A new technique for hepatic portal sampling in the conscious dog.

A technique for implantation of a silastic catheter into the portal vein is described. The central end of the catheter is passed through a puncture hole into a tributary of the portal vein. The peripheral free end, occluded by a rubber membrane, is passed through the abdominal wall and buried under the skin. Once the catheter is in place it can be kept patent for several weeks. Injection of a substance and withdrawal of blood from the portal vein are carried out by percutaneous puncture of the rubber membrane, a virtually painless procedure that can be carried out in fully conscious nonrestrained dogs.