Customized Endovascular Treatment Fixture Construction for Patient-Specific Cerebral Aneurysm Repair
Cerebral aneurysms are pathological bulges in blood vessels of the brain that can rupture and cause brain damage or death. Treating aneurysms by isolating them from circulation can prevent aneurysm rupture. Endovascular techniques for cerebral aneurysm treatment are preferred because they are minimally invasive and have a shorter recovery time, and endovascular coiling is considered the gold standard as a result. The coils used in endovascular treatment come in standard shapes and sizes, mass-manufactured by medical device companies. Clinicians select the coils for treatment based on the aneurysm volume. However, cerebral aneurysms have unique shapes and dimensions, and vary on a patient-specific basis. Therefore, customizing the coils to fit a unique aneurysm morphology by using shape memory alloys could potentially improve endovascular treatment outcomes. In order to shape set a shape memory alloy into a customized coil configuration a fixture based on the aneurysm morphology must first be developed. Digital surface models of aneurysm patient cases were collected from an online repository and isolated from surrounding vasculature. Anchors used to assist in winding coils around these models were then added to create a computational fixture model. These fixtures were 3D printed in stainless steel, and tested on their ability to maintain their shape after being exposed to high temperatures needed in shape setting processes. The study demonstrated that customized fixtures can be created from patient-specific images or models, and manufactured with high levels of accuracy without deformation at high temperatures. The results suggest that 3D printed stainless steel fixtures could be used to develop customized endovascular coils for cerebral aneurysm treatment.