Ultrasonography of the optic nerve sheath to assess intracranial pressure changes after ventriculo-peritoneal shunt surgery in children with hydrocephalus: a prospective observational study.

The optic nerve sheath diameter has been verified by various clinical studies as a non-invasive indicator of intracranial hypertension. The aim of this study was to compare the optic nerve sheath diameter before and immediately after ventriculo-peritoneal shunt surgery in children with hydrocephalus. We analysed transorbital ultrasonographic images recorded after induction of anaesthesia and 30 min after shunt insertion in 34 children, measuring the optic nerve sheath diameters using a linear ultrasound probe. The mean (SD) optic nerve sheath diameters were 5.4 (0.6) mm (right) and 5.3 (0.7) mm (left) before surgery and 4.4 (0.5) mm (right) and 4.5 (0.7) mm (left) after surgery (p < 0.0001 for before and after comparisons for both eyes). The technique allows rapid and non-invasive assessment of intracranial pressure to guide appropriate postoperative management.