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Time to re-assess the treatment of idiopathic intracranial hypertension
  1. Felipe C Albuquerque,
  2. Bradley A Gross,
  3. Michael R Levitt
  1. Division of Neurological Surgery, Barrow Neurological Institute, Phoenix, Arizona, USA
  1. Correspondence to Dr Felipe C Albuquerque, Division of Neurological Surgery, Barrow Neurological Institute, 2910 N 3rd Ave, Phoenix, AZ 85013, USA; felipe.albuquerque{at}bnaneuro.net

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Patients with idiopathic intracranial hypertension (IIH) have debilitating headaches and, in severe cases, life-altering papilledema and visual loss.1 The time-honored approach of cerebrospinal fluid (CSF) diversion for medically refractory IIH is often complicated by patient body habitus and a small ventricular system.2 ,3 The majority of patients with IIH have demonstrable venous sinus stenosis, potentially producing intracranial hypertension as a result of impaired CSF absorption.4 ,5

Preliminary evidence suggests that venous sinus stenting (VSS) may be beneficial.3 ,6 Our own experience shows symptomatic improvement in 70% of patients after stenting with a high rate of stent patency and a low incidence of neurological complications.7 In addition, a follow-up study, a mean of 3 years after treatment, found continued patency and normal drainage of the vein of Labbe in all cases in which it had been covered by a stent.8

Recently, Satti et al3 performed a unique meta-analysis of interventional/surgical procedures performed for the treatment of medically refractory IIH. Results illustrated comparable or superior results for both headache and visual symptoms after VSS in comparison with optic nerve sheath fenestration and CSF diversion. The authors found 18 clinical studies with 712 patients undergoing optic nerve sheath fenestration (mean follow-up 21 months), 17 studies with 435 patients undergoing CSF diversion (mean follow-up 41 months), and 8 studies with 136 patients undergoing VSS (mean follow-up 23 months). Rates of headache improvement were lowest after optic nerve sheath fenestration (44%), but comparably high for CSF diversion and VSS (80% and 83%, respectively). Rates of visual improvement were lowest after CSF diversion (54% improved vision, 70% improved papilledema). Remarkably, VSS had higher rates of visual improvement (78% vs 59%) and papilledema improvement (97% vs 80%) than optic nerve sheath fenestration.

Patients treated with VSS required fewer additional procedures than those undergoing optic nerve sheath fenestration or CSF diversion.3 Indeed, 43% of patients undergoing CSF diversion required additional surgery. The mean number of additional procedures for each shunt failure was 2.78. For patients undergoing optic nerve sheath fenestration, 14.8% required a repeat procedure, including either repeat fenestration (9.2%) or CSF diversion (5.6%). In contrast, repeat procedures were performed in only 10.3% of patients after VSS. Most of these were treated with repeat stenting, with only an additional 2.2% requiring CSF diversion.

Complications were highest after CSF diversion: the minor complication rate was 32.9% and the major complication rate was 7.6%. These included shunt infection, tonsillar herniation, subdural hematoma, and CSF fistula. After optic nerve sheath fenestration, the minor complication rate was 16.4%; this included a variety of ocular symptoms, including diplopia, atonic pupil, peripapillary hemorrhages, disc hemorrhage, cyst formation, and conjunctival abscess. Major complications included esotropia, exotropia, retrobulbar hemorrhage, orbital hematoma, orbital apex syndrome, orbital cellulitis, and optic neuropathy, occurring at a rate of 1.5%. In contrast, the major and minor complication rates of VSS were 2.9% and 4.4%, respectively. The latter included one case each of a retroperitoneal hematoma, femoral pseudoaneurysm, transient hearing loss, urinary tract infection, and syncope.

Collectively, the results of this meta-analysis confirm the superiority of VSS in treatment efficacy, re-treatment rates, and complication rates.3 These provocative findings support the use of VSS in appropriately selected patients with IIH and concomitant venous sinus stenosis with an associated pressure gradient. In an effort to substantiate these retrospective findings, we have designed the ‘OPEN-UP’ trial: Operative Procedures versus Endovascular Neurosurgery for Untreated Pseudotumor.

Specifically, OPEN-UP is a randomized, open-label trial that will determine whether VSS is as safe and effective as CSF diversion in halting or improving visual loss in patients with IIH and moderate-to-severe visual loss. The study population will include patients with IIH as defined by the 2013 International Classification of Headache Disorders with at least moderate visual loss, defined as a perimetric mean deviation of at least −8 dB but better than −30 dB in at least one eye. All patients with IIH will undergo diagnostic cerebral venography with pressure measurements under local anesthesia in order to diagnose venous sinus stenosis. Venous pressures with be measured throughout the dural venous sinus system regardless of any anatomic stenosis or lack thereof. Since a pressure gradient of ≥8 mm Hg has been shown to correlate with treatment success after VSS, this value will be used as a threshold above which patients will be randomized to one of the two treatment arms. Patients without a significant pressure gradient will not be randomized. Randomization will be at a 1:1 ratio between either VSS or CSF diversion and will occur immediately after cerebral venography.

Perimetric mean deviation was chosen as a primary outcome owing to its generalizability, test–retest reliability, and standardization across centers, as well as its sensitivity to severity and progression of visual symptoms of IIH. Based on previous work by the Neuro-Ophthalmology Research Disease Investigator Consortium (NORDIC), the upper limit of −8 dB ensures enough baseline visual loss to consider surgical treatment and allow room for improvement, while the lower limit of −30 dB ensures that patients with severe visual loss unlikely to improve with any treatment are excluded. Secondary outcome measures will include the total number of IIH-related surgeries at 1 year, resolution of venous pressure gradient at 6 months, papilledema at 2-week follow-up, visual acuity at 6 months, quality-of-life measures at 6 months, and medication usage at 1 year.

The population with IIH represents a challenging cohort of patients. This is largely secondary to psychological factors related to chronic medication use and repetitive, and often ineffective, surgical procedures. The subjective symptom of headache and the objective finding of visual loss warrant further research into alternative treatments of IIH. Mounting retrospective data support VSS as a viable, if not preferred, means of dealing with this vexing problem. The time has come to examine this subject through a randomized trial comparing CSF diversion and VSS among those patients with moderate-to-severe visual loss. This is the subgroup of patients with IIH that stands to benefit most from this analysis.

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Footnotes

  • Contributors All authors contributed.

  • Competing interests None declared.

  • Provenance and peer review Commissioned; internally peer reviewed.