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

Abstract

Background: Ischemic injury to the pancreas occurs in various clinical conditions. A method for online monitoring of pathophysiological events in pancreatic parenchyma is missing. Aims: To assess the timing of microdialysis (MD) technique response on temporary changes in pancreatic perfusion, and to evaluate the relationship between MD data and systemic markers of anaerobic metabolism and inflammation. Methods: In anaesthetized normoventilated pigs, MD probes were placed in right (control) and left (ischemic) pancreatic lobes, respectively. Following the clamping of the vessels, ischemia was verified by tissue oxygen tension (P_tiO₂) measurements. Results: P_tiO₂ decreased within 20 min after the clamping of the vessels, already returning to baseline levels at the first sampling point after the removal of the clamp. MD lactate levels increased, whereas pyruvate and glucose levels decreased at 20 min after the induction of ischemia. These trends continued until the end of ischemia and returned to baseline following reperfusion. Serum lactate, amylase and tumor necrosis factor-alpha levels decreased throughout the protocol time. Conclusion: MD data were in concordance with changes in P_tiO₂, which is indicative of local anaerobic metabolism. MD allowed the detection of pathophysiological processes within the ischemic pancreas at a stage when no elevations of systemic markers of ischemia or inflammation were observed.

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).…”

“…S-mD glucose concentration is continuously decreasing in the ischemic segment and this pattern is consistent with findings in all our previous studies. [16][17][18][19][20] Changes in some hemodynamic parameters and blood test were recorded at T3 and T4, indicating global physiological effects of the intervention with intravenous fluids at T2 (Tables 1 and 2). Lactate concentration at site A was decreasing from T2.…”

“…A standard anesthetic protocol of our laboratory was followed. 20 By cutdown technique, a catheter was placed in the common carotid artery via a branch, and a central venous line was inserted in the external jugular vein at left side of the neck. For pressure measurements, a catheter filled with isotonic saline and pressure transducers (DTX pressure transducer; Becton Dickinson, Stockholm, Sweden) positioned at the superior vena cava level were used.…”

Thoracic epidural anaesthesia reduces insulin resistance and inflammatory response in experimental acute pancreatitis

“…Our data indicate that TEA possibly has a protective effect on acinar, ductal, and endothelial cell integrity, comprising oedema formation, as manifested by a difference in the course of tissue oxygen tension between the TC + TEA and TC groups. Lactate concentrations in dialysate collected by intra-parenchymatously placed microdialysis probes correlate well with intra-pancreatic tissue oxygen tension in an experimental pancreatic ischemia-reperfusion model in pigs (17). Lactate concentrations thus mirror the intra-pancreatic metabolic status with a high degree of accuracy.…”

Microdialysis and CO2 sensors detect pancreatic ischemia in a porcine model

“…Microdialysis catheters positioned in the parenchyma have confirmed pancreatic ischemia in a porcine model in vivo [ 17 ], in porcine and human pancreases ex vivo[ 18 ], and we have monitored pancreas grafts with microdialysis catheters on the organ surface [ 19 ]. There is no clinical experience with intraparenchymal pancreatic tissue monitoring.…”