Constriction rate variation produced by partial ligation of the portal vein at pre-hepatic portal hypertension induced in rats.

Background: Partial portal vein ligation causes an increase in portal pressure that remains stable even after the appearance of collateral circulation, with functional adaptation to prolonged decrease in portal blood flow.

Aim: To assess whether different constriction rates produced by partial ligation of the vein interfere with the results of this experimental model in rats.

Methods: Three groups of five rats each were used; in group 1 (sham-operated), dissection and measurement of portal vein diameters were performed.