Evaluation of visible diffuse reflectance spectroscopy in liver tissue: validation of tissue saturations using extracorporeal circulation. J Biomed Opt 2021 May;26(5)
Date
05/23/2021Pubmed ID
34021537Pubmed Central ID
PMC8145982DOI
10.1117/1.JBO.26.5.055002Scopus ID
2-s2.0-85106702253 (requires institutional sign-in at Scopus site) 4 CitationsAbstract
SIGNIFICANCE: Real-time information about oxygen delivery to the hepatic graft is important to direct care and diagnose vascular compromise in the immediate post-transplant period.
AIM: The current study was designed to determine the utility of visible diffuse reflectance spectroscopy (vis-DRS) for measuring liver tissue saturation in vivo.
APPROACH: A custom-built vis-DRS probe was calibrated using phantoms with hemoglobin (Hb) and polystyrene microspheres. Ex vivo (extracorporeal circulation) and in vivo protocols were used in a swine model (n = 15) with validation via blood gas analysis.
RESULTS: In vivo absorption and scattering measured by vis-DRS with and without biliverdin correction correlated closely between analyses. Lin's concordance correlation coefficients are 0.991 for μa and 0.959 for μs ' . Hb measured by blood test and vis-DRS with (R2 = 0.81) and without (R2 = 0.85) biliverdin correction were compared. Vis-DRS data obtained from the ex vivo protocol plotted against the PO2 derived from blood gas analysis showed a good fit for a Hill coefficient of 1.67 and P50 = 34 mmHg (R2 = 0.81). A conversion formula was developed to account for the systematic deviation, which resulted in a goodness-of-fit R2 = 0.76 with the expected oxygen dissociation curve.
CONCLUSIONS: We show that vis-DRS allows for real-time measurement of liver tissue saturation, an indicator for liver perfusion and oxygen delivery.
Author List
Voulgarelis S, Fathi F, Stucke AG, Daley KD, Kim J, Zimmerman MA, Hong JC, Starkey N, Allen KP, Yu BAuthors
Kenneth Paul Allen DVM Associate Professor in the Research Office department at Medical College of WisconsinJoohyun Kim MD, PhD Associate Professor in the Surgery department at Medical College of Wisconsin
Astrid G. Stucke MD Professor in the Anesthesiology department at Medical College of Wisconsin
Bing Yu PH.D. Assistant Professor of Biomedical Engineering in the Biomedical Engineering department at Marquette University
MESH terms used to index this publication - Major topics in bold
AnimalsExtracorporeal Circulation
Hemoglobins
Liver
Oxygen
Spectrum Analysis
Swine