Measurement of portal and hepatic blood flows using a modified method for surgical placement of catheters in the major splanchnic vessels of sheep.

A modified catheterization and para-aminohippurate dye dilution technique was used to measure portal and hepatic blood flows in sheep. Blood flows (mean +/- 1SD) for 7 healthy sheep were 1.54 +/- 0.71 L/min and 1.98 +/- 0.75 L/min for portal and hepatic flows, respectively. Blood flow measurement was facilitated when dye injection rates produced blood para-aminohippurate acid concentrations greater than 15 mg/L. Uniform mixing of dye with blood was confirmed in 1 sheep with 2 portal vein catheters. Surgery to place the catheters was facilitated by using a ventral para-costal approach. Blood gas analysis was useful in confirming the placement of the catheters. Useful catheter life in this experiment was 41 days, which was longer than in previous reports. Treating the catheters with an organo-silane preparation, protecting the catheters against dislodgement, and use of a belly bandage to minimize damage to the external parts of the catheter may have prolonged catheter life in this experiment.