Matjaž Lukač PhD, Jure Košir PhD, Tilen Žel MSc, Marko Kažič BSc, Dominik Šavli MSc, Matija Jezeršek PhD
{"title":"Influence of tissue desiccation on critical temperature for thermal damage during Er:YAG laser skin treatments","authors":"Matjaž Lukač PhD, Jure Košir PhD, Tilen Žel MSc, Marko Kažič BSc, Dominik Šavli MSc, Matija Jezeršek PhD","doi":"10.1002/lsm.23739","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <h3> Objectives</h3>\n \n <p>Erbium lasers have become an accepted tool for performing both ablative and non-ablative medical procedures, especially when minimal invasiveness is desired. Hard-tissue desiccation during Er:YAG laser procedures is a well-known phenomenon in dentistry, the effect of which is to a certain degree being addressed by the accompanying cooling water spray. The desiccation of soft tissue has attracted much less attention due to the soft tissue's high-water content, resulting in a smaller effect on the ablation process.</p>\n </section>\n \n <section>\n \n <h3> Materials and methods</h3>\n \n <p>In this study, the characteristics of skin temperature decay following irradiations with Er:YAG laser pulses were measured using a fast thermal camera.</p>\n </section>\n \n <section>\n \n <h3> Results</h3>\n \n <p>The measurements revealed a substantial increase in temperature decay times and resulting thermal exposure times following irradiations with Er:YAG pulses with fluences below the laser ablation threshold. Based on an analytical model where the skin surface cooling time is calculated from the estimated thickness of the heated superficial layer of the stratum corneum (SC), the observed phenomena is attributed to the accelerated evaporation of water from the SC's surface. By using an Arrhenius damage integral-based variable heat shock model to describe the dependence of the critical temperature on the duration of thermal exposure, it is shown that contrary to what an inexperienced practitioner might expect, the low-to-medium level fluences may result in a larger thermal damage in comparison to treatments where higher fluences are used. This effect may be alleviated by hydrating the skin before Er:YAG treatments.</p>\n </section>\n \n <section>\n \n <h3> Conclusion</h3>\n \n <p>Our study indicates that tissue desiccation may play a more important role than expected for soft-tissue procedures. It is proposed that its effect may be alleviated by hydrating the skin before Er:YAG treatments.</p>\n </section>\n </div>","PeriodicalId":17961,"journal":{"name":"Lasers in Surgery and Medicine","volume":null,"pages":null},"PeriodicalIF":2.2000,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lsm.23739","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Lasers in Surgery and Medicine","FirstCategoryId":"3","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1002/lsm.23739","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"DERMATOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Objectives
Erbium lasers have become an accepted tool for performing both ablative and non-ablative medical procedures, especially when minimal invasiveness is desired. Hard-tissue desiccation during Er:YAG laser procedures is a well-known phenomenon in dentistry, the effect of which is to a certain degree being addressed by the accompanying cooling water spray. The desiccation of soft tissue has attracted much less attention due to the soft tissue's high-water content, resulting in a smaller effect on the ablation process.
Materials and methods
In this study, the characteristics of skin temperature decay following irradiations with Er:YAG laser pulses were measured using a fast thermal camera.
Results
The measurements revealed a substantial increase in temperature decay times and resulting thermal exposure times following irradiations with Er:YAG pulses with fluences below the laser ablation threshold. Based on an analytical model where the skin surface cooling time is calculated from the estimated thickness of the heated superficial layer of the stratum corneum (SC), the observed phenomena is attributed to the accelerated evaporation of water from the SC's surface. By using an Arrhenius damage integral-based variable heat shock model to describe the dependence of the critical temperature on the duration of thermal exposure, it is shown that contrary to what an inexperienced practitioner might expect, the low-to-medium level fluences may result in a larger thermal damage in comparison to treatments where higher fluences are used. This effect may be alleviated by hydrating the skin before Er:YAG treatments.
Conclusion
Our study indicates that tissue desiccation may play a more important role than expected for soft-tissue procedures. It is proposed that its effect may be alleviated by hydrating the skin before Er:YAG treatments.
期刊介绍:
Lasers in Surgery and Medicine publishes the highest quality research and clinical manuscripts in areas relating to the use of lasers in medicine and biology. The journal publishes basic and clinical studies on the therapeutic and diagnostic use of lasers in all the surgical and medical specialties. Contributions regarding clinical trials, new therapeutic techniques or instrumentation, laser biophysics and bioengineering, photobiology and photochemistry, outcomes research, cost-effectiveness, and other aspects of biomedicine are welcome. Using a process of rigorous yet rapid review of submitted manuscripts, findings of high scientific and medical interest are published with a minimum delay.