Professor Diederik Bulters
Consultant Neurosurgeon and ROAR Chief Investigator
Rationale
Unruptured intra-cranial aneurysms are common and found in approximately 3% of the population. There is a chance that these aneurysms rupture and cause a subarachnoid haemorrhage which has a 30% mortality rate. Unruptured aneurysms can be treated prophylactically before they rupture but all treatments have their own risks.
It is important to reserve prophylactic treatment for aneurysms with a high risk of rupture. Currently the ISUIA study and the PHASES score provide estimates of 5 year rupture risk however they are subject to criticism and have never been validated in the UK.
The aim of the Risk of Aneurysm Rupture (ROAR) study is to measure the accuracy of the PHASES score and develop a more accurate prediction model if possible.
Aims
1. Validation – assess the accuracy of the PHASES score at predicting 5 year rupture risk.
2. Predict rupture risk – develop a new risk prediction model incorporating additional variables.
3. Long term risk – determine the pattern of rupture risk beyond 5 years.
Study design
Risk of Aneurysm Rupture (ROAR) is a UK based multi-centre study which incorporates local baseline data collection and national hospitals admission database searches.
Each neurosurgical unit will retrospectively identify their patients with an unruptured intracranial aneurysm and collect baseline clinical and aneurysm characteristics. These patients will be searched against national databases for hospital admissions in England, Wales and Scotland (HES/PEDW/SMD) to identify all cases where the aneurysm went on to rupture.
Each patient will have their PHASES score calculated and the actual rupture rates used to determine the accuracy of the PHASES score.
Eligibility criteria
Inclusion criteria:
1. Age 18 years or older.
2. Intracranial intradural unruptured aneurysm.
3. Confirmed on angiogram (CTA/MRA/DSA).
4. Diagnosis of UIA between January 2006-December 2020.
Exclusion criteria:
1. Mycotic or vasculitic aneurysms.
2. Aneurysm diagnosed on CT or MRI alone.
3. AVM associated flow aneurysms.
4. Extradural aneurysms (eg intra-cavernous).
5. Aneurysms previously treated by either microsurgical or endovascular techniques.
6. Small lesions uncertain as to whether they are truly aneurysmal (“dilatation”, “bulge”, ‘Infundibulum”, etc).
Sample size
In order to build a predictive model which includes co-variates which are rare yet still thought to influence rupture risk (e.g. ADPKD) 20,000 patients will be needed.
Registration numbers
