Kaolin-induced congenital hydrocephalus in utero in fetal lambs and rhesus monkeys.

A model of congenital hydrocephalus in utero in fetal lambs and rhesus monkeys has been produced by the intracisternal injection of kaolin. Initial attempts to produce hydrocephalus using silicone oil were unrewarding. Hydrocephalus had developed by 2 weeks post-injection and could be followed by ultrasonography. The pathological findings were similar to those reported using kaolin in other species. Ventriculoamniotic shunting, when successful, was capable of partially reversing the deleterious effects of hydrocephalus. The major drawback of the present model is that hydrocephalus is produced during the second rather than the first trimester of pregnancy. However, kaolin produces mainly an obstructive hydrocephalus without other associated brain or systemic anomalies.