Venous sinus stent placement is associated with improvement in volumetric skull base thickness

BACKGROUND: Venous sinus stenting (VSS) is an established treatment for patients with idiopathic intracranial hypertension (IIH). However, the associated effect of VSS on skull base remodeling has not been described. METHODS: We performed a single center retrospective study of adults with symptomatic venous sinus stenosis who underwent VSS. Tegmen (tympani and mastoideum) volume was measured on thin cut cranial CT using semi-automated 3D Slicer segmentation. The primary outcome was the within patient change in tegmen volume before and after VSS. Paired analyses were performed for the overall cohort and right-sided stent subgroups. Multivariable linear regression was used to identify factors associated with bilateral tegmen volume change. RESULTS: Of 65 patients treated with VSS from 2022 to 2026, 25 met the inclusion criteria. Mean age was 40.4 years, 92.0% were women, and median imaging follow-up was 295 days. Inter-rater reproducibility was excellent for the volumetric analysis on predefined anatomical segmentation boundaries. Four surgically repaired right-sided skull base patients were excluded from the ipsilateral analysis. Significant post-stenting mean tegmen growth was observed: right 146 mm³ (95% CI 118 to 174; n=21; P<0.001), left 145 mm³ (95% CI 114 to 170; n=25; P<0.001), and bilateral total 299 mm³ (95% CI 250 to 348; n=21; P<0.001). In the right-sided stent cohort, both ipsilateral and contralateral tegmen volumes increased significantly. Longer follow-up duration and pulsatile tinnitus were independently associated with bilateral tegmen volume gain. CONCLUSIONS: VSS was associated with a significant bilateral increase in tegmen volume in patients with IIH.