A cranial nail for fetal shunting.

A small number of human fetal hydrocephalics have been treated by ventriculoamniotic shunts of silastic tubing. The Colorado device appears to be the one most commonly used. The original experimental device tested on a primate model resembled a hollow shingle nail. This was designed by Michedja and Hodgen, contained a spring valve, measured approximately 32 X 4 mm and was placed by hysterotomy. An attractive feature of this design was its fixation by impaction in the skull, preventing displacement by fetal activity, a reported disadvantage with the silastic devices. To our knowledge, no one has used this nail-like design and tailored it to transuterine percutaneous placement in a human case.