and secured by silk. The clamp was released, and the heparin was mixed with blood by gentle pumping with a syringe attached to the free end of the tubing. The syringe was removed; the tubing was looped around, beveled, and used as the second cannula (Fig. ). The sample port, consisting of a Y-fitting, was attached just before the second cannulation was made. The proximal cannulation was done approximately 3 mm. before the portal vein bifurcation into the liver.
The glass Y, fitted with a needle support, provided a means of sampling the blood. A 27-gauge needle was placed in the tubing through the support, and the sampling syringe was attached to the needle. Blood samples were withdrawn slowly to prevent embolism. Heparin was occasionally injected through this port to ensure free blood flow.
The bile duct was then cannulated with PE 50 polyethylene tubing, and samples were introduced into the duodenum of the intestine. At this point, the incision was closed by clamp or sutures. If lumen samples are to be taken, the organs are kept warm with a highintensity lamp and moist with wet gauze.
The procedure has proven useful in drug absorption studies now being conducted in our laboratories.