Experimental portal hypertension in the rat.

Previous attempts to produce sustained portal hypertension in experimental animals by portal venous obstruction have not been successful. Experiments were designed to study the effects of gradual portal venous occlusion plus hepatic lymphatic ligation in the rat. Adult male Lewis rats were divided into three groups: (A) nonoperated or sham-operated; (B) operated, with hepatic lymphatic ligation only; and (C) operated, with placement of a portal vein ameroid constrictor and hepatic lymphatic ligation.