Hepatic artery Flow, Inspired Oxygen, and Hemoglobin Determine Liver Tissue Saturation Measured with Visible Diffuse Reflectance Spectroscopy (vis-DRS) in an in Vivo Swine Model

Authors

Stylianos Voulgarelis, Medical College of Wisconsin
Faraneh Fathi, Marquette University
Bing Yu, Marquette UniversityFollow
Barbara Palkovic, Medical College of Wisconsin
Nikolaos A. Chatzizacharias, Queen Elizabeth Hospital
Kenneth P. Allen, Medical College of Wisconsin
Astrid G. Stucke, Medical College of Wisconsin

Document Type

Article

Publication Date

6-2022

Publisher

Wiley

Source Publication

Pediatric Transplantation

Source ISSN

1397-3142

Original Item ID

DOI: 10.1111/petr.14230

Abstract

Background

Prompt diagnosis of vascular compromise following pediatric liver transplantation and restoration of oxygen delivery to the liver improves organ survival. vis-DRS allows for real-time measurement of liver tissue saturation.

Methods

The current study used vis-DRS to determine changes in liver saturation during clinically relevant conditions of reduced oxygen delivery. In an in vivo swine model (n = 15), we determined liver tissue saturation (S_tO₂) during stepwise reduction in hepatic artery flow, different inspiratory oxygen fraction (FiO₂), and increasing hemodilution. A custom vis-DRS probe was placed directly on the organ.

Results

Liver tissue saturation decreased significantly with a decrease in hepatic artery flow. A reduction in hepatic artery flow to 25% of baseline reduced the S_tO₂ by 15.3 ± 1.4% at FiO₂ 0.3 (mean ± SE, p < .0013), and by 8.3 ± 1.9% at FiO₂ 1.0 (p = .0013). After hemodilution to 7–8 g/dl, S_tO₂ was reduced by 31.8% ± 2.7%, p < .001 (FiO₂ 0.3) and 26.6 ± 2.7%, p < .001 (FiO₂: 1.0) respectively. Portal venous saturation during low hepatic artery flow was consistently higher at FiO₂ 1.0. The gradient between portal venous saturation and liver tissue saturation was consistently greater at lower hemoglobin levels (7.0 ± 1.6% per g/dl hemoglobin, p < .001).

Conclusions

Vis-DRS showed prompt changes in liver tissue saturation with decreases in hepatic artery blood flow. At hepatic artery flows below 50% of baseline, liver saturation depended on FiO₂ and hemoglobin concentration suggesting that during hepatic artery occlusion, packed red blood cell transfusion and increased FiO₂ may be useful measures to reduce hypoxic damage until surgical revascularization.

Comments

Accepted version. Pediatric Transplantation, Vol. 26, No. 4 (June 2022): e14230. DOI. © 2022 Wiley. Used with permission.

Recommended Citation

Voulgarelis, Stylianos; Fathi, Faraneh; Yu, Bing; Palkovic, Barbara; Chatzizacharias, Nikolaos A.; Allen, Kenneth P.; and Stucke, Astrid G., "Hepatic artery Flow, Inspired Oxygen, and Hemoglobin Determine Liver Tissue Saturation Measured with Visible Diffuse Reflectance Spectroscopy (vis-DRS) in an in Vivo Swine Model" (2022). Biomedical Engineering Faculty Research and Publications. 662.
https://epublications.marquette.edu/bioengin_fac/662