Treatment of cerebral aneurysms with hydrogel-coated platinum coils (HydroCoil): early single-center experience

Abstract

Purpose: The authors report their experience using HydroCoils in the treatment of cerebral aneurysms.

Methods: We performed a retrospective review of the first 100 nonrandomized patients (104 coiled saccular cerebral aneurysms) treated with HydroCoils during a 27-month period.

Results: The average percentage of HydroCoil by length detached in treated aneurysms was 45.5% (range, 9.9-100%). Immediate postprocedure angiography demonstrated complete aneurysm occlusion in 34%, neck remnant in 35%, and incomplete occlusion in 32%. Immediate procedure-related morbidity and mortality rates were 5.8% and 0%, respectively. Angiographic follow-up was obtained in 51% (51/100 patients; 53/104 aneurysms; average, 10.3 months; range, 0-31 months). In these 53 angiographically followed aneurysms, the overall recanalization rate was 21%: no recanalization occurred in 23 aneurysms with small size (<10 mm)/small neck (<4 mm) (S/S); 4 recanalizations occurred in 7 aneurysms with small size/wide neck (>4 mm) (S/W); 6 recanalizations (27%) occurred in 22 large (L) aneurysms (>10-25 mm, 70% angiographic follow-up); and 1 giant (G) (>25 mm) aneurysm recanalized. A large proportion of aneurysms that were not initially completely occluded were completely occluded on follow-up (15/43 [35%]). Clinical follow-up was obtained in 73 patients (73%; average, 5.3 months; range, 0-24 months): 93% of these patients were neurologically improved or unchanged. Three patients rehemorrhaged and 3 patients with unruptured aneurysms developed delayed hydrocephalus.

Conclusions: The overall safety profile of HydroCoils appears acceptable. Preliminary midterm observations suggest less coil compaction/aneurysm recanalization in large aneurysms. However, HydroCoil-related delayed hydrocephalus is a concern.

Fig 1.

HydroCoil after hydrogel (translucent) coating has fully expanded around a platinum core.

Fig 2.

Diagrams of angiographic occlusion classes, adapted from Roy et al: class 1, complete; class 2, residual neck; and class 3, aneurysm filling.

Fig 3.

Example of angiographic occlusion classes 1, 2, and 3: class 1, complete occlusion; class 2, persistence of any portion of the original defect of the arterial wall as seen on any single projection but without opacification of the aneurysm sac; and class 3, aneurysm sac opacification.

Fig 4.

Example of class 3 conversion to class 1. Left accessory MCA aneurysm shows aneurysm filling (class 3) in immediate postembolization angiogram. Ten-month follow-up angiogram shows class 1 complete occlusion.