A Pig Model of Hemivascular Liver Occlusion for The Study of Ischemia-Reperfusion Injury: Use of an Infrared System for Detecting Ischemic Areas

Aim: Different animals are used as experimental models for the hepatic Ischemia- Reperfusion (IR) injury investigations and for each one of these animal models, many different surgical approaches have been performed. The aim of our study was to establish a new surgical pig model in which a hemi-liver is used to study the pathophysiology of hepatic IR injury. Contro-lateral hemi- liver is used as an internal control in the same animal. Methods: Liver ischemia was performed in six pigs by clamping the hepatic artery and vein and the portal vein to isolate the left hepatic lobe. Four hours of warm ischemia were followed by 4-hourrs of reperfusion. Biochemical and hematological analyses were performed throughout the experiments. Needle biopsies were obtained prior to ischemia and then hourly during the reperfusion for evaluation of tissue damage. To assess local temperature gradients on the liver surface a focal plane array detector camera was used. Results: Four hours ischemia induced mild signs of hepatic damage on the left ischemic lobe while more dramatic changes were evidenced after 2-hours reperfusion. Absence of tissue damage was detected on the right lobe. The liver functional test reached their maximum value at 2-4 hours after reperfusion. Conclusion: Our model is easy to perform, feasible and reproducible. This surgical model minimizes biases dependent on the individual response of different animals under the same conditions. In this IR model the new technology of an infrared thermocamera was used to control temperature changes and provide clinically important real-time information during surgery.