A rat model of esophageal varices.

We have developed a new method for inducing portal hypertension and esophageal varices in rats--partial ligation of the portal vein after devascularization of the circumference of the left renal vein and complete ligation of the portal vein on the fifth day thereafter. Thirty rats were separated into groups of 10, control (sham operation), complete portal ligation only and complete portal ligation plus devascularization. Two weeks after the surgery, the presence of esophageal varices in rats with complete portal ligation plus devascularization was confirmed by portography and by the histological findings. The diameter (mean +/- SD) of the submucosal veins of the lower esophagus in the complete portal ligation plus devascularization group (219.4 +/- 86.6 microns) was significantly larger than that in the complete portal ligation group (99.8 +/- 53.4 microns) or in the control group (30.5 +/- 16.6 microns) (p less than 0.01). Vascular structures of the lower esophagus closely resembled those in humans with esophageal varices. This new technique is simple, rapid and reliable, and application can be made to various experimental studies on portal hypertension.