Medical Engineering for Neuro-Endovascular Therapy

2001 Fiscal Year Final Research Report Summary

• Project/Area Number: 10357014
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 展開研究
• Research Field: Cerebral neurosurgery
• Research Institution: Mie University
• Principal Investigator: TAKI Waro Mie University, School of Medicine, Professor, 医学部, 教授 (70144368)
• Co-Investigator(Kenkyū-buntansha): IKADA Yoshito Kyoto University, Frontier Medical Sciences, Professor, 再生医学研究センター, 教授 (00025909) ; HOSHINO Tamotsu Mie University, School of Medicine, Assistant, 医学部附属病院, 助手 (00303743) ; MURAO Kenichi Mie University, School of Medicine, Assistant, 医学部, 助手 (60252368) ; OGAWA Atsushi Kaneka Medics, Research fellow, 研究員 ; IWATA Hiroo Kyoto University, Frontier Medical Sciences, Professor, 再生医学研究センター, 教授 (30160120)
• Project Period (FY): 1998 – 2001
• Keywords: Endovascular treatment / cerebral aneurysm / coil / arteriovenous malfomation / liquid embolic material / cyanoacrylate / atherosclerosis / stent / argatroban

Research Abstract

We developped length-changeable coils, coils made of memory shape alloy, nitinol, and fibroblast growth factor (FGF)-2-immobilized coils for embolization of intracranial aneuyrsms. It became possible to detach intentionally wherever among five different points in the length-changeable coil. The nitinol coil aimed at providing custum-made coils made of nitinol, fitting each aneurysmal shape. However, they were not available for clinical use because of their rediolucency. To prevent recanalization and regrowth of aneurysms after embolization, the FGF-2-immobilized coil were developped. It promoted intraaneurysmal fibrosis and re-endothelialization at the neck of aneurysm.
N-butyl-2-cyanoacrylate (NBCA) has been commonly used as a liquid material for embolization of cerebral arteriovenous malformations. However, its adhesive nature often causes adhesion between the tip of the microcatheter and the artery. In the present study, a new non-adhesive cyanoacrylate, isostearyl-2-cyanoacrylate (ISCA), was developped. ISCA could not obliterate the vascular lesions against rapid blood flow due to its low polymerization rate. To increase the polimerization rate, ISCA was mixed with NBCA. Then, the adhesive force of the mixture became extremely low, compared with that of NBCA.
Palmaz-Shatz stents were uniformly coated with argatroban, a selective thrombin inhibitor, to prevent in-stent restenosis, The intra-arterial response to the insertion of ahgatroban coated stent and uncoated stent were investigated. Both argatroban coated and uncoated stents were mounted on balloon catheters and deployed in the rabbit carotid arteries transfemoraly. Twenty-eight days after stent implantation, the carotid arteries including the stent were harvested, and compared by measuring neointimal thickness. There is no significant difference in the neointimal thickness between argatroban coated and uncoated stent.