Immunologic and metabolic effects of caval versus portal venous drainage in small-bowel transplantation.

We compared the immunologic and metabolic effects of systemic (i.e., caval) versus portal venous drainage of small-intestinal allografts in rats. Survival times in either unidirectional rejection or graft-versus-host disease models were not significantly altered by the route of venous drainage. Portoportal and portacaval isografts and controls were then pair-fed after transplantation. After 6 weeks of pair-feeding, weight gain, plasma amino acid concentration, and the histologic appearance of the liver were similar among the three groups. Hepatic protein synthesis was greater in pair-fed rats with portoportal isografts, although this difference disappeared in the fasted state. Our data suggest that there is little immunologic or metabolic advantage of portal versus systemic venous drainage of small-intestinal allografts in rats. Because the latter is technically simpler, it may be preferable in small-bowel transplantation.