TY - JOUR
T1 - Empirical assessment of laser safety for photoacoustic-guided liver surgeries
AU - Huang, Jiaqi
AU - Wiacek, Alycen
AU - Kempski, Kelley M.
AU - Palmer, Theron
AU - Izzi, Jessica
AU - Beck, Sarah
AU - Lediju Bell, Muyinatu A.
N1 - Funding Information:
Alfred P. Sloan Foundation; National Science Foundation (ECCS-175152); National Institutes of Health (T32GM007057-44). This work was supported by the Alfred P. Sloan Research Fellowship in Physics, NSF CAREER Award ECCS-1751522, and in part by NIH National Institute of General Medical Sciences T32GM007057-44. The authors thank Melanie Adams and Mary Archer for animal care and surgery support.
Publisher Copyright:
© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement.
PY - 2021/3/1
Y1 - 2021/3/1
N2 - Photoacoustic imaging is a promising technique to provide guidance during multiple surgeries and procedures. One challenge with this technique is that major blood vessels in the liver are difficult to differentiate from surrounding tissue within current safety limits, which only exist for human skin and eyes. In this paper, we investigate the safety of raising this limit for liver tissue excited with a 750 nm laser wavelength and approximately 30 mJ laser energy (corresponding to approximately 150 mJ/cm2 fluence). Laparotomies were performed on six swine to empirically investigate potential laser-related liver damage. Laser energy was applied for temporal durations of 1 minute, 10 minutes, and 20 minutes. Lasered liver lobes were excised either immediately after laser application (3 swine) or six weeks after surgery (3 swine). Cell damage was assessed using liver damage blood biomarkers and histopathology analyses of 41 tissue samples total. The biomarkers were generally normal over a 6 week post-surgical in vivo study period. Histopathology revealed no cell death, although additional pathology was present (i.e., hemorrhage, inflammation, fibrosis) due to handling, sample resection, and fibrous adhesions as a result of the laparotomy. These results support a new protocol for studying laser-related liver damage, indicating the potential to raise the safety limit for liver photoacoustic imaging to approximately 150 mJ/cm2 with a laser wavelength of 750 nm and for imaging durations up to 10 minutes without causing cell death. This investigation and protocol may be applied to other tissues and extended to additional wavelengths and energies, which is overall promising for introducing new tissue-specific laser safety limits for photoacoustic-guided surgery.
AB - Photoacoustic imaging is a promising technique to provide guidance during multiple surgeries and procedures. One challenge with this technique is that major blood vessels in the liver are difficult to differentiate from surrounding tissue within current safety limits, which only exist for human skin and eyes. In this paper, we investigate the safety of raising this limit for liver tissue excited with a 750 nm laser wavelength and approximately 30 mJ laser energy (corresponding to approximately 150 mJ/cm2 fluence). Laparotomies were performed on six swine to empirically investigate potential laser-related liver damage. Laser energy was applied for temporal durations of 1 minute, 10 minutes, and 20 minutes. Lasered liver lobes were excised either immediately after laser application (3 swine) or six weeks after surgery (3 swine). Cell damage was assessed using liver damage blood biomarkers and histopathology analyses of 41 tissue samples total. The biomarkers were generally normal over a 6 week post-surgical in vivo study period. Histopathology revealed no cell death, although additional pathology was present (i.e., hemorrhage, inflammation, fibrosis) due to handling, sample resection, and fibrous adhesions as a result of the laparotomy. These results support a new protocol for studying laser-related liver damage, indicating the potential to raise the safety limit for liver photoacoustic imaging to approximately 150 mJ/cm2 with a laser wavelength of 750 nm and for imaging durations up to 10 minutes without causing cell death. This investigation and protocol may be applied to other tissues and extended to additional wavelengths and energies, which is overall promising for introducing new tissue-specific laser safety limits for photoacoustic-guided surgery.
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U2 - 10.1364/BOE.415054
DO - 10.1364/BOE.415054
M3 - Article
C2 - 33796347
AN - SCOPUS:85101330739
SN - 2156-7085
VL - 12
SP - 1205
EP - 1216
JO - Biomedical Optics Express
JF - Biomedical Optics Express
IS - 3
ER -