Stenting of Dural Venous Sinuses in Idiopathic Intracranial Hypertension (IIH)

Understanding Idiopathic Intracranial Hypertension (IIH)

Idiopathic intracranial hypertension (IIH) is a condition characterized by elevated intracranial pressure (ICP) without an identifiable cause such as a tumor or hydrocephalus. Patients often present with symptoms including headaches, pulsatile tinnitus, and vision disturbances, primarily due to papilledema. While conservative treatments such as weight loss and carbonic anhydrase inhibitors (e.g., acetazolamide) are first-line therapies, many patients with refractory IIH require more invasive interventions. Among these, dural venous sinus stenting (VSS) has emerged as a promising treatment option.

The Role of Dural Venous Sinuses

The dural venous sinuses are critical components of the brain's venous system, responsible for draining blood from the brain and its surrounding structures. In patients with IIH, stenosis, or narrowing of these sinuses, can contribute to the increased intracranial pressure. This narrowing impedes the normal outflow of cerebrospinal fluid, exacerbating the symptoms of IIH.

Recent advancements in medical imaging have allowed for better visualization of the dural venous sinuses, leading to a more accurate diagnosis of stenosis in patients with IIH. Understanding whether a patient has sinus stenosis is vital in determining the most effective treatment strategy.

Stenting as a Treatment Option

The primary indication for VSS in IIH is the presence of significant venous sinus stenosis that contributes to impaired cerebrospinal fluid (CSF) absorption and venous hypertension. Stenosis is typically identified using venography or MRV (magnetic resonance venography), and eligible patients are those with:

• Refractory IIH symptoms despite optimal medical therapy or risk of optic nerve atrophy.
  
• Documented venous sinus stenosis with a significant trans-stenotic gradient.
  
• No secondary causes of intracranial hypertension.

The Role of Trans-Stenotic Gradient in Management

The trans-stenotic gradient, measured via venography, reflects the pressure difference across the stenosis in the venous sinuses. A gradient of ≥5-7 mmHg is often used as a threshold for stenting consideration. Studies suggest that patients with a higher gradient are more likely to experience symptom relief after stenting, particularly in terms of headache and visual improvements [1].

Conservative Therapy vs. Invasive Management

Initial treatment for IIH includes:

• Lifestyle Modifications: Weight loss is highly effective in reducing ICP and is recommended for all overweight patients.
  
• Pharmacologic Therapy: Acetazolamide, a carbonic anhydrase inhibitor, reduces CSF production and can help control symptoms.
  
  For patients with persistent symptoms despite these interventions, invasive options are considered. VSS offers an alternative to CSF diversion procedures such as ventriculoperitoneal or lumboperitoneal shunting, which carry risks of infection and mechanical failure.

Evidence Supporting Dural Venous Sinus Stenting

Recent studies have demonstrated the efficacy of VSS in IIH management. In a study of 541 patients, VSS led to significant reductions in headache frequency, visual disturbances, and tinnitus. Additionally, the need for medications such as acetazolamide and topiramate was significantly reduced post-stenting [1]. Other studies report durable long-term outcomes, with many patients experiencing sustained symptom relief and reduced ICP measurements [2,3].

Complications remain relatively rare but may include in-stent restenosis or thrombosis.

Conclusion

Dural venous sinus stenting has emerged as a viable option for patients with refractory IIH and significant venous sinus stenosis. While conservative therapy remains the first-line approach, VSS provides an effective alternative for those who fail medical management. The trans-stenotic gradient remains a crucial factor in patient selection, guiding the decision-making process for this intervention. Ongoing research continues to refine patient selection criteria and long-term outcomes of this promising treatment modality.

References

1. Nia, A. M., Srinivasan, V. M., Lall, R., & Kan, P. (2022). Dural venous sinus stenting in idiopathic intracranial hypertension: A national database study of 541 patients. World Neurosurgery. https://doi.org/10.1016/j.wneu.2022.08.035

2.Wang, S., Raynald., Zhang R., et al. (2025). Factors affecting visual outcomes after dural venous sinus stenting in idiopathic intracranial hypertension. Journal of NeuroInterventional Surgery. https://doi: 10.1136/jnis-2024-022727

3. Amans, M. R., & De Leacy, R. (2024). Golden age of cerebral venous and CSF disorders. Journal of NeuroInterventional Surgery. https://doi.org/10.1136/jnis-2024-022553