Determination of organ blood flows during retrograde inferior vena caval perfusion

Abstract

Cerebral, renal, and hepatic blood flows and oxygen metabolism were measured in 8 mongrel dogs undergoing hypothermic (20 °C) retrograde perfusion via the inferior vena cava (IVC) and compared with cardiopulmonary bypass and retrograde superior vena caval perfusion. Inferior vena caval perfusion was performed with aortic drainage and clamping of the superior vena cava at an IVC pressure of 20 or 30 nun Hg. Cerebral, renal, and hepatic blood flows at 30 mm Hg of IVC pressure were 7.5 ± 3.8, 8.1 ± 3.1, and 15.3 ± 5.5 ML· min −1 · 100 g −1, respectively, as determined by the hydrogen clearance method. Organ blood flows during retrograde IVC perfusion were 28%, 42%, and 57% of cardiopulmonary bypass values at a flow rate of 1,000 mL/min and 61%, 119%, and 131% of retrograde superior vena caval perfusion values at 30 mm Hg of superior vena caval pressure, respectively. Oxygen consumption was 7.4 ± 3.7 mL/min. At an IVC pressure of 20 mm Hg, cerebral, renal, and hepatic blood flows and oxygen consumption were 5.1 ± 2.7, 5.9 ± 4.1, and 11.6 ± 4.0 mL · min −1 · 100 g −1 and 3.0 ± 0.8 mL/min. As IVC pressure increased, cerebral, renal, and hepatic blood flows and oxygen consumption increased. However, high IVC pressure was associated with high portal venous pressure, which may produce ascites. Regional blood flow during retrograde IVC perfusion was measured by the colored microsphere method in another 8 normothermic dogs. Inferior vena caval perfusion at 30 mm Hg supplied adequate blood flow to the liver (15.44 ± 12.1 mL · min −1 · 100 g −1) and kidneys (6.35 ± 2.0 mL · min −1 · 100 g −1. Retrograde IVC perfusion may be beneficial to the abdominal organs by providing adequate blood flow and oxygen delivery.