Symptomatic Cerebral Venous Outflow Resistance Responds to Stenting Even in the Absence of Intracranial Hypertension on Manometry: a Multicentre Study

The relative contribution of venous outflow obstruction and intracranial pressure (ICP) to symptomatology and treatment response in Idiopathic Intracranial Hypertension (IIH) remains uncertain. Venous sinus stenting (VSS) is indicated in patients with significant trans-stenotic pressure gradients (TPG) and concordant symptoms. A subset of these patients demonstrates conventionally normal superior sagittal sinus (SSS) pressures. As SSS pressure is often interpreted as a surrogate for ICP, it remains uncertain whether these patients derive benefit from VSS. A multicentre VSS registry was retrospectively queried to identify IIH patients with normal SSS pressure (≤ 15 mmHg). These patients were matched 1:1 to patients with elevated SSS pressure (> 15 mmHg) based on pre-stent TPG. Primary outcomes were improvement in headache, tinnitus and papilledema. Multivariable regression assessed the association between SSS pressure and clinical outcomes, adjusting for residual differences in pre-stent TPG. Among 517 patients undergoing VSS, 33 (6.4