel fractional CO2 laser combined with a bipolar radiofrequency device for a maximum of 5 months. Group A consisted of 39 patients with lesions requiring complete excision, whereas Group B consisted of 40 subjects seeking to enhance aesthetic facial imperfections. The results were assessed by three 'blind' investigators using photographs and clinical observations; in addition, the patients had to give their own subjective assessment of the results.

RESULTS

At the 6-month follow-up, the lesions of the Group A patients had been completely removed, except for one case of a large sebaceous nevus on the scalp. All the Group B patients showed global improvement in skin tightening, removal of fine lines and rhytides and correction of dilated pores and hyperpigmentation, with no significant side-effects and short downtimes.

CONCLUSION

This kind of laser meets the needs of the majority of dermatologists requiring a unique, versatile tool to remove cutaneous lesions and at the same time, safely and effectively treat skin imperfections.

Fractionated carbon dioxide laser treatment of photoaging: prospective study in 45 patients and review of the literature

BACKGROUND

Ablative fractional photothermolysis (AFP) has been reported to be effective for photoaging.

OBJECTIVE

To perform a clinical trial in 45 patients with moderate to severe skin photoaging to quantify improvement with AFP.

MATERIALS AND METHODS

A prospective, single-blind study in 45 patients who presented for desired treatment of photoaging. Patients received a series of two to three treatments with AFP.

RESULTS

Thirty-nine women (86.7%) and six men (13.3%) were enrolled. Patients received two or three treatment sessions (mean 2.4). There were no incidence of adverse events of scarring, prolonged erythema (lasting more than 7 days), postinflammatory hyper- or hypopigmentation, or infection in the 108 treatment sessions given during this study. Mean improvement was 48.5% (95% confidence interval (CI)=44.6-52.4%) for skin texture, 50.3% (95% CI=46.1-54.5%) for skin laxity, 53.9% (95% CI=49.5-58.5%) for dyschromia, and 52.4% (95% CI=47.9-56.9%) for overall cosmetic outcome (all p<.05).

CONCLUSIONS

Significant improvement in photoaging of the face can be achieved using an AFP device with skin types I to III after a series of two to three treatments.

Ablative fractionated CO2 laser treatment of photoaging: a clinical and histologic study

BACKGROUND

Ablative fractional photothermolysis (AFP) has been reported to be effective for changes in skin pigmentation and texture associated with photoaging.

METHODS

A prospective study for the treatment of photoaging using a fractionated ablative carbon dioxide laser in 10 subjects. Assessment of laser efficacy was made using two modalities: histologic examination of skin biopsies and blinded physician clinical photographic assessment. For the histologic portion of the study, patients were randomized to treatment with the device at settings of pulse durations of 500, 1,000, 1,500, and 1,800 μs. Depth of injury was assessed based on histologic evaluation of depth of thermal coagulation. For the clinical portion of the study, treatment was administered to the face using a carbon dioxide laser at settings of 30 W, 500-μm pitch (density of treatment equivalent to ablation of 25% of the skin), and variable pulse duration of 1,000 to 1,500 μs.

RESULTS

The mean score for dyschromia had improved 47.5% (95% confidence interval (CI) = 44.1-50.9%), for skin texture 56.0% (95% CI = 51.9-60.1%), for skin laxity 56.0% (95% CI = 51.3-60.7%), for rhytides 52.5% (95% CI = 48.3-56.7%) and for overall cosmetic outcome 61.5% (95% CI = 56.4%,66.6%) 6 months after treatment. Histologic data revealed a proportional increase in depth of thermal coagulation at each pulse duration. The mean ablation depth was 283 μm for a pulse duration of 500 μs, 375 μm for 1,000 μs, 767 μm for 1,500 μs, and 1.05 mm for 1,800 μs.

CONCLUSIONS

We present a histologic analysis documenting the correlation between longer pulse duration and ablation depth using an AFP device. We identified that pulse duration settings up to 1,800 μs could be used safely with an ablation depth up to 1.1 mm, correlating with injury into the deep reticular dermis.

Management of acne scarring, part I: a comparative review of laser surgical approaches

Acne scarring is the result of a deviation in the orderly pattern of healing and can have profound psychosocial implications for patients. While the most effective means of addressing acne scarring is to prevent its formation through good acne control, there are a number of therapeutic interventions that improve the appearance of acne scars. Many of these procedural modalities have flaws and are limited by operator skill and experience. Laser scar revision, on the other hand, is a precise, well tolerated procedure with clinically demonstrable efficacy and minimal adverse effects that may be used alone or in combination with other scar treatments. The last 20 years has seen a dramatic evolution in laser treatment of acne scars, spanning ablative and nonablative technologies, to the current popularity of fractional laser scar revision. Determining which laser system to use depends upon the type and severity of acne scarring, the amount of recovery a patient can tolerate, and the ultimate goals and expectations of each patient. The importance of proper acne scar classification, laser scar revision techniques, and the evidence that addresses each laser system is reviewed in this article.

Skin anti-aging strategies

Skin aging is a complex biological process influenced by a combination of endogenous or intrinsic and exogenous or extrinsic factors. Because of the fact that skin health and beauty is considered one of the principal factors representing overall "well-being" and the perception of "health" in humans, several anti-aging strategies have been developed during the last years. It is the intention of this article to review the most important anti-aging strategies that dermatologists have nowadays in hand, including including preventive measurements, cosmetological strategies, topical and systemic therapeutic agents and invasive procedures.

Random fractional ultrapulsed CO2 resurfacing of photodamaged facial skin: long-term evaluation

Although numerous papers have recently been published on ablative fractional resurfacing, there is a lack of information in literature on very long-term results. The aim of this retrospective study is to evaluate the efficacy, adverse side effects, and long-term results of a random fractional ultrapulsed CO2 laser on a large population with photodamaged facial skin. Three hundred twelve patients with facial photodamaged skin were enrolled and underwent a single full-face treatment. Six aspects of photodamaged skin were recorded using a 5 point scale at 3, 6, and 24 months after the treatment. The results were compared with a non-parametric statistical test, the Wilcoxon's exact test. Three hundred one patients completed the study. All analyzed features showed a significant statistical improvement 3 months after the procedure. Three months later all features, except for pigmentations, once again showed a significant statistical improvement. Results after 24 months were similar to those assessed 18 months before. No long-term or other serious complications were observed. From the significant number of patients analyzed, long-term results demonstrate not only how fractional ultrapulsed CO2 resurfacing can achieve good results on photodamaged facial skin but also how these results can be considered stable 2 years after the procedure.

Highlights of thirty-year experience of CO2 laser use at the Florence (Italy) department of dermatology

The CO₂ laser has been used extensively in dermatological surgery over the past 30 years and is now recognised as the gold standard for soft tissue vaporization. Considering that the continuous wave CO₂ laser delivery system and the newer “superpulsed” and scanned CO₂ systems have progressively changed our practice and patient satisfaction, a long range documentation can be useful. Our experience has demonstrated that the use of CO₂ laser involves a reduced healing time, an infrequent need for anaesthesia, reduced thermal damage, less bleeding, less inflammation, the possibility of intra-operative histologic and/or cytologic examination, and easy access to anatomically difficult areas. Immediate side effects have been pain, erythema, edema, typically see with older methods, using higher power. The percentage of after-treatment keloids and hypertrophic scars observed was very low (~1%) especially upon the usage of lower parameters. The recurrence of viral lesions (condylomas and warts) have been not more frequent than those due to other techniques. Tumor recurrence is minor compared with radiotherapy or surgery. This method is a valid alternative to surgery and/or diathermocoagulation for microsurgery of soft tissues. Our results are at times not consistent with those published in the literature, stressing the concept that multicentric studies that harmonization methodology and the patient selection are vital.

Novel methods and devices to enhance transdermal drug delivery: the importance of laser radiation in transdermal drug delivery

Skin permeation-enhancement technology is a rapidly developing field, which could significantly increase the number of drugs suitable for transdermal delivery. In this review, we highlight recent advances in both ‘passive’ and ‘active’ transdermal drug-delivery technologies, as well as in the laser ablation method. This paper concludes with a brief forward-looking perspective discussing what can be expected as laser technology continues to develop in the coming years.

Versatility of erbium YAG laser: from fractional skin rejuvenation to full-field skin resurfacing

For the laser surgeon, the Er-YAG laser is an invaluable tool that delivers unsurpassed ablation efficiency, and with appropriate functionality (quasi long-pulse feature) provides sufficient tissue coagulation to remodel deep rhytids. As such, the 2940-nm wavelength is well suited for routine laser skin rejuvenation in full-field, fractional, and point-beam modes with additional benefits, including applicability to diverse skin types, short healing times, and a low likelihood of energy-related complications.

Oral mucosa response to laser patterned microcoagulation (LPM) treatment. An animal study

In this study a minimally invasive microsurgical approach was used for laser patterned microcoagulation (LPM) to initiate gingival and oral mucosal tissue regeneration. We performed a feasibility assessment and histological examination of laser damage and regeneration in the gingiva and oral mucosa using an animal model. The study animals comprised 18 healthy rabbits which were treated in vivo with single pulses from a diode laser at a wavelength of 980 nm and a power of up to 20 W applied to the gingival and oral mucosa at multiple time points. Biopsies were stained with hematoxylin and eosin, nitroblue tetrazolium chloride and picrosirius red, and evaluated by two pathologists blinded to the parameters and date of laser exposure. Histological analysis revealed that the continuity of the epithelial basal cell layer had been reestablished by 1-2 days after LPM, and complete epithelial regeneration had occurred by 7-12 days. A pronounced reactive inflammation developed in the column area 1 day after treatment. High activity of fibroblasts producing new collagen participated in the formation of a network of new thin-wall blood vessel. By the 28th day the tissue structure was almost completely restored with a similar increase of vascularity, and there were no signs of scarring. By the 90th day, tissue structure was completely restored, indicating complete healing. A single LPM treatment induces a wound healing response in the oral mucosa, showing the potential of LPM for the initiation of oral mucosa and gingival regeneration. Complete healing observed in 3 months after treatment with no keratinization change or scar tissue formation.

Can fractional lasers enhance transdermal absorption of topical lidocaine in an in vivo animal model?

BACKGROUND AND OBJECTIVE

It has been shown in vitro that pretreatment of skin with fractional lasers enhances transdermal delivery of drugs. The aim of this study is to demonstrate in vivo firstly that laser enhances transdermal drug absorption and secondly that this can be manipulated by altering laser settings.

STUDY DESIGN/MATERIALS AND METHODS

Four pigs were used in the IACUC approved animal study. On day 0, 5 g of 4% topical lidocaine was applied under occlusion for 60 minutes to a 400 cm(2) area on the abdomen. Blood was drawn at 0, 60, 90, 120, 180, and 240 minutes. On day 7, the Er:YAG laser was used at 500, 250, 50, and 25 µm ablative depth, respectively, over a 400 cm(2) area on the abdomen. Five grams of 4% topical lidocaine was applied immediately with occlusion for 60 minutes, and then removed. Blood was drawn at 0, 60, 90, 120, 180, and 240 minutes. The serum was extracted and analyzed for lidocaine and its metabolite monoethylglycinexylidide (MEGX).

RESULTS

Serum levels of lidocaine and MEGX were undetectable in untreated skin. Following laser treatment both lidocaine and MEGX were detectable. Peak levels of lidocaine were significantly higher (P = 0.0002) at 250 µm (0.62 mg/L), compared to 500 µm (0.45 mg/L), 50 µm (0.48 mg/L), and 25 µm (0.3 mg/L). Peak levels of MEGX were significantly higher (P ≤ 0.0001) at 250 µm (0.048 mg/L), compared to 500 µm (0.018 mg/L), 50 µm (0.036 mg/L), and 25 µm (0.0144 mg/L).

CONCLUSIONS

This study demonstrates that laser pretreatment significantly increases absorption of topical lidocaine so that it is detectable in the blood and that manipulating laser settings can affect drug absorption. Future work will look at translating this effect into clinical benefit.

Formation of fibrosis after nonablative and ablative fractional laser therapy

BACKGROUND

Fractional laser therapy (FLT) has become a widely accepted modality for skin rejuvenation and has also been used in various other skin diseases.

OBJECTIVE

To observe long-term histologic effects of nonablative and ablative FLT in the treatment of pigment disorders.

METHODS

A randomized controlled observer-blinded study was performed in 18 patients with pigment disorders. Two similar test regions were randomized to receive FLT with intermittent topical bleaching or topical bleaching alone. Patients with ashy dermatosis (AD) and postinflammatory hyperpigmentation (PIH) were treated using nonablative 1,550-nm FLT (15 mJ/microbeam, 14-20% coverage), whereas patients with Becker's nevus (BN) were treated with ablative 10,600-nm FLT (10 mJ/microbeam, 35-45% coverage) for three to five sessions. Biopsies were obtained 3 months after the last treatment.

RESULTS

At follow-up, dermal fibrosis was observed in four of eight patients treated using ablative FLT and no patients treated using nonablative FLT (p < .05).

CONCLUSIONS

Assuming that the dermal response is comparable in AD, PIH, and BN, at the given settings, ablative FLT may induce fibrosis, whereas treatment with nonablative FLT does not. Whether formation of fibrosis has to be regarded as dermal remodeling or a subtle subclinical form of scarring should be investigated in future research.

Skin characteristics after fractional photothermolysis

Background

Fractional photothermolysis makes thousands of minute areas called microthermal treatment zones on the skin surface and transmits thermal injury to facilitate heat shock protein formation around the dermis. Potential side effects include acneiform eruption, herpes simplex virus outbreak, erythema, and post-inflammatory hyperpigmentation.

Objective

To investigate and compare the changes in the skin of Asian patients after two different fractional photothermolysis systems (FPS) on a split face.

Methods

A half-split face study was performed with 10,600 nm carbon dioxide FPS on the left and 1,550 nm erbium-doped FPS on the right side of the face. Only one session of laser irradiation and several biophysical measurements were done.

Results

Although both FPS proved to be effective in treating acne scar and wrinkle patients, a slightly higher satisfaction rating was seen with the 10,600 nm FPS treatment. Both types of FPS showed a significant increase in transepidermal water loss which decreased gradually after treatment and returned to pre-treatment level after 1 week. A decreased reviscometer score was sustained for a longer period in wrinkle areas treated with 10,600 nm FPS.

Conclusion

Even though the changes in skin varied according to different FPS wave-length, adverse outcomes, such as increased erythema and TEWL were entirely subdued within 3 months of treatment.

Treatment of Striae Distensae with Nonablative Fractional Laser versus Ablative CO(2) Fractional Laser: A Randomized Controlled Trial

Background

Striae distensae are atrophic dermal scars with overlying epidermal atrophy causing significant cosmetic concern. Although a variety of laser and light sources have been used for the treatment of striae distensae, to date no definite 'gold standard' treatment modality has been determined.

Objective

To assess and compare the efficacy and safety of nonablative fractional photothermolysis and ablative CO₂ fractional laser resurfacing in the treatment of striae distensae.

Methods

Twenty-four ethnic South Korean patients with varying degrees of atrophic striae alba in the abdomen were enrolled in a randomized blind split study. The patients were treated with 1,550 nm fractional Er:Glass laser and ablative fractional CO₂ laser resurfacing. Each half of the abdominal lesion was randomly selected and treated three times at intervals of 4-weeks using the same parameters. Digital photography was conducted and skin elasticity and the width of the widest striae in each subject were measured at the baseline and 4 weeks after the final treatment. Clinical improvement was assessed by comparing pre- and post-treatment clinical photographs by two blinded physicians and participant satisfaction rates were evaluated. Skin biopsies were taken from three participants. All adverse effects were reported during the study.

Results

Although they do not statistically differ, both treatments with nonablative fractional laser and ablative CO₂ fractional laser showed a significant clinical and histopathologic improvement of striae distensae over pretreatment sites.

Conclusion

These results support the use of nonablative fractional laser and ablative CO₂ fractional laser as effective and safe treatment modalities for striae distensae of Asian skin. However, neither treatment showed any greater clinical improvement than the other treatment.

In vivo wound healing and dermal matrix remodelling in response to fractional CO(2) laser intervention: clinicopathological correlation in non-facial skin

PURPOSE

Ablative fractional photothermolysis is a new concept for treatment of aged skin. Despite the low frequency of side effects there are now several reports about scarring, especially in non-facial regions like the neck. Our study aimed to investigate the in vivo wound healing process and remodelling in an area prone to scarring using a fractional ablative CO(2) laser with three different energy protocols.

MATERIALS AND METHODS

Six patients with photo-damaged skin received a single fractional ablative treatment using a 250-µm scanning CO(2) laser. Three areas on the neck were treated with 50, 100 and 300 mJ/microbeam at densities of 200, 150 and 100/cm(2), respectively. Biopsies were taken from untreated skin (control) and 10 minutes, 3 days, 14 days, 21 days and 28 days post-intervention.

RESULTS

Fractional ablation with higher energies resulted in increased total thermal damage. Overall, 50 mJ was effective up to the superficial dermis, 100 mJ up to the mid-dermis, and 300 mJ resulted in deep dermal ablation. The intensity of lymphocytic inflammation and dermal remodelling correlated with the total amount of thermal damage. At 300 mJ, granuloma was present and persisted for at least 4 weeks as opposed to clinical healing, which was completed < 2 weeks.

CONCLUSIONS

With the above-mentioned low and medium parameter settings, ablative fractional photothermolysis is safe and effective in non-facial skin. However, dermal remodelling continues for up to 4 weeks, which should be the minimum space between treatment sessions. Higher energies may induce granuloma formation, possibly a sign of an overstrained remodelling capacity.