Intracranial aneurysms: in vitro study of “intracranial” pressure and parent vessel curvature as potential modifiers of aneurysm pulsation amplitude

Although aneurysm pulsation – or wall motion – has been studied as a potential criterion to identify aneurysms prone to rupture, factors affecting this pulsation are not well understood. The purpose of this study was to test in vitro whether external – “intracranial” – pressure and/or parent vessel curvature impacted aneurysm pulsation and how. In this study, time-resolved CT angiography was used to detect and quantify volume pulsation of silicon aneurysm models using a test bench that could reproduce pulsatile flow within these models. A hermetic pressure box allowed us to test a range of external pressure on a simplified straight aneurysm model. For the second part, four silicon aneurysm models were custom made with varying curve radiuses at the aneurysm neck. Results show that in a simplified in vitro setting an increase in external – “intracranial” – pressure leads to a decrease in pulsation amplitude and vice versa, and that the parent vessel curvature is not correlated with pulsation amplitude.