What is venous sinus stenosis?

The dural venous sinuses are a system of large veins within the layer of tissue lining the brain (dura) that collect venous blood from the numerous smaller veins of the brain. The venous blood is then returned to the heart via the internal jugular vein for oxygenation in the lungs. Asymmetric size or narrowing of the venous sinuses is most often incidental and of little clinical concern. However, a significant venous sinus stenosis can be one of several possible causes of Idiopathic Intracranial Hypertension (IIH), also known as pseudotumor cerebri.

What are the symptoms of venous sinus stenosis?

Although there may not be symptoms associated with venous sinus stenosis by itself, headaches can be one of the most common symptoms of IIH. Progressive visual loss or abnormalities of eye movement may also occur. An eye exam may demonstrate papilledema, or swelling of the optic nerve in the back of the eye due to the increased intracranial pressure.

How is venous sinus stenosis diagnosed?

Venous sinus stenosis is generally initially diagnosed through magnetic resonance venography (MRV). Computed tomography venography (CTV) may also be performed in cases requiring additional anatomic detail. An MRV is often performed in combination with a standard brain MRI, which may show additional findings consistent with IIH. IIH itself is diagnosed with a combination of imaging and clinical presentation items.

How is venous sinus stenosis treated?

Venous Sinus Stenting is a minimally invasive procedure for the treatment of Venous Sinus Stenosis. As the name implies, it involves the placement of a tube of metallic mesh, or stent, in the area of the narrowed vein in order to expand the vein for better blood flow. Treatment of venous sinus stenosis is generally only considered with an established diagnosis of IIH, and particularly if a patient is unable to tolerate medical treatment.

Venous sinus stenosis stenting is a fairly recent development for the treatment of IIH. If the patient is deemed a candidate for stenting through a multidisciplinary discussion between the neurologist, neurosurgeon, and neuroendovascular surgeon, a diagnostic cerebral angiogram/venogram is first performed. A special catheter is then used to measure the pressures of the venous sinuses to detect if a significant pressure gradient is present. If this is detected, the patient is placed on dual antiplatelet therapy (DAPT) consisting of aspirin and Plavix for 7-10 days prior to the interventional procedure. This provides protection against clot forming on the stent once placed. The stent procedure is performed under general anesthesia with the goal of opening up the stenosis and eliminating the pressure gradient. Patients then remain on DAPT for 3-6 months with repeat imaging evaluation and close reassessment of symptoms.