The fate of the cerebrospinal fluid after neuroendoscopic third ventriculostomy

This paper describes the case of a 9-year-old girl with a posterior thalami c/pineal region lesion and secondary obstructive hydrocephalus. The hydroce phalus was treated by neuroendoscopic third ventriculostomy (NTV), and she underwent simultaneous transendoscopic biopsy. The tumour biopsy was haemor rhagic, but the bleeding settled with constant irrigation. The patient rema ined neurologically unchanged, but subsequent imaging revealed an asymptoma tic thoracolumbar spinal subdural haematoma thought to be due to blood flow ing out through the NTV into the subdural space. This demonstrates the subd ural location of the cerebrospinal fluid after NTV.