[Changes in hepatic ultrastructure and function following portal vein resection with a use of an internal shunt...

Experimental studies on ultrastructural and functional changes of mitochondria were carried out using adult dog livers after portal vein resection with an internal shunt bypass. As a comparative study portal vein resection with an external shunt bypass was also carried out. A 10 cm long anti-thrombotic UK catheter was inserted into the portal vein as an internal shunt bypass (internal shunt group). Similarly, a catheter was inserted between the portal vein and inferior caval vein as an external shunt bypass (external shunt group). The time of portal vein shunt bypass was 2 hrs for both groups. During operations, the blood flow of the hepatic artery was blocked. After the bypass was installed, the hepatic artery and the portal vein were declamped. As a control experiment the hepatic artery was clamped without making a shunt bypass (non-shunt group). Left lateral lobe was resected from the liver prior to the shunt implant and then the right lateral lobe was removed 2 hrs after the declamping of the hepatic artery. Biochemical analysis on mitochondria isolated from the livers of the internal and the external shunt groups was carried out. Changes of mitochondrial ultrastructure were also studied using electron microscope. Changes in serum m-GOT and OCT activities were also examined. Essentially no changes were detected in phosphorylating capacities and ultrastructure of mitochondria of the livers obtained from either the external shunt group or the internal shunt group. However m-GOT and OCT activities in the serum were definitely elevated in the external shunt group of animals compared to those in the internal shunt group of animals. This suggests that the permeability of hepatic mitochondrial membranes in the external group of animals was changed probably due to hypoxia. From these results we recommended the application of the internal shunt bypass for hepato-biliary surgery combined with the resection of the portal vein.