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

Research question: What is the clinical and cost-effectiveness of dural vein stenosis stenting (DVSS) compared to cerebrospinal fluid (CSF) shunting in patients with idiopathic intracranial hypertension (IIH)?

Background: IIH is a rare disease of unknown cause that typically affects young women. The incidence has increased by over 350% in the last decade. Morbidity in IIH is high due to the risk of visual loss (permanent in up to 25%) and chronic disabling headaches.

Although the majority of patients can be managed conservatively, approximately 7% experience rapidly progressive loss of vision (termed fulminant IIH) and require emergency surgery to reduce intracranial pressure and preserve vision. Standard of care is CSF shunting, although complication rate is high, with up to 50% requiring revision within the first year.

An alternative, DVSS, is cheaper, but to date there has been no randomised controlled trial to evaluate the safety and efficacy compared to CSF shunting.

Aims and objectives: Primarily to compare DVSS with CSF shunting in terms of visual field changes. In addition we aim to compare major intra-operative and post-operative complications; vision; headache; quality of life and the relative cost-effectiveness of the two approaches. The primary endpoint will be assessed at 12 months, but measures will also be assessed at 24 moths and longer term outcomes evaluated through NHS digital data.

Methods: A multicentre, open-label, randomised controlled trial with integrated health economic evaluation and an internal pilot with an embedded qualitative process evaluation. Patients with IIH and rapidly declining vision suitable for both intervention will be eligible. The intervention is DVSS and the comparator is CSF shunting.

Timelines for delivery: The trial will last for 66 months, incorporating 9 months for development of the trial infrastructure and a 10-month pilot phase with embedded qualitative process evaluation. The main trial will have a further 44-month time-frame for recruitment, randomisation and follow up. A further 3 months will be required for final patient follow-up data gathering, cleaning, analysis, and report preparation.

Anticipated impact and dissemination: If DVSS is non-inferior to CSF shunting in terms of visual field changes then major complications and which intervention enables a more rapid recovery, as well as being more cost-effective, is likely to be widely adopted for treatment of fulminant IIH. Positive outcomes will therefore benefit affected patients and the health service. If no benefit, or poorer outcomes are found, then where possible standard of care with CSF shunting will remain.

The results will be distributed to major stakeholders, including: patients, doctors, professional societies, patient support groups, trial networks and NHS policy makers. The findings will be published in major medical journals and presented in national and international scientific meetings. Findings will also be made available through links on the websites of health professional societies and the UK IIH charity.