Roles of i-ED coils in endovascular treatment of cerebral aneurysms, arteriovenous shunts and cerebrospinal fluid-venous fistulas

Background: Each coil system has its own individual characteristics and roles in endovascular treatment of neurovascular diseases. In this brief report, we focused on the various roles of the i-ED coil system (Kaneka medics, Kanagawa, Japan) in endovascular treatment of cerebral aneurysms, arteriovenous shunts and cerebrospinal fluid (CSF)-venous fistulas. Case Description: We highlighted the specific roles of i-ED coils through illustrated cases: Case 1—a 51-year-old male with ruptured anterior choroidal artery (AChA) aneurysm treated with primary coiling using Complex SilkySoft coils for “filling” and “finishing”, achieving modified Raymond-Roy classification (mRRC) II occlusion, preserving the AChA. Case 2—a 70-year-old female with ruptured flow aneurysm along the artery of Davidoff and Schehter, related to falco-tentorial dural arteriovenous fistula (DAVF). The aneurysm was treated with coiling using small Complex ExtraSoft and SilkySoft coils via flow-directed microcatheter. Case 3—a 58-year-old female with ruptured carotid terminus aneurysm treated with stent-assisted coiling. Coiling of the irregular peripheral lobules of the aneurysm was achieved using Complex infini and Infini coils. Case 4—a 53-year-old female with symptomatic indirect carotico-cavernous fistula treated with transvenous coiling, using extended coil length of Infini and Complex infini to achieve cost effectiveness. Case 5—a 60-year-old female with symptomatic giant cavernous internal carotid artery aneurysm treated with parent artery sacrifice. Electro detach generator (EDG) with additional sound and light indicators allows reliable identification of the coil detachment zone when the proximal coiling microcatheter marker was obscured by the coil mass. Case 6—a 64-year-old female presented with intracranial hypotension from T8/9 CSF-venous fistula, treated with distal coiling via balloon microcatheter (without dual coiling markers), followed by Onyx injection. Reliable identification of the coil detachment zone was achieved with EDG. Case 7—a 77-year-old male with ruptured anterior communicating artery aneurysm, treated with primary coiling using long Infini coil, complicated with “stretched coil”, likely from coil oversizing and excessive manipulation, partially retrieved with no thrombo-embolic complications. Conclusions: Our study illustrates the distinct properties and clinical advantages of i-ED coils within the contemporary landscape of endovascular therapy. Highlighted features include coil compatibility with flow-directed microcatheters, flexible coiling with low shape memory coils, improved cost-effectiveness with extended coil lengths and precise localization of the coil detachment zone by the EDG system.