Quantitative venous flow changes after sinus stenting in idiopathic intracranial hypertension

Background and purpose In patients with idiopathic intracranial hypertension (IIH) and venous sinus stenosis (VSS), venous sinus stenting (VSSt) reduces trans-stenotic pressure gradients and improves symptoms. We aimed to characterize the hemodynamic effects of VSSt by evaluating total paired venous flow and redistribution of venous outflow. Methods This retrospective study included 16 patients with IIH and VSS who underwent 17 VSSt procedures and had quantitative magnetic resonance venography (QMRV) before and after stenting. Flow was measured in the superior sagittal sinus, bilateral transverse and sigmoid sinuses, internal jugular veins, and major cerebral arteries. Follow-up QMRV was performed at a median of 129 days. Paired changes were assessed using Wilcoxon signed rank tests. Results Median trans-stenotic gradient decreased from 15 to 1 mm Hg. Flow increased in the ipsilateral transverse sinus (+154 mL/min, P=0.002), ipsilateral sigmoid sinus (+84.5 mL/min, P=0.049), ipsilateral jugular vein (+101 mL/min, P<0.001), and superior sagittal sinus (+76 mL/min, P=0.008), while decreasing in the contralateral transverse (−99 mL/min, P=0.006) and sigmoid sinuses (−67 mL/min, P=0.006). Flow fraction shifted toward the stented side at the transverse and sigmoid levels, without significant change in total paired outflow at either level. Bilateral jugular outflow increased (+22.9%, P=0.007). Conclusions In this pilot cohort, VSSt was associated with redistribution toward the treated transverse–sigmoid pathway, although changes in total paired flow remain uncertain. Bilateral jugular outflow increased after stenting. Quantitative flow imaging may complement invasive pressure and clinical symptom assessment during longitudinal follow-up after venous sinus stenting.