IIH Intervention: A Clinical Trial Comparing 2 Treatments (Shunts and Stents) Evaluation Of Clinical Effectiveness And Cost Effectiveness (Intervention)

Intervention To Preserve Vision In Idiopathic Intracranial Hypertension: Evaluation Of Clinical Effectiveness And Cost Effectiveness (IIH Intervention)

Background and study aims Idiopathic intracranial hypertension (IIH) is a neurological condition characterised by increased pressure inside the skull, called intracranial pressure (ICP). It is more common in women of reproductive age with obesity. Common symptoms of IIH include headaches, blurred vision and ringing in the ears. If left untreated, the disorder may cause blindness. The majority of patients with IIH are managed with weight loss and medications. Fewer than 10% of patients develop progressive visual loss and require urgent intervention to reduce ICP and preserve vision. This trial will compare the two most common interventions performed in the UK and evaluate their clinical and cost-effectiveness. The first is called cerebrospinal fluid (CSF) shunting and involves a procedure where a thin tube called a shunt is implanted in the body to drain brain fluid. The second is called dural venous sinus stenting (DVSS) and involves a procedure where a metallic mesh tube called a stent is implanted inside a brain blood vessel. Both procedures can preserve vision, but there is no strong evidence to support one over the other. Participants will have the same chance to be treated with CSF shunting or DVSS. The aim of the trial is to know which intervention is the most effective to save the vision and the most cost-effective.

Who can participate? Adults with a diagnosis of IIH at risk of permanent sight loss

What does the study involve? The trial will be conducted in NHS hospitals located in England, Wales and Scotland. Participants are randomly allocated to undergo cerebrospinal fluid (CSF) shunting or dural venous sinus stenting (DVSS). Afterwards the participants will be asked to attend 11 hospital appointments and one telephone appointment. This follow-up will take 2 years from start to finish. Participants will be closely monitored for any side effects and potential device failure, and for changes in vision, headaches and quality of life. The researchers will also collect health data from NHS Digital (the national custodian of NHS health and social care data).

What are the possible benefits and risks of participating? There are no direct benefits from taking part in the trial but the information gained from this trial may help improve treatment for adults with IIH in the future. Participants may be seen more often and/or feel more supported as a consequence of their involvement in the trial. As with any intervention, there are risks and complications, but there are no additional disadvantages or risks involved in taking part in this trial. Both CSF shunting and stenting are treatments for IIH (shunting is widely used internationally, and in some hospitals, stenting is used as part of the standard of care). Participants require an intervention to prevent sight loss. None of these treatments is experimental but at present, there is not enough information to determine which treatment is most suitable and provides the higher level of health benefits to the individual.

Where is the study run from? University of Birmingham (UK)

When is the study starting and how long is it expected to run for? The first site opened in July 2023, and the last patient last visit is expected in May 2028

Who is funding the study? National Institute for Health Research (NIHR, grant number: NIHR131211) (UK)

Who is the main contact? IIH Intervention Trial manager, IIHIntervention@trials.bham.ac.uk (UK)

Study Overview

• Status: Recruiting
• Conditions: IIH - Idiopathic Intracranial Hypertension
• Intervention / Treatment: Device: CSF shunt; Device: DVSS

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Alexandra Sinclair, MBChB, FRCP, PhD; Phone Number: +44 121 414 8040; Email: a.b.sinclair@bham.ac.uk
• Study Contact Backup: Name: IIH Intervention Mailbox; Phone Number: +44 121 371 8107; Email: iihintervention@trials.bham.ac.uk

Study Locations

• United Kingdom
  • Birmingham, United Kingdom
    • Recruiting
    • The Queen Elizabeth Hospital
    • Contact: Georgios Tsermoulas
  • Bristol, United Kingdom
    • Not yet recruiting
    • Southmead Hospital
    • Contact: Richard Edwards
  • Bristol, United Kingdom
    • Not yet recruiting
    • Bristol Eye Hospital
    • Contact: Denise Atan
  • Cambridge, United Kingdom
    • Recruiting
    • Addenbrooke's Hospital
    • Contact: Alexis Yoannides
  • Cardiff, United Kingdom
    • Recruiting
    • University Hospital of Wales
    • Contact: Tom Hughes
  • Edinburgh, United Kingdom
    • Recruiting
    • Princess Alexandra Eye Pavillion
    • Contact: Jonathan Downer
  • Glasgow, United Kingdom
    • Recruiting
    • Queen Elizabeth University Hospital
    • Contact: Pushkar Shah
  • Hull, United Kingdom
    • Recruiting
    • Royal Hull Infirmary
    • Contact: Fayyaz Ahmed
  • Leeds, United Kingdom
    • Recruiting
    • Leeds General Infirmary
    • Contact: Esteban Taleti
  • London, United Kingdom
    • Recruiting
    • King's College Hospital
    • Contact: James McHugh
  • London, United Kingdom
    • Recruiting
    • National Hospital For Neurology and Neurosurgery
    • Contact: Fion Bremmer
  • Newcastle, United Kingdom
    • Recruiting
    • Royal Victoria Infirmary
    • Contact: Gemma Maxwell
  • Nottingham, United Kingdom
    • Recruiting
    • Queen's Medical Centre
    • Contact: Shery Thomas
  • Southampton, United Kingdom
    • Recruiting
    • Southampton General Hospital
    • Contact: Jason McDonald
  • Sunderland, United Kingdom
    • Recruiting
    • Sunderland Eye Infirmary
    • Contact: Gemma Maxwell

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Diagnosis of IIH by the IIH consensus guidelines with papilloedema and at risk of visual loss.
2. Presence of papilloedema (Frisén grade ≥ 3) in at least one eye
3. Age 18 to < 64 years at the time of consent.
4. Patients must be suitable for and willing to proceed with both CSF shunting (VP or Lumboperitoneal shunts only) and DVSS.
5. Able to provide written informed consent.

Exclusion Criteria:

1. Presence of current venous sinus thrombosis on diagnostic brain imaging by either MRI, MRV or CTV
2. Previous surgery for IIH including, optic nerve sheath fenestration, CSF shunting procedures, sub-temporal decompression and DVSS.
3. Previous bariatric surgery within the last 3 months
4. Patients with a past ophthalmic history, except refraction error, affecting the eligible eyes (study eyes) that could affect the vision.
5. Patient is, at the time of signing the informed consent, a user of recreational or illicit drugs (including marijuana) or has had a recent history (within the last year) of drug or alcohol abuse or dependence, in the opinion of the investigator.
6. History of any clinically significant disease or disorder which, in the opinion of the investigator, may either put the subject at risk because of participation in the study, or influence the results or the subject's ability to participate in the study.
7. Have participated in any other interventional study within 30 days prior to the screening visit (of note participation in the IIH Life database or other observational studies will not prevent enrolment to this study).
8. Previous randomisation for treatment in the present study.
9. Pregnant.
10. Absolute or serious contraindication to standard anti-thrombotic regimen peri and post stenting.
11. Secondary causes of raised intracranial pressure. (Refer to Protocol appendix 3 for additional information.)
12. History of significant documented iodine-based contrast allergy.
13. History of documented allergy to nitinol or nickel.
14. Absolute or serious contraindication for general anaesthesia.
15. Previous diagnosis of a hypercoagulable state (Factor V Leiden, Protein C or S deficiency, Anticardiolipin antibodies, Lupus anticoagulant, B2-glycoprotein-1 antibodies, or Hyperhomocysteinaemia).
16. Currently requiring full anticoagulation for other medical reasons, such as atrial fibrillation, artificial valves, deep vein thrombosis or pulmonary embolism.
17. Documented prior non-traumatic intracranial haemorrhage.
18. History of deep vein thrombosis or pulmonary embolism (within the last 24 months).
19. History of severe carotid atherosclerotic disease.
20. History of heart failure, dilated cardiomyopathy or congenital heart disease, etc. that are assessed as at high thrombotic risk.
21. Presence of intracranial vascular malformation considered clinically symptomatic (current or within 24 months).
22. Anatomical anomaly of the venous sinus which would prevent safe catheterisation and stenting (e.g. multi-channel sinus).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: CSF shunting; Cerebrospinal fluid shunt	Device: CSF shunt; CSF shunt may be ventriculoperitoneal (VP) or lumboperitoneal (LP) at the discretion of the treating medical team.
Experimental: DVSS; Dural Venous Sinus Stenting	Device: DVSS; Dural Venous Sinus Stent. Exact make and model of device not mandated by protocol.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Global thickness of the retinal nerve fibre layer (RNFL) over 6 months, as measured by OCT	Global thickness of the retinal nerve fibre layer (RNFL) over 6 months, as measured in micrometers by OCT	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Global thickness of the retinal nerve fibre layer (RNFL)	Global thickness of the retinal nerve fibre layer (RNFL) measured in micrometers by OCT over 12 and 24 months	12 months, 24 months
Total retinal nerve fibre layer thickness	Total retinal thickness measured in micrometers by OCT	6, 12 and 24 months
Disc global volume	Disc global volume measured in micrometers cubed by OCT	6, 12 and 24 months
Disc central thickness	Disc central thickness measured by OCT (micrometers)	6, 12 and 24 months
Disc maximum height	Disc maximum height measured by OCT (micrometers)	6, 12 and 24 months
Macular ganglion cell layer volume	Macular ganglion cell layer volume as measured by OCT in micrometers cubed	over 6, 12 and 24 months
Visual acuity	Visual acuity, measured by logarithm of the minimum angle or resolution (LogMAR) units. Visual acuity (VA) is measured on the logMAR scale by sight tests in clinic using Early treatment diabetic retinopathy study (ETDRS) charts at 4 meters. Values are taken for each eye separately, both uncorrected, and corrected with glasses or contact lenses, and can range from 0, which represents perfect vision i.e. 20/20 (values of-0.1 and -0.2 are also possible representing better than perfect vision), to +2 which represents near blindness i.e. 20/2000. Increases in logMAR represent deterioration in vision.	Over 6, 12 and 24 months
Humphrey Visual Fields (HVF) Perimetric Mean Deviation (PMD)	Humphrey Visual Fields (HVF) 24-2 SITA standard visual field test measured by Perimetric Mean Deviation (PMD). Visual threshold is the intensity of stimulus seen 50% of the time at each location. Higher numbers mean the patient was able to see a more attenuated light, and thus has more sensitive vision at that location. The numerical total deviation map compares the patient's visual sensitivity to an average normal individual of the same age. It is useful to compare with age-matched normal thresholds as sensitivity normally decreases gradually with age. Positive values represent areas of the field where the patient can see dimmer stimuli than the average individual of that age. Negative values represent decreased sensitivity from normal. Reliability indices, including fixation losses, false positives, and false negatives are also included.	Over 6, 12 and 24 months
Proportion of patients re-presenting to hospital within 30 days post-intervention	Proportion of patients re-presenting to hospital within 30 days post-intervention. Percentage	30 days
Proportion of patients being re-admitted to hospital within 30 days post-intervention.	Proportion of patients being re-admitted to hospital within 30 days post-intervention. Percentage	30 days
Proportion of major complication, defined as the incidence of complications graded between III and V or major anaesthesia problems (including complications from revision procedures) according to the Clavien-Dindo classification of surgical complications	Measured by the Clavien-Dindo classification of surgical complications. The Clavien-Dindo scale is a validated, 5-grade, ordinal scale used to grade surgical complications based on the therapeutic interventions required to manage them. It provides a standardised, objective method for reporting postoperative morbidity (grades I-IV) and mortality (grade V), with increasing severity based on the level of care, from minor bedside treatment to ICU-level support or death.	over 6, 12 and 24 months
Proportion with minor complications, defined as Clavien-Dindo grade I-II during hospital stay.	Measured by the Clavien-Dindo scale; grade I-II. The Clavien-Dindo scale is a validated, 5-grade, ordinal scale used to grade surgical complications based on the therapeutic interventions required to manage them. It provides a standardized, objective method for reporting postoperative morbidity (grades I-IV) and mortality (grade V), with increasing severity based on the level of care, from minor bedside treatment to ICU-level support or death.	Over 6, 12 and 24 months
Proportion of patients requiring revision in whom the revision intervention is the same as the primary intervention	Percentage	over 6, 12 and 24 months
Proportion of patients requiring revision in whom the revision intervention crosses over to the alternative intervention	percentage	over 6, 12 and 24 months
Time to first revision	measured in days from day of intervention to day of first revision	measured in days over 6, 12 and 24 months
Number of revisions per patient	number	over 6, 12 and 24 months
Proportion of patients with Adverse Events grade 3 or above measured by the CTCAE version 5.	CTCAE v5. In the CTCAE, symptoms are categorised by organ system, ranging from mild (Grade 1) to death (Grade 5)	Over 6, 12 and 24 months
Monthly headache days	number of days per month with headache reported	over 6, 12, and 24 months
Monthly moderate to severe headache days	Measured by number of headache days per month with a severity greater than or equal to 4. 0-10 scale where 0 is no headache and 10 is the worst imaginable headache. Scores between 4 and 10 will be considered moderate to severe.	over 6, 12 and 24 months
Headache severity (numeric rating scale (NRS) 0-10)	Headache severity measured by (numeric rating scale (NRS) 0-10) where 0 is no headache and 10 is the worst headache	over 6, 12 and 24 months
Moderate to severe headache severity (NRS greater than or equal to 4)	Headache severity measured by (numeric rating scale (NRS) 0-10) where 0 is no headache and 10 is the worst headache. Moderate to severe headache severity (NRS greater than or equal to 4)	Over 6, 12 and 24 months
Monthly use of acute headache analgesics	number of days per month where analgesics are used to treat headaches as documented on the concomitant medication form and the headache diary.	over 6, 12 and 24 months
Quality of Recovery 15 (QoR-15) measured at time of discharge	QoR 15 is a validated, 15-item patient-reported questionnaire used to measure the quality of recovery after surgery and anaesthesia, with a maximum score of 150 indicating excellent recovery.	At time of discharge (usually within 7 days of intervention)
Satisfaction with intervention (5-point Likert scale) measured at time of discharge	5-point Likert scale with 1 - Very Unsatisfied and 5 - Very Satisfied	At time of discharge (usually within 7 days)
Visual Function Questionnaire (NEI-VFQ-25 with 10-Item Neuro-Ophthalmic Supplement)	measure of visual function using a composite score ranging from 0-100, where higher scores indicate better function.	Over 6, 12 and 24 months
Headache Impact Test (HIT-6)	6-question tool that measures the impact of headaches on daily life, producing a total score between 36 and 78. Higher scores indicate greater severity. Scores of 60+ indicate a very severe, 56-59 a substantial, 50-55 some, and 49 or less little to no impact.	Over 6, 12 and 24 months
36-item Short form health survey (SF-36v2)	A patient-reported tool measuring eight health domains, scoring them from 0 to 100, where 0 represents maximum limitations and 100 represents no health restrictions	Over 6, 12 and 24 months
EuroQol 5 dimension 5 level survey (EQ5D-5L)	The EQ-5D-5L consists of 2 pages: the EQ-5D descriptive system and the EQ visual analogue scale (EQ VAS). The descriptive system comprises five dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: no problems (1), slight problems (2), moderate problems (3), severe problems (4) and extreme problems (5). The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. This decision results in a 1-digit number that expresses the level selected for that dimension. The digits for the five dimensions can be combined into a 5-digit number that describes the patient's health state. The EQ VAS records the patient's self-rated health on a vertical visual analogue scale from 0 "worst imaginable health" to 100 "best imaginable health"	Over 6, 12 and 24 months
Time to return to work (if working)	fewer days to return to work is better than more days to return to work	Measured in days from date of intervention for the duration of follow up: reported over 6, 12 and 24 months
Work Productivity and Activity Impairment Questionnaire - General Health (WPAI-GH)	The WPAI measures absenteeism, presenteeism and activity impairment attributable to ill-health over the preceding 7 days. The WPAI calculates percentage impairment (maximum 100%) with higher numbers representing greater work impairment.	Over 6, 12 and 24 months
Proportion of patients requiring ICP lowering medication above a clinically relevant threshold	Measured as a percentage of patients reporting use of ICP lowering medications	Over 6, 12 and 24 months
Healthcare resource use questionnaire	Designed to calculate how much healthcare resource is used by each patient since the last clinic visit. This assesses the economic impact of IIH and will record any major differences in cost per QALY gained on each arm of the trial	over 6, 12 and 24 months

Collaborators and Investigators

• Sponsor: University of Birmingham
• Collaborators: National Institute for Health Research, United Kingdom

Publications and helpful links

Helpful Links

• Trial Website

Study record dates

Study Major Dates

• Study Start (Actual): July 18, 2023
• Primary Completion (Estimated): August 28, 2027
• Study Completion (Estimated): May 28, 2028

Study Registration Dates

• First Submitted: November 13, 2025
• First Submitted That Met QC Criteria: February 23, 2026
• First Posted (Actual): February 27, 2026

Study Record Updates

• Last Update Posted (Actual): February 27, 2026
• Last Update Submitted That Met QC Criteria: February 23, 2026
• Last Verified: February 1, 2026

More Information

Terms related to this study

• Keywords: OCT; stent; intracranial pressure; stenosis; shunt; RNFL; visual loss; papilloedema; DVSS; dural venous sinus stent
• Additional Relevant MeSH Terms: Neurologic Manifestations; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Pathological Conditions, Anatomical; Eye Diseases; Sensation Disorders; Optic Nerve Diseases; Cranial Nerve Diseases; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Intracranial Hypertension; Constriction, Pathologic; Vision Disorders; Pseudotumor Cerebri; Papilledema
• Other Study ID Numbers: RG_21-078; IRAS 314408 (Other Identifier: Health Research Authority)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No