Use of laser auto-fluorescence for evaluating liver grafts

Abstract

There has been an increasing demand for liver transplantation, while the supply of liver grafts remains limited. Strategies to augment the donor pool include "liver-splitting", "domino" procedure, Living-related liver transplantation and the use of marginal donors. Simultaneously, there has been growing interest in Laser-induced fluorescence (LIF) as a diagnostic tool, mainly in oncology. The basis of all optical spectroscopic techniques is that physiological, morphological or biochemical changes associated with physical disorders, affect the interaction between light and tissue. The aim of this experimental study was to analyze the applicability of LIF in evaluating liver grafts, in rats. In this experiment, the animals were divided into two groups according to the temperature of the perfusion medium. The perfusion medium used was saline solution between 0-4• C in one group (CS group) and the same solution, between 22-26• C, in the other group (RT group). Mitochondrial respiratory capacity, swelling and membrane potential along with the cellular ATP content were used as the functional and metabolic indicators of viability. The Cluster-Russia fluorescence spectroscopy system was used to analyze the LIF. Deterioration of mitochondrial function and ATP content occurred progressively and relatively rapidly. LIF reflected the findings of the mitochondrial respiratory control ratio in the CS group, but not in the RT group. The ratio of the intensity of fluorescence detected at 636 nm and 600 nm showed rapid change 5 to 6 hours after perfusion in the CS group. Therefore LIF shows great potential as an auxiliary tool in the analysis of liver grafts, for transplantation. Graph comparing the reduction of the mitochondrial respiratory control ratio (RCR) and hepatic fluorescence in the CS group, during the 12 hours after perfusion

Multi‐excitation fluorescence spectroscopy for analysis of non‐alcoholic fatty liver disease

“…Autofluorescence from liver has previously been studied in a tissue microscopy instrument under 366 nm laser excitation by Croce et al In that study the analysis of the fluorescence spectra and photobleaching from rat livers enabled the determination of the fluorophores responsible for liver autofluorescence 33, 34. Among these, NAD(P)H, vitamin A and collagen were identified as the primary markers to distinguish healthy, steatotic and fibrotic livers.…”

New perspectives for optical techniques in diagnostic and treatment of hepatic diseases

“…Besides the evaluation of steatosis, a recent published work, demonstrated experimentally, the applicability of LIF in evaluating the viability of rat liver previously perfused with saline solution 5 . Mitochondrial function and cellular ATP content of the liver were used as indicators of its metabolic status.…”

Optical fluorescence spectroscopy to detect hepatic necrosis after normothermic ischemia: animal model

“…A method that combines fluorescence spectroscopy with correction by the absorption spectrum and curve trend analysis may quantify oxy-and deoxyhemoglobin at the liver sinusoid 9,10 . Liver tissue properties have been reported as presenting strong correlation with fluorescence spectra 11,12 . The high sensitivity of this method to monitor metabolism activity in vivo has also been reported previously [13][14][15] .…”