Development of Spherical Occlusion Device

Hemorrhagic stroke, with a high mortality and morbidity, is due to the rupture of intracranial aneurysms. The gold standard treatments for intracranial aneurysms include traditional craniotomy and endovascular coiling; however, these treatments has some limitations. Liver cancer is one of the most common cancer in the world and is the third leading cause of cancer death in Taiwan. One of the treatment options is hepatic artery embolization. Due to the unique dual blood supply system, liver receives blood from hepatic portal vein and hepatic arteries. The blood supply to the liver is mainly from hepatic portal vein. On the contrary, the blood supply to hepatic cancer cells is almost from hepatic arteries. As a result, liver works well even when the blood flow in hepatic arteries is cut off. In this research, an implantable medical device concept, spherical occlusion device, is proposed. By directly deploying spherical occlusion device inside the aneurysm, the device is able to reduce the blood flow into aneurysm. Also, by deploying spherical occlusion device in the upstream hepatic artery, it can cut down the blood supply to cancer cells in the downstream. Due to the excellent super-elastic property, nitinol alloy is chosen as the material of the device. Finite element models are developed to analysis the mechanical behavior of the device during manufacturing and deployment procedures. Hemodynamic models are constructed to evaluate the performance of spherical occlusion device. Finite element analysis results show that spherical occlusion device is able to withstand large deformations during all procedures. Results of the hemodynamic models show that the blood flow rate is cut down by deploying spherical occlusion device whether in aneurysm or in upstream hepatic artery.