Embolization of intracranial aneurysms with hydrogel-coated coils versus inert platinum coils - Effects on packing density, coil length and quantity, procedure performance, cost, length of hospital stay, and durability of therapy

Background and Purpose - The durability of aneurysm coil embolization is thought to depend on packing density. The expansile property of hydrogel coating on coils increases volumetric packing per coil length. We describe our experience using hydrogel-coated coils ( HydroCoils) compared with inert platinum coils in intracranial aneurysm embolization. Methods - Fifty aneurysms embolized primarily using HydroCoils from 2003 to 2004 were compared with 57 volume-and shape-matched aneurysms treated with standard platinum coils from 2000 to 2003. Outcome measures included volumetric percentage occlusion ( VPO), length and number of coils used, procedure time, fluoroscopy time, contrast volume, coil cost, length of hospital stay, and durability of therapy. Results - Seventeen/26/5 small/medium/large aneurysms treated with HydroCoils were matched with 29/24/4 small/medium/large aneurysms treated with inert platinum. HydroCoil embolization yielded significantly greater VPO ( 84.8% versus 29.8%; P < 0.001), decreased average total coil length used per aneurysm ( 33.2 versus 44.3 cm), reduced fluoroscopy time ( 53.2 versus 65.2 minutes; P = 0.016), but increased contrast volume used ( 174.8 versus 112.9 cc; P < 0.001). There were no differences in length of hospital stay. Procedure-related morbidity and mortality rates in the HydroCoil cohort were 4% and 0%, respectively. Follow-up angiography at mean 12.3 months revealed lower aneurysm recurrence rates ( 17% versus 24%; number-needed-to-treat [ NNT] 14.3). Initial costs associated with HydroCoil embolization were higher ($5835 versus $4017; P = 0.004) but countered by lower retreatment rates ( 10% versus 17%; NNT 14.3). Conclusions - HydroCoil embolization achieves greater aneurysm packing density with decreased coil length. Initial durability data favor HydroCoils, with lower recurrence and retreatment rates.