Overview
This lecture presents a pediatric case of hydrocephalus related to a high-grade brain tumor, discusses surgical management with endoscopic third ventriculostomy (ETV), and reviews technical, postoperative, and outcome considerations.
Clinical Case: Pediatric Hydrocephalus
- Child presented with headaches, nausea, vomiting, and neck pain due to hydrocephalus from a large thalamic mass.
- Initial management included placement of an external ventricular drain (EVD), leading to immediate symptom improvement.
- MRI revealed a tumor obstructing the aqueduct; partial resection identified a high-grade diffuse midline glioma.
- After multiple treatments, the tumor recurred, again obstructing CSF flow and causing symptomatic hydrocephalus.
Surgical Management: Endoscopic Third Ventriculostomy (ETV)
- Right frontal approach was used with neuronavigation to access the lateral and third ventricles.
- Flexible scope allowed both ETV and tumor biopsy in a single procedure.
- Key anatomic landmarks visualized included mammillary bodies, tuber cinereum, infundibular recess, and optic chiasm.
- Fenestration of the third ventricle floor and any additional membranes allowed CSF flow into the prepontine cistern.
- Successful fenestration indicated by visible pulsatility of the third ventricle floor.
Postoperative Considerations
- Most children are discharged within 1-2 days post-op with rapid symptom resolution.
- Postoperative imaging (often CT) may be used selectively to check for bleeding.
- Monitor for possible hypothalamic injury (e.g., diabetes insipidus) and rare endocrinopathy.
- Antibiotics are used for about a day; steroids may be given to reduce inflammation.
- Main complications include infection (<2%), hemorrhage (rare), and very rare vascular injury.
Outcomes and ETV Success Score
- ETV failure rate at 2 years is ~35%, mostly within 6 months post-op.
- ETV Success Score factors: patient age, hydrocephalus cause, and prior shunt history.
- Highest success in children over 2 years old with aqueductal stenosis or certain tumors and no prior shunt.
- ETV less effective in patients under 6 months, myelomeningocele, prior hemorrhage, or infection.
- Failed ETVs can sometimes be successfully repeated.
Key Terms & Definitions
- Hydrocephalus — buildup of cerebrospinal fluid (CSF) within the brain's ventricles.
- External Ventricular Drain (EVD) — device to temporarily relieve intracranial pressure by draining CSF.
- Endoscopic Third Ventriculostomy (ETV) — surgical procedure creating an opening in the third ventricle floor to bypass an obstruction.
- Prepontine Cistern — CSF-filled space in front of the pons, accessed during ETV.
- ETV Success Score — tool to predict ETV outcomes based on age, cause, and shunt history.
Action Items / Next Steps
- Review the ETV Success Score chart and memorize key predictive factors.
- Understand relevant ventricular anatomy for ETV procedures.
- Prepare for discussion of ETV indications, technique, and complications.