Cerebrospinal fluid shunting or dural venous sinus stenting to preserve vision in idiopathic intracranial hypertension (IIH Intervention): protocol for an open-label, multicentre, randomised controlled phase IIb trial.

INTRODUCTION

Idiopathic intracranial hypertension (IIH) is characterised by raised intracranial pressure (ICP) and typically affects young women with obesity. Patients are at risk of permanent visual loss due to papilloedema. Some require emergency intervention to rapidly reduce papilloedema and preserve vision. The international standard of care for patients with sight-threatening IIH is cerebrospinal fluid (CSF) shunting. However, dural venous sinus stenting (DVSS) is an emerging procedure that is offered at many neuroscience centres internationally as the primary intervention. Currently, there are no randomised controlled trial data supporting the efficacy of any interventional approach for preserving vision in sight-threatening IIH.

METHODS AND ANALYSIS: IIH Intervention is a UK-based two-arm, open-label, multicentre, randomised controlled phase IIb clinical trial with integrated health economic evaluation to compare CSF shunting with DVSS in patients who have confirmed IIH and are at risk of permanent visual loss due to severe papilloedema. The primary outcome is the global thickness of the peripapillary retinal nerve fibre layer (RNFL), an indicator of papilloedema, measured by optical coherence tomography (OCT) over a 6-month period. Secondary outcomes are global thickness of the RNFL over 12 and 24 months, as well as macular ganglion cell layer volume, perimetric mean deviation, headache outcomes, intervention reporting measures (including complications and revisions) and patient-reported outcomes over 6, 12 and 24 months.

ETHICS AND DISSEMINATION: The protocol was approved initially on 12 December 2022 by West Midlands-South Birmingham Research Ethics Committee (ref: 22/WM/0230). Participants will be required to provide written informed consent. The results of this trial will be disseminated through national and international presentations and peer-reviewed publications.

TRIAL REGISTRATION NUMBER: ISRCTN57142415.