O-032 How low is enough? – Defining the threshold with venous gradient pressure for venous sinus stenting in intracranial hypertension patients with venous sinus stenosis

Introduction Venous stenting (VS) in the setting of intracranial hypertension with venous sinus stenosis (VSS) aids in the improvement of debilitating symptoms, such as headache, visual symptoms including visual loss, and tinnitus. However, the lowest threshold of venous sinus pressure gradient across the stenosis remains unknown for patients who would benefit from VS. We aim to compare clinical outcomes between different groups of pre-operative venous sinus gradient pressure. Methods We prospectively collected and retrospectively reviewed data on 51 consecutive patients with symptomatic VSS who underwent VS at our center. Data on demographics, clinical presentation, lumbar puncture readings, venous pressure measurements across the stenotic sinus segment and clinical outcomes were collected and compared between 3 different groups defined by the venous sinus pressure gradient on catheter angiography, as follows: G1 (2–6 mmHg, N=19), G2 (7–10 mmHg, N=14), and G3 (11 mmHg or above, N=18). Continuous variables were compared by Kruskal-Wallis test and discrete variables by Fisher’s exact test. Results are given as median [IQR]. Results Among 51 patients who underwent VSS, median age was 33 years [IQR, 26–37 years], 47 (92%) were female, and median BMI was 34.85 kg/m2 [IQR, 29.3–41.4 34.85 kg/m2]. Headache was the most common symptom on presentation (100%), followed by visual abnormalities (96%), papilledema (92%), tinnitus (88%), and optic disc atrophy (41%). There were no differences in age, BMI, and clinical symptoms at presentation between groups. G1 had the lower post-operative venous gradient pressure (G1, 0 mmHg [0–1 mmHg]; p=0.0200) while G3 had the highest change in venous gradient pressure (G3, 12 mmHg [11–17 mmHg]; p=0.0001) following treatment. At 6-week follow-up, there was no difference between the three groups in the proportion of patients who achieved improvement or resolution of their symptoms (table 1). Among patients who completed their 6-month follow-up, all patients presented with favorable outcomes, although a lower proportion of patients in G3 had a favorable outcome of tinnitus (G3, 73%; p=0.030) (table 1). Conclusion In our cohort we found no difference in outcomes between the three groups of different venous gradient pressure cut-offs. Furthermore, patients in G1 group (2–6 mmHg) showed to have a comparable rate of favorable outcomes, advocating that patients exhibiting a low venous sinus pressure gradient still benefit from therapy to improve their clinical course. Disclosures V. Lopez-Rivera: None. M. Inam: None. E. Lekka: None. F. Sheriff: None. R. Tang: None. S. Sheth: None. P. Chen: None.