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Katta N, Estrada AD, McElroy AB, Milner TE. Er:YAG laser brain surgery with vascular specific coagulation. Lasers Surg Med 2022; 54:1107-1115. [PMID: 35946396 DOI: 10.1002/lsm.23591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 07/14/2022] [Accepted: 07/21/2022] [Indexed: 11/11/2022]
Abstract
BACKGROUND AND OBJECTIVE Erbium:yttrium-aluminum-garnet (Er:YAG) laser ablation can effectively resect water-bearing tissues. Application of Er:YAG resection in neurosurgery is complicated by unpredictable bleeding in surgical field. Recently, an integrated theranostic system combining a dual-wavelength laser surgery system using a thulium (Tm) fiber-laser for coagulation and Er:YAG for resection, combined with optical coherence tomography (OCT) guidance was demonstrated for the in vivo resection of tumor tissue. However, lateral thermal spread in the range of 100 seconds of micrometers is common due to lack of vascular specificity using a Tm fiber-laser for coagulation. In this study, a vascular specific ytterbium (Yb) fiber-laser is utilized for enhanced photocoagulation during in vivo neurosurgery improving the precision of Er:YAG tissue resection with minimal lateral thermal spread. METHODS Mice underwent stereotactic laser surgery with the proposed Yb/Er:YAG dual wavelength vascular specific neurosurgery in vivo. An OCT system (wavelength range 1310 ± 70 nm) and OCT derived angiography images were used to record cortical images to confirm the coagulation of blood vessels and guide subsequent Er:YAG resection steps. After the laser surgery, mice were killed, and histological analysis was carried out using hematoxylin and eosin staining and Nissl staining to compare the lateral thermal spread with our previously reported Tm/Er:YAG neurosurgery where a continuous wave Tm fiber-laser was used for coagulation. RESULTS Coagulation scheme using a Yb fiber-laser allowed stoppage of blood flow in disparately sized blood vessels encountered in the mice brain. Histological analysis of murine brain slices post Yb/Er:YAG laser surgery yielded lower thermal spread compared with Tm/Er:YAG laser surgery, maximizing the efficiency in both hemostasis (blood flow stoppage) and maximizing tissue ablation efficiency with minimal residual thermal damage zone. CONCLUSION In this study, a vascular specific coagulation scheme with Yb/Er:YAG dual-wavelength surgery is presented for neurosurgery. Additionally, Yb/Er:YAG study results are compared with that of a tissue coagulation approach in Tm/Er:YAG surgery previously reported to highlight improved coagulation, reduced nonspecific thermal damage and limited lateral thermal spread. Experimental results suggest that the developed dual-wavelength laser system can effectively resect neural tissues with high localization, minimal lateral thermal spread at the micrometer level while maintaining a bloodless surgical field.
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Affiliation(s)
- Nitesh Katta
- Beckman Laser Institute, University of California at Irvine, East Irvine, California, USA
| | - Arnold D Estrada
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA
| | - Austin B McElroy
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA
| | - Thomas E Milner
- Beckman Laser Institute, University of California at Irvine, East Irvine, California, USA
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Vaginal erbium laser for treatment of stress urinary incontinence: optimization of treatment regimen for a sustained long-term effect. Lasers Med Sci 2022; 37:2157-2164. [PMID: 35067817 DOI: 10.1007/s10103-021-03474-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 11/15/2021] [Indexed: 10/19/2022]
Abstract
Stress urinary incontinence (SUI) is a common health problem that affects roughly 35% of women in the reproductive period. A prospective uncontrolled study was conducted to assess the long-term efficacy and safety of a non-ablative Er:YAG laser treatment of SUI. Forty-three patients participated in the study. All women underwent three sessions of IncontiLase® procedure, and efficacy of laser treatment was assessed by 1-h pad test, 24-h pad test, 3-day voiding diary, and ICIQ-UI SF questionnaire at multiple follow-ups. Statistical analysis was performed using one-way repeated measures ANOVA. Patients were questioned about discomfort during treatment and any adverse events following the laser procedures. All outcome measures showed a significant change over a period of the entire clinical trial. Eighteen-month follow-up revealed a fading of the effect, which was alleviated by single-session maintenance treatments every 6 months. There were no serious adverse events reported during the study. All reported side effects were mild and transient. The application of non-ablative Er:YAG laser for SUI treatment significantly improves the SUI symptoms. High improvement rates and patient satisfaction can be maintained with single-session maintenance treatments performed every 6 months. Long-term safety profile of multiple non-ablative Er:YAG laser treatment is shown. NCT04348994, 16.04.2020, retrospectively registered.
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Lukac M, Zorman A, Lukac N, Perhavec T, Tasic B. Characteristics of Non-Ablative Resurfacing of Soft Tissues by Repetitive Er:YAG Laser Pulse Irradiation. Lasers Surg Med 2021; 53:1266-1278. [PMID: 33792949 PMCID: PMC8518959 DOI: 10.1002/lsm.23402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 02/04/2021] [Accepted: 03/14/2021] [Indexed: 11/12/2022]
Abstract
Background and Objectives Recently, several minimally invasive gynecological, ENT and esthetic procedures have been introduced that are based on delivering “smooth” sequences of Er:YAG laser pulses to cutaneous or mucosal tissue at moderate cumulative fluences that are not only below the ablation threshold but typically also do not require local anesthesia. To explain the observed clinical results using “smooth‐resurfacing,” it has been suggested that in addition to the direct heat injury to deeper‐lying connective tissues, there is an additional mechanism based on indirect triggering of tissue regeneration through short‐exposure, intense heat shocking of epithelia. The goal of this study is to improve understanding of the complex dynamics of the exposure of tissues to a series of short Er:YAG laser pulses, during which the thermal exposure times transition from extremely short to long durations. Study Design/Materials and Methods A physical model of laser‐tissue interaction was used to calculate the temperature evolution at the irradiated surface and deeper within the tissue, in combination with a chemical model of tissue response based on the recently introduced variable heat shock (VHS) model, which assumes that the tissue damage represents a combined effect of two limiting Arrhenius′ processes, defining cell viability at extremely long and short exposure times. Superficial tissue temperature evolution was measured during smooth‐resurfacing of cutaneous and mucosal tissue, and compared with the model. Two modalities of non‐ablative resurfacing were explored: a standard “sub‐resurfacing” modality with cumulative fluences near the ablation threshold, and the “smooth‐resurfacing” modality with fluences below the patient′s pain threshold. An exemplary skin tightening clinical situation was explored by measuring pain tolerance threshold fluences for treatments on abdominal skin with and without topical anesthesia. The obtained temperature data and pain thresholds were then used to study the influence of Er:YAG laser sequence parameters on the superficial (triggering) and deep (coagulative) tissue response. Results The simulations show that for the sub‐resurfacing modality, the parameter range where no excessive damage to the tissue will occur is very narrow. On the other hand, using pain tolerance as an indicator, the smooth‐resurfacing treatments can be performed more safely and without sacrificing the treatment efficacy. Two preferred smooth‐resurfacing treatment modalities were identified. One involves using optimally long pulse sequence durations (≈1–3 seconds) with an optimal number of pulses (N ≈ 10–30), resulting in a maximal short‐exposure superficial tissue response and moderate coagulation depths. And for deeper coagulation, without significant superficial heat shocking, very long pulse sequences (>5 seconds) with a large number of delivered pulses are to be used in combination with topical anesthesia. Conclusions A comparison of the simulations with the established smooth‐resurfacing clinical protocols in gynecology, ENT, and esthetics suggests that, through clinical experience, the clinical protocols have been optimized for the maximal superficial heat shock triggering effect. Further research is needed to gain a better understanding of the proposed role of heat shock triggering in the clinically observed regeneration of cutaneous, vaginal, and oral tissues following Er:YAG laser smooth‐resurfacing. Lasers Surg. Med. © 2021 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals LLC.
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Affiliation(s)
- Matjaz Lukac
- Institut Jozef Stefan, Jamova 39 SI-1000, Ljubljana, Slovenia
| | - Anze Zorman
- Medilase Dermatology & Laser Center, Tbilisijska 59 SI-1000, Ljubljana, Slovenia
| | - Nejc Lukac
- Faculty of Mechanical Engineering, University of Ljubljana, Askerceva 6 SI-1000, Ljubljana, Slovenia
| | | | - Blaz Tasic
- Faculty of Mechanical Engineering, University of Ljubljana, Askerceva 6 SI-1000, Ljubljana, Slovenia
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Botsali A, Beksac B, Gahramanov İ, Caliskan E. Erbium:YAG laser augments the penetration of cryotherapy. Lasers Med Sci 2021; 37:353-358. [PMID: 33528669 DOI: 10.1007/s10103-021-03259-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 01/24/2021] [Indexed: 11/29/2022]
Abstract
Cryotherapy is commonly used during dermatologic practice. Several modifications such as an "add-on" to topicals or intralesional applications have been already defined to enhance efficacy. The aim of this study is to test our hypothesis that ablative laser application before cryotherapy would increase the depth of freezing.Throughout this experiment, target points received either cryotherapy alone or a combination of erbium:yttrium-aluminum garnet (erbium:YAG) laser and cryotherapy. Freezing durations of 10 (C10), 20 (C20), and 30 seconds (C30) were investigated. Erbium:YAG laser groups received equal high energy shots with different pulse durations (100 μs versus 1500 μs) before freezing. The treatment points were arranged on the peripheral side of porcine skin specimens, and dermoscopic images revealing the iceball visible from the lateral side were immediately captured. Repeated experimental results were compared by Wilcoxon's test. The comparison of the vertical length of the iceball between the three different freezing durations of 10 seconds, 20 seconds, and 30 seconds was statistically significant (p<0.05). The vertical length of the iceball was higher in both laser groups receiving 30-second freezing (mean ± SD: 4.32±0.53, 3.9±0.38 for micro-short pulse (MSP) and extra-long pulse (XLP), respectively) when compared with 30-second freezing alone (mean ± SD:3.51±0.44) (p=0.016). The two laser settings did not reveal a difference for the penetration of 30-second freezing (p=0.122). In this study, through visual monitorization of the iceball, erbium:YAG laser is found to augment the penetration of cryotherapy. The defined combination regimen has the potential to ameliorate treatment outcomes of cryotherapy.
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Affiliation(s)
- Aysenur Botsali
- Department of Dermatology, Health Sciences University, Gülhane Training and Research Hospital, General Dr. Tevfik Saglam Cad., SBU Gülhane EAH Dermatoloji ABD Etlik, Ankara, Turkey.
| | - Burcu Beksac
- Department of Dermatology, Health Sciences University, Gülhane Training and Research Hospital, General Dr. Tevfik Saglam Cad., SBU Gülhane EAH Dermatoloji ABD Etlik, Ankara, Turkey
| | - İrfan Gahramanov
- Department of Dermatology, Health Sciences University, Gülhane Training and Research Hospital, General Dr. Tevfik Saglam Cad., SBU Gülhane EAH Dermatoloji ABD Etlik, Ankara, Turkey
| | - Ercan Caliskan
- Department of Dermatology, Health Sciences University, Gülhane Training and Research Hospital, General Dr. Tevfik Saglam Cad., SBU Gülhane EAH Dermatoloji ABD Etlik, Ankara, Turkey
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Hympanova L, Mackova K, El-Domyati M, Vodegel E, Roovers JP, Bosteels J, Krofta L, Deprest J. Effects of non-ablative Er:YAG laser on the skin and the vaginal wall: systematic review of the clinical and experimental literature. Int Urogynecol J 2020; 31:2473-2484. [PMID: 32780174 DOI: 10.1007/s00192-020-04452-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Accepted: 07/16/2020] [Indexed: 10/23/2022]
Abstract
INTRODUCTION AND HYPOTHESIS Er:YAG laser is frequently used in dermatology and gynecology. Clinical studies document high satisfaction rates; however, hard data on the effects at the structural and molecular levels are limited. The aim of this systematic review was to summarize current knowledge about the objective effects of non-ablative Er:YAG laser on the skin and vaginal wall. METHODS We searched MEDLINE, Embase, Cochrane, and the Web of Science. Studies investigating objectively measured effects of non-ablative Er:YAG laser on the skin or vaginal wall were included. Studies of any design were included. Owing to the lack of methodological uniformity, no meta-analysis could be performed and therefore results are presented as a narrative review. RESULTS We identified in vitro or ex vivo studies on human cells or tissues, studies in rats, and clinical studies. Most studies were on the skin (n = 11); the rest were on the vagina (n = 4). The quality of studies is limited and the settings of the laser were very diverse. Although the methods used were not comparable, there were demonstrable effects in all studies. Immediately after application the increase in superficial temperature, partial preservation of epithelium and subepithelial extracellular matrix coagulation were documented. Later, an increase in epithelial thickness, inflammatory response, fibroblast proliferation, an increase in the amount of collagen, and vascularization were described. CONCLUSIONS Er:YAG laser energy may induce changes in the deeper skin or vaginal wall, without causing unwanted epithelial ablation. Laser energy initiates a process of cell activation, production of extracellular matrix, and tissue remodeling.
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Affiliation(s)
- Lucie Hympanova
- Centre for Surgical Technologies, Group Biomedical Sciences, KU Leuven, Herestraat 49, 3000, Leuven, Belgium.,Department of Development and Regeneration, Woman and Child, Group Biomedical Sciences, KU Leuven, Leuven, Belgium.,Institute for the Care of Mother and Child, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Katerina Mackova
- Centre for Surgical Technologies, Group Biomedical Sciences, KU Leuven, Herestraat 49, 3000, Leuven, Belgium.,Department of Development and Regeneration, Woman and Child, Group Biomedical Sciences, KU Leuven, Leuven, Belgium.,Institute for the Care of Mother and Child, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Moetaz El-Domyati
- Department of Dermatology and Venereology, Minia University, Al-Minya, Egypt
| | - Eva Vodegel
- Department of Obstetrics and Gynaecology, Amsterdam University Medical Center, location AMC, Amsterdam, The Netherlands
| | - Jan-Paul Roovers
- Department of Obstetrics and Gynaecology, Amsterdam University Medical Center, location AMC, Amsterdam, The Netherlands
| | - Jan Bosteels
- Department of Development and Regeneration, Woman and Child, Group Biomedical Sciences, KU Leuven, Leuven, Belgium.,CEBAM, The Centre for Evidence-based Medicine, Cochrane Belgium, KU Leuven-University of Leuven, Leuven, Belgium
| | - Ladislav Krofta
- Institute for the Care of Mother and Child, Third Faculty of Medicine, Charles University, Prague, Czech Republic
| | - Jan Deprest
- Centre for Surgical Technologies, Group Biomedical Sciences, KU Leuven, Herestraat 49, 3000, Leuven, Belgium. .,Department of Development and Regeneration, Woman and Child, Group Biomedical Sciences, KU Leuven, Leuven, Belgium. .,Pelvic Floor Unit, University Hospitals KU Leuven, Leuven, Belgium.
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Schmitz L, Hessam S, Scholl L, Reitenbach S, Segert MH, Gambichler T, Stockfleth E, Bechara FG. Histological findings after argon plasma coagulation: an ex-vivo study revealing a possible role in superficial ablative treatment of the skin. Arch Dermatol Res 2018; 310:157-163. [PMID: 29350263 DOI: 10.1007/s00403-018-1810-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 01/09/2018] [Accepted: 01/12/2018] [Indexed: 10/18/2022]
Abstract
Argon plasma coagulation (APC) is an electrosurgical technique which can be used to ablate skin lesions with limited invasion depth into dermal tissue. Hence, APC might be well suited for the removal of epithelial tumours. However, there are no data on the effects of APC on human skin tissue. Thus, the aim of this study was to determine the extent of epidermal and dermal damage after APC of human skin. We performed APC ex-vivo on 91 freshly resected human skin samples, which were obtained after reconstructive surgical closures in actinically damaged areas. Tissue effects were evaluated histologically and compared across different power settings. Using 15, 30, and 45 W, median (interquartile range; IQR) coagulation depths were 110.0 µm (91.7-130.0), 113.3 µm (85.8-135.0), and 130.0 µm (100.0-153.3.0), respectively. Median (IQR) thickness of necrosis zone was 30.0 µm (23.3-40.0) at 15 W, 26.7 µm (20.0-41.6) at 30 W, and 43.3 µm (30.8-57.5) at 45 W. The Kruskal-Wallis test showed significant differences between 15 and 30 W versus 45 W for coagulation depth (P = 0.0414), necrosis zone (P = 0.0017), and necrosis according to overlaying epidermal thickness (P = 0.0467). In summary, APC is a simple and controllable electrosurgical technique to remove epidermal tissue with limited penetration to the dermis. Thus, APC is particularly suited for the ablation of epithelial skin lesions and, therefore, may serve as possible treatment approach for intraepithelial neoplasms such as actinic keratosis.
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Affiliation(s)
- L Schmitz
- Department of Dermatology, Venereology and Allergology, Dermatologic Surgery Unit, Ruhr-University Bochum, Gudrunstr. 56, 44791, Bochum, Germany
| | - S Hessam
- Department of Dermatology, Venereology and Allergology, Dermatologic Surgery Unit, Ruhr-University Bochum, Gudrunstr. 56, 44791, Bochum, Germany
| | - L Scholl
- Department of Dermatology, Venereology and Allergology, Dermatologic Surgery Unit, Ruhr-University Bochum, Gudrunstr. 56, 44791, Bochum, Germany
| | - S Reitenbach
- Department of Dermatology, Venereology and Allergology, Dermatologic Surgery Unit, Ruhr-University Bochum, Gudrunstr. 56, 44791, Bochum, Germany
| | - M H Segert
- Department of Dermatology, Venereology and Allergology, Dermatologic Surgery Unit, Ruhr-University Bochum, Gudrunstr. 56, 44791, Bochum, Germany
| | - T Gambichler
- Department of Dermatology, Venereology and Allergology, Ruhr-University Bochum, Gudrunstr. 56, 44791, Bochum, Germany
| | - E Stockfleth
- Department of Dermatology, Venereology and Allergology, Ruhr-University Bochum, Gudrunstr. 56, 44791, Bochum, Germany
| | - F G Bechara
- Department of Dermatology, Venereology and Allergology, Dermatologic Surgery Unit, Ruhr-University Bochum, Gudrunstr. 56, 44791, Bochum, Germany.
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Ueda A. Treatment of lichen pilaris with a Q-switched Nd:YAG laser in quasi long-pulsed mode: A case report (a secondary publication). Laser Ther 2014; 23:211-20. [PMID: 25368447 DOI: 10.5978/islsm.14-cr-01] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Accepted: 06/16/2014] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND AIMS Lichen pilaris is a very common disease typically seen among young adults on their upper arms as a manifestation of hyperkeratotic lesions occurring in the pores. Only a few treatments have been reported as significantly effective, so often natural resolution over time is the only option. The present study examined the use of a 1064 nm Q-switched Nd:YAG laser (QSNY) in quasi long-pulsed mode, in an attempt to treat a case of lichen pilaris. SUBJECT AND METHODS A 33-year-old male presented with light-brown aggregated papules observed on both sides of the upper arms. The affected areas were treated every other week (QSNY, pulse width 300 µs, pulse energy 3.0 J/cm(2), spot size 6 mm and repetition rate 10 Hz). Clinical photography was taken of the lesions at baseline and three months after the final treatment in addition to macrophotography and 3-D photography, biopsies being taken at both time points for histological comparison. RESULTS The clinical photography and objective image evaluation demonstrated shrinkage of pores and improvement of the unevenness of the skin. Histological examination suggested that the effect of the micropulsed QSNY on the horny layer, epidermal keratinocytes and dermal collagen resulted in a peeling effect and increased dermal collagen density, which eventually led to the shrinkage of the pores and improvement of the skin condition. CONCLUSIONS The results of this single patient case report suggest that the micropulsed QSNY could be an effective treatment option for lichen pilaris, improvement of which is often difficult. Further studies with an appropriately-sized population are merited to confirm these preliminary results.
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Affiliation(s)
- Atsuto Ueda
- Division of Dermatology, Miyazaki Hospital, Nagasaki, JAPAN
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El-Domyati M, Medhat W. Minimally invasive facial rejuvenation: current concepts and future expectations. ACTA ACUST UNITED AC 2014. [DOI: 10.1586/17469872.2013.836845] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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El-Domyati M, El-Ammawi TS, Medhat W, Moawad O, Mahoney MG, Uitto J. Multiple minimally invasive Erbium: Yttrium Aluminum Garnet laser mini-peels for skin rejuvenation: an objective assessment. J Cosmet Dermatol 2012; 11:122-30. [PMID: 22672276 DOI: 10.1111/j.1473-2165.2012.00606.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUND As the demand for minimally invasive rejuvenation is increasing, micropeel resurfacing using Erbium:Yttrium Aluminum Garnet (Er:YAG) laser 2940 nm has been reported for the treatment of photoaged skin without ablation of the epidermis. However, little is known about the efficacy and underlying histologic changes associated with this type of treatment. AIMS The aims of this study are to evaluate the clinical effect and objectively quantify the histological changes in response to multiple sessions of Er:YAG laser 2940 nm mini-peels. PATIENTS AND METHODS Six female volunteers of Fitzpatrick skin type III-IV and Glogau's class I-III wrinkles were subjected to six microresurfacing peels at 2-week intervals using Er:YAG 2940 nm laser at subablative fluences of 2-3 J/cm(2) to treat periorbital rhytides. Quantitative evaluation of collagen types I, III, and VII, newly synthesized collagen, total elastin, and tropoelastin was performed by histochemistry and immunohistochemistry coupled with computerized morphometric analysis at base line, end of treatment, and 3 months post-treatment. RESULTS Compared to the base line, evaluation of volunteers revealed obvious clinical improvement in response to Er:YAG mini-peels. Collagen types I, III, and VII, as well as newly synthesized collagen, together with tropoelastin showed a statistically significant increase in response to treatment, while the mean level of total elastin was significantly decreased in response to treatment. However, this was followed by regression of improvement at 3 months post-treatment but was still better than baseline. CONCLUSIONS This study revealed that multiple Er:YAG mini-peels is a promising treatment option for photoaging as it reverses the signs of photoaged skin with little downtime and side effects. However, to maintain the short-term improvement achieved after treatment, continued Er:YAG 2940 nm laser mini-peels is required.
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10
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El-Domyati M, Abd-El-Raheem T, Abdel-Wahab H, Medhat W, Hosam W, El-Fakahany H, Al Anwer M. Fractional versus ablative erbium:yttrium-aluminum-garnet laser resurfacing for facial rejuvenation: an objective evaluation. J Am Acad Dermatol 2012; 68:103-12. [PMID: 23110966 DOI: 10.1016/j.jaad.2012.09.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Revised: 08/22/2012] [Accepted: 09/04/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND Laser is one of the main tools for skin resurfacing. Erbium:yttrium-aluminum-garnet (Er:YAG) was the second ablative laser, after carbon dioxide, emitting wavelength of 2940 nm. Fractional laser resurfacing has been developed to overcome the drawbacks of ablative lasers. OBJECTIVE We aimed to objectively evaluate the histopathological and immunohistochemical effects of Er:YAG 2940-nm laser for facial rejuvenation (multiple sessions of fractional vs single session of ablative Er:YAG laser). METHODS Facial resurfacing with single-session ablative Er:YAG laser was performed on 6 volunteers. Another 6 were resurfaced using fractional Er:YAG laser (4 sessions). Histopathological (hematoxylin-eosin, orcein, Masson trichrome, and picrosirius red stains) and immunohistochemical assessment for skin biopsy specimens were done before laser resurfacing and after 1 and 6 months. Histometry for epidermal thickness and quantitative assessment for neocollagen formation; collagen I, III, and VII; elastin; and tropoelastin were done for all skin biopsy specimens. RESULTS Both lasers resulted in increased epidermal thickness. Dermal collagen showed increased neocollagen formation with increased concentration of collagen types I, III, and VII. Dermal elastic tissue studies revealed decreased elastin whereas tropoelastin concentration increased after laser resurfacing. Neither laser showed significant difference between their effects clinically and on dermal collagen. Changes in epidermal thickness, elastin, and tropoelastin were significantly more marked after ablative laser. LIMITATIONS The small number of patients is a limitation, yet the results show significant improvement. CONCLUSION Multiple sessions of fractional laser have comparable effects to a single session of ablative Er:YAG laser on dermal collagen but ablative laser has more effect on elastic tissue and epidermis.
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Affiliation(s)
- Moetaz El-Domyati
- Department of Dermatology, Faculty of Medicine, Al-Minya University, Al-Minya, Egypt.
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11
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Lee WR, Shen SC, Al-Suwayeh SA, Li YC, Fang JY. Erbium:YAG laser resurfacing increases skin permeability and the risk of excessive absorption of antibiotics and sunscreens: The influence of skin recovery on drug absorption. Toxicol Lett 2012; 211:150-8. [DOI: 10.1016/j.toxlet.2012.03.797] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Revised: 03/20/2012] [Accepted: 03/21/2012] [Indexed: 11/29/2022]
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12
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Weng Y, Dang Y, Ye X, Liu N, Zhang Z, Ren Q. Investigation of irradiation by different nonablative lasers on primary cultured skin fibroblasts. Clin Exp Dermatol 2011; 36:655-60. [PMID: 21457156 DOI: 10.1111/j.1365-2230.2011.04043.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND A variety of lasers with different wavelengths and biological effects are widely used for nonablative skin rejuvenation, but the underlying mechanisms have not been fully investigated. AIM To investigate the effects of irradiation by different nonablative lasers on collagen synthesis and the antioxidant status of cultured fibroblasts to identify a possible mechanism for laser photorejuvenation. METHODS Cultured skin fibroblasts were irradiated with three different lasers: 532 nm potassium-titanyl phosphate (KTP), 1064 nm Q-switched neodymium:yttrium-aluminium-garnet (Nd:Yag) and 1064 nm long-pulse Nd:YAG, and production of collagen and changes in lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were assayed. RESULTS Irradiation by all three lasers led to a marked increase in collagen production. Two major antioxidant enzymes, SOD and GSH, were significantly increased, whereas MDA was markedly reduced after laser irradiation. No change in LDH activity was found between nonirradiated and irradiated fibroblasts. CONCLUSION This study indicates that the increased collagen synthesis by fibroblasts after laser treatment may be partly due to improved antioxidant capacity, which reduces oxidative stress and thus stimulates new collagen production.
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Affiliation(s)
- Y Weng
- School of Life Science, East China Normal University, Shanghai, China
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13
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Manuskiatti W, Siriphukpong S, Varothai S, Wanitphakdeedecha R, Fitzpatrick RE. Effect of pulse width of a variable square pulse (VSP) erbium:YAG laser on the treatment outcome of periorbital wrinkles in Asians. Int J Dermatol 2010; 49:200-6. [DOI: 10.1111/j.1365-4632.2009.04292.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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White WM, Makin IRS, Barthe PG, Slayton MH, Gliklich RE. Selective creation of thermal injury zones in the superficial musculoaponeurotic system using intense ultrasound therapy: a new target for noninvasive facial rejuvenation. ACTA ACUST UNITED AC 2007; 9:22-9. [PMID: 17224484 DOI: 10.1001/archfaci.9.1.22] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVES To transcutaneously deliver intense ultrasound (IUS) energy to target the facial superficial musculoaponeurotic system (SMAS), to produce discrete thermal injury zones (TIZs) in the SMAS, and to demonstrate the relative sparing of adjacent nontargeted layers superficial and deep to the SMAS layer. METHODS In 6 unfixed human cadaveric specimens, the SMAS layer was visualized and targeted using the ultrasound imaging component of the IUS device. Using 2 IUS handpieces, 202 exposure lines were delivered bilaterally in multiple facial regions by varying combinations of power and exposure time (0.5-8.0 J). Tissue was then excised and examined grossly and histologically for evidence of thermal injury using nitroblue tetrazolium chloride viability stain. RESULTS Reproducible TIZs were produced selectively in the SMAS at depths of up to 7.8 mm, and sparing of surrounding tissue including the epidermis. Higher energy settings and high-density exposure line pattern produced a greater degree of tissue shrinkage. CONCLUSIONS In human cadaveric facial tissue, IUS can noninvasively target and selectively produce TIZs of reproducible location, size, and geometry in the SMAS layer. The ability to produce focused thermal collagen denaturation in the SMAS to induce shrinkage and tissue tightening has not been previously reported and has significant implications for aesthetic facial rejuvenation.
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Affiliation(s)
- W Matthew White
- Division of Facial Plastic and Reconstructive Surgery, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA 02114, USA
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15
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Abstract
OBJECTIVE The aim of this study was to evaluate the efficacy and safety of removing traumatic tattoos in the skin by laser. The objective was to achieve selective dermabrasion on the tattoo site without injuries to the surrounding skin, as in the classical mechanical dermabrasion. METHODS Four patients with traumatic tattoos in the face were treated by a variable pulsed erbium:YAG laser. The fluence of the ablative pulses was 5 J/cm(2). The end-point for the treatment was the macroscopic removal of the foreign bodies. Postoperatively, silver sulphadiazine or polyvinylpyrrolidone was applied daily until wound closure occured. Use of a total sun block was mandatory for a period of 6 months. Pre- and post-operative photographs were taken of all cases. The results were evaluated by a panel of four independent observers, who were asked to judge the percentage of tattoo clearance as well as any evidence of pigmentation problems or scarring. RESULTS All results were rated from good to excellent. In all patients, a nearly complete clearance of the traumatic tattoo was achieved in one laser session. No scarring, skin atrophy, or hypo- or hyperpigmentation was observed. Furthermore, a high patient satisfaction rate was achieved. CONCLUSION The selective ablation of scar/foreign body tissue is a safe procedure. Compared to results reported with 1064-nm laser treatments, where several laser procedures are necessary, better clearance and scar quality was observed. Compared to mechanical dermabrasion, the procedure is more reliable and causes fewer side effects.
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Affiliation(s)
- Bernard Cambier
- Department of Plastic, Reconstructive and Aesthetic Surgery, Academic Hospital Saint-Blasius, Dendermonde, Belgium
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16
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Hammes S, Greve B, Raulin C. Electro-optical synergy (ELOS?) technology for nonablative skin rejuvenation: a preliminary prospective study. J Eur Acad Dermatol Venereol 2006; 20:1070-5. [PMID: 16987260 DOI: 10.1111/j.1468-3083.2006.01702.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVES In this preliminary prospective study, we evaluated the efficacy and safety of nonablative wrinkle treatment using combined radiofrequency (RF) and optical energy (Polaris). The dual energy technology of Polaris, called ELOS, which stands for electro-optical synergy, uses synchronous pulses of bipolar RF current and pulsed visible light (diode laser) delivered in the same pulse. MATERIALS AND METHODS Twenty-four subjects with periorbital and perioral wrinkles received six treatments at 4-week intervals with the Polaris WR (Syneron, Inc., Israel, 900 nm, max. RF energy 100 J/cm(3), max. laser energy 50 J/cm(2)). Each treatment consisted of two passes over the treatment area using pulsed optical and RF parameters that were determined by the patient's skin phenotype and distribution of target chromophores. The follow-up period was 3 months after the last treatment. RESULTS Independent scoring of blinded photographs showed a wrinkle score improvement of at least 1 (0 = no improvement, 1 = medium, 2 = good, 3 = excellent improvement) 3 months after the last of six treatment sessions. There was no difference between periorbital and perioral wrinkle reduction. Fifty-eight per cent (14/24) of the subjects reported a notable wrinkle reduction; 16% noted mild to moderate oedema and erythema lasting for no more than 1 day. Scarring or pigmentary changes were not detected. The average pain score was 0.6 (0 = no pain, 5 = intolerable pain). CONCLUSION Multiple treatments with the Polaris WR produced objective and subjective reduction of periorbital and perioral wrinkles. The occurrence of side-effects and pain was very low. The clinical effect may be caused by matrix coagulation of the deep dermis by the RF and selective thermolysis of blood vessels with the 900 nm diode laser.
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Affiliation(s)
- S Hammes
- Laserklinik Karlsruhe, Kaiserstr. 104, 76133 Karlsruhe, Germany
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17
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Abstract
The trend toward minimally invasive rejuvenation techniques has led to the widespread use of nonablative lasers. Nonablative lasers can be classified in two groups based on their wavelengths: lasers emitting light in the visible range, and those emitting in the infrared range. In this review, different laser and intense pulsed light (IPL) systems are presented and critically discussed along with findings of the studies in the literature.
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Affiliation(s)
- Keyvan Nouri
- Department of Dermatology and Otolaryngology, University of Miami-Miller School of Medicine, Miami, FL, USA.
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18
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Dang Y, Ren Q, Li W, Yang Q, Zhang J. Comparison of biophysical properties of skin measured by using non-invasive techniques in the KM mice following 595 nm pulsed dye, 1064 nm Q-Switched Nd:YAG and 1320 nm Nd:YAG laser non-ablative rejuvenation. Skin Res Technol 2006; 12:119-25. [PMID: 16626386 DOI: 10.1111/j.0909-752x.2006.00137.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
BACKGROUNDS/AIMS The aim of the study was to compare the changes of the biophysical properties and to objectify the effects of 595 nm pulsed dye, 1064 nm Q-switched Nd:YAG and 1320 nm Nd:YAG lasers non-ablative rejuvenation by non-invasive techniques. METHODS KM mice were used for the study. The 595 nm pulsed dye, 1064 nm Q-switched Nd:YAG and 1320 nm Nd:YAG laser treatments were evaluated with biophysical parameter measurements including skin elasticity, skin color, skin trans-epidermal water loss (TEWL) and skin hydration. RESULTS All three lasers improved the biophysical properties in the skin of KM mice. In skin elasticity measurements, the 1064 nm laser treatment showed the lowest ratio (0.61+/-0.09) while the 1320 nm laser showed the highest one (0.76+/-0.07) on day 60. For erythema values, a significant increase was observed immediately after the 1064 nm laser treatment (196.67+/-19.17), but the lowest values occurred with the 1320 nm laser treatment (189.83+/-16.54). None of the three lasers resulted in obvious changes of skin melanin. TEWL increased immediately after laser irradiation, then began to recover and decreased 60 days after the 595 and 1064 nm laser treatments. With the 1320 nm laser treatment the TEWL began to decrease from day 7 and obtained the lowest mean values (5.23+/-1.13). The water-holding capacity increased initially for the 595 and 1320 nm laser irradiation, while decreased for the 1064 nm laser. At day 60 of the experiment, skin hydration values in all animals were superior to those of the controls. The 1320 nm laser treatment caused the highest ratio (1.29+/-0.26). Both the values of TEWL and skin hydration for the 1320 nm laser treated areas differed significantly from the other two lasers. CONCLUSIONS Our data showed the 1064 nm Q-switched Nd:YAG laser treatment was most effective in improving the skins' mechanical properties, while the 1320 nm Nd:YAG laser can enhance greatly the skin barrier function and the water-holding capacity. Moreover, we demonstrated the biophysical properties differed considerably between different areas.
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Affiliation(s)
- Yongyan Dang
- Institute for Laser Medicine & Biophotonics, Shanghai Jiaotong University, Shanghai, China
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19
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Dang YY, Ren QS, Liu HX, Ma JB, Zhang JS. Comparison of histologic, biochemical, and mechanical properties of murine skin treated with the 1064-nm and 1320-nm Nd:YAG lasers. Exp Dermatol 2006; 14:876-82. [PMID: 16274454 DOI: 10.1111/j.1600-0625.2005.00371.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The goal of this study was to compare the effects of the Q-switched 1064-nm Nd:YAG laser and the 1320-nm Nd:YAG laser non-ablative treatments on mouse skin in vivo. Skin elasticity measurements were carried out with a Reviscometer, and skin samples were taken for histological study, hydroxyproline content assay and estimation of collagen type I and III. By the second month after non-ablative treatments, the 1064-nm laser treatment resulted in an average of 25% greater improvement of skin elasticity, 6% more increase of dermal thickness, and 11% higher synthesis of hydroxyproline than the 1320-nm laser. Collagen type III increased markedly after the 1064-nm laser treatment whereas more collagen type I was elicited by the 1320-nm laser. Our results demonstrated that the 1064-nm laser was more effective than the 1320-nm Nd:YAG laser in non-ablative treatments, but the results needed to be confirmed in humans. It appeared that photo-mechanic reaction could cause more collagen type III synthesis whereas the photo-thermal effect was in favor of the formation of collagen type I.
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Affiliation(s)
- Yong-Yan Dang
- Institute for Laser Medicine & Biophotonics, Shanghai Jiaotong University, Shanghai, China
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20
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Dang Y, Ren Q, Hoecker S, Liu H, Ma J, Zhang J. Biophysical, histological and biochemical changes after non-ablative treatments with the 595 and 1320 nm lasers: a comparative study. PHOTODERMATOLOGY PHOTOIMMUNOLOGY & PHOTOMEDICINE 2005; 21:204-9. [PMID: 15998369 DOI: 10.1111/j.1600-0781.2005.00163.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND/PURPOSE The objective was to compare the efficiencies of the 595 nm pulsed dye and the 1320 nm Nd : YAG laser non-ablative rejuvenation. METHODS KM mice were irradiated with the 595 nm pulsed dye and the 1320 nm Nd : YAG lasers. Histological changes were evaluated immediately, 1, 7, 21, 30 and 60 days after the two laser treatments. Skin hydration and hydroxyproline content were measured to quantify the degree of improvement of the skin's water-holding capacity and the rate of hydroxyproline synthesis. RESULTS Although not statistically significant, the 1320 nm Nd : YAG laser treatment induced 9.7% greater improvement of skin hydration than the 595 nm laser while the 595 nm pulsed dye laser treatment led to a thicker dermis and 8.7% greater increase of hydroxyproline than the 1320 nm laser. More than 50% increase of collagen type I was observed in 75% of 595 nm laser-treated sites and 42% of 1320 nm laser-treated sites, and more than 25% increase of collagen type III was observed in 75% of 595 nm laser-treated sites and 50% of 1320 nm laser-treated sites. The 595 nm laser treatment was better in increasing the amount of collagen fibers, especially collagen type I (P < 0.05). CONCLUSION Our results demonstrated that the 595 nm laser appeared to be more effective in increasing new collagen formation, while the 1320 nm laser was superior to the 595 nm laser in improving the skin's water-holding capacity.
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Affiliation(s)
- Yongyan Dang
- Institute for Laser Medicine & Biophotonics, Shanghai Jiaotong University, Shanghai, China
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21
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Drnovsek-Olup B, Beltram M, Pizem J. Repetitive Er:YAG laser irradiation of human skin: a histological evaluation. Lasers Surg Med 2005; 35:146-51. [PMID: 15334619 DOI: 10.1002/lsm.20080] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND AND OBJECTIVE Deep coagulation of skin collagen by Er:YAG laser repetitive pulses has been predicted by previous theoretical models and later demonstrated on animal skin. The goal of this study was to determine the effect of repetitive Er:YAG laser pulses on human skin and its response to this treatment. STUDY DESIGN/MATERIALS AND METHODS Lid skin of six female volunteers with blepharochalasis has been treated with laser at day 0, 7, and 21 before elective surgery-blepharoplasty. The treated skin was excised as part of the procedure and prepared for further histological examination. We used a 2,940 nm Er:YAG laser (Fidelis M320A by Fotona) with 'smooth' mode parameters: fluence from 0.50 to 2.00 J/cm2; six pulses per packet; 550 microsecond/pulse, 250 millisecond/packet; single pass, no overlapping; spot size 5 mm; repetition rate 20 Hz. RESULTS We observed deep collagen denaturation at laser fluences of 1.25 J/cm2 and over; epidermal damage was proportional to fluence with total coagulation of the epidermal layer at fluences of 1.75 J/cm2 and over. At day 7 after laser treatment we observed a complete regeneration of the epidermal layer and a regeneration zone within the dermis with prominent infiltration of CD68+ monocytes/macrophages. At day 21 after laser treatment we observed collagen remodeling and (myo-)fibroblast proliferation at tissue depths of up to 240 microm. CONCLUSIONS Repetitive Er:YAG laser irradiation is effective in deep denaturation and remodeling of human skin collagen in vivo, with less epidermal damage compared to standard Er:YAG laser skin resurfacing.
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Affiliation(s)
- Brigita Drnovsek-Olup
- Department of Oculoplastic Surgery, University Eye Clinic, Medical Centre, Ljubljana, Slovenia.
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22
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Goldberg DJ, Sarradet D, Hussain M, Krishtul A, Phelps R. Clinical, histologic, and ultrastructural changes after nonablative treatment with a 595-nm flashlamp-pumped pulsed dye laser: comparison of varying settings. Dermatol Surg 2004; 30:979-82. [PMID: 15209786 DOI: 10.1111/j.1524-4725.2004.30301.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND The flashlamp-pulsed dye laser has been used for nonablative dermal remodeling. OBJECTIVE We conducted a study analyzing the clinical, histologic, and electron microscopic findings after treatment with different flashlamp-pulsed dye laser settingss in the same subject. RESULTS Most subjects showed mild to moderate improvement after flashlamp-pulsed dye laser laser treatment. There was no statistical difference in the clinical, histologic, or electron microscopic findings with a variety of laser treatment settings. CONCLUSION Nonablative dermal remodeling can be accomplished with not only a variety of different technologies, but also with the same laser using markedly different settings.
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Affiliation(s)
- David J Goldberg
- Skin Laser and Surgery Specialists of New York and New Jersy, Hackensack, New Jersey, USA.
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23
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Clinical, Histologic, and Ultrastructural Changes after Nonablative Treatment with a 595-nm Flashlamp-Pumped Pulsed Dye Laser. Dermatol Surg 2004. [DOI: 10.1097/00042728-200407000-00003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Alam M, Hsu TS, Dover JS, Wrone DA, Arndt KA. Nonablative laser and light treatments: histology and tissue effects--a review. Lasers Surg Med 2003; 33:30-9. [PMID: 12866119 DOI: 10.1002/lsm.10195] [Citation(s) in RCA: 96] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVES Nonablative laser and light treatments have largely replaced ablative laser therapy in clinical use for the improvement of the visible signs of cutaneous photoaging, including rhytides, vascular lesions, and pigmentation. However, the mechanisms underlying the reported clinical efficacy of nonablative treatments are not well-understood. The purpose of this analysis is to critically evaluate what is known about histologic and tissue effects of nonablative laser therapy and suggest future directions for research. STUDY DESIGN/MATERIALS AND METHODS This is a review of the English language literature pertaining to nonablative laser and light treatments available through MEDline (1995-2002), and unpublished reports presented at major national meetings. Only studies that included harvesting and analysis of tissue samples are included. RESULTS AND CONCLUSIONS (a) Thermal injury to the dermis in association with epidermal cooling most likely affects the dermal vasculature, which initiates a cascade of inflammatory events that includes fibroblastic proliferation and apparent up-regulation of collagen expression; (b) There is no indication that nonablative treatments are harmful or able to induce skin cancer; (c) It is possible that the horizontally distributed collagen reported after nonablative treatments is a "microscar," an enlarged Grenz sone associated with repetitive photo-induced trauma; (d) Further research is needed to elucidate the biophysical mechanisms underlying nonablative treatment, as well as to distinguish the utility of different wavelengths on epidermal and dermal improvement.
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Affiliation(s)
- Murad Alam
- Section of Cutaneous and Aesthetic Surgery, Department of Dermatology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA.
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25
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Abstract
UNLABELLED STUDY DESIGN/BACKGROUND AND OBJECTIVES: Currently, ablative laser therapy (with CO2/Er:YAG lasers) is considered an effective and promising method of skin rejuvenation. The induction of collagen synthesis was observed after treatments with the CO2 laser and with the long-pulsed Er:Yag laser. In past years, the undesirable side effects and risks of these methods have led to intensified research efforts in the fields of non-ablative facial rejuvenation as well as subsurfacing by means of non-ablative laser systems and intense pulsed light systems. The objective is to achieve selective, heat-induced denaturalization of dermal collagen that leads to subsequent reactive synthesis of neocollagen but does not damage the epidermis. This article reviews the use of different types of lasers and intense pulsed light sources for the non-ablative treatment of facial rhytides. RESULTS The results of numerous clinical and histological investigations have recently indicated that these new technologies are successful. Some studies demonstrated remarkable effects with non-ablative systems; others, however, showed only limited cosmetic improvement or none at all. CONCLUSIONS After critical review and assessment of current literature on the treatment of rhytides, we have found that non-ablative methods do not appear to be a comparable alternative to ablative skin resurfacing in terms of their efficacy and side effects.
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Edris A, Choi B, Aguilar G, Nelson JS. Measurements of laser light attenuation following cryogen spray cooling spurt termination. Lasers Surg Med 2003; 32:143-7. [PMID: 12561048 DOI: 10.1002/lsm.10151] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVES Cryogen spray cooling (CSC) is used to minimize the risk of epidermal damage during laser dermatological surgery. However, while CSC can protect the epidermis from non-specific thermal damage, the cryogen film on the skin surface may pose a potential problem of laser light attenuation due to optical scattering. STUDY DESIGN/MATERIALS AND METHODS This study is focused on measuring the light transmittance changes that occur following cryogen spurt termination. The wavelengths studied were chosen for their clinical relevance to treatment of hypervascular skin lesions (594 nm) and laser-assisted hair removal (785 nm). Following delivery of cryogen spurts to the surface of an epoxy skin phantom, continuous records of light transmittance for 594 and 785 nm were obtained using an integrating sphere-based light collection apparatus. RESULTS Shortly after spurt termination, there was negligible light attenuation by the cryogen film at the two wavelengths studied. CONCLUSIONS For the typical clinical use of a 30 milliseconds spurt duration and 30 milliseconds delay between spurt termination and delivery of the laser pulse, a minimum average transmittance value of approximately 97% was measured.
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Affiliation(s)
- Ahmad Edris
- College of Medicine, University of California, Irvine, California 92697, USA
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27
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Kao B, Kelly KM, Majaron B, Nelson JS. Novel model for evaluation of epidermal preservation and dermal collagen remodeling following photorejuvenation of human skin. Lasers Surg Med 2003; 32:115-9. [PMID: 12561044 DOI: 10.1002/lsm.10114] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
BACKGROUND AND OBJECTIVES In order to optimize photorejuvenation of human skin, a method must be developed to reliably compare the potential for epidermal preservation and dermal fibroblast stimulation of different laser devices and irradiation parameters. We describe a novel human skin tissue culture model developed for this purpose. MATERIALS AND METHODS An artificial skin model, consisting of human keratinocytes in the epidermis and human fibroblasts and rat-tail collagen in the dermis, was cultured using the floating collagen gel (RAFT) method. Repetitive low-fluence Er:YAG laser irradiation was applied to test the applicability of our RAFT model for characterization of epidermal preservation and dermal fibroblast stimulation post-laser treatment. RESULTS Histopathologic evaluation revealed a thin layer of epidermal keratinocyte preservation immediately after low fluence sub-ablative Er:YAG laser irradiation. One-week post-laser irradiation, the average increase in number of dermal fibroblasts as compared to control was statistically significant (P < 0.01). CONCLUSIONS The RAFT model can be used to assess the potential for epidermal preservation and dermal fibroblast stimulation of different photorejuvenation devices and irradiation parameters and offers several advantages over traditional animal and human skin models.
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Affiliation(s)
- Bunsho Kao
- Department of Dermatology and Surgery, Beckman Laser Institute and Medical Clinic, University of California, Irvine, California 92612, USA
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Abstract
BACKGROUND AND OBJECTIVES Non-ablative technologies are playing an increasing role in the management of photoaging. Newer radiofrequency technologies have added to this therapeutic armamentarium. Shorter wavelength technologies are more effective in targeting pilosebaceous vascular and pigmentary alterations while longer wavelength technologies are most effective in wrinkle reduction mediated through dermal remodeling. An overview of the various technologies available to the practicing laser surgeon are outlined in the present review.
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Affiliation(s)
- Neil S Sadick
- Clinical Professor of Dermatology, Weill Medical College of Cornell University, Ithaca, New York, USA.
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29
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Ross EV, Zelickson BD. Biophysics of nonablative dermal remodeling. SEMINARS IN CUTANEOUS MEDICINE AND SURGERY 2002; 21:251-65. [PMID: 12512648 DOI: 10.1053/sder.2002.36767] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
This article explores the physics of nonablative skin remodeling as well as the histologic sequelae. Although there have been several studies of nonablative skin remodeling, the exact mechanisms of action and thus the optimum device-specific parameters are not yet known. The article is divided into a discussion of the physics of laser-tissue interactions, followed by a review of the types of devices used for nonablative skin remodeling, and the histologic findings that follow treatment.
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Affiliation(s)
- E Victor Ross
- Dermatology Department, Naval Medical Center San Diego, San Diego, CA 92134, USA.
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30
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Abstract
Nonablative skin remodeling has become an attractive option for patients whose lifestyles demand a noninvasive approach to skin rejuvenation. This review addresses the rationales for therapy, specific devices, and study outcomes.
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Affiliation(s)
- Christina A Hardaway
- Department of Dermatology, Naval Medical Center San Diego, San Diego, California, USA
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31
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Kelly KM, Majaron B, Nelson JS. Nonablative laser and light rejuvenation: the newest approach to photodamaged skin. ARCHIVES OF FACIAL PLASTIC SURGERY 2001; 3:230-5. [PMID: 11710855 DOI: 10.1001/archfaci.3.4.230] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- K M Kelly
- Beckman Laser Institute and Medical Clinic, and the Department of Dermatology, University of California, 1002 Health Sciences Rd E, Irvine, CA 92612, USA
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32
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Majaron B, Verkruysse W, Kelly KM, Nelson JS. Er:YAG laser skin resurfacing using repetitive long-pulse exposure and cryogen spray cooling: II. Theoretical analysis. Lasers Surg Med 2001; 28:131-7. [PMID: 11241518 DOI: 10.1002/lsm.1027] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND AND OBJECTIVE To analyze the effects of laser pulse duration and cryogen spray cooling (CSC) on epidermal damage and depth of collagen coagulation in skin resurfacing with repetitive Er:YAG laser irradiation. STUDY DESIGN/MATERIALS AND METHODS Evolution of temperature field in skin is calculated using a simple one-dimensional model of sub-ablative pulsed laser exposure and CSC. The model is solved numerically for laser pulse durations of 150 and 600 microsec, and 6 msec cryogen spurts delivered just prior to ("pre-cooling"), or during and after ("post-cooling") the 600 microsec laser pulse. RESULTS The model indicates a minimal influence of pulse duration on the extent of thermal effect in dermis, but less epidermal damage with 600 microsec pulses as compared to 150 microsec at the same pulse fluence. Application of pre- or post-cooling reduces the peak surface temperature after laser exposure and accelerates its relaxation toward the base temperature to a different degree. However, the temperature profile in skin after 50 msec is in either example very similar to that after a lower-energy laser pulse without CSC. CONCLUSIONS When applied in combination with repetitive Er:YAG laser exposure, CSC strongly affects the amount of heat available for dermal coagulation. As a result, CSC may not provide spatially selective epidermal protection in Er:YAG laser skin resurfacing.
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Affiliation(s)
- B Majaron
- Beckman Laser Institute and Medical Clinic, University of California, Irvine, California 92612, USA.
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