Some hemodynamic parameters of the liver during 24-hour perfusion conditioning using a proprietary device

Abstract

Introduction. The transplantology is one of the most promising and perspective fields of the modern  medicine as the replacement of the organs with unrecoverable disease (irreversible changes) with the donor organs has no alternative so far. Boosting the number of liver pathologies in the world and, on the other hand, successful liver transplantations result in an annual increase in the number of people waiting for transplantation. Therefore, attention was drawn to so-called methods of morpho-functional improvement of organs obtained from "marginal" donors. It was revealed that machine perfusion can improve the condition of the donor organ. Numerous experimental studies show that perfusion of the organ with controlled, normothermic, oxygenated blood is a key factor in liver conditioning and perfusion should be prolonged in order to achieve the desired effect.

Methods. The study was conducted on 5 pigs weighing 20-25 kg. Perfusion of the cannulated liver began one hour after explantation (warm ischemia) with normothermic oxygenated blood. For perfusion, a two-chamber pump of our own design with a hydraulic drive was used, providing pulsating blood flow in the hepatic artery and non-pulsating - in the portal vein. To condition the liver, heparin, insulin, bile preparations, prostacyclin and nutrients in standard doses were introduced into the perfusate. The condition of the liver was assessed by morphological studies, monitoring of hemodynamic parameters in the portal vein and hepatic artery, as well as the amount of bile secreted. Bile acids, cholesterol, bilirubin, glucose, and transaminases were determined in the blood.

Results. In all experiments, perfusion was carried out within physiological hemodynamic parameters (blood pressure in the hepatic artery 82±4.3/58±3.1 mmHg; blood flow in the portal vein 765±36 ml/min. Over 24 hours, the amount of bile released was 114±28 ml). Also, biochemical parameters in the blood iffered slightly from the initial data. Morphological studies showed that less than 3% of cells were suffered by small droplet micro steatosis; mononuclear portal infiltrates were found only in several areas. Mild mixed large droplet micro steatosis and small droplet micro steatosis was found in less than 5 % and 10% of the hepatocytes accordingly on the 16th and 24th hours of perfusion. Similarly the mild venous congestion was present in 1 out of 5 livers after 16-hours perfusion and in 2 out of 5 livers after 24-hours perfusion. The number of necrotic hepatocytes and portal triads infiltrated with mononuclear cells did not exceed 10% and 15% accordingly. However, there were no differences in the degree of biliary damage – cholestasis or ductular proliferation - correlating with the terms of the experiment.

Conclusion. 24-hour liver perfusion conditioning by using of the machine of own design providing the pulsatile blood flow guarantees the satisfactory preservation of liver making it useful for successful transplantation.