A new liver perfusion and preservation system for transplantation research in large animals

Abstract

A kidney perfusion machine, model MOX-100 (Waters Instruments, Ltd, Rochester, MN) was modified to allow continuous perfusion of the portal vein and pulsatile perfusion of the hepatic artery of the liver. Additional apparatus consists of a cooling system, a membrane oxygenator, a filter for foreign bodies, and bubble traps. This system not only allows hypothermic perfusion preservation of the liver graft, but furthermore enables investigation of ex vivo simulation of various circulatory circumstances in which physiological perfusion of the liver is studied. We have used this system to evaluate the viability of liver allografts preserved by cold storage. The liver was placed on the perfusion system and perfused with blood with a hematocrit of approximately 20%, and maintained at 37 degrees C for 3 h. The flows of the hepatic artery and portal vein were adjusted to 0.33 mL and 0.67 mL/g of liver tissue, respectively. Parameters of viability consisted of hourly bile output, oxygen consumption, liver enzymes, electrolytes, vascular resistance, and liver histology. This method of liver assessment in large animals will allow the objective evaluation of organ viability for transplantation and thereby improve the outcome of organ transplantation. Furthermore, this pump enables investigation into the pathophysiology of liver ischemia and preservation.

Figure 1

Photographic view of the liver perfusion and preservation system developed by modifying a kidney perfusion machine, model MOX-100 (Waters Instruments, Ltd, Rochester, MN).

Figure 2

Schematic view of liver perfusion and preservation system.

Figure 3

Results of sanguinous perfusion of fresh porcine liver. (a) Changes in portal venous pressure. (b) Changes in hepatic arterial pressure. Data are expressed as mean ± SD. (c) Changes in bile output. (d) Changes in oxygen consumption. Data are expressed as mean ± SD. (e) Changes in serum glutamic-pyruvic transaminase (SGPT). (f) Changes in serum glutamic–oxaloacetic transaminase (SGOT). Data are expressed as mean ± SD.

Figure 3

Results of sanguinous perfusion of fresh porcine liver. (a) Changes in portal venous pressure. (b) Changes in hepatic arterial pressure. Data are expressed as mean ± SD. (c) Changes in bile output. (d) Changes in oxygen consumption. Data are expressed as mean ± SD. (e) Changes in serum glutamic-pyruvic transaminase (SGPT). (f) Changes in serum glutamic–oxaloacetic transaminase (SGOT). Data are expressed as mean ± SD.

Figure 3

Results of sanguinous perfusion of fresh porcine liver. (a) Changes in portal venous pressure. (b) Changes in hepatic arterial pressure. Data are expressed as mean ± SD. (c) Changes in bile output. (d) Changes in oxygen consumption. Data are expressed as mean ± SD. (e) Changes in serum glutamic-pyruvic transaminase (SGPT). (f) Changes in serum glutamic–oxaloacetic transaminase (SGOT). Data are expressed as mean ± SD.

Figure 4

Histological changes before and after sanguinous perfusion of fresh porcine liver. (a) Liver specimen just prior to sanguinous reperfusion; lobular architecture is well maintained. No steatosis, cholestasis, or hepatocellular necrosis is present. (b) Liver specimen after sanguinous reperfusion (180 min); lobular architecture is still maintained. However, mild sinusoidal congestion is seen in periportal area with scattered necrosis of the hepatocytes. No pathologic changes are noted in midzonal or centrilobular area. (H–E stain; original magnification × 100.) (c) High-power view of Figure 4b. The hepatic artery, the portal vein, and the bile ducts are intact. Microvesicular steatosis is observed around the congested areas (H–E stain; original magnification × 250.)

Figure 4

Histological changes before and after sanguinous perfusion of fresh porcine liver. (a) Liver specimen just prior to sanguinous reperfusion; lobular architecture is well maintained. No steatosis, cholestasis, or hepatocellular necrosis is present. (b) Liver specimen after sanguinous reperfusion (180 min); lobular architecture is still maintained. However, mild sinusoidal congestion is seen in periportal area with scattered necrosis of the hepatocytes. No pathologic changes are noted in midzonal or centrilobular area. (H–E stain; original magnification × 100.) (c) High-power view of Figure 4b. The hepatic artery, the portal vein, and the bile ducts are intact. Microvesicular steatosis is observed around the congested areas (H–E stain; original magnification × 250.)