Effect of orthotopic transplantation of liver on systemic and splanchnic hemodynamics in conscious rat

The long-term cardiovascular effects of orthotopic liver transplantation (OLT) were studied in conscious Lewis rats with a radioactive microsphere technique. Three months after OLT with an all-suture technique for graft revascularization (s-OLT), all hemodynamic parameters were similar to control. OLT with 'cuffs' fitted to the portal vein and intrahepatic inferior vena cava (c-OLT) led to prominent hemodynamic disturbances including 1) hyperkinetic circulation with increased cardiac index (CI; 22%; P < 0.05) and decreased mean arterial pressure (15%; P < 0.05) and total peripheral resistance (TPR; 28%; P < 0.05); 2) a slight increase in portal pressure (11.8 ± 0.9 vs. 9.3 ± 1.7 mmHg in control) and marked portal-systemic shunting (51 ± 11 vs. 0.05 ± 0.04% in control; P < 0.05); 3) increased hepatic arterial blood flow (0.49 ± 0.06 vs. 0.27 ± 0.04 ml · min^-1 · g liver wt^-1; P < 0.05); 4) splanchnic vasodilation with vascular resistance significantly (P < 0.05) lower in the liver, stomach, and large intestine; and 5) increased blood flow and decreased vascular resistance in the kidneys and heart. Ganglionic blockade with chlorisondamine (5 mg/kg body wt iv) indicated that the increase in CI seen in the c-OLT rats was probably sympathetically mediated, whereas the increase in renal blood flow was a reflection of the increase in CI. After ganglionic blocker administration, TPR and regional vascular resistances decreased to approximately the same extent in the control and c-OLT groups, indicating that vascular sympathetic tone was unchanged in the c-OLT rats. Our data suggest that OLT per se (s- OLT) has no long-term effect on hemodynamics in the rat but that c-OLT causes hemodynamic changes similar to those found in portally hypertensive rats.