The vascular safe zone for endoscopic third ventriculostomy: a radiomorphometric study.

BACKGROUND AND

OBJECTIVE

Endoscopic third ventriculostomy (ETV) is a minimally invasive procedure for hydrocephalus management. Variable neuroanatomical features in the floor of the third ventricle (3VF) and the basilar artery (BA) complex contribute to the risk of vascular lesions in the BA complex. This study aims to evaluate the neuroradiological characteristics of the 3VF with the BA complex to determine the ETV fenestration "vascular safe zone".

METHODS

Preoperative neuroimaging studies from a consecutive cohort of adult patients who underwent ETV between January 2016 and March 2025 were retrospectively reviewed. Preoperative MRIs were used to evaluate the neuroradiological axial and sagittal characteristics of the 3VF with the BA complex.

RESULTS

The neuroradiological BA complex position was described. In the sagittal plane, Type II (74 %) was the most common, with mean distances ranging from 4.1 mm to 8 mm. The mean distance from the top of the BA complex to the 3VF was 6.86 mm (SD 1.56 mm). In the axial plane, Classes C and D (71.2 %) were predominant and had varied distances to the 3VF.

CONCLUSIONS

Our results suggest that the "vascular safe zone" for an ETV fenestration is primarily located in the anterior half of the 3VF. 71.2 % of our cases showed that the basilar artery (BA) complex was located in the posterior half. Future research should validate the "vascular safe zone" for ETV fenestration with neuroendoscopy intraoperative observations and assess clinical outcomes, including post-operative complications and success rates, to ensure the effectiveness of the proposed fenestration area.