Objective To establish the rat model of chronic hydrocephalus after intraventricular hemorrhage (IVH).   Methods Totally 110 Sprague Dawley female rats were divided into 3 groups: IVH group (n=50)

saline control group (n=50) and the normal group (n=10). The rats in IVH group were infused autologous whole blood (130 μl) into the right lateral cerebral ventricle. All rats except the normal group were sacrificed on day 1

3

7

14

28 after operation

and the transverse diameter of the lateral ventricle was measured to evaluate hydrocephalus and the index of ventricle. The pathological changes of the brain were observed.   Results  Hydrocephalus occurred in 7 out of 10 rats in IVH group at 28 d. The index of ventricle in IVH group (4.51±1.94) was higher than that of saline control group (1.05±0.41) and the normal group (0.79±0.49) (P0.05). In the brain of the rats in the IVH group

we observed edema of white matter surrounding ventricle

twist and engorge of callosum

proliferation of rhagiocrine cells in 24

72 h after operation

absence of ciliums and microvillares of the ependymal cells on day 28. No similar changes occurred in the other two groups.   Conclusion Injecting autologous blood into right lateral cerebral ventricle can produce chronic hydrocephalus similar to hydrocephalus after intraventricular hemorrhage.