Generation of Realistic Physical Models of Cerebral Aneurysms for In Vitro Flow Visualisation

An aneurysm is a localised persistent dilation of the blood vessel wall. Aneurysm formation is hypothesised to be a consequence of haemodynamically generated forces working on the arterial wall leading to degeneration of the media layer (1). This focal degeneration typically occurs at curved arterial segments and at bifurcation points around the circle of Willis. Intracranial aneurysms are traditionally classified by aetiology and morphology. The majority are idiopathic and saccular. It is estimated that 1.5–6% of the general population have or will develop an intracranial aneurysm, predominantly occurring in women, most of them being asymptomatic (1). If left undetected these aneurysms may rupture with a 30 day mortality rate of 45% (1). There are two treatment options surgical clipping or endovascular coiling. Both of these techniques exclude the aneurysm from the normal circulation. Endovascular coiling is preferred due to its minimally invasive nature. Numerous studies have been done so far based on idealized glass models and using FVM, FEA methods, but very little testing has been carried out on devices using realistic silicone models. This is mainly because of the complexity of the cerebral vasculature. Silicone replicas of both realistic and idealised models were manufactured based on CT scans and anatomical dimensions obtained from literature, respectively (2).