The next generation HydroCoil: initial clinical experience with the HydroFill embolic coil

BACKGROUND: Complete packing of intracranial aneurysms has demonstrated a significant decrease in aneurysm recurrence rates with increased volumetric filling. The HydroCoil Embolization System (HES) was developed to increase volumetric filling within the aneurysm sac to maintain long term occlusion. To further enhance ease of HES deployment, a new next generation embolic coil, the HydroFill coil, was developed. OBJECTIVE: To report the first clinical experience with the HydroFill coil, focusing on safety and effectiveness, with immediate and long term follow-up on cases performed at a single institution by a single operator. METHODS: Retrospective angiographic and clinical analysis was performed on a non-randomized single arm registry of the first consecutive 11 patients with 14 intracranial saccular aneurysms treated during a 9 month period. RESULTS: The immediate angiographic occlusion rate according to the Raymond scale was 100%. Overall packing density of all coils used was 13-135% (mean 64%). The immediate complication rate was 9% (1/11 patients), secondary to a parent vessel occlusion which resolved after intravenous administration of eptifibatide (Integrilin) without neurological sequelae. The angiographic/MR angiography follow-up period for this series was 13-30 months, with an overall complete occlusion rate of 86% (12/14 aneurysms). 2/14 aneurysms (14%) converted from complete occlusion to filling of small neck remnants. Of the two, one (7%) was a cavernous aneurysm that was retreated. CONCLUSIONS: Although this initial case series is small, this study demonstrates safe deployment of the HydroFill coil in ruptured and unruptured aneurysms without major complications, and with a high rate of occlusion on long term follow-up.