Experimental Models in Liver Surgery

Ischemia-Reperfusion (I/R) injury is an important cause of liver damage occurring during surgical procedures including hepatic resections and liver transplantation (LT) [1-3]. The shortage of organs has led centers to expand their criteria for the acceptance of marginal grafts that exhibit poor tolerance to I/R [4]. Some of these include the use of organs from old‐ er donors and grafts such as small-for-size or steatotic livers. However, I/R injury is the un‐ derlying cause of graft dysfunction in marginal organs [4]. Indeed, the use of steatotic livers for transplantation is associated with an increased risk of primary nonfunction or dysfunc‐ tion after surgery [5]. In addition, the occurrence of postoperative liver failure after hepatic resection in a steatotic liver exposed to normothermic ischemia has been reported [6]. A large number of factors and mediators play a part in liver I/R injury. The relationships be‐ tween the signalling pathways involved are highly complex and it is not yet possible to de‐ scribe, with absolute certainty, the events that occur between the beginning of reperfusion and the final outcome of either poor function or a non-functional liver graft. We will show that the mechanisms responsible for hepatic I/R injury depends on the experimental model used, who are valuable tool for understanding the physiopathology of hepatic I/R injury and discovering novel therapeutic targets and drugs. Several strategies to protect the liver from I/R injury have been developed in animal models and, some of these, might find their way into clinical practice. The species used for experimental investigation of hepatic I/R injury range from mice to pigs. The book chapter will discuss the numerous experimental models used to study the complexity of hepatic I/R injury, data reported in choice of the animal model, when selecting an animal species, the age, the sex, the degree of steatosis...etc. Thus, the different strengths and limitations of the different experimental models will be dis‐ cussed. Also the standardized experimental conditions, such as anesthetic and analgesic procedures will be described. We also attempt to highlight the fact that the types of ischemia (cold and warm ischemia) play an important role in experimental liver surgery. The most