Background: HydroSoft (MicroVention, Aliso Viejo, CA), a hydrogel-platinum coil hybrid device, is one of various efforts to overcome recanalization of coiled intracranial aneurysms. The purpose of this study was to evaluate the efficacy and safety of the HydroSoft coils in patients with intracranial aneurysms, and to compare the 12-month outcomes with that of bare platinum coils.
Methods: Four-hundred one patients harboring 430 intracranial aneurysms underwent endovascular embolization with the HydroSoft coils. In the control group, 221 patients harboring 253 aneurysms underwent coil embolization with bare platinum coils. The authors compared the degree of occlusion of the aneurysms, packing attenuations, procedural-related complications, and 12-month follow-up results between the two groups.
Results: There were no significant differences of initial angiographic outcomes and procedure-related complications between the HydroSoft-coil group and the bare-coil group. Mean volumetric packing density of the HydroSoft-coil group was significantly higher than that of the bare platinum coil group (36.0 ± 8.50 % versus 32.1 ± 8.22 %, p < 0.001). The retreatment was performed in four (1.8 %) of 225 followed-up aneurysms among the HydroSoft coil group and 20 (8.8 %) of 227 followed-up aneurysms among the bare platinum coil group (p = 0.001, Fischer's exact test). Multivariate Poisson regression revealed that coil embolization using the HydroSoft coil significantly reduces the retreatment rate of coiled aneurysms at 12-month follow-up (adjusted RR, 0.21; 95 % CI, 0.07-0.64; p = 0.004).
Conclusion: Coil embolization using HydroSoft coils achieves higher volumetric packing density. Twelve-month follow-up data favors HydroSoft coils, with lower retreatment rates.