Neuroendoscopic third ventriculostomy (NTV) has superseded shunting as the
treatment of choice in non-communicating hydrocephalus. Intracranial develo
pmental anomalies have been considered to be relative contraindications for
this procedure. We present one patient with a Dandy-Walker malformation an
d another with septo-optic dysplasia who presented with hydrocephalus. An N
TV was performed successfully in both patients using a flexible neuroendosc
ope and utilising transendoscopic Doppler ultrasound to ensure a safe targe
t area for ventriculostomy.