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Evaluation of visible diffuse reflectance spectroscopy in liver tissue: validation of tissue saturations using extracorporeal circulation. J Biomed Opt 2021 May;26(5)

Date

05/23/2021

Pubmed ID

34021537

Pubmed Central ID

PMC8145982

DOI

10.1117/1.JBO.26.5.055002

Scopus ID

2-s2.0-85106702253   2 Citations

Abstract

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 B

Authors

Kenneth Paul Allen DVM Associate Professor in the Research Office department at Medical College of Wisconsin
Joohyun 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
Stylianos Voulgarelis MD Associate 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

Animals
Extracorporeal Circulation
Hemoglobins
Liver
Oxygen
Spectrum Analysis
Swine