[Prevention of normothermic hepatic ischemia during in situ liver perfusion with three different preservation solutions: experimental analysis by realtime infrared radiation thermography].

OBJECTIVE: To establish the usefulness of infrared radiation thermography on monitoring in situ liver perfusion with different preservation solutions during liver harvesting.
METHODS: Twenty-four adult male Wistar rats, weighing 385.31 g were randomly divided into four groups of six animals each according to the solution used to perfuse the liver (Euro-Collins® solution--EC group; Custodiol® solution--CUST group; Celsior® solution--CEL group and Ringer-Lactate solution--RL group). Under inhalatory ether anesthesia, animals were submitted to upper transversal laparotomy, exposure of median and left-lateral hepatic lobes, heparin injection (500 UI/Kg) through infrahepatic vena cava, portal vein infusion through 18G catheter of cold (4°C) solution according to the group of study. Infrared images, with respective temperature evaluations from hepatic surface, were picked up in real time by Therma CAM SC500® infrared camera positioned at constant distance from three fixed points of the diaphragmatic surface of median and left lateral lobes at the following moments regarding liver perfusion: immediately after laparotomy; after portal vein cannulation and immediately before solution infusion; at each minute from the beginning of liver perfusion during five minutes. Mean temperatures of each moment were compared intra and intergroups with the difference between means test with normal distribution, with significance level of 5% (p=0.05).
RESULTS: There was statistically significant difference of means temperatures between the moment of laparotomy and immediately after cannulation; between this later and after the first minute of perfusion; and between the first and fifth minutes of infusion in all groups of study in a similar way. CEL group showed additional difference between the first and second minutes means temperatures. Intergroup comparison showed Euro-Collins solution with significant less cooling power when compared to all others solutions.
CONCLUSION: It was possible to follow the liver cooling process during preservation solutions perfusion using infrared radiation images. Preservation solutions had similar behaviors, with Celsior® solution showing additional cooling power until the second minute of perfusion. Euro-Collins solution had less cooling power than other solutions studied.