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Advances in hepatic transplantation have opened the possibility of bench surgery for liver disease. Thus, nonconventional methods such as the ex vivo approach (bench procedure) or the in vivo ex situ preserved liver surgery have been performed in selected cases. These methods have been confined to situations and tumour stages otherwise deemed untreatable, or to situations where resection may not be sufficiently radical. To date, primary liver tumours (hepatocellular, cholangiocellular) and colo-rectal metastases are considered to be suitable conditions. The technique used is that of liver grafting. Hypothermic liver perfusion (U.W., 4 degrees C) and pump-driven veno-venous bypass from portal vein and inferior vena cava to the superior vena cava are performed. The principal aim of bench surgery is to avoid the unnecessary removal of a large amount of normal parenchyma. Resection lines follow the segmental structure of the liver. Sometimes, an atypical hepatectomy with a parenchymal exeresis "à la demande" is required. Authors' experience with four patients undergoing ex vivo operation of the liver (three patients) or surgery on an ex situ hypothermic perfused liver (one patient) is reported. The patients had liver metastases from colonic carcinoma (1 M, 2 F) and from renal carcinoma (1 M). Major hepatic resections were performed. One patient (M) died from neoplastic intestinal recurrence after 16 months. Two patients (F) died after 24 and 9 days for sepsis and pulmonary embolism. One patient (M) died intraoperatively from a massive retroperitoneal bleeding. Being able to remove otherwise unresectable hepatic neoplasms is a worthy objective. In the presence of diffuse chemoresistant colo-rectal hepatic metastases, liver bench surgery is a promising therapeutic hope. At the basis of a good hepatic function there are a correct organ preservation, a perfect bench surgical technique with respect for vascularization and biliary drainage of the hepatic remnant, and an accurate hemostasis of the resection surface.

In the cyclosporine era liver orthotopic allotransplantation has shown to be very effective in the treatment of many end-stage liver diseases. Currently, the major limitation in clinical transplantation is the shortage of donor organs unlikely solvable by alternative policies or approaches such as living donors and artificial organs. Animals have been considered as an alternative source of organs offering the following advantages: availability of a predictable and ready supply of donor organs, opportunity to practice transplantation as an elective procedure, possibility to match the size of the graft recipient. However, immunologic barriers are thought to make xenotransplantation impractical between widely divergent (discordant) species. Hyperacute xenograft rejection, in fact, consists of an immediate, diffuse intravascular coagulopathy followed by an aggressive cellular reaction. Recipient preformed natural antibodies and complement are involved in the humoral phase of hyperacute rejection. The violence of this reaction depends on the titer of natural antibodies and on the divergency of the species involved. Species more closely related (concordant) exhibit a less aggressive reaction characterized by an acute cellular rejection. Hepatic allografts and xenografts, though, are unusually resistant to humoral injury and undergo a combination of both humoral and cellular rejection. Preliminary studies have demonstrated a prolonged reduction in natural antibodies accomplished by plasmapheresis and cyclophosphamide combined treatment. Furthermore, new therapeutic agents such as FK 506, rapamycin and deoxyspergualin may find widespread application in clinical transplantation. FK 506 has shown to possess a remarkable efficacy in reversing refractory hepatic allograft rejection as well as ability to inhibit humorally mediated immunity.(ABSTRACT TRUNCATED AT 250 WORDS)