Twelfth rib resection as an approach for portal vein cannulation in sheep.

A surgical technique involving resection of the twelfth rib was used to insert silastic cannulas into the portal veins of three sheep to study amino acid metabolism. Good exposure to the vein was achieved by this method although it required positive ventilation due to the penetration of the thoracic cavity. All cannulas were buried subcutaneously and exteriorized near the dorsal midline. This facilitated continuous infusion into the portal cannula without disturbing cannula placement.