Experimental modified orthotopic piggy-back liver autotransplantation

The classical orthotopic liver autotransplantation is a very challenging and time wasting technique; it includes the division of major hepatic vessels and choledocus, and subsequent reconnection by end to end anastomoses. The caval end to end anastomoses are the most difficult to be performed and the interposition of a prosthesis can be required. We adopted the classical orthotopic liver autotransplantation technique in 2 patients affected with diffused liver metastases from colorectal cancer, for extracorporeal neutron capture therapy (BNCT). The procedure required very long operating times and the extracorporeal circulation (ECC) set up; furthermore the vena cava reconstruction was performed by the interposition of a goretex-prosthesis. We propose a "modified orthotopic piggy-back technique" to simplify liver reconnection and shorten the operating time.

The technique was developed in the swine (25 kg body weight), under general anaesthesia. We performed the resection of the retro-hepatic vena cava with preservation of the caval flow during the anhepatic phase, by interposing a goretex-prosthesis. The reconstruction of the vena cava was then performed by a side-to-side cava-prosthesis anastomosis with lateral clamping of the prosthesis. The procedure was then completed according to the classical technique of liver transplantation.

The mean time for VC reconstruction was 56 (+/-10)min. and the mean time for side-to-side VC-prosthesis anastomosis was 13(+/-4)min.

The "modified orthotopic piggy-back technique" can simplify the reimplant of the liver during autotransplantation and shorten the operating time. Furthermore also the time of total extracorporeal circulation is reduced, as during the anhepatic phase and during the side-to-side cava-prosthesis anastomosis the flow in the inferior vena cava is uninterrupted.