When inserting a ventricular shunt, the length of the ventricular cath
eter is a deciding factor in the avoidance of complications. The autho
r has devised a standardized method of determining this length which h
as been shown to achieve consistently successful results. It is determ
ined from the CT scan scout film of the individual patient with hydroc
ephalus. The length is half the distance between the external auditory
meatus and the mid-point of the coronal suture of the skull. The cath
eter is inserted by the frontal approach and is directed perpendicular
to the skull, aiming at the inner canthus of the ipsilateral eye. The
burrhole is located in the same parasagittal plane as the pupil eithe
r in front of or behind the coronal suture. The catheter tip has been
demonstrated by repeated follow-up CT scans to lie just anterior to th
e foramen of Monro. This method was used in 175 patients and it proved
to be highly successful.