Determination of filling volumes in HydroCoil-treated aneurysms by using three-dimensional computerized tomography angiography

Abstract

Coil embolization of aneurysms has been shown to be as safe and effective as surgical clip ligation, but has a higher recurrence rate. Advances in coil technology aim to reduce aneurysm recurrence by coating the devices with biological substances. An example of this is MicroVention's HydroCoil, which is a platinum coil coated with hydrogel that improves filling volumes by swelling when it contacts blood. The goal of this study was to determine whether this new coil type significantly reduced or prevented recurrences of aneurysms. The authors used three-dimensional computerized tomography angiography to determine aneurysm volumes accurately in 12 patients prior to coil embolization. The percentage filling volume was subsequently calculated for each aneurysm after treatment with HydroCoils and the immediate and 6-month follow-up angiographically confirmed occlusions were evaluated. The data demonstrated that both anterior and posterior intracranial aneurysms with diameters of 3 to 25 mm and volumes of 0.03 to 4.8 ml had filling volumes of 0.02 to 1.36 ml, resulting in filling volumes from 23% in a giant ophthalmic artery aneurysm to 80% in a small anterior communicating artery aneurysm. All of the aneurysms except for the giant one demonstrated stable occlusion on angiographic studies obtained at the 6-month follow-up review. HydroCoil embolization of intracranial aneurysms is safe and effective for small, large, and very large aneurysms. The percentage filling volume is greater than that reported for bare platinum coils in every case except the giant aneurysm. Nevertheless, angiographically confirmed occlusion is not directly related to percentage filling volume, but rather to the ability to occlude the aneurysm neck.