Increased Intracranial Hypertension (IIH), also known as Pseudotumor Cerebri, is defined by increased cerebral spinal fluid (CSF) pressure in the absence of intracranial, metabolic, toxic or hormonal causes of intracranial hypertension. It is characterized by headaches, tinnitus and visual loss, due to optic atrophy, in 50% of cases. Surgical treatments, such as CSF shunt placement and optic nerve sheath fenestration (ONSF), are indicated in case of failure or non-compliance (owing to side effects) of medical treatments (that mainly includes weight loss and drugs, such as Carbonic Anhydrase Inhibitors). However, these surgical treatments are limited by relative high complications and recurrence rate. Indeed, improvement in visual function after ONSF is often transient and the risk of complications, including visual loss, pupillary dysfunction, and vascular complications is up to 40%. With no better treatment option, intraventricular or lumbar shunt placement has become the traditional treatment for medically refractory IIH, despite poor results. Indeed, series of patients with IIH treated with shunt replacement report a complications rate (shunt occlusion, disconnection, infection or intracranial hematoma formation) around 50% and a failure rate up to 64% within 6 months. As a consequence, shunt revision is often required and efficacy of the technique to control the disease is questionable. The role of intracranial transverse sinus stenosis in IIH has recently gained a particular interest. Despite the fact that transverse sinus stenosis in IIH may be due to increased intracranial pressure, some authors believe that the rise in intracranial pressure and its effect are worsened by the secondary appearance of the venous sinus stenosis. To date, very few complications have been reported in IIH patients with venous sinus stent placement.

Brief Title

Stenting of Venous Sinus Stenosis for Medically Refractory Idiopathic Intracranial Hypertension

Official Title

Stenting of Venous Sinus Stenosis for Medically Refractory Idiopathic Intracranial Hypertension

Brief Summary

Increased Intracranial Hypertension (IIH), also known as Pseudotumor Cerebri, is defined by<br /> increased cerebral spinal fluid (CSF) pressure in the absence of intracranial, metabolic,<br /> toxic or hormonal causes of intracranial hypertension. It is characterized by headaches,<br /> tinnitus and visual loss, due to optic atrophy, in 50% of cases. Surgical treatments, such as<br /> CSF shunt placement and optic nerve sheath fenestration (ONSF), are indicated in case of<br /> failure or non-compliance (owing to side effects) of medical treatments (that mainly includes<br /> weight loss and drugs, such as Carbonic Anhydrase Inhibitors). However, these surgical<br /> treatments are limited by relative high complications and recurrence rate. Indeed,<br /> improvement in visual function after ONSF is often transient and the risk of complications,<br /> including visual loss, pupillary dysfunction, and vascular complications is up to 40%. With<br /> no better treatment option, intraventricular or lumbar shunt placement has become the<br /> traditional treatment for medically refractory IIH, despite poor results. Indeed, series of<br /> patients with IIH treated with shunt replacement report a complications rate (shunt<br /> occlusion, disconnection, infection or intracranial hematoma formation) around 50% and a<br /> failure rate up to 64% within 6 months. As a consequence, shunt revision is often required<br /> and efficacy of the technique to control the disease is questionable.<br /><br /> The role of intracranial transverse sinus stenosis in IIH has recently gained a particular<br /> interest. Despite the fact that transverse sinus stenosis in IIH may be due to increased<br /> intracranial pressure, some authors believe that the rise in intracranial pressure and its<br /> effect are worsened by the secondary appearance of the venous sinus stenosis. To date, very<br /> few complications have been reported in IIH patients with venous sinus stent placement.

Detailed Description

Despite the fact that the results of venous stenting in IIH are still preliminary, it
suggests that this technique could become a viable alternative for medically refractory IIH
patients with transverse sinus stenosis. However, prospective studies with long-term,
standardized and independent follow-up are required to evaluate this new alternative with a
higher level of evidence.

Normalization of CSF pressure will be present after venous sinus stenting at 6 months in more
than 70% of patients in a cohort of medically refractory IIH patients. (Refractory IIH is
defined as absence of improvement in papilledema, visual function or headache after three
months of medical treatment or intolerance to the medical regimen).

A complementary hypothesis is that the mean decrease in CSF pressure post stenting will be
equal or more than 15 mmHg.

The proposed research is a prospective cohort study that will be aimed to assess the efficacy
of venous stenting by normalizing CSF pressure and improving symptoms of quality of life in
patients with medically refractory IIH. Concomitantly; it will also estimate its recurrence
and complications rate.

The study will be conducted locally at The Ottawa Hospital with an aim of enrolling 33
patients into the trial.

Interventions The goal of this study is to assess the overall efficacy of venous stenting to
normalize patients CSF pressure with little or no risk. The premise of the study is that
opening the venous sinus will reduce the patient's intracranial pressure and improve their
visual capabilities. Therefore; the aim of treatment is to improve the patient's overall
symptomology related to IIH. The interventionalist and the interventional team can not be
blinded to any of the study procedures or study materials used in this trial.

Patients who undergo stenting of their venous system will have venous pressure measurements
taken. If the degree of stenosis is more than 50% with a difference in pressure in the CSF of
more than 8 mmHg, the patient will be stented.

Venous pressure measurements and transverse sinus stenting First step: Venous pressure
measurements Once the patient is under local anesthesia, femoral venous puncture for cerebral
venogram will be performed. Once femoral venous access has been obtained, catheterization of
the right or left jugular vein is performed. Microcatheterization of the sinus and venous
pressure measurements distal and proximal to the stenosis are done.

Second step: Procedure In preparation for stent, patients will receive Aspirin 81mg daily and
Clopidogrel (Plavix ®) 75 mg daily for 4 days prior to the intervention.

On the day of the procedure, the patient will receive a general anesthesia plus a bolus of
heparin (70UI/Kg).

Endovascular Intervention:

A venous femoral puncture will be completed to allow for a 6-8 French long sheath placement
followed by retrograde catheterization of the right or left jugular vein.

Deployment of the stent across the stenosis with or without venous angioplasty will be done.
Hemostasis with manual compression is completed at the end of the procedure.

After the procedure the patients are admitted overnight for monitoring (on neurosurgery
unit). Patients will be discharged home 24 hours after the procedure and will continue
Aspirin and Clopidogrel (Plavix®) 75mg every day x 3 month then aspirin only.

Outcome Measures

Outcome measures are the tests that investigators perform to prove whether or not a treatment being tested in a clinical trial is having any effect.