The Isolated Perfused Bovine Liver

Abstract

The technique of isolated liver perfusion has several unique features as an investigative tool for the study of hepatic physiology and biochemistry. These include the exclusion of non-hepatic tissues, the maintenance of intact cellular membranes, and the ability to control and reproduce more precisely the experimental hepatic environment than is possible in an entire animal. This investigative team has developed an isolated bovine liver peffusion preparation that is reproducible, bacterially sterile, and capable of continuous functional performance for extended periods of time.The use of a large mammal, such as the bovine calf, as the experimental animal has other useful characteristics; the large liver permits serial tissue sampling, yielding specimens of generous size. The large volume of perfusate, with little intrahepatic accumulation, allows frequent generous sampling of this medium. The use of autogenous blood as the perfusate avoids interaction between foreign proteins which could occur if blood were pooled from several homologous donors.The technique of perfusion reported herein permits simultaneous and independent perfusion through the hepatic artery and portal vein, and repetitive sampling of liver tissue and the circulating perfusate without interruption of the perfusion.This report describes the characterstics of this preparation as experienced in over 90 separate perfusion experiments.

Extracorporeal perfusion of isolated organs of large animals – Bridging the gap between in vitro and in vivo studies

“…Flow controlled set-ups have been used most often (Chapman et al, 1961;Villeneuve et al, 1996;Grosse-Siestrup et al, 2002b;Zeitlin and Eshraghi, 2002;Dragu et al, 2011), but newer evidence suggests that pressure controlled perfusion improves organ preservation (Mancina et al, 2015). Two strategies may be applied in flow controlled experiments: a low flow or a high flow approach.…”

“…However, many studies have been successful without the use of antibiotics. One study with a sterile harvesting process and sterile system reported no bacterial contamination for up to 24 hours (Chapman et al, 1961). However, most perfusion experiments are conducted in an unsterile environment.…”

“…The venous oxygen content can be calculated likewise. In perfusion experiments, the organ's weight is often taken into consideration (Chapman et al, 1961;Jensen et al, 1978), e.g., Patan et al (2009) report an oxygen uptake of 6.4 x 10 -6 ± 8.9 x 10 -5 l/g/min. Measuring oxygen saturation (SO 2 ), partial pressure of oxygen (pO 2 ) and pCO 2 in arterial and venous perfusate samples also sheds light on the oxygen use of the perfused organ (Zeitlin and Eshraghi, 2002;Wagner et al, 2003;Polyak et al, 2008;Constantinescu et al, 2011).…”

“…Both set-ups reported an average weight gain throughout the perfusion period of five hours of 20% (Bäumer et al, 2002;Braun and Kietzmann, 2004). Chapman et al (1961) described the first successful isolated liver perfusion in calves for up to 24 hours by cannulating the hepatic artery and portal vein simultaneously. This report demonstrated tissue viability based, amongst other things, on measurements of oxygen consumption, presence of constant blood flows and pressures, and only very slight changes in histologic parameters.…”

Liver, Biliary Tract and Pancreas

“…Isolated liver perfusion has been accomplished in many species, including .the cat, monkey, rabbit (G), and rat. (2O) It has only been recently, however, that perfusion techniques have been consistently satisfactory in larger animals such as the cow or calf (29,30), the pig (51), and the dog. (93) Although the dog is probably the most convenient and cheapest animal f o r perfusion studies, the canine liver has peculiarities which deserve special comment.…”