Partial Liver Transplantation

Massive hepatic resection is the only option for some patients with primary or secondary liver tumors. With regard to small-for-size (SFS) liver transplantation, the use of partial liver grafts has the potential to substantially reduce the donor shortage by allowing the donor organ to be split between 2 recipients.

Xenotransplantation

Due to the shortage of available human organs the pig has been chosesn as a source for xenotransplantation organs. The first major hurdle in carrying out a cross species xenotransplantation is the occurance of hyperacute rejection triggers by complement activation. (Knoell, EP1336618).

Risk associated with Liver Transplantation

Liver resection has bewcome an increasinly safe procedure, but certain procedures remain high risk, such as massive liver resection and small-for-size (SFS) liver transplantation.

Ischaemic-reperfusion injury (IRI):

IRI is an inevitable phenomenon that results following major liver surgery, including partial hepatecotomy and liver transplantation (Gomez, World J Gastroenterol 2007, February 7: 13(5): 657-670).

Tang teaches that partial grafts form split livers have been introduced to expand the donor pool, briding the gap between the increasing number of potential recipients and the inferior number of eligible liver donors but that there are mroe risks in performing partial or small for size liver transplantation, not only due to technical obstances, but also early graft loss resulting from ischemia reperfusion injury (Tan, Transplantation Proceedings, 39, 1338-1344 (2007)).

–Mechanisms:

(i) complement system: Studies using rat models indicate a central role for complement in hepatic IRI. However, in addition to its role in hepatic IRI, evidence indicates that complement activation is required for normal liver regeneration, following either resection or toxic injury. Data indicates that the complement activaiton products C3a and C5a play an important role in the proliferative response and hepatocyte regeneration via an effect on TNF alpha and IL-6 expression. (he, J. Clinical Investigation, 119(8), 2009).