To establish a rabbit model of esophageal varices and treat the model animals by endoscopic injection sclerotherapy (EIS) to explore the process of tissue repair and provide a theoretical basis for clinical sequential treatment timing.

A rabbit model of esophageal varices was established by complete ligation of the left branch of the portal vein. Then, the animals were treated by EIS. The animals underwent gastroscopic examinations and were sacrificed at 0.5, 1, 3, and 7 days after injection, and tissue samples were collected for conventional HE staining and immunohistochemical staining. The mean optical density of vascular endothelial growth factor (VEGF) in esophageal tissue at various time points after experimental rabbit sclerotherapy was analyzed by one-way analysis of variance.

At 0.5 day after injection of the sclerosing agent, HE staining showed cell damage, proliferation, and discontinuous vein endothelium. Endothelial cell injury was not obvious and there was mild perivascular edema at 1 day. Inflammatory cell infiltration was obvious at 3 days, and vascular wall fibrosis and perivascular fibrosis began to appear at 7 days. The expression of VEGF initially rose, peaked at 3 days, and then declined. On the 0.5th, 1st, 3rd and 7th day after sclerosing agent injection, the average optical density of VEGF was (109±7.3), (125.7±11.9), (155.4±8.2) and (140.0±8.2), respectively. There was a statistically significant difference in the average optical density of VEGF between treatment periods (F=14.435, P<0.001).

The treatment cycle of EIS is about more than a week.