Experiences in making canine models of pre-hepatic portal hypertension

Objective To insure the reliability of animal models of pre hepatic portal hypertension.Methods The size of spleen, diameter and pressure of portal vein of 29 canine models were measured. A partial ligation of portal vein was performed narrowing at 95% of its original cross section, or making the portal vein pressure more than three times to its original pressure and the gastrointestinal venous stasis could not be seen. The features of gastrointestinal venous stasis and collateral circulation were observed during reoperation on the 2nd, 4th, 8th, 12th and 16th weeks postoperatively.Results Four dogs died from abdominal infection, anesthesia and acute enteric necrosis respectively. The higher pressure of portal vein, retroperitoneal edema, hypertrophy of the intestinal wall were noted. Following the formation of collaterals between portal and systemic circulation , the portal vein pressure decreased gradually from 2nd to 8th weeks. From 12th to 16th weeks postoperatively, the portal vein pressure was stabilized but still higher than that of the normal, retropertioneal edema disappeared and collateral vessels could be clearly seen. The pressure of portal vein in the 12th, 16th weeks was lower than that in 2nd, 4th weeks ( P 0.05 ). Conclusions Making animal models of prehepatic portal hypertension by narrowing the diameter of portal vein is a reliable method. The status of models in 12th～16th weeks after operation are similar to children with portal hypertension.