Parenteral nutrition via the portal vein in rats.

A rat model was designed for continuous infusion of complete parenteral nutrition (CPN) via the hepatic portal vein. The purpose was to evaluate possible side effects compared with conventional continuous systemic CPN via the superior caval vein, which bypasses the liver. Observed side effects of transcaval CPN (increase of liver weight and of intraabdominal fatty tissue, granulomatous infiltration of liver and spleen, vascular changes and fat droplets in the lungs) were less when the nutritional substances were infused into the portal vein.