Quantitative detection of hemoglobin saturation in the liver with near-infrared spectroscopy

Abstract

To quantify the changes in oxygen saturation of hemoglobin in the liver in hypoxia and liver transplantation, we applied a novel method using near-infrared spectroscopy. Instead of the conventional two-wave-length method, we obtained near-infrared data from a wide spectral range of 700 nm to 1,000 nm with continuous-wave spectroscopy. To correct the flattened spectral shape caused by photon scattering in living tissue, we then applied an equation taking into account the relationship between absorber concentration and actual absorption in scattering materials as assessed with time-resolved spectroscopy. Hepatic hemoglobin oxygen saturation was calculated with multicomponent analysis. In room air, hepatic hemoglobin oxygen saturation of rabbit was calculated as 57.4% +/- 2.5% (mean +/- S.E.M., n = 7). Arterial, portal and hepatic venous hemoglobin oxygen saturation were simultaneously measured as 97.5% +/- 0.7%, 77.1% +/- 3.4% and 55.5% +/- 4.6%, respectively. The changes in hepatic hemoglobin oxygen saturation seen in graded hypoxia were also close to those in hepatic venous hemoglobin oxygen saturation, suggesting that the average oxygenation state of sinusoidal blood approximates that in the central vein. We tested the clinical applicability of this method in a case of liver transplantation. It was determined that the hepatic hemoglobin oxygen saturation of the graft liver was heterogeneously distributed and that the initially low level of hepatic hemoglobin oxygen saturation was increased by the ligation of portal-systemic shunts.

Transcutaneously measured near-infrared spectroscopic liver tissue oxygenation does not correlate with hepatic venous oxygenation in children

“…Several authors have reported on NIRS measurement of liver tissue oxygenation. [9][10][11][22][23][24][25] Most of these studies were performed in animals, with the NIRS probe attached to the liver surface after laparotomy. The investigators mainly studied relative changes of liver tissue oxygenation during naso-gastric feeding, induced hypovolemia, low cardiac output, graded hypoxia or hepatic vascular in-flow occlusion.…”

Relationship Between Cerebral Oxygenation and Phosphorylation Potential During Secondary Energy Failure in Hypoxic-Ischemic Newborn Piglets

“…The length of the fibers allowed us to perform NIRS measurements simultaneously with 31 P-MRS measurements while the piglets were in the magnet. We used a white plate as a reference to convert the spectrum to an absorption spectrum (20).…”

Changes in tissue oxygenation of the porcine liver measured by near-infrared spectroscopy

“…10,11 The use of NIRS for evaluating hepatic tissue oxygenation is limited to the authors 12 and one main group in Japan. 13 However, there is no basic experimental work to define the significance of the NIRS signal from the liver parenchyma and its relationship with liver blood flow and oxygen supply. As a prelude to human organ transplant work, we have therefore evaluated the application of NIRS for the measurement of hepatic tissue oxygenation and perfusion in a large animal model with hepatic vascular inflow occlusion and graded hypoxia.…”