Partial constriction of the portal vein produced a SD rat portal vein cavernous transformation of animal models

Objective:The animal models of cavernous transformation of the portal vein(CTPV) are established by means of partial constriction of portal vein in order to study the changes of the portal vein pressure and the structure of portal vein and its surrounding tissues during the modeling process,which will provide reliable and stable model animals for clinical and basic research of CTPV.Methods:A total of 100 Sprague-Dawley(SD) rats were randomly divided into two groups: sham operation group and model group,with 50 rats in each group.The partial constriction operation on portal vein was performed in model group with a blunt 21G caliber to establish CTPV animal models;while the exploratory operation on portal vein,not constriction,was performed in sham operation group.10 rats were randomly chosen each time at 1st,2nd,3rd,4th,6th week after surgery(five times) to observe the formation of collateral circulation of portal vein and its peripheral tissues by performing portal vein pressure measurement,portal vein radiography,and histopathological examination.Results:The rats in the sham operation group never devoloped portal vein hypertension at any period of time after surgery.The portal vein angiography showed no formation of collateral circulation.Portal hypertension occurred one week after surgery in the model group.The portal pressure increased gradually in the five time periods after surgery.Portography showed an irregular vascular group in Hepatic Portal Area(HPA) in the 6th week after surgery.By the 6th week after surgery,typical cavernous transformation in portal vein area devoloped.