Hemodynamic characterization of arterialized and nonarterialized liver transplants in the rat

Persistent hyperkinetic circulation after liver transplantation has been described in humans, but similar changes have not been well characterized in the rat model. This study aimed to investigate the hemodynamics of the systemic and splanchnic circulations in both arterialized and nonarterialized hepatic allografts. Orthotopic liver transplantation was performed in four groups of Sprague-Dawley rats. Group A comprised sham-operated rats with hepatic artery ligation that did not receive transplants; group B comprised rats that received transplants without arterialization; group C comprised sham-operated rats with intact hepatic artery that did not receive transplants; and group D comprised rats that received transplants with arterialization. Blood flow measurements were performed three weeks after the surgical procedure, using the radioactive microsphere method. The results showed that rats that received transplants exhibited a significantly higher cardiac index and lower systemic vascular resistance than the control rats. Splanchnic hyperemia was also present with increased mesenteric blood flow. However, there was no difference in hemodynamics between rats that received arterialized transplants and those that received nonarterialized transplants. Arterial collateral vessels from adjacent tissues were observed in the nonarterialized grafts; this was confirmed histologically. It is concluded that rats that undergo orthotopic liver transplantation exhibit hyperdynamic circulation, regardless of the arterial reconstruction procedure, possibly due to extensive collateral formation in the hepatosplanchnic circulation.