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Does Laser Surgery Interfere with Optical Nerve Identification in Maxillofacial Hard and Soft Tissue?—An Experimental Ex Vivo Study

The protection of sensitive structures (e.g., nerves) from iatrogenic damage is of major importance when performing laser surgical procedures. Especially in the head and neck area both function and esthetics can be affected to a great extent. Despite its many benefits, the surgical utilization of a...

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Autores principales: Bergauer, Bastian, Knipfer, Christian, Amann, Andreas, Rohde, Maximilian, Tangermann-Gerk, Katja, Adler, Werner, Schmidt, Michael, Nkenke, Emeka, Stelzle, Florian
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4634421/
https://www.ncbi.nlm.nih.gov/pubmed/26437416
http://dx.doi.org/10.3390/s151025416
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author Bergauer, Bastian
Knipfer, Christian
Amann, Andreas
Rohde, Maximilian
Tangermann-Gerk, Katja
Adler, Werner
Schmidt, Michael
Nkenke, Emeka
Stelzle, Florian
author_facet Bergauer, Bastian
Knipfer, Christian
Amann, Andreas
Rohde, Maximilian
Tangermann-Gerk, Katja
Adler, Werner
Schmidt, Michael
Nkenke, Emeka
Stelzle, Florian
author_sort Bergauer, Bastian
collection PubMed
description The protection of sensitive structures (e.g., nerves) from iatrogenic damage is of major importance when performing laser surgical procedures. Especially in the head and neck area both function and esthetics can be affected to a great extent. Despite its many benefits, the surgical utilization of a laser is therefore still limited to superficial tissue ablation. A remote feedback system which guides the laser in a tissue-specific way would provide a remedy. In this context, it has been shown that nerval structures can be specifically recognized by their optical diffuse reflectance spectra both before and after laser ablation. However, for a translation of these findings to the actual laser ablation process, a nerve protection within the laser pulse is of utmost significance. Thus, it was the aim of the study to evaluate, if the process of Er:YAG laser surgery—which comes with spray water cooling, angulation of the probe (60°) and optical process emissions—interferes with optical tissue differentiation. For the first time, no stable conditions but the ongoing process of laser tissue ablation was examined. Therefore, six different tissue types (nerve, skin, muscle, fat, cortical and cancellous bone) were acquired from 15 pig heads. Measurements were performed during Er:YAG laser ablation. Diffuse reflectance spectra (4500, wavelength range: 350–650 nm) where acquired. Principal component analysis (PCA) and quadratic discriminant analysis (QDA) were calculated for classification purposes. The clinical highly relevant differentiation between nerve and bone was performed correctly with an AUC of 95.3% (cortial bone) respectively 92.4% (cancellous bone). The identification of nerve tissue against the biological very similar fat tissue yielded good results with an AUC value of 83.4% (sensitivity: 72.3%, specificity: of 82.3%). This clearly demonstrates that nerve identification by diffuse reflectance spectroscopy works reliably in the ongoing process of laser ablation in spite of the laser beam, spray water cooling and the tissue alterations entailed by tissue laser ablation. This is an essential step towards a clinical utilization.
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spelling pubmed-46344212015-11-23 Does Laser Surgery Interfere with Optical Nerve Identification in Maxillofacial Hard and Soft Tissue?—An Experimental Ex Vivo Study Bergauer, Bastian Knipfer, Christian Amann, Andreas Rohde, Maximilian Tangermann-Gerk, Katja Adler, Werner Schmidt, Michael Nkenke, Emeka Stelzle, Florian Sensors (Basel) Article The protection of sensitive structures (e.g., nerves) from iatrogenic damage is of major importance when performing laser surgical procedures. Especially in the head and neck area both function and esthetics can be affected to a great extent. Despite its many benefits, the surgical utilization of a laser is therefore still limited to superficial tissue ablation. A remote feedback system which guides the laser in a tissue-specific way would provide a remedy. In this context, it has been shown that nerval structures can be specifically recognized by their optical diffuse reflectance spectra both before and after laser ablation. However, for a translation of these findings to the actual laser ablation process, a nerve protection within the laser pulse is of utmost significance. Thus, it was the aim of the study to evaluate, if the process of Er:YAG laser surgery—which comes with spray water cooling, angulation of the probe (60°) and optical process emissions—interferes with optical tissue differentiation. For the first time, no stable conditions but the ongoing process of laser tissue ablation was examined. Therefore, six different tissue types (nerve, skin, muscle, fat, cortical and cancellous bone) were acquired from 15 pig heads. Measurements were performed during Er:YAG laser ablation. Diffuse reflectance spectra (4500, wavelength range: 350–650 nm) where acquired. Principal component analysis (PCA) and quadratic discriminant analysis (QDA) were calculated for classification purposes. The clinical highly relevant differentiation between nerve and bone was performed correctly with an AUC of 95.3% (cortial bone) respectively 92.4% (cancellous bone). The identification of nerve tissue against the biological very similar fat tissue yielded good results with an AUC value of 83.4% (sensitivity: 72.3%, specificity: of 82.3%). This clearly demonstrates that nerve identification by diffuse reflectance spectroscopy works reliably in the ongoing process of laser ablation in spite of the laser beam, spray water cooling and the tissue alterations entailed by tissue laser ablation. This is an essential step towards a clinical utilization. MDPI 2015-10-01 /pmc/articles/PMC4634421/ /pubmed/26437416 http://dx.doi.org/10.3390/s151025416 Text en © 2015 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Bergauer, Bastian
Knipfer, Christian
Amann, Andreas
Rohde, Maximilian
Tangermann-Gerk, Katja
Adler, Werner
Schmidt, Michael
Nkenke, Emeka
Stelzle, Florian
Does Laser Surgery Interfere with Optical Nerve Identification in Maxillofacial Hard and Soft Tissue?—An Experimental Ex Vivo Study
title Does Laser Surgery Interfere with Optical Nerve Identification in Maxillofacial Hard and Soft Tissue?—An Experimental Ex Vivo Study
title_full Does Laser Surgery Interfere with Optical Nerve Identification in Maxillofacial Hard and Soft Tissue?—An Experimental Ex Vivo Study
title_fullStr Does Laser Surgery Interfere with Optical Nerve Identification in Maxillofacial Hard and Soft Tissue?—An Experimental Ex Vivo Study
title_full_unstemmed Does Laser Surgery Interfere with Optical Nerve Identification in Maxillofacial Hard and Soft Tissue?—An Experimental Ex Vivo Study
title_short Does Laser Surgery Interfere with Optical Nerve Identification in Maxillofacial Hard and Soft Tissue?—An Experimental Ex Vivo Study
title_sort does laser surgery interfere with optical nerve identification in maxillofacial hard and soft tissue?—an experimental ex vivo study
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4634421/
https://www.ncbi.nlm.nih.gov/pubmed/26437416
http://dx.doi.org/10.3390/s151025416
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