Surface microdialysis sampling: a new approach described in a liver ischaemia model

Abstract

We recently have shown that samples from microdialysis (MD) probes placed on the surface of the heart reflect metabolic events in the myocardium. This new interesting observation challenges us to consider whether surface application of MD applies to other parenchymatous organs and their surfaces. In 13 anesthetized pigs, transient liver ischaemia was achieved by occlusion of arterial and venous inflow to the liver. Two probes on liver surface and two in parenchyma were perfused with a flow rate of 1 μl per min (n = 13). An identical set-up was used for probes with a flow rate of 2 μl per min (n = 9). Samples were collected for every 15-min period during 60 min of baseline, 45 min of ischaemia and 60 min of reperfusion. Lactate, glucose, pyruvate and glycerol were analysed in MD samples. We focused on relative changes in the present study. There was a strong agreement in relative lactate and glucose levels between probes placed on liver surface and those on parenchyma. No significant differences in relative changes in lactate and glucose levels were seen between samples from surface probes and probes in liver parenchyma during equilibration, baseline, ischaemia or reperfusion with a flow rate of 1 μl per min. MD sampling applied on the liver surface is a new application area for the MD technique and may be used to monitor liver metabolism during both physiological and pathophysiological conditions.

Microdialysis in Early Detection of Temporary Pancreatic Ischemia in a Porcine Model

“…The placement of an MD probe into the parenchyma of an organ implies a certain degree of invasiveness and ensuing potential adverse effects [3]. It has recently been demonstrated that markers of ischemia as determined by MD probes placed on the surface of the myocardium and the liver are in concordance with levels within the myocardium [14] and liver parenchyma [15], respectively. These results suggest that the placement of MD probes on the surface of the pancreas could likewise provide online information on ongoing pathophysiological processes within the organ.…”

Surface Microdialysis Detects Ischemia After Esophageal Resection—An Experimental Animal Study

“…In this study, we analyzed the selected S-mD lactate and glucose concentrations because these metabolites have shown reproducible changes related to ischemia in our previous studies. [16][17][18][19][20] When considering the lactate changes, levels reaching a plateau could depend on the relation between aerobic and anaerobic metabolism, which in turn is related to the arterial blood supply. Partially preserved microcirculation at the gastric corpus (catheter position B) Table 3 e Intracatheter comparisons of absolute values of mD lactate and mD glucose between baseline and each hour during ischemia at four catheter locations (sites A-D).…”

“…The surface microdialysis (S-mD) catheter measures concentrations of metabolites at the surface of the specific organ, is less invasive, and renders outcome in excellent agreement with intraparenchymal catheters in the heart and liver. [16][17][18] Furthermore, the S-mD method provides outcome in concordance with histopathologically graded ischemia of the small bowel. 19 S-mD allows for online detection and monitoring of organ ischemia within minutes after its onset.…”

The coherence of macrocirculation, microcirculation, and tissue metabolic response during nontraumatic hemorrhagic shock in swine

“…; Abrahamsson et al. , ). However, not placing the catheter in the parenchyma may blunt and/or delay changes in the L/P‐ratio and therefore introduce an error.…”

“…We chose to place the microdialysis catheters, which monitored the kidney and the gut, on the surface and the lumen of the organs. These placements have been shown to mirror the L/P-ratio changes within liver, heart and gut mucosa without injuring the organs (Sollig ard et al 2004;Abrahamsson et al 2011Abrahamsson et al , 2012. However, not placing the catheter in the parenchyma may blunt and/or delay changes in the L/P-ratio and therefore introduce an error.…”