Introduction: Endoscopic third ventriculostomy (ETV) has emerged as a promising answer to the problem of hydrocephalus, whereby an alternative pathway of cerebrospinal fluid (CSF) flow is created through a fenestration in the floor of third ventricle. However, success with ETV and the neuroendoscope demands high technical skill given the acute, yet rare risks of catastrophic injury, including basilar artery injury, memory loss, and endocrine dysfunction. Advances in preoperative imaging have allowed for better patient selection and technical advances in neuroendoscopy have improved visualization of critical neuroanatomical structures.
Methods: We performed a retrospective chart review of adult and pediatric patients treated with neuronavigation guided endoscopic third ventriculostomy (ETV) or intraventricular cyst fenestration for radiographically confirmed, clinically significant congenital or acquired hydrocephalus between 2012–2014; n = 21 patients. All patients underwent successful completion of this procedure without clinically significant acute or longterm complications.
Results: Etiology of obstructive hydrocephalus in our patients ranged from myelomeningocele, recurrent optic nerve gliomas to aqueductal stenosis. Twenty patients were complication free postoperatively except one patient who had temporary diabetes insipidus. As compared to predicted average pre-operative ETVSS score of 59.04%, post operative score was 81%. At long-term follow-up of average 41 months, there was no observed incidence of basilar artery injury, infection, CSF leak or forniceal injury. As compared to published success rates for ETV of 73% shunt independence, our rate was 76% during average first postoperative follow-up of 4.76 months.
Conclusions: Adapting frameless electromagnetic neuronavigation provides real-time, multi-planar orientation during neuroendoscopic intraventricular surgery and reduces the risk of injury to critical brain structures. Intraoperative navigation provides a safe corridor for neuroendoscopy and avoids many complications of skull fixation in both adult and pediatric patients. Adding image guidance to neuroendoscopy increases safety margins for targeting accuracy, especially for patients with challenging anatomic landmarks.
Patient Care: Potentially, by increasing the use of Neuronavigation along with ETV, better patient outcomes can be expected by acquiring surgical precision. We believe such studies will add to the existing literature of ETV studies which can be potentially done on a larger scale with higher number of patients.
Learning Objectives: By the conclusion of this session, participants should be able to (1) Understand the importance and advantages of incorporating Neuronavigation & image guidance to ETV surgeries (2) Understand Risk vs Benefits of ETVs and (3) Understand the importance of predicted vs actual ETVSS (ETV Success Score).
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