Abstract 499: Venous Sinus Stenting Outcomes between Low and High Pressure Gradient Stenoses in Idiopathic Intracranial Hypertension

Introduction Structural disease has been postulated as a possible etiology for the pathophysiology of idiopathic intracranial hypertension (IIH). There is growing evidence that venous sinus stenosis plays a role in propagating IIH through the obstruction of cerebrospinal fluid (CSF) clearance. Venous sinus stenting (VSS) is becoming a common treatment modality for medically refractory IIH with promising results. Although a trans‐stenotic venous pressure gradient (VPG) of ≥8mmHg was initially used to select optimal candidates, VPG thresholds for VSS remain undefined. Our study explores the efficacy of VSS between low and high pressure gradient groups. Methods A retrospective analysis was performed on patients treated with cerebral VSS for IIH at two tertiary hospitals from 2012 to 2024 through a grant‐funded multicenter registry. Demographic information, clinical characteristics, changes in associated signs and symptoms, changes in venous stenosis pressure gradients pre‐ and post‐stenting, and re‐stenting rates were collected for up to 12 months after treatment using a RedCap database. Information was collected through electronic medical record review. Symptom outcome measures were subjective from clinic follow up notes. Patients were dichotomized into VPG groups: low (0‐7mmHg) and high VPG (≥8mmHg). Results Our cohort includes 373 patients, of which 285 (76.4%) were female. Demographics and clinical characteristics information are noted int Table 1. Overall, patients in the low VPG group were older, had lower body mass index (BMI) and lumbar puncture (LP) opening pressures, and were less likely to present with papilledema, headache, or visual disturbances compared to those with higher VPG. Additionally, the low VPG was also more likely to report tinnitus and less likely to be on acetazolamide or topiramate. Venous sinus stenosis detection via non‐invasive imaging, laterality of stenosis, and re‐stenting rates were similar across groups. Additionally, outcome measures were similar across groups: VPG resolution (0‐3mmHg) (81.3% in the <8 mmHg group vs. 87.4% in the ≥8 mmHg group, p=0.19), papilledema improvement (71.4% vs. 71.2%, p=0.98), tinnitus improvement (69.8% vs. 73.2%, p=0.62), and headache improvement (80.7% vs. 77.4%, p=0.58). Conclusion While our cohort demonstrated differences between the two VPG groups, there appears to be similar beneficial results in lowering the venous pressure gradient across stenosis alongside symptomatic improvement with VSS. Future prospective confirmatory studies further liberating these restrictive criteria is warranted. image