Extra-axial Endoscopic Third Ventriculostomy: A Novel Treatment for Managing Hydrocephalus Due to Vertebrobasilar Dolichoectasia

-BACKGROUND: Vertebrobasilar dolichoectasia, a rare vascular anomaly, rarely presents with hydrocephalus. The traditional treatment for hydrocephalus is a ventriculoper-itoneal shunt. Conventional endoscopic third ven-triculostomy can avoid shunt-related complications but is considered risky due to the presence of the dolichoectatic vessel. A subfrontal extra-axial fenestration of the lamina terminalis can circumvent this anatomic constraint and establish cerebrospinal fluid communication between the third ventricle and subarachnoid space.-METHODS: We performed an extra-axial endoscopic third ventriculostomy to manage hydrocephalus due to vertebrobasilar dolichoectasia in a 26-year-old male. The clinical description, surgical technique, outcome, and rationale are described.-RESULTS: The patient had symptomatic improvement in his headaches and vision. There was also improvement in the postoperative ventricular indices: Evans index-19% reduction, frontal occipital horn ratio-14.1% reduction, and third ventricle index-39.5% reduction. A cine-phase magnetic resonance image showed cerebrospinal fluid flow void through the lamina terminalis fenestration, sug-gesting patency.-CONCLUSIONS: Extra-axial endoscopic third ven-triculostomy may be a suitable treatment alternative to circumvent anatomic constraints produced by vertebrobasilar dolichoectasia in performing conventional endoscopic third ventriculostomy.

Automated summary

This study introduces a new treatment method, extra-axial endoscopic third ventriculostomy, for managing hydrocephalus caused by vertebrobasilar dolichoectasia. This method can overcome the anatomical constraints produced by the dolichoectatic vessel and establish cerebrospinal fluid communication between the third ventricle and subarachnoid space.